{"categories":["docs","develop","stack","oss","rs","rc","oss","kubernetes","clients"],"description":"Reference for the Redis Modules API","duplicateOf":"head:data-ai-metadata","location":"body","title":"Modules API reference","tableOfContents":{"sections":[]},"codeExamples":[]}

Modules API reference

Reference for the Redis Modules API

This page is generated automatically from the Redis source code. To report an issue, please open one on the redis/redis repo.

Sections [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#sections "Copy link to clipboard"/index.html)

• Heap allocation raw functions
• Commands API
• Module information and time measurement
• Automatic memory management for modules
• String objects APIs
• Reply APIs
• Commands replication API
• DB and Key APIs – Generic API
• Key API for String type
• Key API for List type
• Key API for Sorted Set type
• Key API for Sorted Set iterator
• Key API for Hash type
• Key API for Stream type
• Calling Redis commands from modules
• Modules data types
• RDB loading and saving functions
• Key digest API (DEBUG DIGEST interface for modules types)
• AOF API for modules data types
• IO context handling
• Logging
• Blocking clients from modules
• Thread Safe Contexts
• Module Keyspace Notifications API
• Modules Cluster API
• Modules Timers API
• Modules EventLoop API
• Modules ACL API
• Modules Dictionary API
• Modules Info fields
• Modules utility APIs
• Modules API exporting / importing
• Module Command Filter API
• Scanning keyspace and hashes
• Module fork API
• Server hooks implementation
• Module Configurations API
• RDB load/save API
• Config access API
• Key eviction API
• Miscellaneous APIs
• Defrag API
• Function index

Heap allocation raw functions [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#heap-allocation-raw-functions "Copy link to clipboard"/index.html)

Memory allocated with these functions are taken into account by Redis key eviction algorithms and are reported in Redis memory usage information.

RedisModule_Alloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_alloc "Copy link to clipboard"/index.html)

void *RedisModule_Alloc(size_t bytes);

Available since: 4.0.0

Use like malloc(). Memory allocated with this function is reported in Redis INFO memory, used for keys eviction according to maxmemory settings and in general is taken into account as memory allocated by Redis. You should avoid using malloc(). This function panics if unable to allocate enough memory.

RedisModule_TryAlloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_tryalloc "Copy link to clipboard"/index.html)

void *RedisModule_TryAlloc(size_t bytes);

Available since: 7.0.0

Similar to RedisModule_Alloc, but returns NULL in case of allocation failure, instead of panicking.

RedisModule_Calloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_calloc "Copy link to clipboard"/index.html)

void *RedisModule_Calloc(size_t nmemb, size_t size);

Available since: 4.0.0

Use like calloc(). Memory allocated with this function is reported in Redis INFO memory, used for keys eviction according to maxmemory settings and in general is taken into account as memory allocated by Redis. You should avoid using calloc() directly.

RedisModule_TryCalloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_trycalloc "Copy link to clipboard"/index.html)

void *RedisModule_TryCalloc(size_t nmemb, size_t size);

Available since: 7.4.0

Similar to RedisModule_Calloc, but returns NULL in case of allocation failure, instead of panicking.

RedisModule_Realloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_realloc "Copy link to clipboard"/index.html)

void* RedisModule_Realloc(void *ptr, size_t bytes);

Available since: 4.0.0

Use like realloc() for memory obtained with RedisModule_Alloc().

RedisModule_TryRealloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_tryrealloc "Copy link to clipboard"/index.html)

void *RedisModule_TryRealloc(void *ptr, size_t bytes);

Available since: 7.4.0

Similar to RedisModule_Realloc, but returns NULL in case of allocation failure, instead of panicking.

RedisModule_Free [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_free "Copy link to clipboard"/index.html)

void RedisModule_Free(void *ptr);

Available since: 4.0.0

Use like free() for memory obtained by RedisModule_Alloc() and RedisModule_Realloc(). However you should never try to free with RedisModule_Free() memory allocated with malloc() inside your module.

RedisModule_Strdup [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_strdup "Copy link to clipboard"/index.html)

char *RedisModule_Strdup(const char *str);

Available since: 4.0.0

Like strdup() but returns memory allocated with RedisModule_Alloc().

RedisModule_PoolAlloc [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_poolalloc "Copy link to clipboard"/index.html)

void *RedisModule_PoolAlloc(RedisModuleCtx *ctx, size_t bytes);

Available since: 4.0.0

Return heap allocated memory that will be freed automatically when the module callback function returns. Mostly suitable for small allocations that are short living and must be released when the callback returns anyway. The returned memory is aligned to the architecture word size if at least word size bytes are requested, otherwise it is just aligned to the next power of two, so for example a 3 bytes request is 4 bytes aligned while a 2 bytes request is 2 bytes aligned.

There is no realloc style function since when this is needed to use the pool allocator is not a good idea.

The function returns NULL if bytes is 0.

Commands API [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#commands-api "Copy link to clipboard"/index.html)

These functions are used to implement custom Redis commands.

For examples, see https://redis.io/docs/latest/develop/reference/modules/.

RedisModule_IsKeysPositionRequest [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_iskeyspositionrequest "Copy link to clipboard"/index.html)

int RedisModule_IsKeysPositionRequest(RedisModuleCtx *ctx);

Available since: 4.0.0

Return non-zero if a module command, that was declared with the flag "getkeys-api", is called in a special way to get the keys positions and not to get executed. Otherwise zero is returned.

RedisModule_KeyAtPosWithFlags [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_keyatposwithflags "Copy link to clipboard"/index.html)

void RedisModule_KeyAtPosWithFlags(RedisModuleCtx *ctx, int pos, int flags);

Available since: 7.0.0

When a module command is called in order to obtain the position of keys, since it was flagged as "getkeys-api" during the registration, the command implementation checks for this special call using the RedisModule_IsKeysPositionRequest() API and uses this function in order to report keys.

The supported flags are the ones used by RedisModule_SetCommandInfo, see REDISMODULE_CMD_KEY_*.

The following is an example of how it could be used:

if (RedisModule_IsKeysPositionRequest(ctx)) {
    RedisModule_KeyAtPosWithFlags(ctx, 2, REDISMODULE_CMD_KEY_RO | REDISMODULE_CMD_KEY_ACCESS);
    RedisModule_KeyAtPosWithFlags(ctx, 1, REDISMODULE_CMD_KEY_RW | REDISMODULE_CMD_KEY_UPDATE | REDISMODULE_CMD_KEY_ACCESS);
}

Note: in the example above the get keys API could have been handled by key-specs (preferred). Implementing the getkeys-api is required only when is it not possible to declare key-specs that cover all keys.

RedisModule_KeyAtPos [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_keyatpos "Copy link to clipboard"/index.html)

void RedisModule_KeyAtPos(RedisModuleCtx *ctx, int pos);

Available since: 4.0.0

This API existed before RedisModule_KeyAtPosWithFlags was added, now deprecated and can be used for compatibility with older versions, before key-specs and flags were introduced.

RedisModule_IsChannelsPositionRequest [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_ischannelspositionrequest "Copy link to clipboard"/index.html)

int RedisModule_IsChannelsPositionRequest(RedisModuleCtx *ctx);

Available since: 7.0.0

Return non-zero if a module command, that was declared with the flag "getchannels-api", is called in a special way to get the channel positions and not to get executed. Otherwise zero is returned.

RedisModule_ChannelAtPosWithFlags [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_channelatposwithflags "Copy link to clipboard"/index.html)

void RedisModule_ChannelAtPosWithFlags(RedisModuleCtx *ctx,
                                       int pos,
                                       int flags);

Available since: 7.0.0

When a module command is called in order to obtain the position of channels, since it was flagged as "getchannels-api" during the registration, the command implementation checks for this special call using the RedisModule_IsChannelsPositionRequest() API and uses this function in order to report the channels.

The supported flags are:

• REDISMODULE_CMD_CHANNEL_SUBSCRIBE: This command will subscribe to the channel.
• REDISMODULE_CMD_CHANNEL_UNSUBSCRIBE: This command will unsubscribe from this channel.
• REDISMODULE_CMD_CHANNEL_PUBLISH: This command will publish to this channel.
• REDISMODULE_CMD_CHANNEL_PATTERN: Instead of acting on a specific channel, will act on any channel specified by the pattern. This is the same access used by the PSUBSCRIBE and PUNSUBSCRIBE commands available in Redis. Not intended to be used with PUBLISH permissions.

The following is an example of how it could be used:

if (RedisModule_IsChannelsPositionRequest(ctx)) {
    RedisModule_ChannelAtPosWithFlags(ctx, 1, REDISMODULE_CMD_CHANNEL_SUBSCRIBE | REDISMODULE_CMD_CHANNEL_PATTERN);
    RedisModule_ChannelAtPosWithFlags(ctx, 1, REDISMODULE_CMD_CHANNEL_PUBLISH);
}

Note: One usage of declaring channels is for evaluating ACL permissions. In this context, unsubscribing is always allowed, so commands will only be checked against subscribe and publish permissions. This is preferred over using RedisModule_ACLCheckChannelPermissions, since it allows the ACLs to be checked before the command is executed.

RedisModule_CreateCommand [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createcommand "Copy link to clipboard"/index.html)

int RedisModule_CreateCommand(RedisModuleCtx *ctx,
                              const char *name,
                              RedisModuleCmdFunc cmdfunc,
                              const char *strflags,
                              int firstkey,
                              int lastkey,
                              int keystep);

Available since: 4.0.0

Register a new command in the Redis server, that will be handled by calling the function pointer 'cmdfunc' using the RedisModule calling convention.

The function returns REDISMODULE_ERR in these cases:

• If creation of module command is called outside the RedisModule_OnLoad.
• The specified command is already busy.
• The command name contains some chars that are not allowed.
• A set of invalid flags were passed.

Otherwise REDISMODULE_OK is returned and the new command is registered.

This function must be called during the initialization of the module inside the RedisModule_OnLoad() function. Calling this function outside of the initialization function is not defined.

The command function type is the following:

 int MyCommand_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc);

And is supposed to always return REDISMODULE_OK.

The set of flags 'strflags' specify the behavior of the command, and should be passed as a C string composed of space separated words, like for example "write deny-oom". The set of flags are:

• "write": The command may modify the data set (it may also read from it).
• "readonly": The command returns data from keys but never writes.
• "admin": The command is an administrative command (may change replication or perform similar tasks).
• "deny-oom": The command may use additional memory and should be denied during out of memory conditions.
• "deny-script": Don't allow this command in Lua scripts.
• "allow-loading": Allow this command while the server is loading data. Only commands not interacting with the data set should be allowed to run in this mode. If not sure don't use this flag.
• "pubsub": The command publishes things on Pub/Sub channels.
• "random": The command may have different outputs even starting from the same input arguments and key values. Starting from Redis 7.0 this flag has been deprecated. Declaring a command as "random" can be done using command tips, see https://redis.io/docs/latest/develop/reference/command-tips/.
• "allow-stale": The command is allowed to run on slaves that don't serve stale data. Don't use if you don't know what this means.
• "no-monitor": Don't propagate the command on monitor. Use this if the command has sensitive data among the arguments.
• "no-slowlog": Don't log this command in the slowlog. Use this if the command has sensitive data among the arguments.
• "fast": The command time complexity is not greater than O(log(N)) where N is the size of the collection or anything else representing the normal scalability issue with the command.
• "getkeys-api": The command implements the interface to return the arguments that are keys. Used when start/stop/step is not enough because of the command syntax.
• "no-cluster": The command should not register in Redis Cluster since is not designed to work with it because, for example, is unable to report the position of the keys, programmatically creates key names, or any other reason.
• "no-auth": This command can be run by an un-authenticated client. Normally this is used by a command that is used to authenticate a client.
• "may-replicate": This command may generate replication traffic, even though it's not a write command.
• "no-mandatory-keys": All the keys this command may take are optional
• "blocking": The command has the potential to block the client.
• "allow-busy": Permit the command while the server is blocked either by a script or by a slow module command, see RedisModule_Yield.
• "getchannels-api": The command implements the interface to return the arguments that are channels.
• "internal": Internal command, one that should not be exposed to the user connections. For example, module commands that are called by the modules, commands that do not perform ACL validations (relying on earlier checks)
• "touches-arbitrary-keys": This command may modify arbitrary keys (i.e. not provided via argv). This flag is used so we don't wrap the replicated commands with MULTI/EXEC.

The last three parameters specify which arguments of the new command are Redis keys. See https://redis.io/commands/command for more information.

• firstkey: One-based index of the first argument that's a key. Position 0 is always the command name itself. 0 for commands with no keys.
• lastkey: One-based index of the last argument that's a key. Negative numbers refer to counting backwards from the last argument (-1 means the last argument provided) 0 for commands with no keys.
• keystep: Step between first and last key indexes. 0 for commands with no keys.

This information is used by ACL, Cluster and the COMMAND command.

NOTE: The scheme described above serves a limited purpose and can only be used to find keys that exist at constant indices. For non-trivial key arguments, you may pass 0,0,0 and use RedisModule_SetCommandInfo to set key specs using a more advanced scheme and use RedisModule_SetCommandACLCategories to set Redis ACL categories of the commands.

RedisModule_GetCommand [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getcommand "Copy link to clipboard"/index.html)

RedisModuleCommand *RedisModule_GetCommand(RedisModuleCtx *ctx,
                                           const char *name);

Available since: 7.0.0

Get an opaque structure, representing a module command, by command name. This structure is used in some of the command-related APIs.

NULL is returned in case of the following errors:

• Command not found
• The command is not a module command
• The command doesn't belong to the calling module

RedisModule_CreateSubcommand [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createsubcommand "Copy link to clipboard"/index.html)

int RedisModule_CreateSubcommand(RedisModuleCommand *parent,
                                 const char *name,
                                 RedisModuleCmdFunc cmdfunc,
                                 const char *strflags,
                                 int firstkey,
                                 int lastkey,
                                 int keystep);

Available since: 7.0.0

Very similar to RedisModule_CreateCommand except that it is used to create a subcommand, associated with another, container, command.

Example: If a module has a configuration command, MODULE.CONFIG, then GET and SET should be individual subcommands, while MODULE.CONFIG is a command, but should not be registered with a valid funcptr:

 if (RedisModule_CreateCommand(ctx,"module.config",NULL,"",0,0,0) == REDISMODULE_ERR)
     return REDISMODULE_ERR;

RedisModuleCommand *parent = RedisModule_GetCommand(ctx,,"module.config");

if (RedisModule_CreateSubcommand(parent,"set",cmd_config_set,"",0,0,0) == REDISMODULE_ERR)
    return REDISMODULE_ERR;

if (RedisModule_CreateSubcommand(parent,"get",cmd_config_get,"",0,0,0) == REDISMODULE_ERR)
    return REDISMODULE_ERR;

Returns REDISMODULE_OK on success and REDISMODULE_ERR in case of the following errors:

• Error while parsing strflags
• Command is marked as no-cluster but cluster mode is enabled
• parent is already a subcommand (we do not allow more than one level of command nesting)
• parent is a command with an implementation (RedisModuleCmdFunc) (A parent command should be a pure container of subcommands)
• parent already has a subcommand called name
• Creating a subcommand is called outside of RedisModule_OnLoad.

RedisModule_AddACLCategory [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_addaclcategory "Copy link to clipboard"/index.html)

int RedisModule_AddACLCategory(RedisModuleCtx *ctx, const char *name);

Available since: 7.4.0

RedisModule_AddACLCategory can be used to add new ACL command categories. Category names can only contain alphanumeric characters, underscores, or dashes. Categories can only be added during the RedisModule_OnLoad function. Once a category has been added, it can not be removed. Any module can register a command to any added categories using RedisModule_SetCommandACLCategories.

Returns:

• REDISMODULE_OK on successfully adding the new ACL category.
• REDISMODULE_ERR on failure.

On error the errno is set to:

• EINVAL if the name contains invalid characters.
• EBUSY if the category name already exists.
• ENOMEM if the number of categories reached the max limit of 64 categories.

RedisModule_SetCommandACLCategories [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setcommandaclcategories "Copy link to clipboard"/index.html)

int RedisModule_SetCommandACLCategories(RedisModuleCommand *command,
                                        const char *aclflags);

Available since: 7.2.0

RedisModule_SetCommandACLCategories can be used to set ACL categories to module commands and subcommands. The set of ACL categories should be passed as a space separated C string 'aclflags'.

Example, the acl flags 'write slow' marks the command as part of the write and slow ACL categories.

On success REDISMODULE_OK is returned. On error REDISMODULE_ERR is returned.

This function can only be called during the RedisModule_OnLoad function. If called outside of this function, an error is returned.

RedisModule_SetCommandInfo [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setcommandinfo "Copy link to clipboard"/index.html)

int RedisModule_SetCommandInfo(RedisModuleCommand *command,
                               const RedisModuleCommandInfo *info);

Available since: 7.0.0

Set additional command information.

Affects the output of COMMAND, COMMAND INFO and COMMAND DOCS, Cluster, ACL and is used to filter commands with the wrong number of arguments before the call reaches the module code.

This function can be called after creating a command using RedisModule_CreateCommand and fetching the command pointer using RedisModule_GetCommand. The information can only be set once for each command and has the following structure:

typedef struct RedisModuleCommandInfo {
    const RedisModuleCommandInfoVersion *version;
    const char *summary;
    const char *complexity;
    const char *since;
    RedisModuleCommandHistoryEntry *history;
    const char *tips;
    int arity;
    RedisModuleCommandKeySpec *key_specs;
    RedisModuleCommandArg *args;
} RedisModuleCommandInfo;

All fields except version are optional. Explanation of the fields:

• version: This field enables compatibility with different Redis versions. Always set this field to REDISMODULE_COMMAND_INFO_VERSION.

• summary: A short description of the command (optional).

• complexity: Complexity description (optional).

• since: The version where the command was introduced (optional). Note: The version specified should be the module's, not Redis version.

• history: An array of RedisModuleCommandHistoryEntry (optional), which is a struct with the following fields:

    const char *since;
    const char *changes;

since is a version string and changes is a string describing the changes. The array is terminated by a zeroed entry, i.e. an entry with both strings set to NULL.

• tips: A string of space-separated tips regarding this command, meant for clients and proxies. See https://redis.io/docs/latest/develop/reference/command-tips/.

• arity: Number of arguments, including the command name itself. A positive number specifies an exact number of arguments and a negative number specifies a minimum number of arguments, so use -N to say >= N. Redis validates a call before passing it to a module, so this can replace an arity check inside the module command implementation. A value of 0 (or an omitted arity field) is equivalent to -2 if the command has sub commands and -1 otherwise.

• key_specs: An array of RedisModuleCommandKeySpec, terminated by an element memset to zero. This is a scheme that tries to describe the positions of key arguments better than the old RedisModule_CreateCommand arguments firstkey, lastkey, keystep and is needed if those three are not enough to describe the key positions. There are two steps to retrieve key positions: begin search (BS) in which index should find the first key and find keys (FK) which, relative to the output of BS, describes how can we will which arguments are keys. Additionally, there are key specific flags.

Key-specs cause the triplet (firstkey, lastkey, keystep) given in RedisModule_CreateCommand to be recomputed, but it is still useful to provide these three parameters in RedisModule_CreateCommand, to better support old Redis versions where RedisModule_SetCommandInfo is not available.

Note that key-specs don't fully replace the "getkeys-api" (see RedisModule_CreateCommand, RedisModule_IsKeysPositionRequest and RedisModule_KeyAtPosWithFlags) so it may be a good idea to supply both key-specs and implement the getkeys-api.

A key-spec has the following structure:

    typedef struct RedisModuleCommandKeySpec {
        const char *notes;
        uint64_t flags;
        RedisModuleKeySpecBeginSearchType begin_search_type;
        union {
            struct {
                int pos;
            } index;
            struct {
                const char *keyword;
                int startfrom;
            } keyword;
        } bs;
        RedisModuleKeySpecFindKeysType find_keys_type;
        union {
            struct {
                int lastkey;
                int keystep;
                int limit;
            } range;
            struct {
                int keynumidx;
                int firstkey;
                int keystep;
            } keynum;
        } fk;
    } RedisModuleCommandKeySpec;

Explanation of the fields of RedisModuleCommandKeySpec:

• notes: Optional notes or clarifications about this key spec.

• flags: A bitwise or of key-spec flags described below.

• begin_search_type: This describes how the first key is discovered. There are two ways to determine the first key:

  • REDISMODULE_KSPEC_BS_UNKNOWN: There is no way to tell where the key args start.
  • REDISMODULE_KSPEC_BS_INDEX: Key args start at a constant index.
  • REDISMODULE_KSPEC_BS_KEYWORD: Key args start just after a specific keyword.
  • bs: This is a union in which the index or keyword branch is used depending on the value of the begin_search_type field.
    • bs.index.pos: The index from which we start the search for keys. (REDISMODULE_KSPEC_BS_INDEX only.)

• bs.keyword.keyword: The keyword (string) that indicates the beginning of key arguments. (REDISMODULE_KSPEC_BS_KEYWORD only.)

• bs.keyword.startfrom: An index in argv from which to start searching. Can be negative, which means start search from the end, in reverse. Example: -2 means to start in reverse from the penultimate argument. (REDISMODULE_KSPEC_BS_KEYWORD only.)

  • find_keys_type: After the "begin search", this describes which arguments are keys. The strategies are:

• REDISMODULE_KSPEC_BS_UNKNOWN: There is no way to tell where the key args are located.

  • REDISMODULE_KSPEC_FK_RANGE: Keys end at a specific index (or relative to the last argument).
  • REDISMODULE_KSPEC_FK_KEYNUM: There's an argument that contains the number of key args somewhere before the keys themselves.

find_keys_type and fk can be omitted if this keyspec describes exactly one key.

• fk: This is a union in which the range or keynum branch is used depending on the value of the find_keys_type field.

  • fk.range (for REDISMODULE_KSPEC_FK_RANGE): A struct with the following fields:
    • lastkey: Index of the last key relative to the result of the begin search step. Can be negative, in which case it's not relative. -1 indicates the last argument, -2 one before the last and so on.

• keystep: How many arguments should we skip after finding a key, in order to find the next one?

• limit: If lastkey is -1, we use limit to stop the search by a factor. 0 and 1 mean no limit. 2 means 1/2 of the remaining args, 3 means 1/3, and so on.

  • fk.keynum (for REDISMODULE_KSPEC_FK_KEYNUM): A struct with the following fields:
    • keynumidx: Index of the argument containing the number of keys to come, relative to the result of the begin search step.

• firstkey: Index of the fist key relative to the result of the begin search step. (Usually it's just after keynumidx, in which case it should be set to keynumidx + 1.)

• keystep: How many arguments should we skip after finding a key, in order to find the next one?

Key-spec flags:

The first four refer to what the command actually does with the value or metadata of the key, and not necessarily the user data or how it affects it. Each key-spec may must have exactly one of these. Any operation that's not distinctly deletion, overwrite or read-only would be marked as RW.

• REDISMODULE_CMD_KEY_RO: Read-Only. Reads the value of the key, but doesn't necessarily return it.

• REDISMODULE_CMD_KEY_RW: Read-Write. Modifies the data stored in the value of the key or its metadata.

• REDISMODULE_CMD_KEY_OW: Overwrite. Overwrites the data stored in the value of the key.

• REDISMODULE_CMD_KEY_RM: Deletes the key.

The next four refer to user data inside the value of the key, not the metadata like LRU, type, cardinality. It refers to the logical operation on the user's data (actual input strings or TTL), being used/returned/copied/changed. It doesn't refer to modification or returning of metadata (like type, count, presence of data). ACCESS can be combined with one of the write operations INSERT, DELETE or UPDATE. Any write that's not an INSERT or a DELETE would be UPDATE.

• REDISMODULE_CMD_KEY_ACCESS: Returns, copies or uses the user data from the value of the key.

• REDISMODULE_CMD_KEY_UPDATE: Updates data to the value, new value may depend on the old value.

• REDISMODULE_CMD_KEY_INSERT: Adds data to the value with no chance of modification or deletion of existing data.

• REDISMODULE_CMD_KEY_DELETE: Explicitly deletes some content from the value of the key.

Other flags:

• REDISMODULE_CMD_KEY_NOT_KEY: The key is not actually a key, but should be routed in cluster mode as if it was a key.

• REDISMODULE_CMD_KEY_INCOMPLETE: The keyspec might not point out all the keys it should cover.

• REDISMODULE_CMD_KEY_VARIABLE_FLAGS: Some keys might have different flags depending on arguments.

• args: An array of RedisModuleCommandArg, terminated by an element memset to zero. RedisModuleCommandArg is a structure with at the fields described below.

    typedef struct RedisModuleCommandArg {
        const char *name;
        RedisModuleCommandArgType type;
        int key_spec_index;
        const char *token;
        const char *summary;
        const char *since;
        int flags;
        struct RedisModuleCommandArg *subargs;
    } RedisModuleCommandArg;

Explanation of the fields:

• name: Name of the argument.

• type: The type of the argument. See below for details. The types REDISMODULE_ARG_TYPE_ONEOF and REDISMODULE_ARG_TYPE_BLOCK require an argument to have sub-arguments, i.e. subargs.

• key_spec_index: If the type is REDISMODULE_ARG_TYPE_KEY you must provide the index of the key-spec associated with this argument. See key_specs above. If the argument is not a key, you may specify -1.

• token: The token preceding the argument (optional). Example: the argument seconds in SET has a token EX. If the argument consists of only a token (for example NX in SET) the type should be REDISMODULE_ARG_TYPE_PURE_TOKEN and value should be NULL.

• summary: A short description of the argument (optional).

• since: The first version which included this argument (optional).

• flags: A bitwise or of the macros REDISMODULE_CMD_ARG_*. See below.

• value: The display-value of the argument. This string is what should be displayed when creating the command syntax from the output of COMMAND. If token is not NULL, it should also be displayed.

Explanation of RedisModuleCommandArgType:

• REDISMODULE_ARG_TYPE_STRING: String argument.
  • REDISMODULE_ARG_TYPE_INTEGER: Integer argument.
  • REDISMODULE_ARG_TYPE_DOUBLE: Double-precision float argument.
  • REDISMODULE_ARG_TYPE_KEY: String argument representing a keyname.
  • REDISMODULE_ARG_TYPE_PATTERN: String, but regex pattern.
  • REDISMODULE_ARG_TYPE_UNIX_TIME: Integer, but Unix timestamp.
  • REDISMODULE_ARG_TYPE_PURE_TOKEN: Argument doesn't have a placeholder. It's just a token without a value. Example: the KEEPTTL option of the SET command.
  • REDISMODULE_ARG_TYPE_ONEOF: Used when the user can choose only one of a few sub-arguments. Requires subargs. Example: the NX and XX options of SET.
  • REDISMODULE_ARG_TYPE_BLOCK: Used when one wants to group together several sub-arguments, usually to apply something on all of them, like making the entire group "optional". Requires subargs. Example: the LIMIT offset count parameters in ZRANGE.

Explanation of the command argument flags:

• REDISMODULE_CMD_ARG_OPTIONAL: The argument is optional (like GET in the SET command).
• REDISMODULE_CMD_ARG_MULTIPLE: The argument may repeat itself (like key in DEL).
• REDISMODULE_CMD_ARG_MULTIPLE_TOKEN: The argument may repeat itself, and so does its token (like GET pattern in SORT).

On success REDISMODULE_OK is returned. On error REDISMODULE_ERR is returned and errno is set to EINVAL if invalid info was provided or EEXIST if info has already been set. If the info is invalid, a warning is logged explaining which part of the info is invalid and why.

Module information and time measurement [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#module-information-and-time-measurement "Copy link to clipboard"/index.html)

RedisModule_IsModuleNameBusy [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_ismodulenamebusy "Copy link to clipboard"/index.html)

int RedisModule_IsModuleNameBusy(const char *name);

Available since: 4.0.3

Return non-zero if the module name is busy. Otherwise zero is returned.

RedisModule_Milliseconds [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_milliseconds "Copy link to clipboard"/index.html)

mstime_t RedisModule_Milliseconds(void);

Available since: 4.0.0

Return the current UNIX time in milliseconds.

RedisModule_MonotonicMicroseconds [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_monotonicmicroseconds "Copy link to clipboard"/index.html)

uint64_t RedisModule_MonotonicMicroseconds(void);

Available since: 7.0.0

Return counter of micro-seconds relative to an arbitrary point in time.

RedisModule_Microseconds [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_microseconds "Copy link to clipboard"/index.html)

ustime_t RedisModule_Microseconds(void);

Available since: 7.2.0

Return the current UNIX time in microseconds

RedisModule_CachedMicroseconds [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_cachedmicroseconds "Copy link to clipboard"/index.html)

ustime_t RedisModule_CachedMicroseconds(void);

Available since: 7.2.0

Return the cached UNIX time in microseconds. It is updated in the server cron job and before executing a command. It is useful for complex call stacks, such as a command causing a key space notification, causing a module to execute a RedisModule_Call, causing another notification, etc. It makes sense that all this callbacks would use the same clock.

RedisModule_BlockedClientMeasureTimeStart [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_blockedclientmeasuretimestart "Copy link to clipboard"/index.html)

int RedisModule_BlockedClientMeasureTimeStart(RedisModuleBlockedClient *bc);

Available since: 6.2.0

Mark a point in time that will be used as the start time to calculate the elapsed execution time when RedisModule_BlockedClientMeasureTimeEnd() is called. Within the same command, you can call multiple times RedisModule_BlockedClientMeasureTimeStart() and RedisModule_BlockedClientMeasureTimeEnd() to accumulate independent time intervals to the background duration. This method always return REDISMODULE_OK.

This function is not thread safe, If used in module thread and blocked callback (possibly main thread) simultaneously, it's recommended to protect them with lock owned by caller instead of GIL.

RedisModule_BlockedClientMeasureTimeEnd [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_blockedclientmeasuretimeend "Copy link to clipboard"/index.html)

int RedisModule_BlockedClientMeasureTimeEnd(RedisModuleBlockedClient *bc);

Available since: 6.2.0

Mark a point in time that will be used as the end time to calculate the elapsed execution time. On success REDISMODULE_OK is returned. This method only returns REDISMODULE_ERR if no start time was previously defined ( meaning RedisModule_BlockedClientMeasureTimeStart was not called ).

RedisModule_Yield [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_yield "Copy link to clipboard"/index.html)

void RedisModule_Yield(RedisModuleCtx *ctx, int flags, const char *busy_reply);

Available since: 7.0.0

This API allows modules to let Redis process background tasks, and some commands during long blocking execution of a module command. The module can call this API periodically. The flags is a bit mask of these:

• REDISMODULE_YIELD_FLAG_NONE: No special flags, can perform some background operations, but not process client commands.
• REDISMODULE_YIELD_FLAG_CLIENTS: Redis can also process client commands.

The busy_reply argument is optional, and can be used to control the verbose error string after the -BUSY error code.

When the REDISMODULE_YIELD_FLAG_CLIENTS is used, Redis will only start processing client commands after the time defined by the busy-reply-threshold config, in which case Redis will start rejecting most commands with -BUSY error, but allow the ones marked with the allow-busy flag to be executed. This API can also be used in thread safe context (while locked), and during loading (in the rdb_load callback, in which case it'll reject commands with the -LOADING error)

RedisModule_SetModuleOptions [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setmoduleoptions "Copy link to clipboard"/index.html)

void RedisModule_SetModuleOptions(RedisModuleCtx *ctx, int options);

Available since: 6.0.0

Set flags defining capabilities or behavior bit flags.

REDISMODULE_OPTIONS_HANDLE_IO_ERRORS: Generally, modules don't need to bother with this, as the process will just terminate if a read error happens, however, setting this flag would allow repl-diskless-load to work if enabled. The module should use RedisModule_IsIOError after reads, before using the data that was read, and in case of error, propagate it upwards, and also be able to release the partially populated value and all it's allocations.

REDISMODULE_OPTION_NO_IMPLICIT_SIGNAL_MODIFIED: See RedisModule_SignalModifiedKey().

REDISMODULE_OPTIONS_HANDLE_REPL_ASYNC_LOAD: Setting this flag indicates module awareness of diskless async replication (repl-diskless-load=swapdb) and that redis could be serving reads during replication instead of blocking with LOADING status.

REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS: Declare that the module wants to get nested key-space notifications. By default, Redis will not fire key-space notifications that happened inside a key-space notification callback. This flag allows to change this behavior and fire nested key-space notifications. Notice: if enabled, the module should protected itself from infinite recursion.

RedisModule_SignalModifiedKey [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_signalmodifiedkey "Copy link to clipboard"/index.html)

int RedisModule_SignalModifiedKey(RedisModuleCtx *ctx,
                                  RedisModuleString *keyname);

Available since: 6.0.0

Signals that the key is modified from user's perspective (i.e. invalidate WATCH and client side caching).

This is done automatically when a key opened for writing is closed, unless the option REDISMODULE_OPTION_NO_IMPLICIT_SIGNAL_MODIFIED has been set using RedisModule_SetModuleOptions().

Automatic memory management for modules [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#automatic-memory-management-for-modules "Copy link to clipboard"/index.html)

RedisModule_AutoMemory [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_automemory "Copy link to clipboard"/index.html)

void RedisModule_AutoMemory(RedisModuleCtx *ctx);

Available since: 4.0.0

Enable automatic memory management.

The function must be called as the first function of a command implementation that wants to use automatic memory.

When enabled, automatic memory management tracks and automatically frees keys, call replies and Redis string objects once the command returns. In most cases this eliminates the need of calling the following functions:

1. RedisModule_CloseKey()
2. RedisModule_FreeCallReply()
3. RedisModule_FreeString()

These functions can still be used with automatic memory management enabled, to optimize loops that make numerous allocations for example.

String objects APIs [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#string-objects-apis "Copy link to clipboard"/index.html)

RedisModule_CreateString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstring "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateString(RedisModuleCtx *ctx,
                                            const char *ptr,
                                            size_t len);

Available since: 4.0.0

Create a new module string object. The returned string must be freed with RedisModule_FreeString(), unless automatic memory is enabled.

The string is created by copying the len bytes starting at ptr. No reference is retained to the passed buffer.

The module context 'ctx' is optional and may be NULL if you want to create a string out of the context scope. However in that case, the automatic memory management will not be available, and the string memory must be managed manually.

RedisModule_CreateStringPrintf [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringprintf "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringPrintf(RedisModuleCtx *ctx,
                                                  const char *fmt,
                                                  ...);

Available since: 4.0.0

Create a new module string object from a printf format and arguments. The returned string must be freed with RedisModule_FreeString(), unless automatic memory is enabled.

The string is created using the sds formatter function sdscatvprintf().

The passed context 'ctx' may be NULL if necessary, see the RedisModule_CreateString() documentation for more info.

RedisModule_CreateStringFromLongLong [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromlonglong "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromLongLong(RedisModuleCtx *ctx,
                                                        long long ll);

Available since: 4.0.0

Like RedisModule_CreateString(), but creates a string starting from a long long integer instead of taking a buffer and its length.

The returned string must be released with RedisModule_FreeString() or by enabling automatic memory management.

RedisModule_CreateStringFromULongLong [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromulonglong "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromULongLong(RedisModuleCtx *ctx,
                                                         unsigned long long ull);

Available since: 7.0.3

Like RedisModule_CreateString(), but creates a string starting from a unsigned long long integer instead of taking a buffer and its length.

RedisModule_CreateStringFromDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromdouble "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromDouble(RedisModuleCtx *ctx,
                                                      double d);

Available since: 6.0.0

Like RedisModule_CreateString(), but creates a string starting from a double instead of taking a buffer and its length.

RedisModule_CreateStringFromLongDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromlongdouble "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromLongDouble(RedisModuleCtx *ctx,
                                                          long double ld,
                                                          int humanfriendly);

Available since: 6.0.0

Like RedisModule_CreateString(), but creates a string starting from a long double.

RedisModule_CreateStringFromString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromstring "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromString(RedisModuleCtx *ctx,
                                                      const RedisModuleString *str);

Available since: 4.0.0

Like RedisModule_CreateString(), but creates a string starting from another RedisModuleString.

RedisModule_CreateStringFromStreamID [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromstreamid "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromStreamID(RedisModuleCtx *ctx,
                                                        const RedisModuleStreamID *id);

Available since: 6.2.0

Creates a string from a stream ID. The returned string must be released with RedisModule_FreeString(), unless automatic memory is enabled.

The passed context ctx may be NULL if necessary. See the RedisModule_CreateString() documentation for more info.

RedisModule_FreeString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_freestring "Copy link to clipboard"/index.html)

void RedisModule_FreeString(RedisModuleCtx *ctx, RedisModuleString *str);

Available since: 4.0.0

Free a module string object obtained with one of the Redis modules API calls that return new string objects.

It is possible to call this function even when automatic memory management is enabled. In that case the string will be released ASAP and removed from the pool of string to release at the end.

If the string was created with a NULL context 'ctx', it is also possible to pass ctx as NULL when releasing the string (but passing a context will not create any issue). Strings created with a context should be freed also passing the context, so if you want to free a string out of context later, make sure to create it using a NULL context.

This API is not thread safe, access to these retained strings (if they originated from a client command arguments) must be done with GIL locked.

RedisModule_RetainString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_retainstring "Copy link to clipboard"/index.html)

void RedisModule_RetainString(RedisModuleCtx *ctx, RedisModuleString *str);

Available since: 4.0.0

Every call to this function, will make the string 'str' requiring an additional call to RedisModule_FreeString() in order to really free the string. Note that the automatic freeing of the string obtained enabling modules automatic memory management counts for one RedisModule_FreeString() call (it is just executed automatically).

Normally you want to call this function when, at the same time the following conditions are true:

1. You have automatic memory management enabled.
2. You want to create string objects.
3. Those string objects you create need to live after the callback function(for example a command implementation) creating them returns.

Usually you want this in order to store the created string object into your own data structure, for example when implementing a new data type.

Note that when memory management is turned off, you don't need any call to RetainString() since creating a string will always result into a string that lives after the callback function returns, if no FreeString() call is performed.

It is possible to call this function with a NULL context.

When strings are going to be retained for an extended duration, it is good practice to also call RedisModule_TrimStringAllocation() in order to optimize memory usage.

Threaded modules that reference retained strings from other threads must explicitly trim the allocation as soon as the string is retained. Not doing so may result with automatic trimming which is not thread safe.

This API is not thread safe, access to these retained strings (if they originated from a client command arguments) must be done with GIL locked.

RedisModule_HoldString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_holdstring "Copy link to clipboard"/index.html)

RedisModuleString* RedisModule_HoldString(RedisModuleCtx *ctx,
                                          RedisModuleString *str);

Available since: 6.0.7

This function can be used instead of RedisModule_RetainString(). The main difference between the two is that this function will always succeed, whereas RedisModule_RetainString() may fail because of an assertion.

The function returns a pointer to RedisModuleString, which is owned by the caller. It requires a call to RedisModule_FreeString() to free the string when automatic memory management is disabled for the context. When automatic memory management is enabled, you can either call RedisModule_FreeString() or let the automation free it.

This function is more efficient than RedisModule_CreateStringFromString() because whenever possible, it avoids copying the underlying RedisModuleString. The disadvantage of using this function is that it might not be possible to use RedisModule_StringAppendBuffer() on the returned RedisModuleString.

It is possible to call this function with a NULL context.

When strings are going to be held for an extended duration, it is good practice to also call RedisModule_TrimStringAllocation() in order to optimize memory usage.

Threaded modules that reference held strings from other threads must explicitly trim the allocation as soon as the string is held. Not doing so may result with automatic trimming which is not thread safe.

This API is not thread safe, access to these retained strings (if they originated from a client command arguments) must be done with GIL locked.

RedisModule_StringPtrLen [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringptrlen "Copy link to clipboard"/index.html)

const char *RedisModule_StringPtrLen(const RedisModuleString *str,
                                     size_t *len);

Available since: 4.0.0

Given a string module object, this function returns the string pointer and length of the string. The returned pointer and length should only be used for read only accesses and never modified.

RedisModule_StringToLongLong [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringtolonglong "Copy link to clipboard"/index.html)

int RedisModule_StringToLongLong(const RedisModuleString *str, long long *ll);

Available since: 4.0.0

Convert the string into a long long integer, storing it at *ll. Returns REDISMODULE_OK on success. If the string can't be parsed as a valid, strict long long (no spaces before/after), REDISMODULE_ERR is returned.

RedisModule_StringToULongLong [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringtoulonglong "Copy link to clipboard"/index.html)

int RedisModule_StringToULongLong(const RedisModuleString *str,
                                  unsigned long long *ull);

Available since: 7.0.3

Convert the string into a unsigned long long integer, storing it at *ull. Returns REDISMODULE_OK on success. If the string can't be parsed as a valid, strict unsigned long long (no spaces before/after), REDISMODULE_ERR is returned.

RedisModule_StringToDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringtodouble "Copy link to clipboard"/index.html)

int RedisModule_StringToDouble(const RedisModuleString *str, double *d);

Available since: 4.0.0

Convert the string into a double, storing it at *d. Returns REDISMODULE_OK on success or REDISMODULE_ERR if the string is not a valid string representation of a double value.

RedisModule_StringToLongDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringtolongdouble "Copy link to clipboard"/index.html)

int RedisModule_StringToLongDouble(const RedisModuleString *str,
                                   long double *ld);

Available since: 6.0.0

Convert the string into a long double, storing it at *ld. Returns REDISMODULE_OK on success or REDISMODULE_ERR if the string is not a valid string representation of a double value.

RedisModule_StringToStreamID [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringtostreamid "Copy link to clipboard"/index.html)

int RedisModule_StringToStreamID(const RedisModuleString *str,
                                 RedisModuleStreamID *id);

Available since: 6.2.0

Convert the string into a stream ID, storing it at *id. Returns REDISMODULE_OK on success and returns REDISMODULE_ERR if the string is not a valid string representation of a stream ID. The special IDs "+" and "-" are allowed.

RedisModule_StringCompare [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringcompare "Copy link to clipboard"/index.html)

int RedisModule_StringCompare(const RedisModuleString *a,
                              const RedisModuleString *b);

Available since: 4.0.0

Compare two string objects, returning -1, 0 or 1 respectively if a < b, a == b, a > b. Strings are compared byte by byte as two binary blobs without any encoding care / collation attempt.

RedisModule_StringAppendBuffer [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringappendbuffer "Copy link to clipboard"/index.html)

int RedisModule_StringAppendBuffer(RedisModuleCtx *ctx,
                                   RedisModuleString *str,
                                   const char *buf,
                                   size_t len);

Available since: 4.0.0

Append the specified buffer to the string 'str'. The string must be a string created by the user that is referenced only a single time, otherwise REDISMODULE_ERR is returned and the operation is not performed.

RedisModule_TrimStringAllocation [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_trimstringallocation "Copy link to clipboard"/index.html)

void RedisModule_TrimStringAllocation(RedisModuleString *str);

Available since: 7.0.0

Trim possible excess memory allocated for a RedisModuleString.

Sometimes a RedisModuleString may have more memory allocated for it than required, typically for argv arguments that were constructed from network buffers. This function optimizes such strings by reallocating their memory, which is useful for strings that are not short lived but retained for an extended duration.

This operation is not thread safe and should only be called when no concurrent access to the string is guaranteed. Using it for an argv string in a module command before the string is potentially available to other threads is generally safe.

Currently, Redis may also automatically trim retained strings when a module command returns. However, doing this explicitly should still be a preferred option:

1. Future versions of Redis may abandon auto-trimming.
2. Auto-trimming as currently implemented is not thread safe. A background thread manipulating a recently retained string may end up in a race condition with the auto-trim, which could result with data corruption.

Reply APIs [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#reply-apis "Copy link to clipboard"/index.html)

These functions are used for sending replies to the client.

Most functions always return REDISMODULE_OK so you can use it with 'return' in order to return from the command implementation with:

if (... some condition ...)
    return RedisModule_ReplyWithLongLong(ctx,mycount);

Reply with collection functions [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#reply-with-collection-functions "Copy link to clipboard"/index.html)

After starting a collection reply, the module must make calls to other ReplyWith* style functions in order to emit the elements of the collection. Collection types include: Array, Map, Set and Attribute.

When producing collections with a number of elements that is not known beforehand, the function can be called with a special flag REDISMODULE_POSTPONED_LEN (REDISMODULE_POSTPONED_ARRAY_LEN in the past), and the actual number of elements can be later set with RedisModule_ReplySet*Length() call (which will set the latest "open" count if there are multiple ones).

RedisModule_WrongArity [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_wrongarity "Copy link to clipboard"/index.html)

int RedisModule_WrongArity(RedisModuleCtx *ctx);

Available since: 4.0.0

Send an error about the number of arguments given to the command, citing the command name in the error message. Returns REDISMODULE_OK.

Example:

if (argc != 3) return RedisModule_WrongArity(ctx);

RedisModule_ReplyWithLongLong [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithlonglong "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithLongLong(RedisModuleCtx *ctx, long long ll);

Available since: 4.0.0

Send an integer reply to the client, with the specified long long value. The function always returns REDISMODULE_OK.

RedisModule_ReplyWithError [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywitherror "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithError(RedisModuleCtx *ctx, const char *err);

Available since: 4.0.0

Reply with the error 'err'.

Note that 'err' must contain all the error, including the initial error code. The function only provides the initial "-", so the usage is, for example:

RedisModule_ReplyWithError(ctx,"ERR Wrong Type");

and not just:

RedisModule_ReplyWithError(ctx,"Wrong Type");

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithErrorFormat [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywitherrorformat "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithErrorFormat(RedisModuleCtx *ctx,
                                     const char *fmt,
                                     ...);

Available since: 7.2.0

Reply with the error create from a printf format and arguments.

Note that 'fmt' must contain all the error, including the initial error code. The function only provides the initial "-", so the usage is, for example:

RedisModule_ReplyWithErrorFormat(ctx,"ERR Wrong Type: %s",type);

and not just:

RedisModule_ReplyWithErrorFormat(ctx,"Wrong Type: %s",type);

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithSimpleString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithsimplestring "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithSimpleString(RedisModuleCtx *ctx, const char *msg);

Available since: 4.0.0

Reply with a simple string (+... \r\n in RESP protocol). This replies are suitable only when sending a small non-binary string with small overhead, like "OK" or similar replies.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithArray [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywitharray "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithArray(RedisModuleCtx *ctx, long len);

Available since: 4.0.0

Reply with an array type of 'len' elements.

After starting an array reply, the module must make len calls to other ReplyWith* style functions in order to emit the elements of the array. See Reply APIs section for more details.

Use RedisModule_ReplySetArrayLength() to set deferred length.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithMap [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithmap "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithMap(RedisModuleCtx *ctx, long len);

Available since: 7.0.0

Reply with a RESP3 Map type of 'len' pairs. Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

After starting a map reply, the module must make len*2 calls to other ReplyWith* style functions in order to emit the elements of the map. See Reply APIs section for more details.

If the connected client is using RESP2, the reply will be converted to a flat array.

Use RedisModule_ReplySetMapLength() to set deferred length.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithSet [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithset "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithSet(RedisModuleCtx *ctx, long len);

Available since: 7.0.0

Reply with a RESP3 Set type of 'len' elements. Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

After starting a set reply, the module must make len calls to other ReplyWith* style functions in order to emit the elements of the set. See Reply APIs section for more details.

If the connected client is using RESP2, the reply will be converted to an array type.

Use RedisModule_ReplySetSetLength() to set deferred length.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithAttribute [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithattribute "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithAttribute(RedisModuleCtx *ctx, long len);

Available since: 7.0.0

Add attributes (metadata) to the reply. Should be done before adding the actual reply. see https://github.com/antirez/RESP3/blob/master/spec.md#attribute-type

After starting an attribute's reply, the module must make len*2 calls to other ReplyWith* style functions in order to emit the elements of the attribute map. See Reply APIs section for more details.

Use RedisModule_ReplySetAttributeLength() to set deferred length.

Not supported by RESP2 and will return REDISMODULE_ERR, otherwise the function always returns REDISMODULE_OK.

RedisModule_ReplyWithNullArray [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithnullarray "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithNullArray(RedisModuleCtx *ctx);

Available since: 6.0.0

Reply to the client with a null array, simply null in RESP3, null array in RESP2.

Note: In RESP3 there's no difference between Null reply and NullArray reply, so to prevent ambiguity it's better to avoid using this API and use RedisModule_ReplyWithNull instead.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithEmptyArray [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithemptyarray "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithEmptyArray(RedisModuleCtx *ctx);

Available since: 6.0.0

Reply to the client with an empty array.

The function always returns REDISMODULE_OK.

RedisModule_ReplySetArrayLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replysetarraylength "Copy link to clipboard"/index.html)

void RedisModule_ReplySetArrayLength(RedisModuleCtx *ctx, long len);

Available since: 4.0.0

When RedisModule_ReplyWithArray() is used with the argument REDISMODULE_POSTPONED_LEN, because we don't know beforehand the number of items we are going to output as elements of the array, this function will take care to set the array length.

Since it is possible to have multiple array replies pending with unknown length, this function guarantees to always set the latest array length that was created in a postponed way.

For example in order to output an array like [1,[10,20,30]] we could write:

 RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_LEN);
 RedisModule_ReplyWithLongLong(ctx,1);
 RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_LEN);
 RedisModule_ReplyWithLongLong(ctx,10);
 RedisModule_ReplyWithLongLong(ctx,20);
 RedisModule_ReplyWithLongLong(ctx,30);
 RedisModule_ReplySetArrayLength(ctx,3); // Set len of 10,20,30 array.
 RedisModule_ReplySetArrayLength(ctx,2); // Set len of top array

Note that in the above example there is no reason to postpone the array length, since we produce a fixed number of elements, but in the practice the code may use an iterator or other ways of creating the output so that is not easy to calculate in advance the number of elements.

RedisModule_ReplySetMapLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replysetmaplength "Copy link to clipboard"/index.html)

void RedisModule_ReplySetMapLength(RedisModuleCtx *ctx, long len);

Available since: 7.0.0

Very similar to RedisModule_ReplySetArrayLength except len should exactly half of the number of ReplyWith* functions called in the context of the map. Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

RedisModule_ReplySetSetLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replysetsetlength "Copy link to clipboard"/index.html)

void RedisModule_ReplySetSetLength(RedisModuleCtx *ctx, long len);

Available since: 7.0.0

Very similar to RedisModule_ReplySetArrayLength Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

RedisModule_ReplySetAttributeLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replysetattributelength "Copy link to clipboard"/index.html)

void RedisModule_ReplySetAttributeLength(RedisModuleCtx *ctx, long len);

Available since: 7.0.0

Very similar to RedisModule_ReplySetMapLength Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

Must not be called if RedisModule_ReplyWithAttribute returned an error.

RedisModule_ReplyWithStringBuffer [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithstringbuffer "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithStringBuffer(RedisModuleCtx *ctx,
                                      const char *buf,
                                      size_t len);

Available since: 4.0.0

Reply with a bulk string, taking in input a C buffer pointer and length.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithCString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithcstring "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithCString(RedisModuleCtx *ctx, const char *buf);

Available since: 5.0.6

Reply with a bulk string, taking in input a C buffer pointer that is assumed to be null-terminated.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithstring "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithString(RedisModuleCtx *ctx, RedisModuleString *str);

Available since: 4.0.0

Reply with a bulk string, taking in input a RedisModuleString object.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithEmptyString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithemptystring "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithEmptyString(RedisModuleCtx *ctx);

Available since: 6.0.0

Reply with an empty string.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithVerbatimStringType [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithverbatimstringtype "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithVerbatimStringType(RedisModuleCtx *ctx,
                                            const char *buf,
                                            size_t len,
                                            const char *ext);

Available since: 7.0.0

Reply with a binary safe string, which should not be escaped or filtered taking in input a C buffer pointer, length and a 3 character type/extension.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithVerbatimString [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithverbatimstring "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithVerbatimString(RedisModuleCtx *ctx,
                                        const char *buf,
                                        size_t len);

Available since: 6.0.0

Reply with a binary safe string, which should not be escaped or filtered taking in input a C buffer pointer and length.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithNull [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithnull "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithNull(RedisModuleCtx *ctx);

Available since: 4.0.0

Reply to the client with a NULL.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithBool [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithbool "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithBool(RedisModuleCtx *ctx, int b);

Available since: 7.0.0

Reply with a RESP3 Boolean type. Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

In RESP3, this is boolean type In RESP2, it's a string response of "1" and "0" for true and false respectively.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithCallReply [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithcallreply "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithCallReply(RedisModuleCtx *ctx,
                                   RedisModuleCallReply *reply);

Available since: 4.0.0

Reply exactly what a Redis command returned us with RedisModule_Call(). This function is useful when we use RedisModule_Call() in order to execute some command, as we want to reply to the client exactly the same reply we obtained by the command.

Return:

• REDISMODULE_OK on success.
• REDISMODULE_ERR if the given reply is in RESP3 format but the client expects RESP2. In case of an error, it's the module writer responsibility to translate the reply to RESP2 (or handle it differently by returning an error). Notice that for module writer convenience, it is possible to pass 0 as a parameter to the fmt argument of RedisModule_Call so that the RedisModuleCallReply will return in the same protocol (RESP2 or RESP3) as set in the current client's context.

RedisModule_ReplyWithDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithdouble "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithDouble(RedisModuleCtx *ctx, double d);

Available since: 4.0.0

Reply with a RESP3 Double type. Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

Send a string reply obtained converting the double 'd' into a bulk string. This function is basically equivalent to converting a double into a string into a C buffer, and then calling the function RedisModule_ReplyWithStringBuffer() with the buffer and length.

In RESP3 the string is tagged as a double, while in RESP2 it's just a plain string that the user will have to parse.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithBigNumber [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithbignumber "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithBigNumber(RedisModuleCtx *ctx,
                                   const char *bignum,
                                   size_t len);

Available since: 7.0.0

Reply with a RESP3 BigNumber type. Visit https://github.com/antirez/RESP3/blob/master/spec.md for more info about RESP3.

In RESP3, this is a string of length len that is tagged as a BigNumber, however, it's up to the caller to ensure that it's a valid BigNumber. In RESP2, this is just a plain bulk string response.

The function always returns REDISMODULE_OK.

RedisModule_ReplyWithLongDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replywithlongdouble "Copy link to clipboard"/index.html)

int RedisModule_ReplyWithLongDouble(RedisModuleCtx *ctx, long double ld);

Available since: 6.0.0

Send a string reply obtained converting the long double 'ld' into a bulk string. This function is basically equivalent to converting a long double into a string into a C buffer, and then calling the function RedisModule_ReplyWithStringBuffer() with the buffer and length. The double string uses human readable formatting (see addReplyHumanLongDouble in networking.c).

The function always returns REDISMODULE_OK.

Commands replication API [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#commands-replication-api "Copy link to clipboard"/index.html)

RedisModule_Replicate [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replicate "Copy link to clipboard"/index.html)

int RedisModule_Replicate(RedisModuleCtx *ctx,
                          const char *cmdname,
                          const char *fmt,
                          ...);

Available since: 4.0.0

Replicate the specified command and arguments to slaves and AOF, as effect of execution of the calling command implementation.

The replicated commands are always wrapped into the MULTI/EXEC that contains all the commands replicated in a given module command execution, in the order they were executed.

Modules should try to use one interface or the other.

This command follows exactly the same interface of RedisModule_Call(), so a set of format specifiers must be passed, followed by arguments matching the provided format specifiers.

Please refer to RedisModule_Call() for more information.

Using the special "A" and "R" modifiers, the caller can exclude either the AOF or the replicas from the propagation of the specified command. Otherwise, by default, the command will be propagated in both channels.

Note about calling this function from a thread safe context: [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#note-about-calling-this-function-from-a-thread-safe-context "Copy link to clipboard"/index.html)

Normally when you call this function from the callback implementing a module command, or any other callback provided by the Redis Module API, Redis will accumulate all the calls to this function in the context of the callback, and will propagate all the commands wrapped in a MULTI/EXEC transaction. However when calling this function from a threaded safe context that can live an undefined amount of time, and can be locked/unlocked in at will, it is important to note that this API is not thread-safe and must be executed while holding the GIL.

Return value [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#return-value "Copy link to clipboard"/index.html)

The command returns REDISMODULE_ERR if the format specifiers are invalid or the command name does not belong to a known command.

RedisModule_ReplicateVerbatim [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_replicateverbatim "Copy link to clipboard"/index.html)

int RedisModule_ReplicateVerbatim(RedisModuleCtx *ctx);

Available since: 4.0.0

This function will replicate the command exactly as it was invoked by the client. Note that the replicated commands are always wrapped into the MULTI/EXEC that contains all the commands replicated in a given module command execution, in the order they were executed.

Basically this form of replication is useful when you want to propagate the command to the slaves and AOF file exactly as it was called, since the command can just be re-executed to deterministically re-create the new state starting from the old one.

It is important to note that this API is not thread-safe and must be executed while holding the GIL.

The function always returns REDISMODULE_OK.

DB and Key APIs – Generic API [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#db-and-key-apis--generic-api "Copy link to clipboard"/index.html)

RedisModule_GetClientId [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getclientid "Copy link to clipboard"/index.html)

unsigned long long RedisModule_GetClientId(RedisModuleCtx *ctx);

Available since: 4.0.0

Return the ID of the current client calling the currently active module command. The returned ID has a few guarantees:

1. The ID is different for each different client, so if the same client executes a module command multiple times, it can be recognized as having the same ID, otherwise the ID will be different.
2. The ID increases monotonically. Clients connecting to the server later are guaranteed to get IDs greater than any past ID previously seen.

Valid IDs are from 1 to 2^64 - 1. If 0 is returned it means there is no way to fetch the ID in the context the function was currently called.

After obtaining the ID, it is possible to check if the command execution is actually happening in the context of AOF loading, using this macro:

 if (RedisModule_IsAOFClient(RedisModule_GetClientId(ctx)) {
     // Handle it differently.
 }

RedisModule_GetClientUserNameById [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getclientusernamebyid "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_GetClientUserNameById(RedisModuleCtx *ctx,
                                                     uint64_t id);

Available since: 6.2.1

Return the ACL user name used by the client with the specified client ID. Client ID can be obtained with RedisModule_GetClientId() API. If the client does not exist, NULL is returned and errno is set to ENOENT. If the client isn't using an ACL user, NULL is returned and errno is set to ENOTSUP

RedisModule_GetClientInfoById [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getclientinfobyid "Copy link to clipboard"/index.html)

int RedisModule_GetClientInfoById(void *ci, uint64_t id);

Available since: 6.0.0

Return information about the client with the specified ID (that was previously obtained via the RedisModule_GetClientId() API). If the client exists, REDISMODULE_OK is returned, otherwise REDISMODULE_ERR is returned.

When the client exist and the ci pointer is not NULL, but points to a structure of type RedisModuleClientInfoV1, previously initialized with the correct REDISMODULE_CLIENTINFO_INITIALIZER_V1, the structure is populated with the following fields:

 uint64_t flags;         // REDISMODULE_CLIENTINFO_FLAG_*
 uint64_t id;            // Client ID
 char addr[46];          // IPv4 or IPv6 address.
 uint16_t port;          // TCP port.
 uint16_t db;            // Selected DB.

Note: the client ID is useless in the context of this call, since we already know, however the same structure could be used in other contexts where we don't know the client ID, yet the same structure is returned.

With flags having the following meaning:

REDISMODULE_CLIENTINFO_FLAG_SSL          Client using SSL connection.
REDISMODULE_CLIENTINFO_FLAG_PUBSUB       Client in Pub/Sub mode.
REDISMODULE_CLIENTINFO_FLAG_BLOCKED      Client blocked in command.
REDISMODULE_CLIENTINFO_FLAG_TRACKING     Client with keys tracking on.
REDISMODULE_CLIENTINFO_FLAG_UNIXSOCKET   Client using unix domain socket.
REDISMODULE_CLIENTINFO_FLAG_MULTI        Client in MULTI state.

However passing NULL is a way to just check if the client exists in case we are not interested in any additional information.

This is the correct usage when we want the client info structure returned:

 RedisModuleClientInfo ci = REDISMODULE_CLIENTINFO_INITIALIZER;
 int retval = RedisModule_GetClientInfoById(&ci,client_id);
 if (retval == REDISMODULE_OK) {
     printf("Address: %s\n", ci.addr);
 }

RedisModule_GetClientNameById [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getclientnamebyid "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_GetClientNameById(RedisModuleCtx *ctx,
                                                 uint64_t id);

Available since: 7.0.3

Returns the name of the client connection with the given ID.

If the client ID does not exist or if the client has no name associated with it, NULL is returned.

RedisModule_SetClientNameById [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setclientnamebyid "Copy link to clipboard"/index.html)

int RedisModule_SetClientNameById(uint64_t id, RedisModuleString *name);

Available since: 7.0.3

Sets the name of the client with the given ID. This is equivalent to the client calling CLIENT SETNAME name.

Returns REDISMODULE_OK on success. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• ENOENT if the client does not exist
• EINVAL if the name contains invalid characters

RedisModule_PublishMessage [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_publishmessage "Copy link to clipboard"/index.html)

int RedisModule_PublishMessage(RedisModuleCtx *ctx,
                               RedisModuleString *channel,
                               RedisModuleString *message);

Available since: 6.0.0

Publish a message to subscribers (see PUBLISH command).

RedisModule_PublishMessageShard [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_publishmessageshard "Copy link to clipboard"/index.html)

int RedisModule_PublishMessageShard(RedisModuleCtx *ctx,
                                    RedisModuleString *channel,
                                    RedisModuleString *message);

Available since: 7.0.0

Publish a message to shard-subscribers (see SPUBLISH command).

RedisModule_GetSelectedDb [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getselecteddb "Copy link to clipboard"/index.html)

int RedisModule_GetSelectedDb(RedisModuleCtx *ctx);

Available since: 4.0.0

Return the currently selected DB.

RedisModule_GetContextFlags [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getcontextflags "Copy link to clipboard"/index.html)

int RedisModule_GetContextFlags(RedisModuleCtx *ctx);

Available since: 4.0.3

Return the current context's flags. The flags provide information on the current request context (whether the client is a Lua script or in a MULTI), and about the Redis instance in general, i.e replication and persistence.

It is possible to call this function even with a NULL context, however in this case the following flags will not be reported:

• LUA, MULTI, REPLICATED, DIRTY (see below for more info).

Available flags and their meaning:

• REDISMODULE_CTX_FLAGS_LUA: The command is running in a Lua script

• REDISMODULE_CTX_FLAGS_MULTI: The command is running inside a transaction

• REDISMODULE_CTX_FLAGS_REPLICATED: The command was sent over the replication link by the MASTER

• REDISMODULE_CTX_FLAGS_MASTER: The Redis instance is a master

• REDISMODULE_CTX_FLAGS_SLAVE: The Redis instance is a slave

• REDISMODULE_CTX_FLAGS_READONLY: The Redis instance is read-only

• REDISMODULE_CTX_FLAGS_CLUSTER: The Redis instance is in cluster mode

• REDISMODULE_CTX_FLAGS_AOF: The Redis instance has AOF enabled

• REDISMODULE_CTX_FLAGS_RDB: The instance has RDB enabled

• REDISMODULE_CTX_FLAGS_MAXMEMORY: The instance has Maxmemory set

• REDISMODULE_CTX_FLAGS_EVICT: Maxmemory is set and has an eviction policy that may delete keys

• REDISMODULE_CTX_FLAGS_OOM: Redis is out of memory according to the maxmemory setting.

• REDISMODULE_CTX_FLAGS_OOM_WARNING: Less than 25% of memory remains before reaching the maxmemory level.

• REDISMODULE_CTX_FLAGS_LOADING: Server is loading RDB/AOF

• REDISMODULE_CTX_FLAGS_REPLICA_IS_STALE: No active link with the master.

• REDISMODULE_CTX_FLAGS_REPLICA_IS_CONNECTING: The replica is trying to connect with the master.

• REDISMODULE_CTX_FLAGS_REPLICA_IS_TRANSFERRING: Master -> Replica RDB transfer is in progress.

• REDISMODULE_CTX_FLAGS_REPLICA_IS_ONLINE: The replica has an active link with its master. This is the contrary of STALE state.

• REDISMODULE_CTX_FLAGS_ACTIVE_CHILD: There is currently some background process active (RDB, AUX or module).

• REDISMODULE_CTX_FLAGS_MULTI_DIRTY: The next EXEC will fail due to dirty CAS (touched keys).

• REDISMODULE_CTX_FLAGS_IS_CHILD: Redis is currently running inside background child process.

• REDISMODULE_CTX_FLAGS_RESP3: Indicate the that client attached to this context is using RESP3.

• REDISMODULE_CTX_FLAGS_SERVER_STARTUP: The Redis instance is starting

• REDISMODULE_CTX_FLAGS_DEBUG_ENABLED: Debug commands are enabled for this context.

• REDISMODULE_CTX_FLAGS_TRIM_IN_PROGRESS: Trim is in progress due to slot migration.

RedisModule_AvoidReplicaTraffic [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_avoidreplicatraffic "Copy link to clipboard"/index.html)

int RedisModule_AvoidReplicaTraffic(void);

Available since: 6.0.0

Returns true if a client sent the CLIENT PAUSE command to the server or if Redis Cluster does a manual failover, pausing the clients. This is needed when we have a master with replicas, and want to write, without adding further data to the replication channel, that the replicas replication offset, match the one of the master. When this happens, it is safe to failover the master without data loss.

However modules may generate traffic by calling RedisModule_Call() with the "!" flag, or by calling RedisModule_Replicate(), in a context outside commands execution, for instance in timeout callbacks, threads safe contexts, and so forth. When modules will generate too much traffic, it will be hard for the master and replicas offset to match, because there is more data to send in the replication channel.

So modules may want to try to avoid very heavy background work that has the effect of creating data to the replication channel, when this function returns true. This is mostly useful for modules that have background garbage collection tasks, or that do writes and replicate such writes periodically in timer callbacks or other periodic callbacks.

RedisModule_SelectDb [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_selectdb "Copy link to clipboard"/index.html)

int RedisModule_SelectDb(RedisModuleCtx *ctx, int newid);

Available since: 4.0.0

Change the currently selected DB. Returns an error if the id is out of range.

Note that the client will retain the currently selected DB even after the Redis command implemented by the module calling this function returns.

If the module command wishes to change something in a different DB and returns back to the original one, it should call RedisModule_GetSelectedDb() before in order to restore the old DB number before returning.

RedisModule_KeyExists [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_keyexists "Copy link to clipboard"/index.html)

int RedisModule_KeyExists(RedisModuleCtx *ctx, robj *keyname);

Available since: 7.0.0

Check if a key exists, without affecting its last access time.

This is equivalent to calling RedisModule_OpenKey with the mode REDISMODULE_READ | REDISMODULE_OPEN_KEY_NOTOUCH, then checking if NULL was returned and, if not, calling RedisModule_CloseKey on the opened key.

RedisModule_OpenKey [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_openkey "Copy link to clipboard"/index.html)

RedisModuleKey *RedisModule_OpenKey(RedisModuleCtx *ctx,
                                    robj *keyname,
                                    int mode);

Available since: 4.0.0

Return a handle representing a Redis key, so that it is possible to call other APIs with the key handle as argument to perform operations on the key.

The return value is the handle representing the key, that must be closed with RedisModule_CloseKey().

If the key does not exist and REDISMODULE_WRITE mode is requested, the handle is still returned, since it is possible to perform operations on a yet not existing key (that will be created, for example, after a list push operation). If the mode is just REDISMODULE_READ instead, and the key does not exist, NULL is returned. However it is still safe to call RedisModule_CloseKey() and RedisModule_KeyType() on a NULL value.

Extra flags that can be pass to the API under the mode argument:

• REDISMODULE_OPEN_KEY_NOTOUCH - Avoid touching the LRU/LFU of the key when opened.
• REDISMODULE_OPEN_KEY_NONOTIFY - Don't trigger keyspace event on key misses.
• REDISMODULE_OPEN_KEY_NOSTATS - Don't update keyspace hits/misses counters.
• REDISMODULE_OPEN_KEY_NOEXPIRE - Avoid deleting lazy expired keys.
• REDISMODULE_OPEN_KEY_NOEFFECTS - Avoid any effects from fetching the key.
• REDISMODULE_OPEN_KEY_ACCESS_EXPIRED - Access expired keys that have not yet been deleted

RedisModule_GetOpenKeyModesAll [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getopenkeymodesall "Copy link to clipboard"/index.html)

int RedisModule_GetOpenKeyModesAll(void);

Available since: 7.2.0

Returns the full OpenKey modes mask, using the return value the module can check if a certain set of OpenKey modes are supported by the redis server version in use. Example:

   int supportedMode = RedisModule_GetOpenKeyModesAll();
   if (supportedMode & REDISMODULE_OPEN_KEY_NOTOUCH) {
         // REDISMODULE_OPEN_KEY_NOTOUCH is supported
   } else{
         // REDISMODULE_OPEN_KEY_NOTOUCH is not supported
   }

RedisModule_CloseKey [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_closekey "Copy link to clipboard"/index.html)

void RedisModule_CloseKey(RedisModuleKey *key);

Available since: 4.0.0

Close a key handle.

RedisModule_KeyType [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_keytype "Copy link to clipboard"/index.html)

int RedisModule_KeyType(RedisModuleKey *key);

Available since: 4.0.0

Return the type of the key. If the key pointer is NULL then REDISMODULE_KEYTYPE_EMPTY is returned.

RedisModule_ValueLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_valuelength "Copy link to clipboard"/index.html)

size_t RedisModule_ValueLength(RedisModuleKey *key);

Available since: 4.0.0

Return the length of the value associated with the key. For strings this is the length of the string. For all the other types is the number of elements (just counting keys for hashes).

If the key pointer is NULL or the key is empty, zero is returned.

RedisModule_DeleteKey [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_deletekey "Copy link to clipboard"/index.html)

int RedisModule_DeleteKey(RedisModuleKey *key);

Available since: 4.0.0

If the key is open for writing, remove it, and setup the key to accept new writes as an empty key (that will be created on demand). On success REDISMODULE_OK is returned. If the key is not open for writing REDISMODULE_ERR is returned.

RedisModule_UnlinkKey [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_unlinkkey "Copy link to clipboard"/index.html)

int RedisModule_UnlinkKey(RedisModuleKey *key);

Available since: 4.0.7

If the key is open for writing, unlink it (that is delete it in a non-blocking way, not reclaiming memory immediately) and setup the key to accept new writes as an empty key (that will be created on demand). On success REDISMODULE_OK is returned. If the key is not open for writing REDISMODULE_ERR is returned.

RedisModule_GetExpire [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getexpire "Copy link to clipboard"/index.html)

mstime_t RedisModule_GetExpire(RedisModuleKey *key);

Available since: 4.0.0

Return the key expire value, as milliseconds of remaining TTL. If no TTL is associated with the key or if the key is empty, REDISMODULE_NO_EXPIRE is returned.

RedisModule_SetExpire [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setexpire "Copy link to clipboard"/index.html)

int RedisModule_SetExpire(RedisModuleKey *key, mstime_t expire);

Available since: 4.0.0

Set a new expire for the key. If the special expire REDISMODULE_NO_EXPIRE is set, the expire is cancelled if there was one (the same as the PERSIST command).

Note that the expire must be provided as a positive integer representing the number of milliseconds of TTL the key should have.

The function returns REDISMODULE_OK on success or REDISMODULE_ERR if the key was not open for writing or is an empty key.

RedisModule_GetAbsExpire [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getabsexpire "Copy link to clipboard"/index.html)

mstime_t RedisModule_GetAbsExpire(RedisModuleKey *key);

Available since: 6.2.2

Return the key expire value, as absolute Unix timestamp. If no TTL is associated with the key or if the key is empty, REDISMODULE_NO_EXPIRE is returned.

RedisModule_SetAbsExpire [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setabsexpire "Copy link to clipboard"/index.html)

int RedisModule_SetAbsExpire(RedisModuleKey *key, mstime_t expire);

Available since: 6.2.2

Set a new expire for the key. If the special expire REDISMODULE_NO_EXPIRE is set, the expire is cancelled if there was one (the same as the PERSIST command).

Note that the expire must be provided as a positive integer representing the absolute Unix timestamp the key should have.

The function returns REDISMODULE_OK on success or REDISMODULE_ERR if the key was not open for writing or is an empty key.

RedisModule_CreateKeyMetaClass [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createkeymetaclass "Copy link to clipboard"/index.html)

RedisModuleKeyMetaClassId RedisModule_CreateKeyMetaClass(RedisModuleCtx *ctx,;

Available since: 8.6.0

Register a new key metadata class exported by the module.

Key metadata allows modules to attach up to 8 bytes of metadata to any Redis key, regardless of the key's type. This metadata persists across key operations like COPY, RENAME, MOVE, and can be saved/loaded from RDB files.

The parameters are the following:

• metaname: A 9 characters metadata class name that MUST be unique in the Redis Modules ecosystem. Use the charset A-Z a-z 0-9, plus the two "-_" characters. A good idea is to use, for example <metaname>-<vendor>. For example "idx-RediSearch" may mean "Index metadata by RediSearch module". To use both lower case and upper case letters helps in order to prevent collisions.

• metaver: Encoding version, which is the version of the serialization that a module used in order to persist metadata. As long as the "metaname" matches, the RDB loading will be dispatched to the metadata class callbacks whatever 'metaver' is used, however the module can understand if the encoding it must load is of an older version of the module. For example the module "idx-RediSearch" initially used metaver=0. Later after an upgrade, it started to serialize metadata in a different format and to register the class with metaver=1. However this module may still load old data produced by an older version if the rdb_load callback is able to check the metaver value and act accordingly. The metaver must be a positive value between 0 and 1023.

• confPtr is a pointer to a RedisModuleKeyMetaClassConfig structure that should be populated with the configuration and callbacks, like in the following example:

    RedisModuleKeyMetaClassConfig config = {
        .version = REDISMODULE_KEY_META_VERSION,
        .flags = 1 << REDISMODULE_META_ALLOW_IGNORE,
        .reset_value = 0,
        .copy = myMeta_CopyCallback,
        .rename = myMeta_RenameCallback,
        .move = myMeta_MoveCallback,
        .unlink = myMeta_UnlinkCallback,
        .free = myMeta_FreeCallback,
        .rdb_load = myMeta_RDBLoadCallback,
        .rdb_save = myMeta_RDBSaveCallback,
        .aof_rewrite = myMeta_AOFRewriteCallback,
        .defrag = myMeta_DefragCallback,
        .mem_usage = myMeta_MemUsageCallback,
        .free_effort = myMeta_FreeEffortCallback
    }

Redis does NOT take ownership of the config structure itself. The confPtr parameter only needs to remain valid during the RedisModule_CreateKeyMetaClass() call and can be freed immediately after.

• version: Module must set it to REDISMODULE_KEY_META_VERSION. This field is bumped when new fields are added; Redis keeps backward compatibility in RedisModule_CreateKeyMetaClass().

• flags: Currently supports REDISMODULE_META_ALLOW_IGNORE (value 0). When set, metadata will be silently ignored during RDB load if the module is not available or if rdb_load callback is NULL. Otherwise, RDB loading will fail if metadata is encountered but cannot be loaded.

• reset_value: The value to which metadata should be reset when it is being "removed" from a key. Typically 0, but can be any 8-byte value. This is especially relevant when metadata is a pointer/handler to external resources.

IMPORTANT GUARANTEE: Redis only invokes callbacks when meta != reset_value.

• copy: A callback function pointer for COPY command (optional).

  • Return 1 to attach meta to the new key, or 0 to skip attaching metadata.
  • If NULL, metadata is ignored during copy.
  • The meta value may be modified in-place to produce a different value for the new key.

• rename: A callback function pointer for RENAME command (optional).

  • If NULL, then metadata is kept during rename.
  • The meta value may be modified in-place to produce a different value for the new key.

• move: A callback function pointer for MOVE command (optional).

  • Return 1 to keep metadata, 0 to drop.
  • If NULL, then metadata is kept during move.
  • The meta value may be modified in-place to produce a different value for the new key.

• unlink: A callback function pointer for unlink operations (optional).

  • If not provided, then metadata is ignored during unlink.
  • Indication that key may soon be freed by background thread.
  • Pointer to meta is provided for modification. If the metadata holds a pointer or handle to resources and you free them here, you should set *meta=reset_value to prevent the free callback from being invoked (Redis skips callbacks when meta == reset_value, see reset_value documentation above).

• free: A callback function pointer for cleanup (optional). Invoked when a key with this metadata is deleted/overwritten/expired, or when Redis needs to release per-key metadata during lifecycle operations. The module should free any external allocation referenced by meta if it uses the 8 bytes as a handle/pointer. This callback may run in a background thread and is not protected by GIL. It also might be called during RDB loading if the load fails after some metadata has been successfully loaded. In this case, keyname will be NULL since the key hasn't been created yet.

• rdb_load: A callback function pointer for RDB loading (optional).

  • Called during RDB loading when metadata for this class is encountered.
  • Behavior when NULL:

If rdb_load is NULL AND REDISMODULE_META_ALLOW_IGNORE flag is set, the metadata will be silently ignored during RDB load. If rdb_load is NULL AND the flag is NOT set, RDB loading will fail if metadata for this class is encountered.

• Behavior when class is not registered:

If the class was saved with REDISMODULE_META_ALLOW_IGNORE flag but is not registered at load time, the metadata will be silently ignored. Otherwise, RDB loading will fail.

• Callback responsibilities:

Read custom serialized data from rdb using RedisModule_Load*() APIs Deserialize and reconstruct the 8-byte metadata value Write the final 8-byte value into *meta Return appropriate status code (see below) Database ID can be derived from rdb if needed. The associated key will be loaded immediately after this callback returns.

• Parameters:

rdb: RDB I/O context (use RedisModule_Load*() functions to read data) meta: Pointer to 8-byte metadata slot (write your deserialized value here) encver: Encoding version (the metadata class version at save time)

• Return values:

1: Attach value *meta to the key (success) 0: Ignore/skip metadata (don't attach, but continue loading - not an error) -1: Error - abort RDB load (e.g., invalid data, version incompatibility) Module MUST clean up any allocated metadata before returning -1.

• rdb_save: A callback function pointer for RDB saving (optional).

  • If set to NULL, Redis will not save metadata to RDB.
  • Callback should write data using RDB assisting functions: RedisModule_Save*().

• aof_rewrite: A callback function pointer for AOF rewrite (optional). Called during AOF rewrite to emit commands that reconstruct the metadata. IMPORTANT: For AOF/RDB persistence to work correctly, metadata classes must be registered in RedisModule_OnLoad() so they are available when loading persisted data on server startup.

• defrag: A callback function pointer for active defragmentation (optional). If the metadata contains pointers, this callback should defragment them.

• mem_usage: A callback function pointer for MEMORY USAGE command (optional). Should return the memory used by the metadata in bytes.

• free_effort: A callback function pointer for lazy free (optional). Should return the complexity of freeing the metadata to determine if lazy free should be used.

Note: the metadata class name "AAAAAAAAA" is reserved and produces an error.

If RedisModule_CreateKeyMetaClass() is called outside of RedisModule_OnLoad() function and outside of server startup, there is already a metadata class registered with the same name, or if the metadata class name or metaver is invalid, a negative value is returned. Otherwise the new metadata class is registered into Redis, and a reference of type RedisModuleKeyMetaClassId is returned: the caller of the function should store this reference into a global variable to make future use of it in the modules metadata API, since a single module may register multiple metadata classes. Example code fragment:

 static RedisModuleKeyMetaClassId IndexMetaClass;

int RedisModule_OnLoad(RedisModuleCtx *ctx) {
     // some code here ...
     IndexMetaClass = RedisModule_CreateKeyMetaClass(...);
 }

RedisModule_ReleaseKeyMetaClass [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_releasekeymetaclass "Copy link to clipboard"/index.html)

int RedisModule_ReleaseKeyMetaClass(RedisModuleKeyMetaClassId id);

Available since: 8.6.0

Release a class by its ID. Returns 1 on success, 0 on failure.

RedisModule_SetKeyMeta [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setkeymeta "Copy link to clipboard"/index.html)

int RedisModule_SetKeyMeta(RedisModuleKeyMetaClassId id,
                           RedisModuleKey *key,
                           uint64_t metadata);

Available since: 8.6.0

Set metadata of class id on an opened key. If metadata is already attached, it will be overwritten. The caller is responsible for retrieving and freeing any existing pointer-based metadata before setting a new value.

RedisModule_GetKeyMeta [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getkeymeta "Copy link to clipboard"/index.html)

int RedisModule_GetKeyMeta(RedisModuleKeyMetaClassId id,
                           RedisModuleKey *key,
                           uint64_t *metadata);

Available since: 8.6.0

Get metadata of class id from an opened key.

RedisModule_ResetDataset [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_resetdataset "Copy link to clipboard"/index.html)

void RedisModule_ResetDataset(int restart_aof, int async);

Available since: 6.0.0

Performs similar operation to FLUSHALL, and optionally start a new AOF file (if enabled) If restart_aof is true, you must make sure the command that triggered this call is not propagated to the AOF file. When async is set to true, db contents will be freed by a background thread.

RedisModule_DbSize [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_dbsize "Copy link to clipboard"/index.html)

unsigned long long RedisModule_DbSize(RedisModuleCtx *ctx);

Available since: 6.0.0

Returns the number of keys in the current db.

RedisModule_RandomKey [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_randomkey "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_RandomKey(RedisModuleCtx *ctx);

Available since: 6.0.0

Returns a name of a random key, or NULL if current db is empty.

RedisModule_GetKeyNameFromOptCtx [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getkeynamefromoptctx "Copy link to clipboard"/index.html)

const RedisModuleString *RedisModule_GetKeyNameFromOptCtx(RedisModuleKeyOptCtx *ctx);

Available since: 7.0.0

Returns the name of the key currently being processed.

RedisModule_GetToKeyNameFromOptCtx [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_gettokeynamefromoptctx "Copy link to clipboard"/index.html)

const RedisModuleString *RedisModule_GetToKeyNameFromOptCtx(RedisModuleKeyOptCtx *ctx);

Available since: 7.0.0

Returns the name of the target key currently being processed.

RedisModule_GetDbIdFromOptCtx [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getdbidfromoptctx "Copy link to clipboard"/index.html)

int RedisModule_GetDbIdFromOptCtx(RedisModuleKeyOptCtx *ctx);

Available since: 7.0.0

Returns the dbid currently being processed.

RedisModule_GetToDbIdFromOptCtx [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_gettodbidfromoptctx "Copy link to clipboard"/index.html)

int RedisModule_GetToDbIdFromOptCtx(RedisModuleKeyOptCtx *ctx);

Available since: 7.0.0

Returns the target dbid currently being processed.

Key API for String type [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#key-api-for-string-type "Copy link to clipboard"/index.html)

See also RedisModule_ValueLength(), which returns the length of a string.

RedisModule_StringSet [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringset "Copy link to clipboard"/index.html)

int RedisModule_StringSet(RedisModuleKey *key, RedisModuleString *str);

Available since: 4.0.0

If the key is open for writing, set the specified string 'str' as the value of the key, deleting the old value if any. On success REDISMODULE_OK is returned. If the key is not open for writing or there is an active iterator, REDISMODULE_ERR is returned.

RedisModule_StringDMA [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringdma "Copy link to clipboard"/index.html)

char *RedisModule_StringDMA(RedisModuleKey *key, size_t *len, int mode);

Available since: 4.0.0

Prepare the key associated string value for DMA access, and returns a pointer and size (by reference), that the user can use to read or modify the string in-place accessing it directly via pointer.

The 'mode' is composed by bitwise OR-ing the following flags:

REDISMODULE_READ -- Read access
REDISMODULE_WRITE -- Write access

If the DMA is not requested for writing, the pointer returned should only be accessed in a read-only fashion.

On error (wrong type) NULL is returned.

DMA access rules:

1. No other key writing function should be called since the moment the pointer is obtained, for all the time we want to use DMA access to read or modify the string.

2. Each time RedisModule_StringTruncate() is called, to continue with the DMA access, RedisModule_StringDMA() should be called again to re-obtain a new pointer and length.

3. If the returned pointer is not NULL, but the length is zero, no byte can be touched (the string is empty, or the key itself is empty) so a RedisModule_StringTruncate() call should be used if there is to enlarge the string, and later call StringDMA() again to get the pointer.

RedisModule_StringTruncate [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_stringtruncate "Copy link to clipboard"/index.html)

int RedisModule_StringTruncate(RedisModuleKey *key, size_t newlen);

Available since: 4.0.0

If the key is open for writing and is of string type, resize it, padding with zero bytes if the new length is greater than the old one.

After this call, RedisModule_StringDMA() must be called again to continue DMA access with the new pointer.

The function returns REDISMODULE_OK on success, and REDISMODULE_ERR on error, that is, the key is not open for writing, is not a string or resizing for more than 512 MB is requested.

If the key is empty, a string key is created with the new string value unless the new length value requested is zero.

Key API for List type [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#key-api-for-list-type "Copy link to clipboard"/index.html)

Many of the list functions access elements by index. Since a list is in essence a doubly-linked list, accessing elements by index is generally an O(N) operation. However, if elements are accessed sequentially or with indices close together, the functions are optimized to seek the index from the previous index, rather than seeking from the ends of the list.

This enables iteration to be done efficiently using a simple for loop:

long n = RedisModule_ValueLength(key);
for (long i = 0; i < n; i++) {
    RedisModuleString *elem = RedisModule_ListGet(key, i);
    // Do stuff...
}

Note that after modifying a list using RedisModule_ListPop, RedisModule_ListSet or RedisModule_ListInsert, the internal iterator is invalidated so the next operation will require a linear seek.

Modifying a list in any another way, for example using RedisModule_Call(), while a key is open will confuse the internal iterator and may cause trouble if the key is used after such modifications. The key must be reopened in this case.

See also RedisModule_ValueLength(), which returns the length of a list.

RedisModule_ListPush [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_listpush "Copy link to clipboard"/index.html)

int RedisModule_ListPush(RedisModuleKey *key,
                         int where,
                         RedisModuleString *ele);

Available since: 4.0.0

Push an element into a list, on head or tail depending on 'where' argument (REDISMODULE_LIST_HEAD or REDISMODULE_LIST_TAIL). If the key refers to an empty key opened for writing, the key is created. On success, REDISMODULE_OK is returned. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if key or ele is NULL.
• ENOTSUP if the key is of another type than list.
• EBADF if the key is not opened for writing.

Note: Before Redis 7.0, errno was not set by this function.

RedisModule_ListPop [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_listpop "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_ListPop(RedisModuleKey *key, int where);

Available since: 4.0.0

Pop an element from the list, and returns it as a module string object that the user should be free with RedisModule_FreeString() or by enabling automatic memory. The where argument specifies if the element should be popped from the beginning or the end of the list (REDISMODULE_LIST_HEAD or REDISMODULE_LIST_TAIL). On failure, the command returns NULL and sets errno as follows:

• EINVAL if key is NULL.
• ENOTSUP if the key is empty or of another type than list.
• EBADF if the key is not opened for writing.

Note: Before Redis 7.0, errno was not set by this function.

RedisModule_ListGet [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_listget "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_ListGet(RedisModuleKey *key, long index);

Available since: 7.0.0

Returns the element at index index in the list stored at key, like the LINDEX command. The element should be free'd using RedisModule_FreeString() or using automatic memory management.

The index is zero-based, so 0 means the first element, 1 the second element and so on. Negative indices can be used to designate elements starting at the tail of the list. Here, -1 means the last element, -2 means the penultimate and so forth.

When no value is found at the given key and index, NULL is returned and errno is set as follows:

• EINVAL if key is NULL.
• ENOTSUP if the key is not a list.
• EBADF if the key is not opened for reading.
• EDOM if the index is not a valid index in the list.

RedisModule_ListSet [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_listset "Copy link to clipboard"/index.html)

int RedisModule_ListSet(RedisModuleKey *key,
                        long index,
                        RedisModuleString *value);

Available since: 7.0.0

Replaces the element at index index in the list stored at key.

On success, REDISMODULE_OK is returned. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if key or value is NULL.
• ENOTSUP if the key is not a list.
• EBADF if the key is not opened for writing.
• EDOM if the index is not a valid index in the list.

RedisModule_ListInsert [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_listinsert "Copy link to clipboard"/index.html)

int RedisModule_ListInsert(RedisModuleKey *key,
                           long index,
                           RedisModuleString *value);

Available since: 7.0.0

Inserts an element at the given index.

The index is zero-based, so 0 means the first element, 1 the second element and so on. Negative indices can be used to designate elements starting at the tail of the list. Here, -1 means the last element, -2 means the penultimate and so forth. The index is the element's index after inserting it.

On success, REDISMODULE_OK is returned. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if key or value is NULL.
• ENOTSUP if the key of another type than list.
• EBADF if the key is not opened for writing.
• EDOM if the index is not a valid index in the list.

RedisModule_ListDelete [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_listdelete "Copy link to clipboard"/index.html)

int RedisModule_ListDelete(RedisModuleKey *key, long index);

Available since: 7.0.0

Removes an element at the given index. The index is 0-based. A negative index can also be used, counting from the end of the list.

On success, REDISMODULE_OK is returned. On failure, REDISMODULE_ERR is returned and errno is set as follows:

Key API for Sorted Set type [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#key-api-for-sorted-set-type "Copy link to clipboard"/index.html)

See also RedisModule_ValueLength(), which returns the length of a sorted set.

RedisModule_ZsetAdd [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetadd "Copy link to clipboard"/index.html)

int RedisModule_ZsetAdd(RedisModuleKey *key,
                        double score,
                        RedisModuleString *ele,
                        int *flagsptr);

Available since: 4.0.0

Add a new element into a sorted set, with the specified 'score'. If the element already exists, the score is updated.

A new sorted set is created at value if the key is an empty open key setup for writing.

Additional flags can be passed to the function via a pointer, the flags are both used to receive input and to communicate state when the function returns. 'flagsptr' can be NULL if no special flags are used.

The input flags are:

REDISMODULE_ZADD_XX: Element must already exist. Do nothing otherwise.
REDISMODULE_ZADD_NX: Element must not exist. Do nothing otherwise.
REDISMODULE_ZADD_GT: If element exists, new score must be greater than the current score.
                     Do nothing otherwise. Can optionally be combined with XX.
REDISMODULE_ZADD_LT: If element exists, new score must be less than the current score.
                     Do nothing otherwise. Can optionally be combined with XX.

The output flags are:

REDISMODULE_ZADD_ADDED: The new element was added to the sorted set.
REDISMODULE_ZADD_UPDATED: The score of the element was updated.
REDISMODULE_ZADD_NOP: No operation was performed because XX or NX flags.

On success the function returns REDISMODULE_OK. On the following errors REDISMODULE_ERR is returned:

• The key was not opened for writing.
• The key is of the wrong type.
• 'score' double value is not a number (NaN).

RedisModule_ZsetIncrby [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetincrby "Copy link to clipboard"/index.html)

int RedisModule_ZsetIncrby(RedisModuleKey *key,
                           double score,
                           RedisModuleString *ele,
                           int *flagsptr,
                           double *newscore);

Available since: 4.0.0

This function works exactly like RedisModule_ZsetAdd(), but instead of setting a new score, the score of the existing element is incremented, or if the element does not already exist, it is added assuming the old score was zero.

The input and output flags, and the return value, have the same exact meaning, with the only difference that this function will return REDISMODULE_ERR even when 'score' is a valid double number, but adding it to the existing score results into a NaN (not a number) condition.

This function has an additional field 'newscore', if not NULL is filled with the new score of the element after the increment, if no error is returned.

RedisModule_ZsetRem [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetrem "Copy link to clipboard"/index.html)

int RedisModule_ZsetRem(RedisModuleKey *key,
                        RedisModuleString *ele,
                        int *deleted);

Available since: 4.0.0

Remove the specified element from the sorted set. The function returns REDISMODULE_OK on success, and REDISMODULE_ERR on one of the following conditions:

• The key was not opened for writing.
• The key is of the wrong type.

The return value does NOT indicate the fact the element was really removed (since it existed) or not, just if the function was executed with success.

In order to know if the element was removed, the additional argument 'deleted' must be passed, that populates the integer by reference setting it to 1 or 0 depending on the outcome of the operation. The 'deleted' argument can be NULL if the caller is not interested to know if the element was really removed.

Empty keys will be handled correctly by doing nothing.

RedisModule_ZsetScore [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetscore "Copy link to clipboard"/index.html)

int RedisModule_ZsetScore(RedisModuleKey *key,
                          RedisModuleString *ele,
                          double *score);

Available since: 4.0.0

On success retrieve the double score associated at the sorted set element 'ele' and returns REDISMODULE_OK. Otherwise REDISMODULE_ERR is returned to signal one of the following conditions:

• There is no such element 'ele' in the sorted set.
• The key is not a sorted set.
• The key is an open empty key.

Key API for Sorted Set iterator [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#key-api-for-sorted-set-iterator "Copy link to clipboard"/index.html)

RedisModule_ZsetRangeStop [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetrangestop "Copy link to clipboard"/index.html)

void RedisModule_ZsetRangeStop(RedisModuleKey *key);

Available since: 4.0.0

Stop a sorted set iteration.

RedisModule_ZsetRangeEndReached [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetrangeendreached "Copy link to clipboard"/index.html)

int RedisModule_ZsetRangeEndReached(RedisModuleKey *key);

Available since: 4.0.0

Return the "End of range" flag value to signal the end of the iteration.

RedisModule_ZsetFirstInScoreRange [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetfirstinscorerange "Copy link to clipboard"/index.html)

int RedisModule_ZsetFirstInScoreRange(RedisModuleKey *key,
                                      double min,
                                      double max,
                                      int minex,
                                      int maxex);

Available since: 4.0.0

Setup a sorted set iterator seeking the first element in the specified range. Returns REDISMODULE_OK if the iterator was correctly initialized otherwise REDISMODULE_ERR is returned in the following conditions:

1. The value stored at key is not a sorted set or the key is empty.

The range is specified according to the two double values 'min' and 'max'. Both can be infinite using the following two macros:

• REDISMODULE_POSITIVE_INFINITE for positive infinite value
• REDISMODULE_NEGATIVE_INFINITE for negative infinite value

'minex' and 'maxex' parameters, if true, respectively setup a range where the min and max value are exclusive (not included) instead of inclusive.

RedisModule_ZsetLastInScoreRange [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetlastinscorerange "Copy link to clipboard"/index.html)

int RedisModule_ZsetLastInScoreRange(RedisModuleKey *key,
                                     double min,
                                     double max,
                                     int minex,
                                     int maxex);

Available since: 4.0.0

Exactly like RedisModule_ZsetFirstInScoreRange() but the last element of the range is selected for the start of the iteration instead.

RedisModule_ZsetFirstInLexRange [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetfirstinlexrange "Copy link to clipboard"/index.html)

int RedisModule_ZsetFirstInLexRange(RedisModuleKey *key,
                                    RedisModuleString *min,
                                    RedisModuleString *max);

Available since: 4.0.0

Setup a sorted set iterator seeking the first element in the specified lexicographical range. Returns REDISMODULE_OK if the iterator was correctly initialized otherwise REDISMODULE_ERR is returned in the following conditions:

1. The value stored at key is not a sorted set or the key is empty.
2. The lexicographical range 'min' and 'max' format is invalid.

'min' and 'max' should be provided as two RedisModuleString objects in the same format as the parameters passed to the ZRANGEBYLEX command. The function does not take ownership of the objects, so they can be released ASAP after the iterator is setup.

RedisModule_ZsetLastInLexRange [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetlastinlexrange "Copy link to clipboard"/index.html)

int RedisModule_ZsetLastInLexRange(RedisModuleKey *key,
                                   RedisModuleString *min,
                                   RedisModuleString *max);

Available since: 4.0.0

Exactly like RedisModule_ZsetFirstInLexRange() but the last element of the range is selected for the start of the iteration instead.

RedisModule_ZsetRangeCurrentElement [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetrangecurrentelement "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_ZsetRangeCurrentElement(RedisModuleKey *key,
                                                       double *score);

Available since: 4.0.0

Return the current sorted set element of an active sorted set iterator or NULL if the range specified in the iterator does not include any element.

RedisModule_ZsetRangeNext [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetrangenext "Copy link to clipboard"/index.html)

int RedisModule_ZsetRangeNext(RedisModuleKey *key);

Available since: 4.0.0

Go to the next element of the sorted set iterator. Returns 1 if there was a next element, 0 if we are already at the latest element or the range does not include any item at all.

RedisModule_ZsetRangePrev [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_zsetrangeprev "Copy link to clipboard"/index.html)

int RedisModule_ZsetRangePrev(RedisModuleKey *key);

Available since: 4.0.0

Go to the previous element of the sorted set iterator. Returns 1 if there was a previous element, 0 if we are already at the first element or the range does not include any item at all.

Key API for Hash type [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#key-api-for-hash-type "Copy link to clipboard"/index.html)

See also RedisModule_ValueLength(), which returns the number of fields in a hash.

RedisModule_HashSet [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_hashset "Copy link to clipboard"/index.html)

int RedisModule_HashSet(RedisModuleKey *key, int flags, ...);

Available since: 4.0.0

Set the field of the specified hash field to the specified value. If the key is an empty key open for writing, it is created with an empty hash value, in order to set the specified field.

The function is variadic and the user must specify pairs of field names and values, both as RedisModuleString pointers (unless the CFIELD option is set, see later). At the end of the field/value-ptr pairs, NULL must be specified as last argument to signal the end of the arguments in the variadic function.

Example to set the hash argv[1] to the value argv[2]:

 RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[1],argv[2],NULL);

The function can also be used in order to delete fields (if they exist) by setting them to the specified value of REDISMODULE_HASH_DELETE:

 RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[1],
                     REDISMODULE_HASH_DELETE,NULL);

The behavior of the command changes with the specified flags, that can be set to REDISMODULE_HASH_NONE if no special behavior is needed.

REDISMODULE_HASH_NX: The operation is performed only if the field was not
                     already existing in the hash.
REDISMODULE_HASH_XX: The operation is performed only if the field was
                     already existing, so that a new value could be
                     associated to an existing filed, but no new fields
                     are created.
REDISMODULE_HASH_CFIELDS: The field names passed are null terminated C
                          strings instead of RedisModuleString objects.
REDISMODULE_HASH_COUNT_ALL: Include the number of inserted fields in the
                            returned number, in addition to the number of
                            updated and deleted fields. (Added in Redis
                            6.2.)

Unless NX is specified, the command overwrites the old field value with the new one.

When using REDISMODULE_HASH_CFIELDS, field names are reported using normal C strings, so for example to delete the field "foo" the following code can be used:

 RedisModule_HashSet(key,REDISMODULE_HASH_CFIELDS,"foo",
                     REDISMODULE_HASH_DELETE,NULL);

Return value:

The number of fields existing in the hash prior to the call, which have been updated (its old value has been replaced by a new value) or deleted. If the flag REDISMODULE_HASH_COUNT_ALL is set, inserted fields not previously existing in the hash are also counted.

If the return value is zero, errno is set (since Redis 6.2) as follows:

• EINVAL if any unknown flags are set or if key is NULL.
• ENOTSUP if the key is associated with a non Hash value.
• EBADF if the key was not opened for writing.
• ENOENT if no fields were counted as described under Return value above. This is not actually an error. The return value can be zero if all fields were just created and the COUNT_ALL flag was unset, or if changes were held back due to the NX and XX flags.

NOTICE: The return value semantics of this function are very different between Redis 6.2 and older versions. Modules that use it should determine the Redis version and handle it accordingly.

RedisModule_HashGet [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_hashget "Copy link to clipboard"/index.html)

int RedisModule_HashGet(RedisModuleKey *key, int flags, ...);

Available since: 4.0.0

Get fields from a hash value. This function is called using a variable number of arguments, alternating a field name (as a RedisModuleString pointer) with a pointer to a RedisModuleString pointer, that is set to the value of the field if the field exists, or NULL if the field does not exist. At the end of the field/value-ptr pairs, NULL must be specified as last argument to signal the end of the arguments in the variadic function.

This is an example usage:

 RedisModuleString *first, *second;
 RedisModule_HashGet(mykey,REDISMODULE_HASH_NONE,argv[1],&first,
                     argv[2],&second,NULL);

As with RedisModule_HashSet() the behavior of the command can be specified passing flags different than REDISMODULE_HASH_NONE:

REDISMODULE_HASH_CFIELDS: field names as null terminated C strings.

REDISMODULE_HASH_EXISTS: instead of setting the value of the field expecting a RedisModuleString pointer to pointer, the function just reports if the field exists or not and expects an integer pointer as the second element of each pair.

REDISMODULE_HASH_EXPIRE_TIME: retrieves the expiration time of a field in the hash. The function expects a mstime_t pointer as the second element of each pair. If the field does not exist or has no expiration, the value is set to REDISMODULE_NO_EXPIRE. This flag must not be used with REDISMODULE_HASH_EXISTS.

Example of REDISMODULE_HASH_CFIELDS:

 RedisModuleString *username, *hashedpass;
 RedisModule_HashGet(mykey,REDISMODULE_HASH_CFIELDS,"username",&username,"hp",&hashedpass, NULL);

Example of REDISMODULE_HASH_EXISTS:

 int exists;
 RedisModule_HashGet(mykey,REDISMODULE_HASH_EXISTS,"username",&exists,NULL);

Example of REDISMODULE_HASH_EXPIRE_TIME:

 mstime_t hpExpireTime;
 RedisModule_HashGet(mykey,REDISMODULE_HASH_EXPIRE_TIME,"hp",&hpExpireTime,NULL);

The function returns REDISMODULE_OK on success and REDISMODULE_ERR if the key is not a hash value.

Memory management:

The returned RedisModuleString objects should be released with RedisModule_FreeString(), or by enabling automatic memory management.

RedisModule_HashFieldMinExpire [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_hashfieldminexpire "Copy link to clipboard"/index.html)

mstime_t RedisModule_HashFieldMinExpire(RedisModuleKey *key);

Available since: 8.0.0

Retrieves the minimum expiration time of fields in a hash.

Return:

• The minimum expiration time (in milliseconds) of the hash fields if at least one field has an expiration set.
• REDISMODULE_NO_EXPIRE if no fields have an expiration set or if the key is not a hash.

Key API for Stream type [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#key-api-for-stream-type "Copy link to clipboard"/index.html)

For an introduction to streams, see https://redis.io/docs/latest/develop/data-types/streams/.

The type RedisModuleStreamID, which is used in stream functions, is a struct with two 64-bit fields and is defined as

typedef struct RedisModuleStreamID {
    uint64_t ms;
    uint64_t seq;
} RedisModuleStreamID;

See also RedisModule_ValueLength(), which returns the length of a stream, and the conversion functions RedisModule_StringToStreamID() and RedisModule_CreateStringFromStreamID().

RedisModule_StreamAdd [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamadd "Copy link to clipboard"/index.html)

int RedisModule_StreamAdd(RedisModuleKey *key,
                          int flags,
                          RedisModuleStreamID *id,
                          RedisModuleString **argv,
                          long numfields);

Available since: 6.2.0

Adds an entry to a stream. Like XADD without trimming.

• key: The key where the stream is (or will be) stored

• flags: A bit field of

• REDISMODULE_STREAM_ADD_AUTOID: Assign a stream ID automatically, like * in the XADD command.

• id: If the AUTOID flag is set, this is where the assigned ID is returned. Can be NULL if AUTOID is set, if you don't care to receive the ID. If AUTOID is not set, this is the requested ID.

• argv: A pointer to an array of size numfields * 2 containing the fields and values.

• numfields: The number of field-value pairs in argv.

Returns REDISMODULE_OK if an entry has been added. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if called with invalid arguments
• ENOTSUP if the key refers to a value of a type other than stream
• EBADF if the key was not opened for writing
• EDOM if the given ID was 0-0 or not greater than all other IDs in the stream (only if the AUTOID flag is unset)
• EFBIG if the stream has reached the last possible ID
• ERANGE if the elements are too large to be stored.

RedisModule_StreamDelete [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamdelete "Copy link to clipboard"/index.html)

int RedisModule_StreamDelete(RedisModuleKey *key, RedisModuleStreamID *id);

Available since: 6.2.0

Deletes an entry from a stream.

• key: A key opened for writing, with no stream iterator started.
• id: The stream ID of the entry to delete.

Returns REDISMODULE_OK on success. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if called with invalid arguments
• ENOTSUP if the key refers to a value of a type other than stream or if the key is empty
• EBADF if the key was not opened for writing or if a stream iterator is associated with the key
• ENOENT if no entry with the given stream ID exists

See also RedisModule_StreamIteratorDelete() for deleting the current entry while iterating using a stream iterator.

RedisModule_StreamIteratorStart [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamiteratorstart "Copy link to clipboard"/index.html)

int RedisModule_StreamIteratorStart(RedisModuleKey *key,
                                    int flags,
                                    RedisModuleStreamID *start,
                                    RedisModuleStreamID *end);

Available since: 6.2.0

Sets up a stream iterator.

• key: The stream key opened for reading using RedisModule_OpenKey().

• flags:

• REDISMODULE_STREAM_ITERATOR_EXCLUSIVE: Don't include start and end in the iterated range.

  • REDISMODULE_STREAM_ITERATOR_REVERSE: Iterate in reverse order, starting from the end of the range.

• start: The lower bound of the range. Use NULL for the beginning of the stream.

• end: The upper bound of the range. Use NULL for the end of the stream.

Returns REDISMODULE_OK on success. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if called with invalid arguments
• ENOTSUP if the key refers to a value of a type other than stream or if the key is empty
• EBADF if the key was not opened for writing or if a stream iterator is already associated with the key
• EDOM if start or end is outside the valid range

Returns REDISMODULE_OK on success and REDISMODULE_ERR if the key doesn't refer to a stream or if invalid arguments were given.

The stream IDs are retrieved using RedisModule_StreamIteratorNextID() and for each stream ID, the fields and values are retrieved using RedisModule_StreamIteratorNextField(). The iterator is freed by calling RedisModule_StreamIteratorStop().

Example (error handling omitted):

RedisModule_StreamIteratorStart(key, 0, startid_ptr, endid_ptr);
RedisModuleStreamID id;
long numfields;
while (RedisModule_StreamIteratorNextID(key, &id, &numfields) ==
       REDISMODULE_OK) {
    RedisModuleString *field, *value;
    while (RedisModule_StreamIteratorNextField(key, &field, &value) ==
           REDISMODULE_OK) {
        //
        // ... Do stuff ...
        //
        RedisModule_FreeString(ctx, field);
        RedisModule_FreeString(ctx, value);
    }
}
RedisModule_StreamIteratorStop(key);

RedisModule_StreamIteratorStop [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamiteratorstop "Copy link to clipboard"/index.html)

int RedisModule_StreamIteratorStop(RedisModuleKey *key);

Available since: 6.2.0

Stops a stream iterator created using RedisModule_StreamIteratorStart() and reclaims its memory.

Returns REDISMODULE_OK on success. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if called with a NULL key
• ENOTSUP if the key refers to a value of a type other than stream or if the key is empty
• EBADF if the key was not opened for writing or if no stream iterator is associated with the key

RedisModule_StreamIteratorNextID [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamiteratornextid "Copy link to clipboard"/index.html)

int RedisModule_StreamIteratorNextID(RedisModuleKey *key,
                                     RedisModuleStreamID *id,
                                     long *numfields);

Available since: 6.2.0

Finds the next stream entry and returns its stream ID and the number of fields.

• key: Key for which a stream iterator has been started using RedisModule_StreamIteratorStart().
• id: The stream ID returned. NULL if you don't care.
• numfields: The number of fields in the found stream entry. NULL if you don't care.

Returns REDISMODULE_OK and sets *id and *numfields if an entry was found. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if called with a NULL key
• ENOTSUP if the key refers to a value of a type other than stream or if the key is empty
• EBADF if no stream iterator is associated with the key
• ENOENT if there are no more entries in the range of the iterator

In practice, if RedisModule_StreamIteratorNextID() is called after a successful call to RedisModule_StreamIteratorStart() and with the same key, it is safe to assume that an REDISMODULE_ERR return value means that there are no more entries.

Use RedisModule_StreamIteratorNextField() to retrieve the fields and values. See the example at RedisModule_StreamIteratorStart().

RedisModule_StreamIteratorNextField [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamiteratornextfield "Copy link to clipboard"/index.html)

int RedisModule_StreamIteratorNextField(RedisModuleKey *key,
                                        RedisModuleString **field_ptr,
                                        RedisModuleString **value_ptr);

Available since: 6.2.0

Retrieves the next field of the current stream ID and its corresponding value in a stream iteration. This function should be called repeatedly after calling RedisModule_StreamIteratorNextID() to fetch each field-value pair.

• key: Key where a stream iterator has been started.
• field_ptr: This is where the field is returned.
• value_ptr: This is where the value is returned.

Returns REDISMODULE_OK and points *field_ptr and *value_ptr to freshly allocated RedisModuleString objects. The string objects are freed automatically when the callback finishes if automatic memory is enabled. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if called with a NULL key
• ENOTSUP if the key refers to a value of a type other than stream or if the key is empty
• EBADF if no stream iterator is associated with the key
• ENOENT if there are no more fields in the current stream entry

In practice, if RedisModule_StreamIteratorNextField() is called after a successful call to RedisModule_StreamIteratorNextID() and with the same key, it is safe to assume that an REDISMODULE_ERR return value means that there are no more fields.

See the example at RedisModule_StreamIteratorStart().

RedisModule_StreamIteratorDelete [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamiteratordelete "Copy link to clipboard"/index.html)

int RedisModule_StreamIteratorDelete(RedisModuleKey *key);

Available since: 6.2.0

Deletes the current stream entry while iterating.

This function can be called after RedisModule_StreamIteratorNextID() or after any calls to RedisModule_StreamIteratorNextField().

Returns REDISMODULE_OK on success. On failure, REDISMODULE_ERR is returned and errno is set as follows:

• EINVAL if key is NULL
• ENOTSUP if the key is empty or is of another type than stream
• EBADF if the key is not opened for writing, if no iterator has been started
• ENOENT if the iterator has no current stream entry

RedisModule_StreamTrimByLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamtrimbylength "Copy link to clipboard"/index.html)

long long RedisModule_StreamTrimByLength(RedisModuleKey *key,
                                         int flags,
                                         long long length);

Available since: 6.2.0

Trim a stream by length, similar to XTRIM with MAXLEN.

• key: Key opened for writing.

• flags: A bitfield of

• REDISMODULE_STREAM_TRIM_APPROX: Trim less if it improves performance, like XTRIM with ~.

• length: The number of stream entries to keep after trimming.

Returns the number of entries deleted. On failure, a negative value is returned and errno is set as follows:

• EINVAL if called with invalid arguments
• ENOTSUP if the key is empty or of a type other than stream
• EBADF if the key is not opened for writing

RedisModule_StreamTrimByID [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_streamtrimbyid "Copy link to clipboard"/index.html)

long long RedisModule_StreamTrimByID(RedisModuleKey *key,
                                     int flags,
                                     RedisModuleStreamID *id);

Available since: 6.2.0

Trim a stream by ID, similar to XTRIM with MINID.

• key: Key opened for writing.

• flags: A bitfield of

• REDISMODULE_STREAM_TRIM_APPROX: Trim less if it improves performance, like XTRIM with ~.

• id: The smallest stream ID to keep after trimming.

Returns the number of entries deleted. On failure, a negative value is returned and errno is set as follows:

• EINVAL if called with invalid arguments
• ENOTSUP if the key is empty or of a type other than stream
• EBADF if the key is not opened for writing

Calling Redis commands from modules [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#calling-redis-commands-from-modules "Copy link to clipboard"/index.html)

RedisModule_Call() sends a command to Redis. The remaining functions handle the reply.

RedisModule_FreeCallReply [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_freecallreply "Copy link to clipboard"/index.html)

void RedisModule_FreeCallReply(RedisModuleCallReply *reply);

Available since: 4.0.0

Free a Call reply and all the nested replies it contains if it's an array.

RedisModule_CallReplyType [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplytype "Copy link to clipboard"/index.html)

int RedisModule_CallReplyType(RedisModuleCallReply *reply);

Available since: 4.0.0

Return the reply type as one of the following:

• REDISMODULE_REPLY_UNKNOWN
• REDISMODULE_REPLY_STRING
• REDISMODULE_REPLY_ERROR
• REDISMODULE_REPLY_INTEGER
• REDISMODULE_REPLY_ARRAY
• REDISMODULE_REPLY_NULL
• REDISMODULE_REPLY_MAP
• REDISMODULE_REPLY_SET
• REDISMODULE_REPLY_BOOL
• REDISMODULE_REPLY_DOUBLE
• REDISMODULE_REPLY_BIG_NUMBER
• REDISMODULE_REPLY_VERBATIM_STRING
• REDISMODULE_REPLY_ATTRIBUTE
• REDISMODULE_REPLY_PROMISE

RedisModule_CallReplyLength [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplylength "Copy link to clipboard"/index.html)

size_t RedisModule_CallReplyLength(RedisModuleCallReply *reply);

Available since: 4.0.0

Return the reply type length, where applicable.

RedisModule_CallReplyArrayElement [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplyarrayelement "Copy link to clipboard"/index.html)

RedisModuleCallReply *RedisModule_CallReplyArrayElement(RedisModuleCallReply *reply,
                                                        size_t idx);

Available since: 4.0.0

Return the 'idx'-th nested call reply element of an array reply, or NULL if the reply type is wrong or the index is out of range.

RedisModule_CallReplyInteger [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplyinteger "Copy link to clipboard"/index.html)

long long RedisModule_CallReplyInteger(RedisModuleCallReply *reply);

Available since: 4.0.0

Return the long long of an integer reply.

RedisModule_CallReplyDouble [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplydouble "Copy link to clipboard"/index.html)

double RedisModule_CallReplyDouble(RedisModuleCallReply *reply);

Available since: 7.0.0

Return the double value of a double reply.

RedisModule_CallReplyBigNumber [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplybignumber "Copy link to clipboard"/index.html)

const char *RedisModule_CallReplyBigNumber(RedisModuleCallReply *reply,
                                           size_t *len);

Available since: 7.0.0

Return the big number value of a big number reply.

RedisModule_CallReplyVerbatim [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplyverbatim "Copy link to clipboard"/index.html)

const char *RedisModule_CallReplyVerbatim(RedisModuleCallReply *reply,
                                          size_t *len,
                                          const char **format);

Available since: 7.0.0

Return the value of a verbatim string reply, An optional output argument can be given to get verbatim reply format.

RedisModule_CallReplyBool [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplybool "Copy link to clipboard"/index.html)

int RedisModule_CallReplyBool(RedisModuleCallReply *reply);

Available since: 7.0.0

Return the Boolean value of a Boolean reply.

RedisModule_CallReplySetElement [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplysetelement "Copy link to clipboard"/index.html)

RedisModuleCallReply *RedisModule_CallReplySetElement(RedisModuleCallReply *reply,
                                                      size_t idx);

Available since: 7.0.0

Return the 'idx'-th nested call reply element of a set reply, or NULL if the reply type is wrong or the index is out of range.

RedisModule_CallReplyMapElement [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplymapelement "Copy link to clipboard"/index.html)

int RedisModule_CallReplyMapElement(RedisModuleCallReply *reply,
                                    size_t idx,
                                    RedisModuleCallReply **key,
                                    RedisModuleCallReply **val);

Available since: 7.0.0

Retrieve the 'idx'-th key and value of a map reply.

Returns:

• REDISMODULE_OK on success.
• REDISMODULE_ERR if idx out of range or if the reply type is wrong.

The key and value arguments are used to return by reference, and may be NULL if not required.

RedisModule_CallReplyAttribute [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplyattribute "Copy link to clipboard"/index.html)

RedisModuleCallReply *RedisModule_CallReplyAttribute(RedisModuleCallReply *reply);

Available since: 7.0.0

Return the attribute of the given reply, or NULL if no attribute exists.

RedisModule_CallReplyAttributeElement [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplyattributeelement "Copy link to clipboard"/index.html)

int RedisModule_CallReplyAttributeElement(RedisModuleCallReply *reply,
                                          size_t idx,
                                          RedisModuleCallReply **key,
                                          RedisModuleCallReply **val);

Available since: 7.0.0

Retrieve the 'idx'-th key and value of an attribute reply.

Returns:

• REDISMODULE_OK on success.
• REDISMODULE_ERR if idx out of range or if the reply type is wrong.

The key and value arguments are used to return by reference, and may be NULL if not required.

RedisModule_CallReplyPromiseSetUnblockHandler [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplypromisesetunblockhandler "Copy link to clipboard"/index.html)

void RedisModule_CallReplyPromiseSetUnblockHandler(RedisModuleCallReply *reply,
                                                   RedisModuleOnUnblocked on_unblock,
                                                   void *private_data);

Available since: 7.2.0

Set unblock handler (callback and private data) on the given promise RedisModuleCallReply. The given reply must be of promise type (REDISMODULE_REPLY_PROMISE).

RedisModule_CallReplyPromiseAbort [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplypromiseabort "Copy link to clipboard"/index.html)

int RedisModule_CallReplyPromiseAbort(RedisModuleCallReply *reply,
                                      void **private_data);

Available since: 7.2.0

Abort the execution of a given promise RedisModuleCallReply. return REDMODULE_OK in case the abort was done successfully and REDISMODULE_ERR if its not possible to abort the execution (execution already finished). In case the execution was aborted (REDMODULE_OK was returned), the private_data out parameter will be set with the value of the private data that was given on ' RedisModule_CallReplyPromiseSetUnblockHandler' so the caller will be able to release the private data.

If the execution was aborted successfully, it is promised that the unblock handler will not be called. That said, it is possible that the abort operation will successes but the operation will still continue. This can happened if, for example, a module implements some blocking command and does not respect the disconnect callback. For pure Redis commands this can not happened.

RedisModule_CallReplyStringPtr [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_callreplystringptr "Copy link to clipboard"/index.html)

const char *RedisModule_CallReplyStringPtr(RedisModuleCallReply *reply,
                                           size_t *len);

Available since: 4.0.0

Return the pointer and length of a string or error reply.

RedisModule_CreateStringFromCallReply [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_createstringfromcallreply "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CreateStringFromCallReply(RedisModuleCallReply *reply);

Available since: 4.0.0

Return a new string object from a call reply of type string, error or integer. Otherwise (wrong reply type) return NULL.

RedisModule_SetContextUser [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_setcontextuser "Copy link to clipboard"/index.html)

void RedisModule_SetContextUser(RedisModuleCtx *ctx,
                                const RedisModuleUser *user);

Available since: 7.0.6

Modifies the user that RedisModule_Call will use (e.g. for ACL checks)

RedisModule_GetContextUser [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_getcontextuser "Copy link to clipboard"/index.html)

const RedisModuleUser *RedisModule_GetContextUser(RedisModuleCtx *ctx);

Available since: unreleased

Returns the user associated with the context via RedisModule_SetContextUser. Returns NULL if no user was set on the context. The returned pointer is borrowed from the context — do NOT free it.

RedisModule_Call [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/#redismodule_call "Copy link to clipboard"/index.html)

RedisModuleCallReply *RedisModule_Call(RedisModuleCtx *ctx,
                                       const char *cmdname,
                                       const char *fmt,
                                       ...);

Available since: 4.0.0

Exported API to call any Redis command from modules.

• cmdname: The Redis command to call.

• fmt: A format specifier string for the command's arguments. Each of the arguments should be specified by a valid type specification. The format specifier can also contain the modifiers !, A, 3 and R which don't have a corresponding argument.

  • b -- The argument is a buffer and is immediately followed by another argument that is the buffer's length.

• c -- The argument is a pointer to a plain C string (null-terminated).

• l -- The argument is a long long integer.

• s -- The argument is a RedisModuleString.

• v -- The argument(s) is a vector of RedisModuleString.

• ! -- Sends the Redis command and its arguments to replicas and AOF.

• A -- Suppress AOF propagation, send only to replicas (requires !).

• R -- Suppress replicas propagation, send only to AOF (requires !).

• 3 -- Return a RESP3 reply. This will change the command reply. e.g., HGETALL returns a map instead of a flat array.

• 0 -- Return the reply in auto mode, i.e. the reply format will be the same as the client attached to the given RedisModuleCtx. This will probably used when you want to pass the reply directly to the client.

• C -- Run a command as the user attached to the context. User is either attached automatically via the client that directly issued the command and created the context or via RedisModule_SetContextUser. If the context is not directly created by an issued command (such as a background context and no user was set on it via RedisModule_SetContextUser, RedisModule_Call will fail. Checks if the command can be executed according to ACL rules and causes the command to run as the determined user, so that any future user dependent activity, such as ACL checks within scripts will proceed as expected. Otherwise, the command will run as the Redis unrestricted user. Upon sending a command from an internal connection, this flag is ignored and the command will run as the Redis unrestricted user.

• S -- Run the command in a script mode, this means that it will raise an error if a command which are not allowed inside a script (flagged with the deny-script flag) is invoked (like SHUTDOWN). In addition, on script mode, write commands are not allowed if there are not enough good replicas (as configured with min-replicas-to-write) or when the server is unable to persist to the disk.

• W -- Do not allow to run any write command (flagged with the write flag).

• M -- Do not allow deny-oom flagged commands when over the memory limit.

• E -- Return error as RedisModuleCallReply. If there is an error before invoking the command, the error is returned using errno mechanism. This flag allows to get the error also as an error CallReply with relevant error message.

• 'D' -- A "Dry Run" mode. Return before executing the underlying call(). If everything succeeded, it will return with a NULL, otherwise it will return with a CallReply object denoting the error, as if it was called with the 'E' code.

• 'K' -- Allow running blocking commands. If enabled and the command gets blocked, a special REDISMODULE_REPLY_PROMISE will be returned. This reply type indicates that the command was blocked and the reply will be given asynchronously. The module can use this reply object to set a handler which will be called when the command gets unblocked using RedisModule_CallReplyPromiseSetUnblockHandler. The handler must be set immediately after the command invocation (without releasing the Redis lock in between). If the handler is not set, the blocking command will still continue its execution but the reply will be ignored (fire and forget), notice that this is dangerous in case of role change, as explained below. The module can use RedisModule_CallReplyPromiseAbort to abort the command invocation if it was not yet finished (see RedisModule_CallReplyPromiseAbort documentation for more details). It is also the module's responsibility to abort the execution on role change, either by using server event (to get notified when the instance becomes a replica) or relying on the disconnect callback of the original client. Failing to do so can result in a write operation on a replica. Unlike other call replies, promise call reply must be freed while the Redis GIL is locked. Notice that on unblocking, the only promise is that the unblock handler will be called, If the blocking RedisModule_Call caused the module to also block some real client (using RedisModule_BlockClient), it is the module responsibility to unblock this client on the unblock handler. On the unblock handler it is only allowed to perform the following: \* Calling additional Redis commands using RedisModule_Call \* Open keys using RedisModule_OpenKey \* Replicate data to the replica or AOF

       Specifically, it is not allowed to call any Redis module API which are client related such as:
       * RedisModule_Reply* API's
       * RedisModule_BlockClient
       * RedisModule_GetCurrentUserName
    ```
- **...**: The actual arguments to the Redis command.

On success a `RedisModuleCallReply` object is returned, otherwise
NULL is returned and errno is set to the following values:

- EBADF: wrong format specifier.
- EINVAL: wrong command arity.
- ENOENT: command does not exist.
- EPERM: operation in Cluster instance with key in non local slot.
- EROFS: operation in Cluster instance when a write command is sent
in a readonly state.
- ENETDOWN: operation in Cluster instance when cluster is down.
- ENOTSUP: No ACL user for the specified module context
- EACCES: Command cannot be executed, according to ACL rules
- ENOSPC: Write or deny-oom command is not allowed
- ESPIPE: Command not allowed on script mode

Example code fragment:

reply = RedisModule_Call(ctx,"INCRBY","sc",argv[1],"10"); if (RedisModule_CallReplyType(reply) == REDISMODULE_REPLY_INTEGER) { long long myval = RedisModule_CallReplyInteger(reply); // Do something with myval. }

This API is documented here: [https://redis.io/docs/latest/develop/reference/modules/](/content/docs/latest/develop/reference/modules/index.html)

### `RedisModule_CallReplyProto` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_callreplyproto "Copy link to clipboard"/index.html)

const char *RedisModule_CallReplyProto(RedisModuleCallReply *reply, size_t *len);

**Available since:** 4.0.0

Return a pointer, and a length, to the protocol returned by the command
that returned the reply object.

## Modules data types  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-data-types "Copy link to clipboard"/index.html)

When String DMA or using existing data structures is not enough, it is
possible to create new data types from scratch and export them to
Redis. The module must provide a set of callbacks for handling the
new values exported (for example in order to provide RDB saving/loading,
AOF rewrite, and so forth). In this section we define this API.

### `RedisModule_CreateDataType` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_createdatatype "Copy link to clipboard"/index.html)

moduleType *RedisModule_CreateDataType(RedisModuleCtx *ctx, const char *name, int encver, void *typemethods_ptr);

**Available since:** 4.0.0

Register a new data type exported by the module. The parameters are the
following. Please for in depth documentation check the modules API
documentation, especially [https://redis.io/docs/latest/develop/reference/modules/modules-native-types/](/content/docs/latest/develop/reference/modules/modules-native-types/index.html).

- **name**: A 9 characters data type name that MUST be unique in the Redis
Modules ecosystem. Be creative... and there will be no collisions. Use
the charset A-Z a-z 9-0, plus the two "-\_" characters. A good
idea is to use, for example `<typename>-<vendor>`. For example
"tree-AntZ" may mean "Tree data structure by @antirez". To use both
lower case and upper case letters helps in order to prevent collisions.

- **encver**: Encoding version, which is, the version of the serialization
that a module used in order to persist data. As long as the "name"
matches, the RDB loading will be dispatched to the type callbacks
whatever 'encver' is used, however the module can understand if
the encoding it must load are of an older version of the module.
For example the module "tree-AntZ" initially used encver=0. Later
after an upgrade, it started to serialize data in a different format
and to register the type with encver=1. However this module may
still load old data produced by an older version if the `rdb_load`
callback is able to check the encver value and act accordingly.
The encver must be a positive value between 0 and 1023.

- **typemethods\_ptr** is a pointer to a `RedisModuleTypeMethods` structure
that should be populated with the methods callbacks and structure
version, like in the following example:

RedisModuleTypeMethods tm = {
    .version = REDISMODULE_TYPE_METHOD_VERSION,
    .rdb_load = myType_RDBLoadCallBack,
    .rdb_save = myType_RDBSaveCallBack,
    .aof_rewrite = myType_AOFRewriteCallBack,
    .free = myType_FreeCallBack,

// Optional fields .digest = myType_DigestCallBack, .mem_usage = myType_MemUsageCallBack, .aux_load = myType_AuxRDBLoadCallBack, .aux_save = myType_AuxRDBSaveCallBack, .free_effort = myType_FreeEffortCallBack, .unlink = myType_UnlinkCallBack, .copy = myType_CopyCallback, .defrag = myType_DefragCallback

// Enhanced optional fields .mem_usage2 = myType_MemUsageCallBack2, .free_effort2 = myType_FreeEffortCallBack2, .unlink2 = myType_UnlinkCallBack2, .copy2 = myType_CopyCallback2, }

- **rdb\_load**: A callback function pointer that loads data from RDB files.

- **rdb\_save**: A callback function pointer that saves data to RDB files.

- **aof\_rewrite**: A callback function pointer that rewrites data as commands.

- **digest**: A callback function pointer that is used for `DEBUG DIGEST`.

- **free**: A callback function pointer that can free a type value.

- **aux\_save**: A callback function pointer that saves out of keyspace data to RDB files.
'when' argument is either `REDISMODULE_AUX_BEFORE_RDB` or `REDISMODULE_AUX_AFTER_RDB`.

- **aux\_load**: A callback function pointer that loads out of keyspace data from RDB files.
Similar to `aux_save`, returns `REDISMODULE_OK` on success, and ERR otherwise.

- **free\_effort**: A callback function pointer that used to determine whether the module's
memory needs to be lazy reclaimed. The module should return the complexity involved by
freeing the value. for example: how many pointers are gonna be freed. Note that if it
returns 0, we'll always do an async free.

- **unlink**: A callback function pointer that used to notifies the module that the key has
been removed from the DB by redis, and may soon be freed by a background thread. Note that
it won't be called on FLUSHALL/FLUSHDB (both sync and async), and the module can use the
`RedisModuleEvent_FlushDB` to hook into that.

- **copy**: A callback function pointer that is used to make a copy of the specified key.
The module is expected to perform a deep copy of the specified value and return it.
In addition, hints about the names of the source and destination keys is provided.
A NULL return value is considered an error and the copy operation fails.
Note: if the target key exists and is being overwritten, the copy callback will be
called first, followed by a free callback to the value that is being replaced.

- **defrag**: A callback function pointer that is used to request the module to defrag
a key. The module should then iterate pointers and call the relevant `RedisModule_Defrag*()`
functions to defragment pointers or complex types. The module should continue
iterating as long as [`RedisModule_DefragShouldStop()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragShouldStop/index.html) returns a zero value, and return a
zero value if finished or non-zero value if more work is left to be done. If more work
needs to be done, [`RedisModule_DefragCursorSet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorSet/index.html) and [`RedisModule_DefragCursorGet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorGet/index.html) can be used to track
this work across different calls.
Normally, the defrag mechanism invokes the callback without a time limit, so
[`RedisModule_DefragShouldStop()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragShouldStop/index.html) always returns zero. The "late defrag" mechanism which has
a time limit and provides cursor support is used only for keys that are determined
to have significant internal complexity. To determine this, the defrag mechanism
uses the `free_effort` callback and the 'active-defrag-max-scan-fields' config directive.
NOTE: The value is passed as a `void**` and the function is expected to update the
pointer if the top-level value pointer is defragmented and consequently changes.

- **mem\_usage2**: Similar to `mem_usage`, but provides the `RedisModuleKeyOptCtx` parameter
so that meta information such as key name and db id can be obtained, and
the `sample_size` for size estimation (see MEMORY USAGE command).

- **free\_effort2**: Similar to `free_effort`, but provides the `RedisModuleKeyOptCtx` parameter
so that meta information such as key name and db id can be obtained.

- **unlink2**: Similar to `unlink`, but provides the `RedisModuleKeyOptCtx` parameter
so that meta information such as key name and db id can be obtained.

- **copy2**: Similar to `copy`, but provides the `RedisModuleKeyOptCtx` parameter
so that meta information such as key names and db ids can be obtained.

- **aux\_save2**: Similar to `aux_save`, but with small semantic change, if the module
saves nothing on this callback then no data about this aux field will be written to the
RDB and it will be possible to load the RDB even if the module is not loaded.

Note: the module name "AAAAAAAAA" is reserved and produces an error, it
happens to be pretty lame as well.

If [`RedisModule_CreateDataType()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateDataType/index.html) is called outside of `RedisModule_OnLoad()` function,
there is already a module registering a type with the same name,
or if the module name or encver is invalid, NULL is returned.
Otherwise the new type is registered into Redis, and a reference of
type `RedisModuleType` is returned: the caller of the function should store
this reference into a global variable to make future use of it in the
modules type API, since a single module may register multiple types.
Example code fragment:

static RedisModuleType *BalancedTreeType;

int RedisModule_OnLoad(RedisModuleCtx *ctx) { // some code here ... BalancedTreeType = RedisModule_CreateDataType(...); }

### `RedisModule_ModuleTypeSetValue` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_moduletypesetvalue "Copy link to clipboard"/index.html)

int RedisModule_ModuleTypeSetValue(RedisModuleKey *key, moduleType *mt, void *value);

**Available since:** 4.0.0

If the key is open for writing, set the specified module type object
as the value of the key, deleting the old value if any.
On success `REDISMODULE_OK` is returned. If the key is not open for
writing or there is an active iterator, `REDISMODULE_ERR` is returned.

### `RedisModule_ModuleTypeGetType` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_moduletypegettype "Copy link to clipboard"/index.html)

moduleType *RedisModule_ModuleTypeGetType(RedisModuleKey *key);

**Available since:** 4.0.0

Assuming [`RedisModule_KeyType()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KeyType/index.html) returned `REDISMODULE_KEYTYPE_MODULE` on
the key, returns the module type pointer of the value stored at key.

If the key is NULL, is not associated with a module type, or is empty,
then NULL is returned instead.

### `RedisModule_ModuleTypeGetValue` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_moduletypegetvalue "Copy link to clipboard"/index.html)

void *RedisModule_ModuleTypeGetValue(RedisModuleKey *key);

**Available since:** 4.0.0

Assuming [`RedisModule_KeyType()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KeyType/index.html) returned `REDISMODULE_KEYTYPE_MODULE` on
the key, returns the module type low-level value stored at key, as
it was set by the user via [`RedisModule_ModuleTypeSetValue()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ModuleTypeSetValue/index.html).

If the key is NULL, is not associated with a module type, or is empty,
then NULL is returned instead.

## RDB loading and saving functions  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#rdb-loading-and-saving-functions "Copy link to clipboard"/index.html)

### `RedisModule_IsIOError` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_isioerror "Copy link to clipboard"/index.html)

int RedisModule_IsIOError(RedisModuleIO *io);

**Available since:** 6.0.0

Returns true if any previous IO API failed.
for `Load*` APIs the `REDISMODULE_OPTIONS_HANDLE_IO_ERRORS` flag must be set with
[`RedisModule_SetModuleOptions`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetModuleOptions/index.html) first.

### `RedisModule_SaveUnsigned` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_saveunsigned "Copy link to clipboard"/index.html)

void RedisModule_SaveUnsigned(RedisModuleIO *io, uint64_t value);

**Available since:** 4.0.0

Save an unsigned 64 bit value into the RDB file. This function should only
be called in the context of the `rdb_save` method of modules implementing new
data types.

### `RedisModule_LoadUnsigned` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadunsigned "Copy link to clipboard"/index.html)

uint64_t RedisModule_LoadUnsigned(RedisModuleIO *io);

**Available since:** 4.0.0

Load an unsigned 64 bit value from the RDB file. This function should only
be called in the context of the `rdb_load` method of modules implementing
new data types.

### `RedisModule_SaveSigned` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savesigned "Copy link to clipboard"/index.html)

void RedisModule_SaveSigned(RedisModuleIO *io, int64_t value);

**Available since:** 4.0.0

Like [`RedisModule_SaveUnsigned()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveUnsigned/index.html) but for signed 64 bit values.

### `RedisModule_LoadSigned` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadsigned "Copy link to clipboard"/index.html)

int64_t RedisModule_LoadSigned(RedisModuleIO *io);

**Available since:** 4.0.0

Like [`RedisModule_LoadUnsigned()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadUnsigned/index.html) but for signed 64 bit values.

### `RedisModule_SaveString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savestring "Copy link to clipboard"/index.html)

void RedisModule_SaveString(RedisModuleIO *io, RedisModuleString *s);

**Available since:** 4.0.0

In the context of the `rdb_save` method of a module type, saves a
string into the RDB file taking as input a `RedisModuleString`.

The string can be later loaded with [`RedisModule_LoadString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadString/index.html) or
other Load family functions expecting a serialized string inside
the RDB file.

### `RedisModule_SaveStringBuffer` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savestringbuffer "Copy link to clipboard"/index.html)

void RedisModule_SaveStringBuffer(RedisModuleIO *io, const char *str, size_t len);

**Available since:** 4.0.0

Like [`RedisModule_SaveString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveString/index.html) but takes a raw C pointer and length
as input.

### `RedisModule_LoadString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadstring "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_LoadString(RedisModuleIO *io);

**Available since:** 4.0.0

In the context of the `rdb_load` method of a module data type, loads a string
from the RDB file, that was previously saved with [`RedisModule_SaveString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveString/index.html)
functions family.

The returned string is a newly allocated `RedisModuleString` object, and
the user should at some point free it with a call to [`RedisModule_FreeString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeString/index.html).

If the data structure does not store strings as `RedisModuleString` objects,
the similar function [`RedisModule_LoadStringBuffer()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadStringBuffer/index.html) could be used instead.

### `RedisModule_LoadStringBuffer` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadstringbuffer "Copy link to clipboard"/index.html)

char *RedisModule_LoadStringBuffer(RedisModuleIO *io, size_t *lenptr);

**Available since:** 4.0.0

Like [`RedisModule_LoadString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadString/index.html) but returns a heap allocated string that
was allocated with [`RedisModule_Alloc()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Alloc/index.html), and can be resized or freed with
[`RedisModule_Realloc()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Realloc/index.html) or [`RedisModule_Free()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Free/index.html).

The size of the string is stored at '\*lenptr' if not NULL.
The returned string is not automatically NULL terminated, it is loaded
exactly as it was stored inside the RDB file.

### `RedisModule_SaveDouble` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savedouble "Copy link to clipboard"/index.html)

void RedisModule_SaveDouble(RedisModuleIO *io, double value);

**Available since:** 4.0.0

In the context of the `rdb_save` method of a module data type, saves a double
value to the RDB file. The double can be a valid number, a NaN or infinity.
It is possible to load back the value with [`RedisModule_LoadDouble()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadDouble/index.html).

### `RedisModule_LoadDouble` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loaddouble "Copy link to clipboard"/index.html)

double RedisModule_LoadDouble(RedisModuleIO *io);

**Available since:** 4.0.0

In the context of the `rdb_save` method of a module data type, loads back the
double value saved by [`RedisModule_SaveDouble()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveDouble/index.html).

### `RedisModule_SaveFloat` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savefloat "Copy link to clipboard"/index.html)

void RedisModule_SaveFloat(RedisModuleIO *io, float value);

**Available since:** 4.0.0

In the context of the `rdb_save` method of a module data type, saves a float
value to the RDB file. The float can be a valid number, a NaN or infinity.
It is possible to load back the value with [`RedisModule_LoadFloat()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadFloat/index.html).

### `RedisModule_LoadFloat` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadfloat "Copy link to clipboard"/index.html)

float RedisModule_LoadFloat(RedisModuleIO *io);

**Available since:** 4.0.0

In the context of the `rdb_save` method of a module data type, loads back the
float value saved by [`RedisModule_SaveFloat()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveFloat/index.html).

### `RedisModule_SaveLongDouble` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savelongdouble "Copy link to clipboard"/index.html)

void RedisModule_SaveLongDouble(RedisModuleIO *io, long double value);

**Available since:** 6.0.0

In the context of the `rdb_save` method of a module data type, saves a long double
value to the RDB file. The double can be a valid number, a NaN or infinity.
It is possible to load back the value with [`RedisModule_LoadLongDouble()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadLongDouble/index.html).

### `RedisModule_LoadLongDouble` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadlongdouble "Copy link to clipboard"/index.html)

long double RedisModule_LoadLongDouble(RedisModuleIO *io);

**Available since:** 6.0.0

In the context of the `rdb_save` method of a module data type, loads back the
long double value saved by [`RedisModule_SaveLongDouble()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveLongDouble/index.html).

## Key digest API (DEBUG DIGEST interface for modules types)  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#key-digest-api-debug-digest-interface-for-modules-types "Copy link to clipboard"/index.html)

### `RedisModule_DigestAddStringBuffer` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_digestaddstringbuffer "Copy link to clipboard"/index.html)

void RedisModule_DigestAddStringBuffer(RedisModuleDigest *md, const char *ele, size_t len);

**Available since:** 4.0.0

Add a new element to the digest. This function can be called multiple times
one element after the other, for all the elements that constitute a given
data structure. The function call must be followed by the call to
[`RedisModule_DigestEndSequence`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DigestEndSequence/index.html) eventually, when all the elements that are
always in a given order are added. See the Redis Modules data types
documentation for more info. However this is a quick example that uses Redis
data types as an example.

To add a sequence of unordered elements (for example in the case of a Redis
Set), the pattern to use is:

foreach element { AddElement(element); EndSequence(); }

Because Sets are not ordered, so every element added has a position that
does not depend from the other. However if instead our elements are
ordered in pairs, like field-value pairs of a Hash, then one should
use:

foreach key,value { AddElement(key); AddElement(value); EndSequence(); }

Because the key and value will be always in the above order, while instead
the single key-value pairs, can appear in any position into a Redis hash.

A list of ordered elements would be implemented with:

foreach element { AddElement(element); } EndSequence();

### `RedisModule_DigestAddLongLong` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_digestaddlonglong "Copy link to clipboard"/index.html)

void RedisModule_DigestAddLongLong(RedisModuleDigest *md, long long ll);

**Available since:** 4.0.0

Like [`RedisModule_DigestAddStringBuffer()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DigestAddStringBuffer/index.html) but takes a `long long` as input
that gets converted into a string before adding it to the digest.

### `RedisModule_DigestEndSequence` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_digestendsequence "Copy link to clipboard"/index.html)

void RedisModule_DigestEndSequence(RedisModuleDigest *md);

**Available since:** 4.0.0

See the documentation for `RedisModule_DigestAddElement()`.

### `RedisModule_LoadDataTypeFromStringEncver` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loaddatatypefromstringencver "Copy link to clipboard"/index.html)

void *RedisModule_LoadDataTypeFromStringEncver(const RedisModuleString *str, const moduleType *mt, int encver);

**Available since:** 7.0.0

Decode a serialized representation of a module data type 'mt', in a specific encoding version 'encver'
from string 'str' and return a newly allocated value, or NULL if decoding failed.

This call basically reuses the '`rdb_load`' callback which module data types
implement in order to allow a module to arbitrarily serialize/de-serialize
keys, similar to how the Redis 'DUMP' and 'RESTORE' commands are implemented.

Modules should generally use the `REDISMODULE_OPTIONS_HANDLE_IO_ERRORS` flag and
make sure the de-serialization code properly checks and handles IO errors
(freeing allocated buffers and returning a NULL).

If this is NOT done, Redis will handle corrupted (or just truncated) serialized
data by producing an error message and terminating the process.

### `RedisModule_LoadDataTypeFromString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loaddatatypefromstring "Copy link to clipboard"/index.html)

void *RedisModule_LoadDataTypeFromString(const RedisModuleString *str, const moduleType *mt);

**Available since:** 6.0.0

Similar to [`RedisModule_LoadDataTypeFromStringEncver`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadDataTypeFromStringEncver/index.html), original version of the API, kept
for backward compatibility.

### `RedisModule_SaveDataTypeToString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_savedatatypetostring "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_SaveDataTypeToString(RedisModuleCtx *ctx, void *data, const moduleType *mt);

**Available since:** 6.0.0

Encode a module data type 'mt' value 'data' into serialized form, and return it
as a newly allocated `RedisModuleString`.

This call basically reuses the '`rdb_save`' callback which module data types
implement in order to allow a module to arbitrarily serialize/de-serialize
keys, similar to how the Redis 'DUMP' and 'RESTORE' commands are implemented.

### `RedisModule_GetKeyNameFromDigest` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getkeynamefromdigest "Copy link to clipboard"/index.html)

const RedisModuleString *RedisModule_GetKeyNameFromDigest(RedisModuleDigest *dig);

**Available since:** 7.0.0

Returns the name of the key currently being processed.

### `RedisModule_GetDbIdFromDigest` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getdbidfromdigest "Copy link to clipboard"/index.html)

int RedisModule_GetDbIdFromDigest(RedisModuleDigest *dig);

**Available since:** 7.0.0

Returns the database id of the key currently being processed.

## AOF API for modules data types  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#aof-api-for-modules-data-types "Copy link to clipboard"/index.html)

### `RedisModule_EmitAOF` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_emitaof "Copy link to clipboard"/index.html)

void RedisModule_EmitAOF(RedisModuleIO *io, const char *cmdname, const char *fmt, ...);

**Available since:** 4.0.0

Emits a command into the AOF during the AOF rewriting process. This function
is only called in the context of the `aof_rewrite` method of data types exported
by a module. The command works exactly like [`RedisModule_Call()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Call/index.html) in the way
the parameters are passed, but it does not return anything as the error
handling is performed by Redis itself.

## IO context handling  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#io-context-handling "Copy link to clipboard"/index.html)

### `RedisModule_GetKeyNameFromIO` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getkeynamefromio "Copy link to clipboard"/index.html)

const RedisModuleString *RedisModule_GetKeyNameFromIO(RedisModuleIO *io);

**Available since:** 5.0.5

Returns the name of the key currently being processed.
There is no guarantee that the key name is always available, so this may return NULL.

### `RedisModule_GetKeyNameFromModuleKey` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getkeynamefrommodulekey "Copy link to clipboard"/index.html)

const RedisModuleString *RedisModule_GetKeyNameFromModuleKey(RedisModuleKey *key);

**Available since:** 6.0.0

Returns a `RedisModuleString` with the name of the key from `RedisModuleKey`.

### `RedisModule_GetDbIdFromModuleKey` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getdbidfrommodulekey "Copy link to clipboard"/index.html)

int RedisModule_GetDbIdFromModuleKey(RedisModuleKey *key);

**Available since:** 7.0.0

Returns a database id of the key from `RedisModuleKey`.

### `RedisModule_GetDbIdFromIO` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getdbidfromio "Copy link to clipboard"/index.html)

int RedisModule_GetDbIdFromIO(RedisModuleIO *io);

**Available since:** 7.0.0

Returns the database id of the key currently being processed.
There is no guarantee that this info is always available, so this may return -1.

## Logging  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#logging "Copy link to clipboard"/index.html)

### `RedisModule_Log` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_log "Copy link to clipboard"/index.html)

void RedisModule_Log(RedisModuleCtx *ctx, const char *levelstr, const char *fmt, ...);

**Available since:** 4.0.0

Produces a log message to the standard Redis log, the format accepts
printf-alike specifiers, while level is a string describing the log
level to use when emitting the log, and must be one of the following:

- "debug" (`REDISMODULE_LOGLEVEL_DEBUG`)
- "verbose" (`REDISMODULE_LOGLEVEL_VERBOSE`)
- "notice" (`REDISMODULE_LOGLEVEL_NOTICE`)
- "warning" (`REDISMODULE_LOGLEVEL_WARNING`)

If the specified log level is invalid, verbose is used by default.
There is a fixed limit to the length of the log line this function is able
to emit, this limit is not specified but is guaranteed to be more than
a few lines of text.

The ctx argument may be NULL if cannot be provided in the context of the
caller for instance threads or callbacks, in which case a generic "module"
will be used instead of the module name.

### `RedisModule_LogIOError` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_logioerror "Copy link to clipboard"/index.html)

void RedisModule_LogIOError(RedisModuleIO *io, const char *levelstr, const char *fmt, ...);

**Available since:** 4.0.0

Log errors from RDB / AOF serialization callbacks.

This function should be used when a callback is returning a critical
error to the caller since cannot load or save the data for some
critical reason.

### `RedisModule__Assert` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule__assert "Copy link to clipboard"/index.html)

void RedisModule__Assert(const char *estr, const char *file, int line);

**Available since:** 6.0.0

Redis-like assert function.

The macro `RedisModule_Assert(expression)` is recommended, rather than
calling this function directly.

A failed assertion will shut down the server and produce logging information
that looks identical to information generated by Redis itself.

### `RedisModule_LatencyAddSample` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_latencyaddsample "Copy link to clipboard"/index.html)

void RedisModule_LatencyAddSample(const char *event, mstime_t latency);

**Available since:** 6.0.0

Allows adding event to the latency monitor to be observed by the LATENCY
command. The call is skipped if the latency is smaller than the configured
latency-monitor-threshold.

## Blocking clients from modules  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#blocking-clients-from-modules "Copy link to clipboard"/index.html)

For a guide about blocking commands in modules, see
[https://redis.io/docs/latest/develop/reference/modules/modules-blocking-ops/](/content/docs/latest/develop/reference/modules/modules-blocking-ops/index.html).

### `RedisModule_RegisterAuthCallback` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerauthcallback "Copy link to clipboard"/index.html)

void RedisModule_RegisterAuthCallback(RedisModuleCtx *ctx, RedisModuleAuthCallback cb);

**Available since:** 7.2.0

This API registers a callback to execute in addition to normal password based authentication.
Multiple callbacks can be registered across different modules. When a Module is unloaded, all the
auth callbacks registered by it are unregistered.
The callbacks are attempted (in the order of most recently registered first) when the AUTH/HELLO
(with AUTH field provided) commands are called.
The callbacks will be called with a module context along with a username and a password, and are
expected to take one of the following actions:
(1) Authenticate - Use the `RedisModule_AuthenticateClient`\\* API and return `REDISMODULE_AUTH_HANDLED`.
This will immediately end the auth chain as successful and add the OK reply.
(2) Deny Authentication - Return `REDISMODULE_AUTH_HANDLED` without authenticating or blocking the
client. Optionally, `err` can be set to a custom error message and `err` will be automatically
freed by the server.
This will immediately end the auth chain as unsuccessful and add the ERR reply.
(3) Block a client on authentication - Use the [`RedisModule_BlockClientOnAuth`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnAuth/index.html) API and return
`REDISMODULE_AUTH_HANDLED`. Here, the client will be blocked until the [`RedisModule_UnblockClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html) API is used
which will trigger the auth reply callback (provided through the [`RedisModule_BlockClientOnAuth`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnAuth/index.html)).
In this reply callback, the Module should authenticate, deny or skip handling authentication.
(4) Skip handling Authentication - Return `REDISMODULE_AUTH_NOT_HANDLED` without blocking the
client. This will allow the engine to attempt the next module auth callback.
If none of the callbacks authenticate or deny auth, then password based auth is attempted and
will authenticate or add failure logs and reply to the clients accordingly.

Note: If a client is disconnected while it was in the middle of blocking module auth, that
occurrence of the AUTH or HELLO command will not be tracked in the INFO command stats.

The following is an example of how non-blocking module based authentication can be used:

int auth_cb(RedisModuleCtx *ctx, RedisModuleString *username, RedisModuleString *password, RedisModuleString **err) { const char *user = RedisModule_StringPtrLen(username, NULL); const char *pwd = RedisModule_StringPtrLen(password, NULL); if (!strcmp(user,"foo") && !strcmp(pwd,"valid_password")) { RedisModule_AuthenticateClientWithACLUser(ctx, "foo", 3, NULL, NULL, NULL); return REDISMODULE_AUTH_HANDLED; }

else if (!strcmp(user,"foo") && !strcmp(pwd,"wrong_password")) { RedisModuleString *log = RedisModule_CreateString(ctx, "Module Auth", 11); RedisModule_ACLAddLogEntryByUserName(ctx, username, log, REDISMODULE_ACL_LOG_AUTH); RedisModule_FreeString(ctx, log); const char *err_msg = "Auth denied by Misc Module."; *err = RedisModule_CreateString(ctx, err_msg, strlen(err_msg)); return REDISMODULE_AUTH_HANDLED; } return REDISMODULE_AUTH_NOT_HANDLED; }

int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) { if (RedisModule_Init(ctx,"authmodule",1,REDISMODULE_APIVER_1)== REDISMODULE_ERR) return REDISMODULE_ERR; RedisModule_RegisterAuthCallback(ctx, auth_cb); return REDISMODULE_OK; }

### `RedisModule_BlockClient` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockclient "Copy link to clipboard"/index.html)

RedisModuleBlockedClient *RedisModule_BlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, ;

**Available since:** 4.0.0

Block a client in the context of a blocking command, returning a handle
which will be used, later, in order to unblock the client with a call to
[`RedisModule_UnblockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html). The arguments specify callback functions
and a timeout after which the client is unblocked.

The callbacks are called in the following contexts:

reply_callback: called after a successful RedisModule_UnblockClient() call in order to reply to the client and unblock it.

timeout_callback: called when the timeout is reached or if CLIENT UNBLOCK is invoked, in order to send an error to the client.

free_privdata: called in order to free the private data that is passed by RedisModule_UnblockClient() call.

Note: [`RedisModule_UnblockClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html) should be called for every blocked client,
even if client was killed, timed-out or disconnected. Failing to do so
will result in memory leaks.

There are some cases where [`RedisModule_BlockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html) cannot be used:

1. If the client is a Lua script.
2. If the client is executing a MULTI block.

In these cases, a call to [`RedisModule_BlockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html) will **not** block the
client, but instead produce a specific error reply.

A module that registers a `timeout_callback` function can also be unblocked
using the `CLIENT UNBLOCK` command, which will trigger the timeout callback.
If a callback function is not registered, then the blocked client will be
treated as if it is not in a blocked state and `CLIENT UNBLOCK` will return
a zero value.

Measuring background time: By default the time spent in the blocked command
is not account for the total command duration. To include such time you should
use [`RedisModule_BlockedClientMeasureTimeStart()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockedClientMeasureTimeStart/index.html) and [`RedisModule_BlockedClientMeasureTimeEnd()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockedClientMeasureTimeEnd/index.html) one,
or multiple times within the blocking command background work.

### `RedisModule_BlockClientOnAuth` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockclientonauth "Copy link to clipboard"/index.html)

RedisModuleBlockedClient *RedisModule_BlockClientOnAuth(RedisModuleCtx *ctx, RedisModuleAuthCallback reply_callback, ;

**Available since:** 7.2.0

Block the current client for module authentication in the background. If module auth is not in
progress on the client, the API returns NULL. Otherwise, the client is blocked and the `RedisModule_BlockedClient`
is returned similar to the [`RedisModule_BlockClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html) API.
Note: Only use this API from the context of a module auth callback.

### `RedisModule_BlockClientGetPrivateData` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockclientgetprivatedata "Copy link to clipboard"/index.html)

void *RedisModule_BlockClientGetPrivateData(RedisModuleBlockedClient *blocked_client);

**Available since:** 7.2.0

Get the private data that was previusely set on a blocked client

### `RedisModule_BlockClientSetPrivateData` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockclientsetprivatedata "Copy link to clipboard"/index.html)

void RedisModule_BlockClientSetPrivateData(RedisModuleBlockedClient *blocked_client, void *private_data);

**Available since:** 7.2.0

Set private data on a blocked client

### `RedisModule_BlockClientOnKeys` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockclientonkeys "Copy link to clipboard"/index.html)

RedisModuleBlockedClient *RedisModule_BlockClientOnKeys(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, ;

**Available since:** 6.0.0

This call is similar to [`RedisModule_BlockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html), however in this case we
don't just block the client, but also ask Redis to unblock it automatically
once certain keys become "ready", that is, contain more data.

Basically this is similar to what a typical Redis command usually does,
like BLPOP or BZPOPMAX: the client blocks if it cannot be served ASAP,
and later when the key receives new data (a list push for instance), the
client is unblocked and served.

However in the case of this module API, when the client is unblocked?

1. If you block on a key of a type that has blocking operations associated,
like a list, a sorted set, a stream, and so forth, the client may be
unblocked once the relevant key is targeted by an operation that normally
unblocks the native blocking operations for that type. So if we block
on a list key, an RPUSH command may unblock our client and so forth.
2. If you are implementing your native data type, or if you want to add new
unblocking conditions in addition to "1", you can call the modules API
[`RedisModule_SignalKeyAsReady()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SignalKeyAsReady/index.html).

Anyway we can't be sure if the client should be unblocked just because the
key is signaled as ready: for instance a successive operation may change the
key, or a client in queue before this one can be served, modifying the key
as well and making it empty again. So when a client is blocked with
[`RedisModule_BlockClientOnKeys()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html) the reply callback is not called after
[`RedisModule_UnblockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html) is called, but every time a key is signaled as ready:
if the reply callback can serve the client, it returns `REDISMODULE_OK`
and the client is unblocked, otherwise it will return `REDISMODULE_ERR`
and we'll try again later.

The reply callback can access the key that was signaled as ready by
calling the API [`RedisModule_GetBlockedClientReadyKey()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetBlockedClientReadyKey/index.html), that returns
just the string name of the key as a `RedisModuleString` object.

Thanks to this system we can setup complex blocking scenarios, like
unblocking a client only if a list contains at least 5 items or other
more fancy logics.

Note that another difference with [`RedisModule_BlockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html), is that here
we pass the private data directly when blocking the client: it will
be accessible later in the reply callback. Normally when blocking with
[`RedisModule_BlockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html) the private data to reply to the client is
passed when calling [`RedisModule_UnblockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html) but here the unblocking
is performed by Redis itself, so we need to have some private data before
hand. The private data is used to store any information about the specific
unblocking operation that you are implementing. Such information will be
freed using the `free_privdata` callback provided by the user.

However the reply callback will be able to access the argument vector of
the command, so the private data is often not needed.

Note: Under normal circumstances [`RedisModule_UnblockClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html) should not be
called for clients that are blocked on keys (Either the key will
become ready or a timeout will occur). If for some reason you do want
to call RedisModule\_UnblockClient it is possible, but it must NOT be
called from module threads and the client will be handled as if it
timed out (You must implement the timeout callback in that case).

### `RedisModule_BlockClientOnKeysWithFlags` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockclientonkeyswithflags "Copy link to clipboard"/index.html)

RedisModuleBlockedClient *RedisModule_BlockClientOnKeysWithFlags(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, ;

**Available since:** 7.2.0

Same as [`RedisModule_BlockClientOnKeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html), but can take `REDISMODULE_BLOCK_`\\* flags
Can be either `REDISMODULE_BLOCK_UNBLOCK_DEFAULT`, which means default behavior (same
as calling [`RedisModule_BlockClientOnKeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html))

The flags is a bit mask of these:

- `REDISMODULE_BLOCK_UNBLOCK_DELETED`: The clients should to be awakened in case any of `keys` are deleted.
Mostly useful for commands that require the key to exist (like XREADGROUP)

### `RedisModule_SignalKeyAsReady` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_signalkeyasready "Copy link to clipboard"/index.html)

void RedisModule_SignalKeyAsReady(RedisModuleCtx *ctx, RedisModuleString *key);

**Available since:** 6.0.0

This function is used in order to potentially unblock a client blocked
on keys with [`RedisModule_BlockClientOnKeys()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html). When this function is called,
all the clients blocked for this key will get their `reply_callback` called.

### `RedisModule_UnblockClient` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_unblockclient "Copy link to clipboard"/index.html)

int RedisModule_UnblockClient(RedisModuleBlockedClient *bc, void *privdata);

**Available since:** 4.0.0

Unblock a client blocked by `RedisModule_BlockedClient`. This will trigger
the reply callbacks to be called in order to reply to the client.
The 'privdata' argument will be accessible by the reply callback, so
the caller of this function can pass any value that is needed in order to
actually reply to the client.

A common usage for 'privdata' is a thread that computes something that
needs to be passed to the client, included but not limited some slow
to compute reply or some reply obtained via networking.

Note 1: this function can be called from threads spawned by the module when
the client was blocked using [`RedisModule_BlockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html).

Note 2: when we unblock a client that is blocked for keys using the API
[`RedisModule_BlockClientOnKeys()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html), the privdata argument here is not used.
Unblocking a client that was blocked for keys using this API will still
require the client to get some reply, so the function will use the
"timeout" handler in order to do so (The privdata provided in
[`RedisModule_BlockClientOnKeys()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html) is accessible from the timeout
callback via [`RedisModule_GetBlockedClientPrivateData`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetBlockedClientPrivateData/index.html)).

### `RedisModule_AbortBlock` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_abortblock "Copy link to clipboard"/index.html)

int RedisModule_AbortBlock(RedisModuleBlockedClient *bc);

**Available since:** 4.0.0

Abort a blocked client blocking operation: the client will be unblocked
without firing any callback.

### `RedisModule_SetDisconnectCallback` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_setdisconnectcallback "Copy link to clipboard"/index.html)

void RedisModule_SetDisconnectCallback(RedisModuleBlockedClient *bc, RedisModuleDisconnectFunc callback);

**Available since:** 5.0.0

Set a callback that will be called if a blocked client disconnects
before the module has a chance to call [`RedisModule_UnblockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html)

Usually what you want to do there, is to cleanup your module state
so that you can call [`RedisModule_UnblockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html) safely, otherwise
the client will remain blocked forever if the timeout is large.

Notes:

1. It is not safe to call Reply\* family functions here, it is also
useless since the client is gone.

2. This callback is not called if the client disconnects because of
a timeout. In such a case, the client is unblocked automatically
and the timeout callback is called.

### `RedisModule_IsBlockedReplyRequest` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_isblockedreplyrequest "Copy link to clipboard"/index.html)

int RedisModule_IsBlockedReplyRequest(RedisModuleCtx *ctx);

**Available since:** 4.0.0

Return non-zero if a module command was called in order to fill the
reply for a blocked client.

### `RedisModule_IsBlockedTimeoutRequest` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_isblockedtimeoutrequest "Copy link to clipboard"/index.html)

int RedisModule_IsBlockedTimeoutRequest(RedisModuleCtx *ctx);

**Available since:** 4.0.0

Return non-zero if a module command was called in order to fill the
reply for a blocked client that timed out.

### `RedisModule_GetBlockedClientPrivateData` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getblockedclientprivatedata "Copy link to clipboard"/index.html)

void *RedisModule_GetBlockedClientPrivateData(RedisModuleCtx *ctx);

**Available since:** 4.0.0

Get the private data set by [`RedisModule_UnblockClient()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html)

### `RedisModule_GetBlockedClientReadyKey` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getblockedclientreadykey "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_GetBlockedClientReadyKey(RedisModuleCtx *ctx);

**Available since:** 6.0.0

Get the key that is ready when the reply callback is called in the context
of a client blocked by [`RedisModule_BlockClientOnKeys()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html).

### `RedisModule_GetBlockedClientHandle` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getblockedclienthandle "Copy link to clipboard"/index.html)

RedisModuleBlockedClient *RedisModule_GetBlockedClientHandle(RedisModuleCtx *ctx);

**Available since:** 5.0.0

Get the blocked client associated with a given context.
This is useful in the reply and timeout callbacks of blocked clients,
before sometimes the module has the blocked client handle references
around, and wants to cleanup it.

### `RedisModule_BlockedClientDisconnected` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_blockedclientdisconnected "Copy link to clipboard"/index.html)

int RedisModule_BlockedClientDisconnected(RedisModuleCtx *ctx);

**Available since:** 5.0.0

Return true if when the free callback of a blocked client is called,
the reason for the client to be unblocked is that it disconnected
while it was blocked.

## Thread Safe Contexts  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#thread-safe-contexts "Copy link to clipboard"/index.html)

### `RedisModule_GetThreadSafeContext` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getthreadsafecontext "Copy link to clipboard"/index.html)

RedisModuleCtx *RedisModule_GetThreadSafeContext(RedisModuleBlockedClient *bc);

**Available since:** 4.0.0

Return a context which can be used inside threads to make Redis context
calls with certain modules APIs. If 'bc' is not NULL then the module will
be bound to a blocked client, and it will be possible to use the
`RedisModule_Reply*` family of functions to accumulate a reply for when the
client will be unblocked. Otherwise the thread safe context will be
detached by a specific client.

To call non-reply APIs, the thread safe context must be prepared with:

RedisModule_ThreadSafeContextLock(ctx); ... make your call here ... RedisModule_ThreadSafeContextUnlock(ctx);

This is not needed when using `RedisModule_Reply*` functions, assuming
that a blocked client was used when the context was created, otherwise
no `RedisModule_Reply`\\* call should be made at all.

NOTE: If you're creating a detached thread safe context (bc is NULL),
consider using [`RedisModule_GetDetachedThreadSafeContext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDetachedThreadSafeContext/index.html) which will also retain
the module ID and thus be more useful for logging.

### `RedisModule_GetDetachedThreadSafeContext` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getdetachedthreadsafecontext "Copy link to clipboard"/index.html)

RedisModuleCtx *RedisModule_GetDetachedThreadSafeContext(RedisModuleCtx *ctx);

**Available since:** 6.0.9

Return a detached thread safe context that is not associated with any
specific blocked client, but is associated with the module's context.

This is useful for modules that wish to hold a global context over
a long term, for purposes such as logging.

### `RedisModule_FreeThreadSafeContext` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_freethreadsafecontext "Copy link to clipboard"/index.html)

void RedisModule_FreeThreadSafeContext(RedisModuleCtx *ctx);

**Available since:** 4.0.0

Release a thread safe context.

### `RedisModule_ThreadSafeContextLock` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_threadsafecontextlock "Copy link to clipboard"/index.html)

void RedisModule_ThreadSafeContextLock(RedisModuleCtx *ctx);

**Available since:** 4.0.0

Acquire the server lock before executing a thread safe API call.
This is not needed for `RedisModule_Reply*` calls when there is
a blocked client connected to the thread safe context.

### `RedisModule_ThreadSafeContextTryLock` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_threadsafecontexttrylock "Copy link to clipboard"/index.html)

int RedisModule_ThreadSafeContextTryLock(RedisModuleCtx *ctx);

**Available since:** 6.0.8

Similar to [`RedisModule_ThreadSafeContextLock`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ThreadSafeContextLock/index.html) but this function
would not block if the server lock is already acquired.

If successful (lock acquired) `REDISMODULE_OK` is returned,
otherwise `REDISMODULE_ERR` is returned and errno is set
accordingly.

### `RedisModule_ThreadSafeContextUnlock` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_threadsafecontextunlock "Copy link to clipboard"/index.html)

void RedisModule_ThreadSafeContextUnlock(RedisModuleCtx *ctx);

**Available since:** 4.0.0

Release the server lock after a thread safe API call was executed.

## Module Keyspace Notifications API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#module-keyspace-notifications-api "Copy link to clipboard"/index.html)

### `RedisModule_SubscribeToKeyspaceEvents` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_subscribetokeyspaceevents "Copy link to clipboard"/index.html)

int RedisModule_SubscribeToKeyspaceEvents(RedisModuleCtx *ctx, int types, RedisModuleNotificationFunc callback);

**Available since:** 4.0.9

Subscribe to keyspace notifications. This is a low-level version of the
keyspace-notifications API. A module can register callbacks to be notified
when keyspace events occur.

Notification events are filtered by their type (string events, set events,
etc), and the subscriber callback receives only events that match a specific
mask of event types.

When subscribing to notifications with [`RedisModule_SubscribeToKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEvents/index.html)
the module must provide an event type-mask, denoting the events the subscriber
is interested in. This can be an ORed mask of any of the following flags:

- `REDISMODULE_NOTIFY_GENERIC`: Generic commands like DEL, EXPIRE, RENAME

- `REDISMODULE_NOTIFY_STRING`: String events

- `REDISMODULE_NOTIFY_LIST`: List events

- `REDISMODULE_NOTIFY_SET`: Set events

- `REDISMODULE_NOTIFY_HASH`: Hash events

- `REDISMODULE_NOTIFY_ZSET`: Sorted Set events

- `REDISMODULE_NOTIFY_EXPIRED`: Expiration events

- `REDISMODULE_NOTIFY_EVICTED`: Eviction events

- `REDISMODULE_NOTIFY_STREAM`: Stream events

- `REDISMODULE_NOTIFY_MODULE`: Module types events

- `REDISMODULE_NOTIFY_KEYMISS`: Key-miss events
Notice, key-miss event is the only type
of event that is fired from within a read command.
Performing RedisModule\_Call with a write command from within
this notification is wrong and discourage. It will
cause the read command that trigger the event to be
replicated to the AOF/Replica.

- `REDISMODULE_NOTIFY_NEW`: New key notification

- `REDISMODULE_NOTIFY_OVERWRITTEN`: Overwritten events

- `REDISMODULE_NOTIFY_TYPE_CHANGED`: Type-changed events

- `REDISMODULE_NOTIFY_KEY_TRIMMED`: Key trimmed events after a slot migration operation

- `REDISMODULE_NOTIFY_RATE_LIMIT`: Rate limit event

- `REDISMODULE_NOTIFY_ALL`: All events (Excluding `REDISMODULE_NOTIFY_KEYMISS`,
REDISMODULE\_NOTIFY\_NEW, REDISMODULE\_NOTIFY\_OVERWRITTEN,
REDISMODULE\_NOTIFY\_TYPE\_CHANGED, REDISMODULE\_NOTIFY\_KEY\_TRIMMED
and REDISMODULE\_NOTIFY\_RATE\_LIMIT)

- `REDISMODULE_NOTIFY_LOADED`: A special notification available only for modules,
indicates that the key was loaded from persistence.
Notice, when this event fires, the given key
can not be retained, use RedisModule\_CreateStringFromString
instead.

We do not distinguish between key events and keyspace events, and it is up
to the module to filter the actions taken based on the key.

The subscriber signature is:

int (*RedisModuleNotificationFunc) (RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key);

`type` is the event type bit, that must match the mask given at registration
time. The event string is the actual command being executed, and key is the
relevant Redis key.

Notification callback gets executed with a redis context that can not be
used to send anything to the client, and has the db number where the event
occurred as its selected db number.

Notice that it is not necessary to enable notifications in redis.conf for
module notifications to work.

Warning: the notification callbacks are performed in a synchronous manner,
so notification callbacks must to be fast, or they would slow Redis down.
If you need to take long actions, use threads to offload them.

Moreover, the fact that the notification is executed synchronously means
that the notification code will be executed in the middle on Redis logic
(commands logic, eviction, expire). Changing the key space while the logic
runs is dangerous and discouraged. In order to react to key space events with
write actions, please refer to [`RedisModule_AddPostNotificationJob`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AddPostNotificationJob/index.html).

See [https://redis.io/docs/latest/develop/use/keyspace-notifications/](/content/docs/latest/develop/use/keyspace-notifications/index.html) for more information.

### `RedisModule_UnsubscribeFromKeyspaceEvents` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_unsubscribefromkeyspaceevents "Copy link to clipboard"/index.html)

int RedisModule_UnsubscribeFromKeyspaceEvents(RedisModuleCtx *ctx, int types, RedisModuleNotificationFunc callback);

**Available since:** 8.2.0

[`RedisModule_UnsubscribeFromKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnsubscribeFromKeyspaceEvents/index.html) \- Unregister a module's callback from keyspace notifications for specific event types.

This function removes a previously registered subscription identified by both the event mask and the callback function.
It is useful to reduce performance overhead when the module no longer requires notifications for certain events.

Parameters:

- ctx: The `RedisModuleCtx` associated with the calling module.
- types: The event mask representing the keyspace notification types to unsubscribe from.
- callback: The callback function pointer that was originally registered for these events.

Returns:

- `REDISMODULE_OK` on successful removal of the subscription.
- `REDISMODULE_ERR` if no matching subscription was found or if invalid parameters were provided.

### `RedisModule_SubscribeToKeyspaceEventsWithSubkeys` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_subscribetokeyspaceeventswithsubkeys "Copy link to clipboard"/index.html)

int RedisModule_SubscribeToKeyspaceEventsWithSubkeys(RedisModuleCtx *ctx, int types, int flags, RedisModuleNotificationWithSubkeysFunc callback);

**Available since:** unreleased

Subscribe to keyspace notifications with subkey information.

This is the extended version of [`RedisModule_SubscribeToKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEvents/index.html). When subkeys
are available, the `subkeys` array and `count` are passed to the callback.
`subkeys` contains only the names of affected subkeys (values are not included),
and `count` is the number of elements. The array may contain duplicates when
the same subkey appears more than once in a command (e.g. HSET key f1 v1 f1 v2
produces subkeys=\["f1","f1"\], count=2). When no subkeys are present, `subkeys`
will be NULL and `count` will be 0. Whether events without subkeys are delivered
depends on the `flags` parameter (see below).

`types` is a bit mask of event types the module is interested in
(using the same `REDISMODULE_NOTIFY_`\\* flags as [`RedisModule_SubscribeToKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEvents/index.html)).

`flags` controls delivery filtering:

- `REDISMODULE_NOTIFY_FLAG_NONE`: The callback is invoked for all matching
events regardless of whether subkeys are present, so a separate
[`RedisModule_SubscribeToKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEvents/index.html) registration can be omitted.
- `REDISMODULE_NOTIFY_FLAG_SUBKEYS_REQUIRED`: The callback is only invoked
when subkeys are not empty. Events without subkey information (e.g. SET,
EXPIRE, DEL) are skipped.

The callback signature is:
void callback(`RedisModuleCtx` \*ctx, int type, const char \*event,
RedisModuleString \*key, RedisModuleString \*\*subkeys, int count);

The subkeys array and its contents are only valid during the callback.
The underlying objects may be stack-allocated or temporary, so
[`RedisModule_RetainString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RetainString/index.html) must NOT be used on them. To keep a subkey beyond
the callback (e.g. in a [`RedisModule_AddPostNotificationJob`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AddPostNotificationJob/index.html) callback), use
[`RedisModule_HoldString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_HoldString/index.html) (which handles static objects by copying) or
[`RedisModule_CreateStringFromString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromString/index.html) to make a deep copy before returning.

### `RedisModule_UnsubscribeFromKeyspaceEventsWithSubkeys` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_unsubscribefromkeyspaceeventswithsubkeys "Copy link to clipboard"/index.html)

int RedisModule_UnsubscribeFromKeyspaceEventsWithSubkeys(RedisModuleCtx *ctx, int types, int flags, RedisModuleNotificationWithSubkeysFunc callback);

**Available since:** unreleased

Unregister a module's callback from keyspace notifications with subkeys
for specific event types.

This function removes a previously registered subscription identified by
the event mask, delivery flags, and the callback function.

Parameters:

- ctx: The `RedisModuleCtx` associated with the calling module.
- types: The event mask representing the notification types to unsubscribe from.
- flags: The delivery flags that were used during registration.
- callback: The callback function pointer that was originally registered.

Returns:

- `REDISMODULE_OK` on successful removal of the subscription.
- `REDISMODULE_ERR` if no matching subscription was found.

### `RedisModule_AddPostNotificationJob` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_addpostnotificationjob "Copy link to clipboard"/index.html)

int RedisModule_AddPostNotificationJob(RedisModuleCtx *ctx, RedisModulePostNotificationJobFunc callback, void *privdata, void (free_privdata)(void));

**Available since:** 7.2.0

When running inside a key space notification callback, it is dangerous and highly discouraged to perform any write
operation (See [`RedisModule_SubscribeToKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEvents/index.html)). In order to still perform write actions in this scenario,
Redis provides [`RedisModule_AddPostNotificationJob`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AddPostNotificationJob/index.html) API. The API allows to register a job callback which Redis will call
when the following condition are promised to be fulfilled:

1. It is safe to perform any write operation.
2. The job will be called atomically along side the key space notification.

Notice, one job might trigger key space notifications that will trigger more jobs.
This raises a concerns of entering an infinite loops, we consider infinite loops
as a logical bug that need to be fixed in the module, an attempt to protect against
infinite loops by halting the execution could result in violation of the feature correctness
and so Redis will make no attempt to protect the module from infinite loops.

'`free_pd`' can be NULL and in such case will not be used.

Return `REDISMODULE_OK` on success and `REDISMODULE_ERR` if was called while loading data from disk (AOF or RDB) or
if the instance is a readonly replica.

### `RedisModule_GetNotifyKeyspaceEvents` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getnotifykeyspaceevents "Copy link to clipboard"/index.html)

int RedisModule_GetNotifyKeyspaceEvents(void);

**Available since:** 6.0.0

Get the configured bitmap of notify-keyspace-events (Could be used
for additional filtering in `RedisModuleNotificationFunc`)

### `RedisModule_NotifyKeyspaceEvent` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_notifykeyspaceevent "Copy link to clipboard"/index.html)

int RedisModule_NotifyKeyspaceEvent(RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key);

**Available since:** 6.0.0

Expose notifyKeyspaceEvent to modules

### `RedisModule_NotifyKeyspaceEventWithSubkeys` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_notifykeyspaceeventwithsubkeys "Copy link to clipboard"/index.html)

int RedisModule_NotifyKeyspaceEventWithSubkeys(RedisModuleCtx *ctx, int type, const char *event, ;

**Available since:** unreleased

Like [`RedisModule_NotifyKeyspaceEvent`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_NotifyKeyspaceEvent/index.html), but also triggers subkey-level notifications
when subkeys are provided. Both key-level (keyspace/keyevent) and
subkey-level (subkeyspace/subkeyevent/subkeyspaceitem/subkeyspaceevent)
channels are published to, depending on the server configuration.

This is the extended version of [`RedisModule_NotifyKeyspaceEvent`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_NotifyKeyspaceEvent/index.html) and can actually
replace it. When called with subkeys=NULL and count=0, it behaves
identically to [`RedisModule_NotifyKeyspaceEvent`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_NotifyKeyspaceEvent/index.html).

## Modules Cluster API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-cluster-api "Copy link to clipboard"/index.html)

### `RedisModule_RegisterClusterMessageReceiver` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerclustermessagereceiver "Copy link to clipboard"/index.html)

void RedisModule_RegisterClusterMessageReceiver(RedisModuleCtx *ctx, uint8_t type, RedisModuleClusterMessageReceiver callback);

**Available since:** 5.0.0

Register a callback receiver for cluster messages of type 'type'. If there
was already a registered callback, this will replace the callback function
with the one provided, otherwise if the callback is set to NULL and there
is already a callback for this function, the callback is unregistered
(so this API call is also used in order to delete the receiver).

### `RedisModule_SendClusterMessage` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_sendclustermessage "Copy link to clipboard"/index.html)

int RedisModule_SendClusterMessage(RedisModuleCtx *ctx, const char *target_id, uint8_t type, const char *msg, uint32_t len);

**Available since:** 5.0.0

Send a message to all the nodes in the cluster if `target` is NULL, otherwise
at the specified target, which is a `REDISMODULE_NODE_ID_LEN` bytes node ID, as
returned by the receiver callback or by the nodes iteration functions.

The function returns `REDISMODULE_OK` if the message was successfully sent,
otherwise if the node is not connected or such node ID does not map to any
known cluster node, `REDISMODULE_ERR` is returned.

### `RedisModule_GetClusterNodesList` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getclusternodeslist "Copy link to clipboard"/index.html)

char **RedisModule_GetClusterNodesList(RedisModuleCtx *ctx, size_t *numnodes);

**Available since:** 5.0.0

Return an array of string pointers, each string pointer points to a cluster
node ID of exactly `REDISMODULE_NODE_ID_LEN` bytes (without any null term).
The number of returned node IDs is stored into `*numnodes`.
However if this function is called by a module not running an a Redis
instance with Redis Cluster enabled, NULL is returned instead.

The IDs returned can be used with [`RedisModule_GetClusterNodeInfo()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClusterNodeInfo/index.html) in order
to get more information about single node.

The array returned by this function must be freed using the function
[`RedisModule_FreeClusterNodesList()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeClusterNodesList/index.html).

Example:

size_t count, j; char **ids = RedisModule_GetClusterNodesList(ctx,&count); for (j = 0; j < count; j++) { RedisModule_Log(ctx,"notice","Node %.*s", REDISMODULE_NODE_ID_LEN,ids[j]); } RedisModule_FreeClusterNodesList(ids);

### `RedisModule_FreeClusterNodesList` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_freeclusternodeslist "Copy link to clipboard"/index.html)

void RedisModule_FreeClusterNodesList(char **ids);

**Available since:** 5.0.0

Free the node list obtained with [`RedisModule_GetClusterNodesList`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClusterNodesList/index.html).

### `RedisModule_GetMyClusterID` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getmyclusterid "Copy link to clipboard"/index.html)

const char *RedisModule_GetMyClusterID(void);

**Available since:** 5.0.0

Return this node ID (`REDISMODULE_CLUSTER_ID_LEN` bytes) or NULL if the cluster
is disabled.

### `RedisModule_GetClusterSize` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getclustersize "Copy link to clipboard"/index.html)

size_t RedisModule_GetClusterSize(void);

**Available since:** 5.0.0

Return the number of nodes in the cluster, regardless of their state
(handshake, noaddress, ...) so that the number of active nodes may actually
be smaller, but not greater than this number. If the instance is not in
cluster mode, zero is returned.

### `RedisModule_GetClusterNodeInfo` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getclusternodeinfo "Copy link to clipboard"/index.html)

int RedisModule_GetClusterNodeInfo(RedisModuleCtx *ctx, const char *id, char *ip, char *master_id, int *port, int *flags);

**Available since:** 5.0.0

Populate the specified info for the node having as ID the specified 'id',
then returns `REDISMODULE_OK`. Otherwise if the format of node ID is invalid
or the node ID does not exist from the POV of this local node, `REDISMODULE_ERR`
is returned.

The arguments `ip`, `master_id`, `port` and `flags` can be NULL in case we don't
need to populate back certain info. If an `ip` and `master_id` (only populated
if the instance is a slave) are specified, they point to buffers holding
at least `REDISMODULE_NODE_ID_LEN` bytes. The strings written back as `ip`
and `master_id` are not null terminated.

The list of flags reported is the following:

- `REDISMODULE_NODE_MYSELF`: This node
- `REDISMODULE_NODE_MASTER`: The node is a master
- `REDISMODULE_NODE_SLAVE`: The node is a replica
- `REDISMODULE_NODE_PFAIL`: We see the node as failing
- `REDISMODULE_NODE_FAIL`: The cluster agrees the node is failing
- `REDISMODULE_NODE_NOFAILOVER`: The slave is configured to never failover

### `RedisModule_SetClusterFlags` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_setclusterflags "Copy link to clipboard"/index.html)

void RedisModule_SetClusterFlags(RedisModuleCtx *ctx, uint64_t flags);

**Available since:** 5.0.0

Set Redis Cluster flags in order to change the normal behavior of
Redis Cluster, especially with the goal of disabling certain functions.
This is useful for modules that use the Cluster API in order to create
a different distributed system, but still want to use the Redis Cluster
message bus. Flags that can be set:

- `CLUSTER_MODULE_FLAG_NO_FAILOVER`
- `CLUSTER_MODULE_FLAG_NO_REDIRECTION`

With the following effects:

- `NO_FAILOVER`: prevent Redis Cluster slaves from failing over a dead master.
Also disables the replica migration feature.

- `NO_REDIRECTION`: Every node will accept any key, without trying to perform
partitioning according to the Redis Cluster algorithm.
Slots information will still be propagated across the
cluster, but without effect.

### `RedisModule_ClusterDisableTrim` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clusterdisabletrim "Copy link to clipboard"/index.html)

int RedisModule_ClusterDisableTrim(RedisModuleCtx *ctx);

**Available since:** 8.4.1

[`RedisModule_ClusterDisableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterDisableTrim/index.html) allows a module to temporarily prevent slot trimming
after a slot migration. This is useful when the module has asynchronous
operations that rely on keys in migrating slots, which would be trimmed.

The module must call [`RedisModule_ClusterEnableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterEnableTrim/index.html) once it has completed those
operations to re-enable trimming.

Trimming uses a reference counter: every call to [`RedisModule_ClusterDisableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterDisableTrim/index.html)
increments the counter, and every [`RedisModule_ClusterEnableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterEnableTrim/index.html) call decrements it.
Trimming remains disabled as long as the counter is greater than zero.

Disable automatic slot trimming.

### `RedisModule_ClusterEnableTrim` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clusterenabletrim "Copy link to clipboard"/index.html)

int RedisModule_ClusterEnableTrim(RedisModuleCtx *ctx);

**Available since:** 8.4.1

Enable automatic slot trimming. See also comments on [`RedisModule_ClusterDisableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterDisableTrim/index.html).

### `RedisModule_ClusterKeySlot` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clusterkeyslot "Copy link to clipboard"/index.html)

unsigned int RedisModule_ClusterKeySlot(RedisModuleString *key);

**Available since:** 7.4.0

Returns the cluster slot of a key, similar to the `CLUSTER KEYSLOT` command.
This function works even if cluster mode is not enabled.

### `RedisModule_ClusterKeySlotC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clusterkeyslotc "Copy link to clipboard"/index.html)

unsigned int RedisModule_ClusterKeySlotC(const char *keystr, size_t keylen);

**Available since:** 8.4.0

Like [`RedisModule_ClusterKeySlot`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterKeySlot/index.html), but gets a char pointer and a length.
Returns the cluster slot of a key, similar to the `CLUSTER KEYSLOT` command.
This function works even if cluster mode is not enabled.

### `RedisModule_ClusterCanonicalKeyNameInSlot` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clustercanonicalkeynameinslot "Copy link to clipboard"/index.html)

const char *RedisModule_ClusterCanonicalKeyNameInSlot(unsigned int slot);

**Available since:** 7.4.0

Returns a short string that can be used as a key or as a hash tag in a key,
such that the key maps to the given cluster slot. Returns NULL if slot is not
a valid slot.

### `RedisModule_ClusterCanAccessKeysInSlot` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clustercanaccesskeysinslot "Copy link to clipboard"/index.html)

int RedisModule_ClusterCanAccessKeysInSlot(int slot);

**Available since:** 8.4.0

Returns 1 if keys in the specified slot can be accessed by this node, 0 otherwise.

This function returns 1 in the following cases:

- The slot is owned by this node or by its master if this node is a replica
- The slot is being imported under the old slot migration approach (CLUSTER SETSLOT  IMPORTING ..)
- Not in cluster mode (all slots are accessible)

Returns 0 for:

- Invalid slot numbers (< 0 or >= 16384)
- Slots owned by other nodes

### `RedisModule_ClusterPropagateForSlotMigration` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clusterpropagateforslotmigration "Copy link to clipboard"/index.html)

int RedisModule_ClusterPropagateForSlotMigration(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...);

**Available since:** 8.4.0

Propagate commands along with slot migration.

This function allows modules to add commands that will be sent to the
destination node before the actual slot migration begins. It should only be
called during the `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_MIGRATE_MODULE_PROPAGATE` event.

This function can be called multiple times within the same event to
replicate multiple commands. All commands will be sent before the
actual slot data migration begins.

Note: This function is only available in the fork child process just before
slot snapshot delivery begins.

On success `REDISMODULE_OK` is returned, otherwise
`REDISMODULE_ERR` is returned and errno is set to the following values:

- EINVAL: function arguments or format specifiers are invalid.
- EBADF: not called in the correct context, e.g. not called in the `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_MIGRATE_MODULE_PROPAGATE` event.
- ENOENT: command does not exist.
- ENOTSUP: command is cross-slot.
- ERANGE: command contains keys that are not within the migrating slot range.

### `RedisModule_ClusterGetLocalSlotRanges` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clustergetlocalslotranges "Copy link to clipboard"/index.html)

RedisModuleSlotRangeArray *RedisModule_ClusterGetLocalSlotRanges(RedisModuleCtx *ctx);

**Available since:** 8.4.0

Returns the locally owned slot ranges for the node.

An optional `ctx` can be provided to enable auto-memory management.
If cluster mode is disabled, the array will include all slots (0–16383).
If the node is a replica, the slot ranges of its master are returned.

The returned array must be freed with [`RedisModule_ClusterFreeSlotRanges()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterFreeSlotRanges/index.html).

### `RedisModule_ClusterFreeSlotRanges` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_clusterfreeslotranges "Copy link to clipboard"/index.html)

void RedisModule_ClusterFreeSlotRanges(RedisModuleCtx *ctx, RedisModuleSlotRangeArray *slots);

**Available since:** 8.4.0

Frees a slot range array returned by [`RedisModule_ClusterGetLocalSlotRanges()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterGetLocalSlotRanges/index.html).
Pass the `ctx` pointer only if the array was created with a context.

## Modules Timers API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-timers-api "Copy link to clipboard"/index.html)

Module timers are a high precision "green timers" abstraction where
every module can register even millions of timers without problems, even if
the actual event loop will just have a single timer that is used to awake the
module timers subsystem in order to process the next event.

All the timers are stored into a radix tree, ordered by expire time, when
the main Redis event loop timer callback is called, we try to process all
the timers already expired one after the other. Then we re-enter the event
loop registering a timer that will expire when the next to process module
timer will expire.

Every time the list of active timers drops to zero, we unregister the
main event loop timer, so that there is no overhead when such feature is
not used.

### `RedisModule_CreateTimer` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_createtimer "Copy link to clipboard"/index.html)

RedisModuleTimerID RedisModule_CreateTimer(RedisModuleCtx *ctx, mstime_t period, RedisModuleTimerProc callback, void *data);

**Available since:** 5.0.0

Create a new timer that will fire after `period` milliseconds, and will call
the specified function using `data` as argument. The returned timer ID can be
used to get information from the timer or to stop it before it fires.
Note that for the common use case of a repeating timer (Re-registration
of the timer inside the `RedisModuleTimerProc` callback) it matters when
this API is called:
If it is called at the beginning of 'callback' it means
the event will triggered every 'period'.
If it is called at the end of 'callback' it means
there will 'period' milliseconds gaps between events.
(If the time it takes to execute 'callback' is negligible the two
statements above mean the same)

### `RedisModule_StopTimer` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_stoptimer "Copy link to clipboard"/index.html)

int RedisModule_StopTimer(RedisModuleCtx *ctx, RedisModuleTimerID id, void **data);

**Available since:** 5.0.0

Stop a timer, returns `REDISMODULE_OK` if the timer was found, belonged to the
calling module, and was stopped, otherwise `REDISMODULE_ERR` is returned.
If not NULL, the data pointer is set to the value of the data argument when
the timer was created.

### `RedisModule_GetTimerInfo` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_gettimerinfo "Copy link to clipboard"/index.html)

int RedisModule_GetTimerInfo(RedisModuleCtx *ctx, RedisModuleTimerID id, uint64_t *remaining, void **data);

**Available since:** 5.0.0

Obtain information about a timer: its remaining time before firing
(in milliseconds), and the private data pointer associated with the timer.
If the timer specified does not exist or belongs to a different module
no information is returned and the function returns `REDISMODULE_ERR`, otherwise
`REDISMODULE_OK` is returned. The arguments remaining or data can be NULL if
the caller does not need certain information.

## Modules EventLoop API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-eventloop-api "Copy link to clipboard"/index.html)

### `RedisModule_EventLoopAdd` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_eventloopadd "Copy link to clipboard"/index.html)

int RedisModule_EventLoopAdd(int fd, int mask, RedisModuleEventLoopFunc func, void *user_data);

**Available since:** 7.0.0

Add a pipe / socket event to the event loop.

- `mask` must be one of the following values:
  - `REDISMODULE_EVENTLOOP_READABLE`
  - `REDISMODULE_EVENTLOOP_WRITABLE`
  - `REDISMODULE_EVENTLOOP_READABLE | REDISMODULE_EVENTLOOP_WRITABLE`

On success `REDISMODULE_OK` is returned, otherwise
`REDISMODULE_ERR` is returned and errno is set to the following values:

- ERANGE: `fd` is negative or higher than `maxclients` Redis config.
- EINVAL: `callback` is NULL or `mask` value is invalid.

`errno` might take other values in case of an internal error.

Example:

void onReadable(int fd, void *user_data, int mask) { char buf[32]; int bytes = read(fd,buf,sizeof(buf)); printf("Read %d bytes \n", bytes); } RedisModule_EventLoopAdd(fd, REDISMODULE_EVENTLOOP_READABLE, onReadable, NULL);

### `RedisModule_EventLoopDel` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_eventloopdel "Copy link to clipboard"/index.html)

int RedisModule_EventLoopDel(int fd, int mask);

**Available since:** 7.0.0

Delete a pipe / socket event from the event loop.

On success `REDISMODULE_OK` is returned, otherwise
`REDISMODULE_ERR` is returned and errno is set to the following values:

- ERANGE: `fd` is negative or higher than `maxclients` Redis config.
- EINVAL: `mask` value is invalid.

### `RedisModule_EventLoopAddOneShot` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_eventloopaddoneshot "Copy link to clipboard"/index.html)

int RedisModule_EventLoopAddOneShot(RedisModuleEventLoopOneShotFunc func, void *user_data);

**Available since:** 7.0.0

This function can be called from other threads to trigger callback on Redis
main thread. On success `REDISMODULE_OK` is returned. If `func` is NULL
`REDISMODULE_ERR` is returned and errno is set to EINVAL.

## Modules ACL API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-acl-api "Copy link to clipboard"/index.html)

Implements a hook into the authentication and authorization within Redis.

### `RedisModule_CreateModuleUser` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_createmoduleuser "Copy link to clipboard"/index.html)

RedisModuleUser *RedisModule_CreateModuleUser(const char *name);

**Available since:** 6.0.0

Creates a Redis ACL user that the module can use to authenticate a client.
After obtaining the user, the module should set what such user can do
using the `RedisModule_SetUserACL()` function. Once configured, the user
can be used in order to authenticate a connection, with the specified
ACL rules, using the `RedisModule_AuthClientWithUser()` function.

Note that:

- Users created here are not listed by the ACL command.
- Users created here are not checked for duplicated name, so it's up to
the module calling this function to take care of not creating users
with the same name.
- The created user can be used to authenticate multiple Redis connections.

The caller can later free the user using the function
[`RedisModule_FreeModuleUser()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeModuleUser/index.html). When this function is called, if there are
still clients authenticated with this user, they are disconnected.
The function to free the user should only be used when the caller really
wants to invalidate the user to define a new one with different
capabilities.

### `RedisModule_FreeModuleUser` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_freemoduleuser "Copy link to clipboard"/index.html)

int RedisModule_FreeModuleUser(RedisModuleUser *user);

**Available since:** 6.0.0

Frees a given user and disconnects all of the clients that have been
authenticated with it. See [`RedisModule_CreateModuleUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateModuleUser/index.html) for detailed usage.

### `RedisModule_SetModuleUserACL` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_setmoduleuseracl "Copy link to clipboard"/index.html)

int RedisModule_SetModuleUserACL(RedisModuleUser user, const char acl);

**Available since:** 6.0.0

Sets the permissions of a user created through the redis module
interface. The syntax is the same as ACL SETUSER, so refer to the
documentation in acl.c for more information. See [`RedisModule_CreateModuleUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateModuleUser/index.html)
for detailed usage.

Returns `REDISMODULE_OK` on success and `REDISMODULE_ERR` on failure
and will set an errno describing why the operation failed.

### `RedisModule_SetModuleUserACLString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_setmoduleuseraclstring "Copy link to clipboard"/index.html)

int RedisModule_SetModuleUserACLString(RedisModuleCtx *ctx, RedisModuleUser *user, const char *acl, RedisModuleString **error);

**Available since:** 7.0.6

Sets the permission of a user with a complete ACL string, such as one
would use on the redis ACL SETUSER command line API. This differs from
[`RedisModule_SetModuleUserACL`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetModuleUserACL/index.html), which only takes single ACL operations at a time.

Returns `REDISMODULE_OK` on success and `REDISMODULE_ERR` on failure
if a `RedisModuleString` is provided in error, a string describing the error
will be returned

### `RedisModule_GetModuleUserACLString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getmoduleuseraclstring "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_GetModuleUserACLString(RedisModuleUser *user);

**Available since:** 7.0.6

Get the ACL string for a given user
Returns a `RedisModuleString`

### `RedisModule_GetCurrentUserName` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getcurrentusername "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_GetCurrentUserName(RedisModuleCtx *ctx);

**Available since:** 7.0.0

Retrieve the user name of the client connection behind the current context.
The user name can be used later, in order to get a `RedisModuleUser`.
See more information in [`RedisModule_GetModuleUserFromUserName`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetModuleUserFromUserName/index.html).

### `RedisModule_GetModuleUserFromUserName` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getmoduleuserfromusername "Copy link to clipboard"/index.html)

RedisModuleUser *RedisModule_GetModuleUserFromUserName(RedisModuleString *name);

**Available since:** 7.0.0

A `RedisModuleUser` can be used to check if command, key or channel can be executed or
accessed according to the ACLs rules associated with that user.
When a Module wants to do ACL checks on a general ACL user (not created by [`RedisModule_CreateModuleUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateModuleUser/index.html)),
it can get the `RedisModuleUser` from this API, based on the user name retrieved by [`RedisModule_GetCurrentUserName`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCurrentUserName/index.html).

Since a general ACL user can be deleted at any time, this `RedisModuleUser` should be used only in the context
where this function was called. In order to do ACL checks out of that context, the Module can store the user name,
and call this API at any other context.

Returns NULL if the user is disabled or the user does not exist.
The caller should later free the user using the function [`RedisModule_FreeModuleUser()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeModuleUser/index.html).

### `RedisModule_ACLCheckCommandPermissions` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_aclcheckcommandpermissions "Copy link to clipboard"/index.html)

int RedisModule_ACLCheckCommandPermissions(RedisModuleUser *user, RedisModuleString **argv, int argc);

**Available since:** 7.0.0

Checks if the command can be executed by the user, according to the ACLs associated with it.

On success a `REDISMODULE_OK` is returned, otherwise
`REDISMODULE_ERR` is returned and errno is set to the following values:

- ENOENT: Specified command does not exist.
- EINVAL: Invalid number of arguments for the specified command.
- EACCES: Command cannot be executed, according to ACL rules

### `RedisModule_ACLCheckKeyPermissions` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_aclcheckkeypermissions "Copy link to clipboard"/index.html)

int RedisModule_ACLCheckKeyPermissions(RedisModuleUser *user, RedisModuleString *key, int flags);

**Available since:** 7.0.0

Check if the key can be accessed by the user according to the ACLs attached to the user
and the flags representing the key access. The flags are the same that are used in the
keyspec for logical operations. These flags are documented in [`RedisModule_SetCommandInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetCommandInfo/index.html) as
the `REDISMODULE_CMD_KEY_ACCESS`, `REDISMODULE_CMD_KEY_UPDATE`, `REDISMODULE_CMD_KEY_INSERT`,
and `REDISMODULE_CMD_KEY_DELETE` flags.

If no flags are supplied, the user is still required to have some access to the key for
this command to return successfully.

If the user is able to access the key then `REDISMODULE_OK` is returned, otherwise
`REDISMODULE_ERR` is returned and errno is set to one of the following values:

- EINVAL: The provided flags are invalid.
- EACCESS: The user does not have permission to access the key.

### `RedisModule_ACLCheckKeyPrefixPermissions` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_aclcheckkeyprefixpermissions "Copy link to clipboard"/index.html)

int RedisModule_ACLCheckKeyPrefixPermissions(RedisModuleUser *user, RedisModuleString *prefix, int flags);

**Available since:** 8.0.0

Check if the user can access keys matching the given key prefix according to the ACLs
attached to the user and the flags representing key access. The flags are the same that
are used in the keyspec for logical operations. These flags are documented in
[`RedisModule_SetCommandInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetCommandInfo/index.html) as the `REDISMODULE_CMD_KEY_ACCESS`,
`REDISMODULE_CMD_KEY_UPDATE`, `REDISMODULE_CMD_KEY_INSERT`, and `REDISMODULE_CMD_KEY_DELETE` flags.

If no flags are supplied, the user is still required to have some access to keys matching
the prefix for this command to return successfully.

If the user is able to access keys matching the prefix, then `REDISMODULE_OK` is returned.
Otherwise, `REDISMODULE_ERR` is returned and errno is set to one of the following values:

- EINVAL: The provided flags are invalid.
- EACCES: The user does not have permission to access keys matching the prefix.

### `RedisModule_ACLCheckChannelPermissions` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_aclcheckchannelpermissions "Copy link to clipboard"/index.html)

int RedisModule_ACLCheckChannelPermissions(RedisModuleUser *user, RedisModuleString *ch, int flags);

**Available since:** 7.0.0

Check if the pubsub channel can be accessed by the user based off of the given
access flags. See [`RedisModule_ChannelAtPosWithFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ChannelAtPosWithFlags/index.html) for more information about the
possible flags that can be passed in.

If the user is able to access the pubsub channel then `REDISMODULE_OK` is returned, otherwise
`REDISMODULE_ERR` is returned and errno is set to one of the following values:

- EINVAL: The provided flags are invalid.
- EACCESS: The user does not have permission to access the pubsub channel.

### `RedisModule_ACLAddLogEntry` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_acladdlogentry "Copy link to clipboard"/index.html)

int RedisModule_ACLAddLogEntry(RedisModuleCtx *ctx, RedisModuleUser *user, RedisModuleString *object, RedisModuleACLLogEntryReason reason);

**Available since:** 7.0.0

Adds a new entry in the ACL log.
Returns `REDISMODULE_OK` on success and `REDISMODULE_ERR` on error.

For more information about ACL log, please refer to [https://redis.io/commands/acl-log](/content/commands/acl-log/index.html)

### `RedisModule_ACLAddLogEntryByUserName` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_acladdlogentrybyusername "Copy link to clipboard"/index.html)

int RedisModule_ACLAddLogEntryByUserName(RedisModuleCtx *ctx, RedisModuleString *username, RedisModuleString *object, RedisModuleACLLogEntryReason reason);

**Available since:** 7.2.0

Adds a new entry in the ACL log with the `username``RedisModuleString` provided.
Returns `REDISMODULE_OK` on success and `REDISMODULE_ERR` on error.

For more information about ACL log, please refer to [https://redis.io/commands/acl-log](/content/commands/acl-log/index.html)

### `RedisModule_AuthenticateClientWithUser` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_authenticateclientwithuser "Copy link to clipboard"/index.html)

int RedisModule_AuthenticateClientWithUser(RedisModuleCtx *ctx, RedisModuleUser *module_user, RedisModuleUserChangedFunc callback, void *privdata, uint64_t *client_id);

**Available since:** 6.0.0

Authenticate the current context's user with the provided redis acl user.
Returns `REDISMODULE_ERR` if the user is disabled.

See authenticateClientWithUser for information about callback, `client_id`,
and general usage for authentication.

### `RedisModule_AuthenticateClientWithACLUser` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_authenticateclientwithacluser "Copy link to clipboard"/index.html)

int RedisModule_AuthenticateClientWithACLUser(RedisModuleCtx *ctx, const char *name, size_t len, RedisModuleUserChangedFunc callback, void *privdata, uint64_t *client_id);

**Available since:** 6.0.0

Authenticate the current context's user with the provided redis acl user.
Returns `REDISMODULE_ERR` if the user is disabled or the user does not exist.

See authenticateClientWithUser for information about callback, `client_id`,
and general usage for authentication.

### `RedisModule_DeauthenticateAndCloseClient` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_deauthenticateandcloseclient "Copy link to clipboard"/index.html)

int RedisModule_DeauthenticateAndCloseClient(RedisModuleCtx *ctx, uint64_t client_id);

**Available since:** 6.0.0

Deauthenticate and close the client. The client resources will not be
immediately freed, but will be cleaned up in a background job. This is
the recommended way to deauthenticate a client since most clients can't
handle users becoming deauthenticated. Returns `REDISMODULE_ERR` when the
client doesn't exist and `REDISMODULE_OK` when the operation was successful.

The client ID is returned from the [`RedisModule_AuthenticateClientWithUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AuthenticateClientWithUser/index.html) and
[`RedisModule_AuthenticateClientWithACLUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AuthenticateClientWithACLUser/index.html) APIs, but can be obtained through
the CLIENT api or through server events.

This function is not thread safe, and must be executed within the context
of a command or thread safe context.

### `RedisModule_RedactClientCommandArgument` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_redactclientcommandargument "Copy link to clipboard"/index.html)

int RedisModule_RedactClientCommandArgument(RedisModuleCtx *ctx, int pos);

**Available since:** 7.0.0

Redact the client command argument specified at the given position. Redacted arguments
are obfuscated in user facing commands such as SLOWLOG or MONITOR, as well as
never being written to server logs. This command may be called multiple times on the
same position.

Note that the command name, position 0, can not be redacted.

Returns `REDISMODULE_OK` if the argument was redacted and `REDISMODULE_ERR` if there
was an invalid parameter passed in or the position is outside the client
argument range.

### `RedisModule_GetClientCertificate` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getclientcertificate "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_GetClientCertificate(RedisModuleCtx *ctx, uint64_t client_id);

**Available since:** 6.0.9

Return the X.509 client-side certificate used by the client to authenticate
this connection.

The return value is an allocated `RedisModuleString` that is a X.509 certificate
encoded in PEM (Base64) format. It should be freed (or auto-freed) by the caller.

A NULL value is returned in the following conditions:

- Connection ID does not exist
- Connection is not a TLS connection
- Connection is a TLS connection but no client certificate was used

## Modules Dictionary API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-dictionary-api "Copy link to clipboard"/index.html)

Implements a sorted dictionary (actually backed by a radix tree) with
the usual get / set / del / num-items API, together with an iterator
capable of going back and forth.

### `RedisModule_CreateDict` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_createdict "Copy link to clipboard"/index.html)

RedisModuleDict *RedisModule_CreateDict(RedisModuleCtx *ctx);

**Available since:** 5.0.0

Create a new dictionary. The 'ctx' pointer can be the current module context
or NULL, depending on what you want. Please follow the following rules:

1. Use a NULL context if you plan to retain a reference to this dictionary
that will survive the time of the module callback where you created it.
2. Use a NULL context if no context is available at the time you are creating
the dictionary (of course...).
3. However use the current callback context as 'ctx' argument if the
dictionary time to live is just limited to the callback scope. In this
case, if enabled, you can enjoy the automatic memory management that will
reclaim the dictionary memory, as well as the strings returned by the
Next / Prev dictionary iterator calls.

### `RedisModule_FreeDict` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_freedict "Copy link to clipboard"/index.html)

void RedisModule_FreeDict(RedisModuleCtx *ctx, RedisModuleDict *d);

**Available since:** 5.0.0

Free a dictionary created with [`RedisModule_CreateDict()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateDict/index.html). You need to pass the
context pointer 'ctx' only if the dictionary was created using the
context instead of passing NULL.

### `RedisModule_DictSize` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictsize "Copy link to clipboard"/index.html)

uint64_t RedisModule_DictSize(RedisModuleDict *d);

**Available since:** 5.0.0

Return the size of the dictionary (number of keys).

### `RedisModule_DictSetC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictsetc "Copy link to clipboard"/index.html)

int RedisModule_DictSetC(RedisModuleDict *d, void *key, size_t keylen, void *ptr);

**Available since:** 5.0.0

Store the specified key into the dictionary, setting its value to the
pointer 'ptr'. If the key was added with success, since it did not
already exist, `REDISMODULE_OK` is returned. Otherwise if the key already
exists the function returns `REDISMODULE_ERR`.

### `RedisModule_DictReplaceC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictreplacec "Copy link to clipboard"/index.html)

int RedisModule_DictReplaceC(RedisModuleDict *d, void *key, size_t keylen, void *ptr);

**Available since:** 5.0.0

Like [`RedisModule_DictSetC()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictSetC/index.html) but will replace the key with the new
value if the key already exists.

### `RedisModule_DictSet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictset "Copy link to clipboard"/index.html)

int RedisModule_DictSet(RedisModuleDict *d, RedisModuleString *key, void *ptr);

**Available since:** 5.0.0

Like [`RedisModule_DictSetC()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictSetC/index.html) but takes the key as a `RedisModuleString`.

### `RedisModule_DictReplace` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictreplace "Copy link to clipboard"/index.html)

int RedisModule_DictReplace(RedisModuleDict *d, RedisModuleString *key, void *ptr);

**Available since:** 5.0.0

Like [`RedisModule_DictReplaceC()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictReplaceC/index.html) but takes the key as a `RedisModuleString`.

### `RedisModule_DictGetC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictgetc "Copy link to clipboard"/index.html)

void *RedisModule_DictGetC(RedisModuleDict *d, void *key, size_t keylen, int *nokey);

**Available since:** 5.0.0

Return the value stored at the specified key. The function returns NULL
both in the case the key does not exist, or if you actually stored
NULL at key. So, optionally, if the 'nokey' pointer is not NULL, it will
be set by reference to 1 if the key does not exist, or to 0 if the key
exists.

### `RedisModule_DictGet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictget "Copy link to clipboard"/index.html)

void *RedisModule_DictGet(RedisModuleDict *d, RedisModuleString *key, int *nokey);

**Available since:** 5.0.0

Like [`RedisModule_DictGetC()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictGetC/index.html) but takes the key as a `RedisModuleString`.

### `RedisModule_DictDelC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictdelc "Copy link to clipboard"/index.html)

int RedisModule_DictDelC(RedisModuleDict *d, void *key, size_t keylen, void *oldval);

**Available since:** 5.0.0

Remove the specified key from the dictionary, returning `REDISMODULE_OK` if
the key was found and deleted, or `REDISMODULE_ERR` if instead there was
no such key in the dictionary. When the operation is successful, if
'oldval' is not NULL, then '\*oldval' is set to the value stored at the
key before it was deleted. Using this feature it is possible to get
a pointer to the value (for instance in order to release it), without
having to call [`RedisModule_DictGet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictGet/index.html) before deleting the key.

### `RedisModule_DictDel` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictdel "Copy link to clipboard"/index.html)

int RedisModule_DictDel(RedisModuleDict *d, RedisModuleString *key, void *oldval);

**Available since:** 5.0.0

Like [`RedisModule_DictDelC()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictDelC/index.html) but gets the key as a `RedisModuleString`.

### `RedisModule_DictIteratorStartC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictiteratorstartc "Copy link to clipboard"/index.html)

RedisModuleDictIter *RedisModule_DictIteratorStartC(RedisModuleDict *d, const char *op, void *key, size_t keylen);

**Available since:** 5.0.0

Return an iterator, setup in order to start iterating from the specified
key by applying the operator 'op', which is just a string specifying the
comparison operator to use in order to seek the first element. The
operators available are:

- `^` – Seek the first (lexicographically smaller) key.
- `$` – Seek the last (lexicographically bigger) key.
- `>` – Seek the first element greater than the specified key.
- `>=` – Seek the first element greater or equal than the specified key.
- `<` – Seek the first element smaller than the specified key.
- `<=` – Seek the first element smaller or equal than the specified key.
- `==` – Seek the first element matching exactly the specified key.

Note that for `^` and `$` the passed key is not used, and the user may
just pass NULL with a length of 0.

If the element to start the iteration cannot be seeked based on the
key and operator passed, [`RedisModule_DictNext()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictNext/index.html) / Prev() will just return
`REDISMODULE_ERR` at the first call, otherwise they'll produce elements.

### `RedisModule_DictIteratorStart` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictiteratorstart "Copy link to clipboard"/index.html)

RedisModuleDictIter *RedisModule_DictIteratorStart(RedisModuleDict *d, const char *op, RedisModuleString *key);

**Available since:** 5.0.0

Exactly like [`RedisModule_DictIteratorStartC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStartC/index.html), but the key is passed as a
`RedisModuleString`.

### `RedisModule_DictIteratorStop` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictiteratorstop "Copy link to clipboard"/index.html)

void RedisModule_DictIteratorStop(RedisModuleDictIter *di);

**Available since:** 5.0.0

Release the iterator created with [`RedisModule_DictIteratorStart()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStart/index.html). This call
is mandatory otherwise a memory leak is introduced in the module.

### `RedisModule_DictIteratorReseekC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictiteratorreseekc "Copy link to clipboard"/index.html)

int RedisModule_DictIteratorReseekC(RedisModuleDictIter *di, const char *op, void *key, size_t keylen);

**Available since:** 5.0.0

After its creation with [`RedisModule_DictIteratorStart()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStart/index.html), it is possible to
change the currently selected element of the iterator by using this
API call. The result based on the operator and key is exactly like
the function [`RedisModule_DictIteratorStart()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStart/index.html), however in this case the
return value is just `REDISMODULE_OK` in case the seeked element was found,
or `REDISMODULE_ERR` in case it was not possible to seek the specified
element. It is possible to reseek an iterator as many times as you want.

### `RedisModule_DictIteratorReseek` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictiteratorreseek "Copy link to clipboard"/index.html)

int RedisModule_DictIteratorReseek(RedisModuleDictIter *di, const char *op, RedisModuleString *key);

**Available since:** 5.0.0

Like [`RedisModule_DictIteratorReseekC()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorReseekC/index.html) but takes the key as a
`RedisModuleString`.

### `RedisModule_DictNextC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictnextc "Copy link to clipboard"/index.html)

void *RedisModule_DictNextC(RedisModuleDictIter *di, size_t *keylen, void **dataptr);

**Available since:** 5.0.0

Return the current item of the dictionary iterator `di` and steps to the
next element. If the iterator already yield the last element and there
are no other elements to return, NULL is returned, otherwise a pointer
to a string representing the key is provided, and the `*keylen` length
is set by reference (if keylen is not NULL). The `*dataptr`, if not NULL
is set to the value of the pointer stored at the returned key as auxiliary
data (as set by the [`RedisModule_DictSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictSet/index.html) API).

Usage example:

... create the iterator here ... char *key; void *data; while((key = RedisModule_DictNextC(iter,&keylen,&data)) != NULL) { printf("%.*s %p\n", (int)keylen, key, data); }

The returned pointer is of type void because sometimes it makes sense
to cast it to a `char*` sometimes to an unsigned `char*` depending on the
fact it contains or not binary data, so this API ends being more
comfortable to use.

The validity of the returned pointer is until the next call to the
next/prev iterator step. Also the pointer is no longer valid once the
iterator is released.

### `RedisModule_DictPrevC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictprevc "Copy link to clipboard"/index.html)

void *RedisModule_DictPrevC(RedisModuleDictIter *di, size_t *keylen, void **dataptr);

**Available since:** 5.0.0

This function is exactly like [`RedisModule_DictNext()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictNext/index.html) but after returning
the currently selected element in the iterator, it selects the previous
element (lexicographically smaller) instead of the next one.

### `RedisModule_DictNext` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictnext "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_DictNext(RedisModuleCtx *ctx, RedisModuleDictIter *di, void **dataptr);

**Available since:** 5.0.0

Like `RedisModuleNextC()`, but instead of returning an internally allocated
buffer and key length, it returns directly a module string object allocated
in the specified context 'ctx' (that may be NULL exactly like for the main
API [`RedisModule_CreateString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateString/index.html)).

The returned string object should be deallocated after use, either manually
or by using a context that has automatic memory management active.

### `RedisModule_DictPrev` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictprev "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_DictPrev(RedisModuleCtx *ctx, RedisModuleDictIter *di, void **dataptr);

**Available since:** 5.0.0

Like [`RedisModule_DictNext()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictNext/index.html) but after returning the currently selected
element in the iterator, it selects the previous element (lexicographically
smaller) instead of the next one.

### `RedisModule_DictCompareC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictcomparec "Copy link to clipboard"/index.html)

int RedisModule_DictCompareC(RedisModuleDictIter *di, const char *op, void *key, size_t keylen);

**Available since:** 5.0.0

Compare the element currently pointed by the iterator to the specified
element given by key/keylen, according to the operator 'op' (the set of
valid operators are the same valid for [`RedisModule_DictIteratorStart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStart/index.html)).
If the comparison is successful the command returns `REDISMODULE_OK`
otherwise `REDISMODULE_ERR` is returned.

This is useful when we want to just emit a lexicographical range, so
in the loop, as we iterate elements, we can also check if we are still
on range.

The function return `REDISMODULE_ERR` if the iterator reached the
end of elements condition as well.

### `RedisModule_DictCompare` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_dictcompare "Copy link to clipboard"/index.html)

int RedisModule_DictCompare(RedisModuleDictIter *di, const char *op, RedisModuleString *key);

**Available since:** 5.0.0

Like [`RedisModule_DictCompareC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictCompareC/index.html) but gets the key to compare with the current
iterator key as a `RedisModuleString`.

## Modules Info fields  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-info-fields "Copy link to clipboard"/index.html)

### `RedisModule_InfoAddSection` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoaddsection "Copy link to clipboard"/index.html)

int RedisModule_InfoAddSection(RedisModuleInfoCtx *ctx, const char *name);

**Available since:** 6.0.0

Used to start a new section, before adding any fields. the section name will
be prefixed by `<modulename>_` and must only include A-Z,a-z,0-9.
NULL or empty string indicates the default section (only `<modulename>`) is used.
When return value is `REDISMODULE_ERR`, the section should and will be skipped.

### `RedisModule_InfoBeginDictField` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infobegindictfield "Copy link to clipboard"/index.html)

int RedisModule_InfoBeginDictField(RedisModuleInfoCtx *ctx, const char *name);

**Available since:** 6.0.0

Starts a dict field, similar to the ones in INFO KEYSPACE. Use normal
`RedisModule_InfoAddField`\\* functions to add the items to this field, and
terminate with [`RedisModule_InfoEndDictField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoEndDictField/index.html).

### `RedisModule_InfoEndDictField` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoenddictfield "Copy link to clipboard"/index.html)

int RedisModule_InfoEndDictField(RedisModuleInfoCtx *ctx);

**Available since:** 6.0.0

Ends a dict field, see [`RedisModule_InfoBeginDictField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoBeginDictField/index.html)

### `RedisModule_InfoAddFieldString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoaddfieldstring "Copy link to clipboard"/index.html)

int RedisModule_InfoAddFieldString(RedisModuleInfoCtx *ctx, const char *field, RedisModuleString *value);

**Available since:** 6.0.0

Used by `RedisModuleInfoFunc` to add info fields.
Each field will be automatically prefixed by `<modulename>_`.
Field names or values must not include `\r\n` or `:`.

### `RedisModule_InfoAddFieldCString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoaddfieldcstring "Copy link to clipboard"/index.html)

int RedisModule_InfoAddFieldCString(RedisModuleInfoCtx *ctx, const char *field, const char *value);

**Available since:** 6.0.0

See [`RedisModule_InfoAddFieldString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldString/index.html).

### `RedisModule_InfoAddFieldDouble` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoaddfielddouble "Copy link to clipboard"/index.html)

int RedisModule_InfoAddFieldDouble(RedisModuleInfoCtx *ctx, const char *field, double value);

**Available since:** 6.0.0

See [`RedisModule_InfoAddFieldString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldString/index.html).

### `RedisModule_InfoAddFieldLongLong` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoaddfieldlonglong "Copy link to clipboard"/index.html)

int RedisModule_InfoAddFieldLongLong(RedisModuleInfoCtx *ctx, const char *field, long long value);

**Available since:** 6.0.0

See [`RedisModule_InfoAddFieldString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldString/index.html).

### `RedisModule_InfoAddFieldULongLong` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_infoaddfieldulonglong "Copy link to clipboard"/index.html)

int RedisModule_InfoAddFieldULongLong(RedisModuleInfoCtx *ctx, const char *field, unsigned long long value);

**Available since:** 6.0.0

See [`RedisModule_InfoAddFieldString()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldString/index.html).

### `RedisModule_RegisterInfoFunc` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerinfofunc "Copy link to clipboard"/index.html)

int RedisModule_RegisterInfoFunc(RedisModuleCtx *ctx, RedisModuleInfoFunc cb);

**Available since:** 6.0.0

Registers callback for the INFO command. The callback should add INFO fields
by calling the `RedisModule_InfoAddField*()` functions.

### `RedisModule_GetServerInfo` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getserverinfo "Copy link to clipboard"/index.html)

RedisModuleServerInfoData *RedisModule_GetServerInfo(RedisModuleCtx *ctx, const char *section);

**Available since:** 6.0.0

Get information about the server similar to the one that returns from the
INFO command. This function takes an optional 'section' argument that may
be NULL. The return value holds the output and can be used with
[`RedisModule_ServerInfoGetField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetField/index.html) and alike to get the individual fields.
When done, it needs to be freed with [`RedisModule_FreeServerInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeServerInfo/index.html) or with the
automatic memory management mechanism if enabled.

### `RedisModule_FreeServerInfo` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_freeserverinfo "Copy link to clipboard"/index.html)

void RedisModule_FreeServerInfo(RedisModuleCtx *ctx, RedisModuleServerInfoData *data);

**Available since:** 6.0.0

Free data created with [`RedisModule_GetServerInfo()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetServerInfo/index.html). You need to pass the
context pointer 'ctx' only if the dictionary was created using the
context instead of passing NULL.

### `RedisModule_ServerInfoGetField` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_serverinfogetfield "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_ServerInfoGetField(RedisModuleCtx *ctx, RedisModuleServerInfoData data, const char field);

**Available since:** 6.0.0

Get the value of a field from data collected with [`RedisModule_GetServerInfo()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetServerInfo/index.html). You
need to pass the context pointer 'ctx' only if you want to use auto memory
mechanism to release the returned string. Return value will be NULL if the
field was not found.

### `RedisModule_ServerInfoGetFieldC` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_serverinfogetfieldc "Copy link to clipboard"/index.html)

const char *RedisModule_ServerInfoGetFieldC(RedisModuleServerInfoData data, const char field);

**Available since:** 6.0.0

Similar to [`RedisModule_ServerInfoGetField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetField/index.html), but returns a char\* which should not be freed but the caller.

### `RedisModule_ServerInfoGetFieldSigned` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_serverinfogetfieldsigned "Copy link to clipboard"/index.html)

long long RedisModule_ServerInfoGetFieldSigned(RedisModuleServerInfoData data, const char field, int *out_err);

**Available since:** 6.0.0

Get the value of a field from data collected with [`RedisModule_GetServerInfo()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetServerInfo/index.html). If the
field is not found, or is not numerical or out of range, return value will be
0, and the optional `out_err` argument will be set to `REDISMODULE_ERR`.

### `RedisModule_ServerInfoGetFieldUnsigned` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_serverinfogetfieldunsigned "Copy link to clipboard"/index.html)

unsigned long long RedisModule_ServerInfoGetFieldUnsigned(RedisModuleServerInfoData data, const char field, int *out_err);

**Available since:** 6.0.0

### `RedisModule_ServerInfoGetFieldDouble` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_serverinfogetfielddouble "Copy link to clipboard"/index.html)

double RedisModule_ServerInfoGetFieldDouble(RedisModuleServerInfoData data, const char field, int *out_err);

**Available since:** 6.0.0

Get the value of a field from data collected with [`RedisModule_GetServerInfo()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetServerInfo/index.html). If the
field is not found, or is not a double, return value will be 0, and the
optional `out_err` argument will be set to `REDISMODULE_ERR`.

## Modules utility APIs  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-utility-apis "Copy link to clipboard"/index.html)

### `RedisModule_GetRandomBytes` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getrandombytes "Copy link to clipboard"/index.html)

void RedisModule_GetRandomBytes(unsigned char *dst, size_t len);

**Available since:** 5.0.0

Return random bytes using SHA1 in counter mode with a /dev/urandom
initialized seed. This function is fast so can be used to generate
many bytes without any effect on the operating system entropy pool.
Currently this function is not thread safe.

### `RedisModule_GetRandomHexChars` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getrandomhexchars "Copy link to clipboard"/index.html)

void RedisModule_GetRandomHexChars(char *dst, size_t len);

**Available since:** 5.0.0

Like [`RedisModule_GetRandomBytes()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetRandomBytes/index.html) but instead of setting the string to
random bytes the string is set to random characters in the in the
hex charset \[0-9a-f\].

## Modules API exporting / importing  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#modules-api-exporting--importing "Copy link to clipboard"/index.html)

### `RedisModule_ExportSharedAPI` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_exportsharedapi "Copy link to clipboard"/index.html)

int RedisModule_ExportSharedAPI(RedisModuleCtx *ctx, const char *apiname, void *func);

**Available since:** 5.0.4

This function is called by a module in order to export some API with a
given name. Other modules will be able to use this API by calling the
symmetrical function [`RedisModule_GetSharedAPI()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetSharedAPI/index.html) and casting the return value to
the right function pointer.

The function will return `REDISMODULE_OK` if the name is not already taken,
otherwise `REDISMODULE_ERR` will be returned and no operation will be
performed.

IMPORTANT: the apiname argument should be a string literal with static
lifetime. The API relies on the fact that it will always be valid in
the future.

### `RedisModule_GetSharedAPI` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getsharedapi "Copy link to clipboard"/index.html)

void *RedisModule_GetSharedAPI(RedisModuleCtx *ctx, const char *apiname);

**Available since:** 5.0.4

Request an exported API pointer. The return value is just a void pointer
that the caller of this function will be required to cast to the right
function pointer, so this is a private contract between modules.

If the requested API is not available then NULL is returned. Because
modules can be loaded at different times with different order, this
function calls should be put inside some module generic API registering
step, that is called every time a module attempts to execute a
command that requires external APIs: if some API cannot be resolved, the
command should return an error.

Here is an example:

int ... myCommandImplementation(void) { if (getExternalAPIs() == 0) { reply with an error here if we cannot have the APIs } // Use the API: myFunctionPointer(foo); }

And the function registerAPI() is:

int getExternalAPIs(void) { static int api_loaded = 0; if (api_loaded != 0) return 1; // APIs already resolved.

myFunctionPointer = RedisModule_GetSharedAPI("..."); if (myFunctionPointer == NULL) return 0;

return 1; }

## Module Command Filter API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#module-command-filter-api "Copy link to clipboard"/index.html)

### `RedisModule_RegisterCommandFilter` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registercommandfilter "Copy link to clipboard"/index.html)

RedisModuleCommandFilter *RedisModule_RegisterCommandFilter(RedisModuleCtx *ctx, RedisModuleCommandFilterFunc callback, int flags);

**Available since:** 5.0.5

Register a new command filter function.

Command filtering makes it possible for modules to extend Redis by plugging
into the execution flow of all commands.

A registered filter gets called before Redis executes _any_ command. This
includes both core Redis commands and commands registered by any module. The
filter applies in all execution paths including:

1. Invocation by a client.
2. Invocation through [`RedisModule_Call()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Call/index.html) by any module.
3. Invocation through Lua `redis.call()`.
4. Replication of a command from a master.

The filter executes in a special filter context, which is different and more
limited than a `RedisModuleCtx`. Because the filter affects any command, it
must be implemented in a very efficient way to reduce the performance impact
on Redis. All Redis Module API calls that require a valid context (such as
[`RedisModule_Call()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Call/index.html), [`RedisModule_OpenKey()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_OpenKey/index.html), etc.) are not supported in a
filter context.

The `RedisModuleCommandFilterCtx` can be used to inspect or modify the
executed command and its arguments. As the filter executes before Redis
begins processing the command, any change will affect the way the command is
processed. For example, a module can override Redis commands this way:

1. Register a `MODULE.SET` command which implements an extended version of
the Redis `SET` command.
2. Register a command filter which detects invocation of `SET` on a specific
pattern of keys. Once detected, the filter will replace the first
argument from `SET` to `MODULE.SET`.
3. When filter execution is complete, Redis considers the new command name
and therefore executes the module's own command.

Note that in the above use case, if `MODULE.SET` itself uses
[`RedisModule_Call()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Call/index.html) the filter will be applied on that call as well. If
that is not desired, the `REDISMODULE_CMDFILTER_NOSELF` flag can be set when
registering the filter.

The `REDISMODULE_CMDFILTER_NOSELF` flag prevents execution flows that
originate from the module's own [`RedisModule_Call()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Call/index.html) from reaching the filter. This
flag is effective for all execution flows, including nested ones, as long as
the execution begins from the module's command context or a thread-safe
context that is associated with a blocking command.

Detached thread-safe contexts are _not_ associated with the module and cannot
be protected by this flag.

If multiple filters are registered (by the same or different modules), they
are executed in the order of registration.

### `RedisModule_UnregisterCommandFilter` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_unregistercommandfilter "Copy link to clipboard"/index.html)

int RedisModule_UnregisterCommandFilter(RedisModuleCtx *ctx, RedisModuleCommandFilter *filter);

**Available since:** 5.0.5

Unregister a command filter.

### `RedisModule_CommandFilterArgsCount` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_commandfilterargscount "Copy link to clipboard"/index.html)

int RedisModule_CommandFilterArgsCount(RedisModuleCommandFilterCtx *fctx);

**Available since:** 5.0.5

Return the number of arguments a filtered command has. The number of
arguments include the command itself.

### `RedisModule_CommandFilterArgGet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_commandfilterargget "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_CommandFilterArgGet(RedisModuleCommandFilterCtx *fctx, int pos);

**Available since:** 5.0.5

Return the specified command argument. The first argument (position 0) is
the command itself, and the rest are user-provided args.

### `RedisModule_CommandFilterArgInsert` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_commandfilterarginsert "Copy link to clipboard"/index.html)

int RedisModule_CommandFilterArgInsert(RedisModuleCommandFilterCtx *fctx, int pos, RedisModuleString *arg);

**Available since:** 5.0.5

Modify the filtered command by inserting a new argument at the specified
position. The specified `RedisModuleString` argument may be used by Redis
after the filter context is destroyed, so it must not be auto-memory
allocated, freed or used elsewhere.

### `RedisModule_CommandFilterArgReplace` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_commandfilterargreplace "Copy link to clipboard"/index.html)

int RedisModule_CommandFilterArgReplace(RedisModuleCommandFilterCtx *fctx, int pos, RedisModuleString *arg);

**Available since:** 5.0.5

Modify the filtered command by replacing an existing argument with a new one.
The specified `RedisModuleString` argument may be used by Redis after the
filter context is destroyed, so it must not be auto-memory allocated, freed
or used elsewhere.

### `RedisModule_CommandFilterArgDelete` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_commandfilterargdelete "Copy link to clipboard"/index.html)

int RedisModule_CommandFilterArgDelete(RedisModuleCommandFilterCtx *fctx, int pos);

**Available since:** 5.0.5

Modify the filtered command by deleting an argument at the specified
position.

### `RedisModule_CommandFilterGetClientId` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_commandfiltergetclientid "Copy link to clipboard"/index.html)

unsigned long long RedisModule_CommandFilterGetClientId(RedisModuleCommandFilterCtx *fctx);

**Available since:** 7.2.0

Get Client ID for client that issued the command we are filtering

### `RedisModule_MallocSize` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_mallocsize "Copy link to clipboard"/index.html)

size_t RedisModule_MallocSize(void* ptr);

**Available since:** 6.0.0

For a given pointer allocated via [`RedisModule_Alloc()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Alloc/index.html) or
[`RedisModule_Realloc()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Realloc/index.html), return the amount of memory allocated for it.
Note that this may be different (larger) than the memory we allocated
with the allocation calls, since sometimes the underlying allocator
will allocate more memory.

### `RedisModule_MallocUsableSize` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_mallocusablesize "Copy link to clipboard"/index.html)

size_t RedisModule_MallocUsableSize(void *ptr);

**Available since:** 7.0.1

Similar to [`RedisModule_MallocSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocSize/index.html), the difference is that [`RedisModule_MallocUsableSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocUsableSize/index.html)
returns the usable size of memory by the module.

### `RedisModule_MallocSizeString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_mallocsizestring "Copy link to clipboard"/index.html)

size_t RedisModule_MallocSizeString(RedisModuleString* str);

**Available since:** 7.0.0

Same as [`RedisModule_MallocSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocSize/index.html), except it works on `RedisModuleString` pointers.

### `RedisModule_MallocSizeDict` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_mallocsizedict "Copy link to clipboard"/index.html)

size_t RedisModule_MallocSizeDict(RedisModuleDict* dict);

**Available since:** 7.0.0

Same as [`RedisModule_MallocSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocSize/index.html), except it works on `RedisModuleDict` pointers.
Note that the returned value is only the overhead of the underlying structures,
it does not include the allocation size of the keys and values.

### `RedisModule_GetUsedMemoryRatio` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getusedmemoryratio "Copy link to clipboard"/index.html)

float RedisModule_GetUsedMemoryRatio(void);

**Available since:** 6.0.0

Return the a number between 0 to 1 indicating the amount of memory
currently used, relative to the Redis "maxmemory" configuration.

- 0 - No memory limit configured.
- Between 0 and 1 - The percentage of the memory used normalized in 0-1 range.
- Exactly 1 - Memory limit reached.
- Greater 1 - More memory used than the configured limit.

## Scanning keyspace and hashes  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#scanning-keyspace-and-hashes "Copy link to clipboard"/index.html)

### `RedisModule_ScanCursorCreate` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_scancursorcreate "Copy link to clipboard"/index.html)

RedisModuleScanCursor *RedisModule_ScanCursorCreate(void);

**Available since:** 6.0.0

Create a new cursor to be used with [`RedisModule_Scan`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Scan/index.html)

### `RedisModule_ScanCursorRestart` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_scancursorrestart "Copy link to clipboard"/index.html)

void RedisModule_ScanCursorRestart(RedisModuleScanCursor *cursor);

**Available since:** 6.0.0

Restart an existing cursor. The keys will be rescanned.

### `RedisModule_ScanCursorDestroy` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_scancursordestroy "Copy link to clipboard"/index.html)

void RedisModule_ScanCursorDestroy(RedisModuleScanCursor *cursor);

**Available since:** 6.0.0

Destroy the cursor struct.

### `RedisModule_Scan` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_scan "Copy link to clipboard"/index.html)

int RedisModule_Scan(RedisModuleCtx *ctx, RedisModuleScanCursor *cursor, RedisModuleScanCB fn, void *privdata);

**Available since:** 6.0.0

Scan API that allows a module to scan all the keys and value in
the selected db.

Callback for scan implementation.

void scan_callback(RedisModuleCtx *ctx, RedisModuleString *keyname, RedisModuleKey *key, void *privdata);

- `ctx`: the redis module context provided to for the scan.
- `keyname`: owned by the caller and need to be retained if used after this
function.
- `key`: holds info on the key and value, it is provided as best effort, in
some cases it might be NULL, in which case the user should (can) use
[`RedisModule_OpenKey()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_OpenKey/index.html) (and CloseKey too).
when it is provided, it is owned by the caller and will be free when the
callback returns.
- `privdata`: the user data provided to [`RedisModule_Scan()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Scan/index.html).

The way it should be used:

RedisModuleScanCursor *c = RedisModule_ScanCursorCreate(); while(RedisModule_Scan(ctx, c, callback, privateData)); RedisModule_ScanCursorDestroy(c);

It is also possible to use this API from another thread while the lock
is acquired during the actual call to [`RedisModule_Scan`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Scan/index.html):

RedisModuleScanCursor *c = RedisModule_ScanCursorCreate(); RedisModule_ThreadSafeContextLock(ctx); while(RedisModule_Scan(ctx, c, callback, privateData)){ RedisModule_ThreadSafeContextUnlock(ctx); // do some background job RedisModule_ThreadSafeContextLock(ctx); } RedisModule_ScanCursorDestroy(c);

The function will return 1 if there are more elements to scan and
0 otherwise, possibly setting errno if the call failed.

It is also possible to restart an existing cursor using [`RedisModule_ScanCursorRestart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanCursorRestart/index.html).

IMPORTANT: This API is very similar to the Redis SCAN command from the
point of view of the guarantees it provides. This means that the API
may report duplicated keys, but guarantees to report at least one time
every key that was there from the start to the end of the scanning process.

NOTE: If you do database changes within the callback, you should be aware
that the internal state of the database may change. For instance it is safe
to delete or modify the current key, but may not be safe to delete any
other key.
Moreover playing with the Redis keyspace while iterating may have the
effect of returning more duplicates. A safe pattern is to store the keys
names you want to modify elsewhere, and perform the actions on the keys
later when the iteration is complete. However this can cost a lot of
memory, so it may make sense to just operate on the current key when
possible during the iteration, given that this is safe.

### `RedisModule_ScanKey` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_scankey "Copy link to clipboard"/index.html)

int RedisModule_ScanKey(RedisModuleKey *key, RedisModuleScanCursor *cursor, RedisModuleScanKeyCB fn, void *privdata);

**Available since:** 6.0.0

Scan api that allows a module to scan the elements in a hash, set or sorted set key

Callback for scan implementation.

void scan_callback(RedisModuleKey key, RedisModuleString field, RedisModuleString* value, void *privdata);

- key - the redis key context provided to for the scan.
- field - field name, owned by the caller and need to be retained if used
after this function.
- value - value string or NULL for set type, owned by the caller and need to
be retained if used after this function.
- privdata - the user data provided to [`RedisModule_ScanKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanKey/index.html).

The way it should be used:

RedisModuleScanCursor *c = RedisModule_ScanCursorCreate(); RedisModuleKey *key = RedisModule_OpenKey(...); while(RedisModule_ScanKey(key, c, callback, privateData)); RedisModule_CloseKey(key); RedisModule_ScanCursorDestroy(c);

It is also possible to use this API from another thread while the lock is acquired during
the actual call to [`RedisModule_ScanKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanKey/index.html), and re-opening the key each time:

RedisModuleScanCursor *c = RedisModule_ScanCursorCreate(); RedisModule_ThreadSafeContextLock(ctx); RedisModuleKey *key = RedisModule_OpenKey(...); while(RedisModule_ScanKey(ctx, c, callback, privateData)){ RedisModule_CloseKey(key); RedisModule_ThreadSafeContextUnlock(ctx); // do some background job RedisModule_ThreadSafeContextLock(ctx); key = RedisModule_OpenKey(...); } RedisModule_CloseKey(key); RedisModule_ScanCursorDestroy(c);

The function will return 1 if there are more elements to scan and 0 otherwise,
possibly setting errno if the call failed.
It is also possible to restart an existing cursor using [`RedisModule_ScanCursorRestart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanCursorRestart/index.html).

NOTE: Certain operations are unsafe while iterating the object. For instance
while the API guarantees to return at least one time all the elements that
are present in the data structure consistently from the start to the end
of the iteration (see HSCAN and similar commands documentation), the more
you play with the elements, the more duplicates you may get. In general
deleting the current element of the data structure is safe, while removing
the key you are iterating is not safe.

## Module fork API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#module-fork-api "Copy link to clipboard"/index.html)

### `RedisModule_Fork` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_fork "Copy link to clipboard"/index.html)

int RedisModule_Fork(RedisModuleForkDoneHandler cb, void *user_data);

**Available since:** 6.0.0

Create a background child process with the current frozen snapshot of the
main process where you can do some processing in the background without
affecting / freezing the traffic and no need for threads and GIL locking.
Note that Redis allows for only one concurrent fork.
When the child wants to exit, it should call [`RedisModule_ExitFromChild`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ExitFromChild/index.html).
If the parent wants to kill the child it should call [`RedisModule_KillForkChild`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KillForkChild/index.html)
The done handler callback will be executed on the parent process when the
child existed (but not when killed)
Return: -1 on failure, on success the parent process will get a positive PID
of the child, and the child process will get 0.

### `RedisModule_SendChildHeartbeat` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_sendchildheartbeat "Copy link to clipboard"/index.html)

void RedisModule_SendChildHeartbeat(double progress);

**Available since:** 6.2.0

The module is advised to call this function from the fork child once in a while,
so that it can report progress and COW memory to the parent which will be
reported in INFO.
The `progress` argument should between 0 and 1, or -1 when not available.

### `RedisModule_ExitFromChild` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_exitfromchild "Copy link to clipboard"/index.html)

int RedisModule_ExitFromChild(int retcode);

**Available since:** 6.0.0

Call from the child process when you want to terminate it.
retcode will be provided to the done handler executed on the parent process.

### `RedisModule_KillForkChild` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_killforkchild "Copy link to clipboard"/index.html)

int RedisModule_KillForkChild(int child_pid);

**Available since:** 6.0.0

Can be used to kill the forked child process from the parent process.
`child_pid` would be the return value of [`RedisModule_Fork`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Fork/index.html).

## Server hooks implementation  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#server-hooks-implementation "Copy link to clipboard"/index.html)

### `RedisModule_SubscribeToServerEvent` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_subscribetoserverevent "Copy link to clipboard"/index.html)

int RedisModule_SubscribeToServerEvent(RedisModuleCtx *ctx, RedisModuleEvent event, RedisModuleEventCallback callback);

**Available since:** 6.0.0

Register to be notified, via a callback, when the specified server event
happens. The callback is called with the event as argument, and an additional
argument which is a void pointer and should be cased to a specific type
that is event-specific (but many events will just use NULL since they do not
have additional information to pass to the callback).

If the callback is NULL and there was a previous subscription, the module
will be unsubscribed. If there was a previous subscription and the callback
is not null, the old callback will be replaced with the new one.

The callback must be of this type:

int (*RedisModuleEventCallback)(RedisModuleCtx *ctx, RedisModuleEvent eid, uint64_t subevent, void *data);

The 'ctx' is a normal Redis module context that the callback can use in
order to call other modules APIs. The 'eid' is the event itself, this
is only useful in the case the module subscribed to multiple events: using
the 'id' field of this structure it is possible to check if the event
is one of the events we registered with this callback. The 'subevent' field
depends on the event that fired.

Finally the 'data' pointer may be populated, only for certain events, with
more relevant data.

Here is a list of events you can use as 'eid' and related sub events:

- `RedisModuleEvent_ReplicationRoleChanged`:

This event is called when the instance switches from master
to replica or the other way around, however the event is
also called when the replica remains a replica but starts to
replicate with a different master.

The following sub events are available:

- `REDISMODULE_SUBEVENT_REPLROLECHANGED_NOW_MASTER`
  - `REDISMODULE_SUBEVENT_REPLROLECHANGED_NOW_REPLICA`

The 'data' field can be casted by the callback to a
`RedisModuleReplicationInfo` structure with the following fields:

int master; // true if master, false if replica char *masterhost; // master instance hostname for NOW_REPLICA int masterport; // master instance port for NOW_REPLICA char *replid1; // Main replication ID char *replid2; // Secondary replication ID uint64_t repl1_offset; // Main replication offset uint64_t repl2_offset; // Offset of replid2 validity

- `RedisModuleEvent_Persistence`

This event is called when RDB saving or AOF rewriting starts
and ends. The following sub events are available:

- `REDISMODULE_SUBEVENT_PERSISTENCE_RDB_START`
  - `REDISMODULE_SUBEVENT_PERSISTENCE_AOF_START`
  - `REDISMODULE_SUBEVENT_PERSISTENCE_SYNC_RDB_START`
  - `REDISMODULE_SUBEVENT_PERSISTENCE_SYNC_AOF_START`
  - `REDISMODULE_SUBEVENT_PERSISTENCE_ENDED`
  - `REDISMODULE_SUBEVENT_PERSISTENCE_FAILED`

The above events are triggered not just when the user calls the
relevant commands like BGSAVE, but also when a saving operation
or AOF rewriting occurs because of internal server triggers.
The SYNC\_RDB\_START sub events are happening in the foreground due to
SAVE command, FLUSHALL, or server shutdown, and the other RDB and
AOF sub events are executed in a background fork child, so any
action the module takes can only affect the generated AOF or RDB,
but will not be reflected in the parent process and affect connected
clients and commands. Also note that the AOF\_START sub event may end
up saving RDB content in case of an AOF with rdb-preamble.

- `RedisModuleEvent_FlushDB`

The FLUSHALL, FLUSHDB or an internal flush (for instance
because of replication, after the replica synchronization)
happened. The following sub events are available:

- `REDISMODULE_SUBEVENT_FLUSHDB_START`
  - `REDISMODULE_SUBEVENT_FLUSHDB_END`

The data pointer can be casted to a RedisModuleFlushInfo
structure with the following fields:

int32_t async; // True if the flush is done in a thread. // See for instance FLUSHALL ASYNC. // In this case the END callback is invoked // immediately after the database is put // in the free list of the thread. int32_t dbnum; // Flushed database number, -1 for all the DBs // in the case of the FLUSHALL operation.

The start event is called _before_ the operation is initiated, thus
allowing the callback to call DBSIZE or other operation on the
yet-to-free keyspace.

- `RedisModuleEvent_Loading`

Called on loading operations: at startup when the server is
started, but also after a first synchronization when the
replica is loading the RDB file from the master.
The following sub events are available:

- `REDISMODULE_SUBEVENT_LOADING_RDB_START`
  - `REDISMODULE_SUBEVENT_LOADING_AOF_START`
  - `REDISMODULE_SUBEVENT_LOADING_REPL_START`
  - `REDISMODULE_SUBEVENT_LOADING_ENDED`
  - `REDISMODULE_SUBEVENT_LOADING_FAILED`

Note that AOF loading may start with an RDB data in case of
rdb-preamble, in which case you'll only receive an AOF\_START event.

- `RedisModuleEvent_ClientChange`

Called when a client connects or disconnects.
The data pointer can be casted to a RedisModuleClientInfo
structure, documented in RedisModule\_GetClientInfoById().
The following sub events are available:
  - `REDISMODULE_SUBEVENT_CLIENT_CHANGE_CONNECTED`
  - `REDISMODULE_SUBEVENT_CLIENT_CHANGE_DISCONNECTED`
- `RedisModuleEvent_Shutdown`

The server is shutting down. No subevents are available.

- `RedisModuleEvent_ReplicaChange`

This event is called when the instance (that can be both a
master or a replica) get a new online replica, or lose a
replica since it gets disconnected.
The following sub events are available:

- `REDISMODULE_SUBEVENT_REPLICA_CHANGE_ONLINE`
  - `REDISMODULE_SUBEVENT_REPLICA_CHANGE_OFFLINE`

No additional information is available so far: future versions
of Redis will have an API in order to enumerate the replicas
connected and their state.

- `RedisModuleEvent_CronLoop`

This event is called every time Redis calls the serverCron()
function in order to do certain bookkeeping. Modules that are
required to do operations from time to time may use this callback.
Normally Redis calls this function 10 times per second, but
this changes depending on the "hz" configuration.
No sub events are available.

The data pointer can be casted to a RedisModuleCronLoop
structure with the following fields:

int32_t hz;  // Approximate number of events per second.

- `RedisModuleEvent_MasterLinkChange`

This is called for replicas in order to notify when the
replication link becomes functional (up) with our master,
or when it goes down. Note that the link is not considered
up when we just connected to the master, but only if the
replication is happening correctly.
The following sub events are available:
  - `REDISMODULE_SUBEVENT_MASTER_LINK_UP`
  - `REDISMODULE_SUBEVENT_MASTER_LINK_DOWN`
- `RedisModuleEvent_ModuleChange`

This event is called when a new module is loaded or one is unloaded.
The following sub events are available:

- `REDISMODULE_SUBEVENT_MODULE_LOADED`
  - `REDISMODULE_SUBEVENT_MODULE_UNLOADED`

The data pointer can be casted to a RedisModuleModuleChange
structure with the following fields:

const char* module_name; // Name of module loaded or unloaded. int32_t module_version; // Module version.

- `RedisModuleEvent_LoadingProgress`

This event is called repeatedly called while an RDB or AOF file
is being loaded.
The following sub events are available:

- `REDISMODULE_SUBEVENT_LOADING_PROGRESS_RDB`
  - `REDISMODULE_SUBEVENT_LOADING_PROGRESS_AOF`

The data pointer can be casted to a RedisModuleLoadingProgress
structure with the following fields:

int32_t hz; // Approximate number of events per second. int32_t progress; // Approximate progress between 0 and 1024, // or -1 if unknown.

- `RedisModuleEvent_SwapDB`

This event is called when a SWAPDB command has been successfully
Executed.
For this event call currently there is no subevents available.

The data pointer can be casted to a RedisModuleSwapDbInfo
structure with the following fields:

int32_t dbnum_first;    // Swap Db first dbnum
int32_t dbnum_second;   // Swap Db second dbnum

- `RedisModuleEvent_ReplBackup`

WARNING: Replication Backup events are deprecated since Redis 7.0 and are never fired.
See RedisModuleEvent\_ReplAsyncLoad for understanding how Async Replication Loading events
are now triggered when repl-diskless-load is set to swapdb.

Called when repl-diskless-load config is set to swapdb,
And redis needs to backup the current database for the
possibility to be restored later. A module with global data and
maybe with aux\_load and aux\_save callbacks may need to use this
notification to backup / restore / discard its globals.
The following sub events are available:
  - `REDISMODULE_SUBEVENT_REPL_BACKUP_CREATE`
  - `REDISMODULE_SUBEVENT_REPL_BACKUP_RESTORE`
  - `REDISMODULE_SUBEVENT_REPL_BACKUP_DISCARD`
- `RedisModuleEvent_ReplAsyncLoad`

Called when repl-diskless-load config is set to swapdb and a replication with a master of same
data set history (matching replication ID) occurs.
In which case redis serves current data set while loading new database in memory from socket.
Modules must have declared they support this mechanism in order to activate it, through
REDISMODULE\_OPTIONS\_HANDLE\_REPL\_ASYNC\_LOAD flag.
The following sub events are available:
  - `REDISMODULE_SUBEVENT_REPL_ASYNC_LOAD_STARTED`
  - `REDISMODULE_SUBEVENT_REPL_ASYNC_LOAD_ABORTED`
  - `REDISMODULE_SUBEVENT_REPL_ASYNC_LOAD_COMPLETED`
- `RedisModuleEvent_ForkChild`

Called when a fork child (AOFRW, RDBSAVE, module fork...) is born/dies
The following sub events are available:
  - `REDISMODULE_SUBEVENT_FORK_CHILD_BORN`
  - `REDISMODULE_SUBEVENT_FORK_CHILD_DIED`
- `RedisModuleEvent_EventLoop`

Called on each event loop iteration, once just before the event loop goes
to sleep or just after it wakes up.
The following sub events are available:
  - `REDISMODULE_SUBEVENT_EVENTLOOP_BEFORE_SLEEP`
  - `REDISMODULE_SUBEVENT_EVENTLOOP_AFTER_SLEEP`
- `RedisModule_Event_Config`

Called when a configuration event happens
The following sub events are available:

- `REDISMODULE_SUBEVENT_CONFIG_CHANGE`

The data pointer can be casted to a RedisModuleConfigChange
structure with the following fields:

const char **config_names; // An array of C string pointers containing the // name of each modified configuration item uint32_t num_changes; // The number of elements in the config_names array

- `RedisModule_Event_Key`

Called when a key is removed from the keyspace. We can't modify any key in
the event.
The following sub events are available:

- `REDISMODULE_SUBEVENT_KEY_DELETED`
  - `REDISMODULE_SUBEVENT_KEY_EXPIRED`
  - `REDISMODULE_SUBEVENT_KEY_EVICTED`
  - `REDISMODULE_SUBEVENT_KEY_OVERWRITTEN`

The data pointer can be casted to a RedisModuleKeyInfo
structure with the following fields:

RedisModuleKey *key; // Key name

- `RedisModuleEvent_ClusterSlotMigration`

Called when an atomic slot migration (ASM) event happens.
IMPORT events are triggered on the destination side of a slot migration
operation. These notifications let modules prepare for the upcoming
ownership change, observe successful completion once the cluster config
reflects the new owner, or detect a failure in which case slot ownership
remains with the source.

Similarly, MIGRATE events triggered on the source side of a slot
migration operation to let modules prepare for the ownership change and
observe the completion of the slot migration. MIGRATE\_MODULE\_PROPAGATE
event is triggered in the fork just before snapshot delivery; modules may
use it to enqueue commands that will be delivered first. See
RedisModule\_ClusterPropagateForSlotMigration() for details.

- `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_IMPORT_STARTED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_IMPORT_FAILED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_IMPORT_COMPLETED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_MIGRATE_STARTED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_MIGRATE_FAILED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_MIGRATE_COMPLETED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_MIGRATE_MODULE_PROPAGATE`

The data pointer can be casted to a RedisModuleClusterSlotMigrationInfo
structure with the following fields:

char source_node_id[REDISMODULE_NODE_ID_LEN + 1]; char destination_node_id[REDISMODULE_NODE_ID_LEN + 1]; const char *task_id; // Task ID RedisModuleSlotRangeArray *slots; // Slot ranges

- `RedisModuleEvent_ClusterSlotMigrationTrim`

Called when trimming keys after a slot migration. Fires on the source
after a successful migration to clean up migrated keys, or on the
destination after a failed import to discard partial imports. Two methods
are supported. In the first method, keys are deleted in a background
thread; this is reported via the TRIM\_BACKGROUND event. In the second
method, Redis performs incremental deletions on the main thread via the
cron loop to avoid stalls; this is reported via the TRIM\_STARTED and
TRIM\_COMPLETED events. Each deletion emits REDISMODULE\_NOTIFY\_KEY\_TRIMMED
so modules can react to individual key deletions. Redis selects the
method automatically: background by default; switches to main thread
trimming when a module subscribes to REDISMODULE\_NOTIFY\_KEY\_TRIMMED.

The following sub events are available:

- `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_TRIM_STARTED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_TRIM_COMPLETED`
  - `REDISMODULE_SUBEVENT_CLUSTER_SLOT_MIGRATION_TRIM_BACKGROUND`

The data pointer can be casted to a RedisModuleClusterSlotMigrationTrimInfo
structure with the following fields:

RedisModuleSlotRangeArray *slots; // Slot ranges

The function returns `REDISMODULE_OK` if the module was successfully subscribed
for the specified event. If the API is called from a wrong context or unsupported event
is given then `REDISMODULE_ERR` is returned.

### `RedisModule_IsSubEventSupported` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_issubeventsupported "Copy link to clipboard"/index.html)

int RedisModule_IsSubEventSupported(RedisModuleEvent event, int64_t subevent);

**Available since:** 6.0.9

For a given server event and subevent, return zero if the
subevent is not supported and non-zero otherwise.

## Module Configurations API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#module-configurations-api "Copy link to clipboard"/index.html)

### `RedisModule_RegisterStringConfig` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerstringconfig "Copy link to clipboard"/index.html)

int RedisModule_RegisterStringConfig(RedisModuleCtx *ctx, const char *name, const char *default_val, unsigned int flags, RedisModuleConfigGetStringFunc getfn, RedisModuleConfigSetStringFunc setfn, RedisModuleConfigApplyFunc applyfn, void *privdata);

**Available since:** 7.0.0

Create a string config that Redis users can interact with via the Redis config file,
`CONFIG SET`, `CONFIG GET`, and `CONFIG REWRITE` commands.

The actual config value is owned by the module, and the `getfn`, `setfn` and optional
`applyfn` callbacks that are provided to Redis in order to access or manipulate the
value. The `getfn` callback retrieves the value from the module, while the `setfn`
callback provides a value to be stored into the module config.
The optional `applyfn` callback is called after a `CONFIG SET` command modified one or
more configs using the `setfn` callback and can be used to atomically apply a config
after several configs were changed together.
If there are multiple configs with `applyfn` callbacks set by a single `CONFIG SET`
command, they will be deduplicated if their `applyfn` function and `privdata` pointers
are identical, and the callback will only be run once.
Both the `setfn` and `applyfn` can return an error if the provided value is invalid or
cannot be used.
The config also declares a type for the value that is validated by Redis and
provided to the module. The config system provides the following types:

- Redis String: Binary safe string data.
- Enum: One of a finite number of string tokens, provided during registration.
- Numeric: 64 bit signed integer, which also supports min and max values.
- Bool: Yes or no value.

The `setfn` callback is expected to return `REDISMODULE_OK` when the value is successfully
applied. It can also return `REDISMODULE_ERR` if the value can't be applied, and the
\*err pointer can be set with a `RedisModuleString` error message to provide to the client.
This `RedisModuleString` will be freed by redis after returning from the set callback.

All configs are registered with a name, a type, a default value, private data that is made
available in the callbacks, as well as several flags that modify the behavior of the config.
The name must only contain alphanumeric characters or dashes. The supported flags are:

- `REDISMODULE_CONFIG_DEFAULT`: The default flags for a config. This creates a config that can be modified after startup.
- `REDISMODULE_CONFIG_IMMUTABLE`: This config can only be provided loading time.
- `REDISMODULE_CONFIG_SENSITIVE`: The value stored in this config is redacted from all logging.
- `REDISMODULE_CONFIG_HIDDEN`: The name is hidden from `CONFIG GET` with pattern matching.
- `REDISMODULE_CONFIG_PROTECTED`: This config will be only be modifiable based off the value of enable-protected-configs.
- `REDISMODULE_CONFIG_DENY_LOADING`: This config is not modifiable while the server is loading data.
- `REDISMODULE_CONFIG_MEMORY`: For numeric configs, this config will convert data unit notations into their byte equivalent.
- `REDISMODULE_CONFIG_BITFLAGS`: For enum configs, this config will allow multiple entries to be combined as bit flags.

Default values are used on startup to set the value if it is not provided via the config file
or command line. Default values are also used to compare to on a config rewrite.

Notes:

1. On string config sets that the string passed to the set callback will be freed after execution and the module must retain it.
2. On string config gets the string will not be consumed and will be valid after execution.

Example implementation:

RedisModuleString *strval; int adjustable = 1; RedisModuleString *getStringConfigCommand(const char *name, void *privdata) { return strval; }

int setStringConfigCommand(const char *name, RedisModuleString *new, void *privdata, RedisModuleString **err) { if (adjustable) { RedisModule_Free(strval); RedisModule_RetainString(NULL, new); strval = new; return REDISMODULE_OK; } *err = RedisModule_CreateString(NULL, "Not adjustable.", 15); return REDISMODULE_ERR; } ... RedisModule_RegisterStringConfig(ctx, "string", NULL, REDISMODULE_CONFIG_DEFAULT, getStringConfigCommand, setStringConfigCommand, NULL, NULL);

If the registration fails, `REDISMODULE_ERR` is returned and one of the following
errno is set:

- EBUSY: Registering the Config outside of `RedisModule_OnLoad`.
- EINVAL: The provided flags are invalid for the registration or the name of the config contains invalid characters.
- EALREADY: The provided configuration name is already used.

### `RedisModule_RegisterBoolConfig` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerboolconfig "Copy link to clipboard"/index.html)

int RedisModule_RegisterBoolConfig(RedisModuleCtx *ctx, const char *name, int default_val, unsigned int flags, RedisModuleConfigGetBoolFunc getfn, RedisModuleConfigSetBoolFunc setfn, RedisModuleConfigApplyFunc applyfn, void *privdata);

**Available since:** 7.0.0

Create a bool config that server clients can interact with via the
`CONFIG SET`, `CONFIG GET`, and `CONFIG REWRITE` commands. See
[`RedisModule_RegisterStringConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterStringConfig/index.html) for detailed information about configs.

### `RedisModule_RegisterEnumConfig` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerenumconfig "Copy link to clipboard"/index.html)

int RedisModule_RegisterEnumConfig(RedisModuleCtx *ctx, const char *name, int default_val, unsigned int flags, const char **enum_values, const int *int_values, int num_enum_vals, RedisModuleConfigGetEnumFunc getfn, RedisModuleConfigSetEnumFunc setfn, RedisModuleConfigApplyFunc applyfn, void *privdata);

**Available since:** 7.0.0

Create an enum config that server clients can interact with via the
`CONFIG SET`, `CONFIG GET`, and `CONFIG REWRITE` commands.
Enum configs are a set of string tokens to corresponding integer values, where
the string value is exposed to Redis clients but the value passed Redis and the
module is the integer value. These values are defined in `enum_values`, an array
of null-terminated c strings, and `int_vals`, an array of enum values who has an
index partner in `enum_values`.
Example Implementation:
const char \*enum\_vals\[3\] = {"first", "second", "third"};
const int int\_vals\[3\] = {0, 2, 4};
int enum\_val = 0;

int getEnumConfigCommand(const char *name, void *privdata) { return enum_val; }

int setEnumConfigCommand(const char *name, int val, void *privdata, const char **err) { enum_val = val; return REDISMODULE_OK; } ... RedisModule_RegisterEnumConfig(ctx, "enum", 0, REDISMODULE_CONFIG_DEFAULT, enum_vals, int_vals, 3, getEnumConfigCommand, setEnumConfigCommand, NULL, NULL);

Note that you can use `REDISMODULE_CONFIG_BITFLAGS` so that multiple enum string
can be combined into one integer as bit flags, in which case you may want to
sort your enums so that the preferred combinations are present first.

See [`RedisModule_RegisterStringConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterStringConfig/index.html) for detailed general information about configs.

### `RedisModule_RegisterNumericConfig` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registernumericconfig "Copy link to clipboard"/index.html)

int RedisModule_RegisterNumericConfig(RedisModuleCtx *ctx, const char *name, long long default_val, unsigned int flags, long long min, long long max, RedisModuleConfigGetNumericFunc getfn, RedisModuleConfigSetNumericFunc setfn, RedisModuleConfigApplyFunc applyfn, void *privdata);

**Available since:** 7.0.0

Create an integer config that server clients can interact with via the
`CONFIG SET`, `CONFIG GET`, and `CONFIG REWRITE` commands. See
[`RedisModule_RegisterStringConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterStringConfig/index.html) for detailed information about configs.

### `RedisModule_LoadDefaultConfigs` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loaddefaultconfigs "Copy link to clipboard"/index.html)

int RedisModule_LoadDefaultConfigs(RedisModuleCtx *ctx);

**Available since:** 8.0.0

Applies all default configurations for the parameters the module registered.
Only call this function if the module would like to make changes to the
configuration values before the actual values are applied by [`RedisModule_LoadConfigs`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadConfigs/index.html).
Otherwise it's sufficient to call [`RedisModule_LoadConfigs`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadConfigs/index.html), it should already set the default values if needed.
This makes it possible to distinguish between default values and user provided values and apply other changes between setting the defaults and the user values.
This will return `REDISMODULE_ERR` if it is called:

1. outside `RedisModule_OnLoad`
2. more than once
3. after the [`RedisModule_LoadConfigs`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadConfigs/index.html) call

### `RedisModule_LoadConfigs` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_loadconfigs "Copy link to clipboard"/index.html)

int RedisModule_LoadConfigs(RedisModuleCtx *ctx);

**Available since:** 7.0.0

Applies all pending configurations on the module load. This should be called
after all of the configurations have been registered for the module inside of `RedisModule_OnLoad`.
This will return `REDISMODULE_ERR` if it is called outside `RedisModule_OnLoad`.
This API needs to be called when configurations are provided in either `MODULE LOADEX`
or provided as startup arguments.

## RDB load/save API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#rdb-loadsave-api "Copy link to clipboard"/index.html)

### `RedisModule_RdbStreamCreateFromFile` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_rdbstreamcreatefromfile "Copy link to clipboard"/index.html)

RedisModuleRdbStream *RedisModule_RdbStreamCreateFromFile(const char *filename);

**Available since:** 7.2.0

Create a stream object to save/load RDB to/from a file.

This function returns a pointer to `RedisModuleRdbStream` which is owned
by the caller. It requires a call to [`RedisModule_RdbStreamFree()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RdbStreamFree/index.html) to free
the object.

### `RedisModule_RdbStreamFree` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_rdbstreamfree "Copy link to clipboard"/index.html)

void RedisModule_RdbStreamFree(RedisModuleRdbStream *stream);

**Available since:** 7.2.0

Release an RDB stream object.

### `RedisModule_RdbLoad` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_rdbload "Copy link to clipboard"/index.html)

int RedisModule_RdbLoad(RedisModuleCtx *ctx, RedisModuleRdbStream *stream, int flags);

**Available since:** 7.2.0

Load RDB file from the `stream`. Dataset will be cleared first and then RDB
file will be loaded.

`flags` must be zero. This parameter is for future use.

On success `REDISMODULE_OK` is returned, otherwise `REDISMODULE_ERR` is returned
and errno is set accordingly.

Example:

RedisModuleRdbStream *s = RedisModule_RdbStreamCreateFromFile("exp.rdb"); RedisModule_RdbLoad(ctx, s, 0); RedisModule_RdbStreamFree(s);

### `RedisModule_RdbSave` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_rdbsave "Copy link to clipboard"/index.html)

int RedisModule_RdbSave(RedisModuleCtx *ctx, RedisModuleRdbStream *stream, int flags);

**Available since:** 7.2.0

Save dataset to the RDB stream.

`flags` must be zero. This parameter is for future use.

On success `REDISMODULE_OK` is returned, otherwise `REDISMODULE_ERR` is returned
and errno is set accordingly.

Example:

RedisModuleRdbStream *s = RedisModule_RdbStreamCreateFromFile("exp.rdb"); RedisModule_RdbSave(ctx, s, 0); RedisModule_RdbStreamFree(s);

### `RedisModule_GetInternalSecret` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getinternalsecret "Copy link to clipboard"/index.html)

const char* RedisModule_GetInternalSecret(RedisModuleCtx *ctx, size_t *len);

**Available since:** 8.0.0

Returns the internal secret of the cluster.
Should be used to authenticate as an internal connection to a node in the
cluster, and by that gain the permissions to execute internal commands.

## Config access API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#config-access-api "Copy link to clipboard"/index.html)

### `RedisModule_ConfigIteratorCreate` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configiteratorcreate "Copy link to clipboard"/index.html)

RedisModuleConfigIterator *RedisModule_ConfigIteratorCreate(RedisModuleCtx *ctx, const char *pattern);

**Available since:** 8.2.0

Get an iterator to all configs.
Optional `ctx` can be provided if use of auto-memory is desired.
Optional `pattern` can be provided to filter configs by name. If `pattern` is
NULL all configs will be returned.

The returned iterator can be used to iterate over all configs using
[`RedisModule_ConfigIteratorNext()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorNext/index.html).

Example usage:

// Below is same as RedisModule_ConfigIteratorCreate(ctx, NULL) RedisModuleConfigIterator iter = RedisModule_ConfigIteratorCreate(ctx, ""); const char *config_name = NULL; while ((config_name = RedisModule_ConfigIteratorNext(iter)) != NULL) { RedisModuleString *value = NULL; if (RedisModule_ConfigGet(ctx, config_name, &value) == REDISMODULE_OK) { // Do something with value... RedisModule_FreeString(ctx, value); } } RedisModule_ConfigIteratorRelease(ctx, iter);

// Or optionally one can check the type to get the config value directly // via the appropriate API in case performance is of consideration iter = RedisModule_ConfigIteratorCreate(ctx, "*"); while ((config_name = RedisModule_ConfigIteratorNext(iter)) != NULL) { RedisModuleConfigType type = RedisModule_ConfigGetType(config_name); if (type == REDISMODULE_CONFIG_TYPE_STRING) { RedisModuleString *value; RedisModule_ConfigGet(ctx, config_name, &value); // Do something with value... RedisModule_FreeString(ctx, value); } if (type == REDISMODULE_CONFIG_TYPE_NUMERIC) { long long value; RedisModule_ConfigGetNumeric(ctx, config_name, &value); // Do something with value... } else if (type == REDISMODULE_CONFIG_TYPE_BOOL) { int value; RedisModule_ConfigGetBool(ctx, config_name, &value); // Do something with value... } else if (type == REDISMODULE_CONFIG_TYPE_ENUM) { RedisModuleString *value; RedisModule_ConfigGetEnum(ctx, config_name, &value); // Do something with value... RedisModule_Free(value); } } RedisModule_ConfigIteratorRelease(ctx, iter);

Returns a pointer to `RedisModuleConfigIterator`. Unless auto-memory is enabled
the caller is responsible for freeing the iterator using
[`RedisModule_ConfigIteratorRelease()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorRelease/index.html).

### `RedisModule_ConfigIteratorRelease` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configiteratorrelease "Copy link to clipboard"/index.html)

void RedisModule_ConfigIteratorRelease(RedisModuleCtx *ctx, RedisModuleConfigIterator *iter);

**Available since:** 8.2.0

Release the iterator returned by [`RedisModule_ConfigIteratorCreate()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorCreate/index.html). If auto-memory
is enabled and manual release is needed one must pass the same `RedisModuleCtx`
that was used to create the iterator.

### `RedisModule_ConfigGetType` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configgettype "Copy link to clipboard"/index.html)

int RedisModule_ConfigGetType(const char *name, RedisModuleConfigType *res);

**Available since:** 8.2.0

Get the type of a config as `RedisModuleConfigType`. One may use this in order
to get or set the values of the config with the appropriate function if the
generic [`RedisModule_ConfigGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigGet/index.html) and [`RedisModule_ConfigSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSet/index.html) APIs are performing
poorly.

Intended usage of this function is when iteration over the configs is
performed. See [`RedisModule_ConfigIteratorNext()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorNext/index.html) for example usage. If setting
or getting individual configs one can check the config type by hand in
redis.conf (or via other sources if config is added by a module) and use the
appropriate function without the need to call this function.

Explanation of config types:

- `REDISMODULE_CONFIG_TYPE_BOOL`: Config is a boolean. One can use `RedisModule_Config`(Get/Set)Bool
- `REDISMODULE_CONFIG_TYPE_NUMERIC`: Config is a numeric value. One can use `RedisModule_Config`(Get/Set)Numeric
- `REDISMODULE_CONFIG_TYPE_STRING`: Config is a string. One can use the generic `RedisModule_Config`(Get/Set)
- `REDISMODULE_CONFIG_TYPE_ENUM`: Config is an enum. One can use `RedisModule_Config`(Get/Set)Enum

If a config with the given name exists `res` is populated with its type, else
`REDISMODULE_ERR` is returned.

### `RedisModule_ConfigIteratorNext` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configiteratornext "Copy link to clipboard"/index.html)

const char *RedisModule_ConfigIteratorNext(RedisModuleConfigIterator *iter);

**Available since:** 8.2.0

Go to the next element of the config iterator.

Returns the name of the next config, or NULL if there are no more configs.
Returned string is non-owning and thus should not be freed.
If a pattern was provided when creating the iterator, only configs matching
the pattern will be returned.

See [`RedisModule_ConfigIteratorCreate()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorCreate/index.html) for example usage.

### `RedisModule_ConfigGet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configget "Copy link to clipboard"/index.html)

int RedisModule_ConfigGet(RedisModuleCtx *ctx, const char *name, RedisModuleString **res);

**Available since:** 8.2.0

Get the value of a config as a string. This function can be used to get the
value of any config, regardless of its type.

The string is allocated by the module and must be freed by the caller unless
auto memory is enabled.

If the config does not exist, `REDISMODULE_ERR` is returned, else `REDISMODULE_OK`
is returned and `res` is populated with the value.

### `RedisModule_ConfigGetBool` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configgetbool "Copy link to clipboard"/index.html)

int RedisModule_ConfigGetBool(RedisModuleCtx *ctx, const char *name, int *res);

**Available since:** 8.2.0

Get the value of a bool config.

If the config does not exist or is not a bool config, `REDISMODULE_ERR` is
returned, else `REDISMODULE_OK` is returned and `res` is populated with the
value.

### `RedisModule_ConfigGetEnum` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configgetenum "Copy link to clipboard"/index.html)

int RedisModule_ConfigGetEnum(RedisModuleCtx *ctx, const char *name, RedisModuleString **res);

**Available since:** 8.2.0

Get the value of an enum config.

If the config does not exist or is not an enum config, `REDISMODULE_ERR` is
returned, else `REDISMODULE_OK` is returned and `res` is populated with the value.
If the config has multiple arguments they are returned as a space-separated
string.

### `RedisModule_ConfigGetNumeric` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configgetnumeric "Copy link to clipboard"/index.html)

int RedisModule_ConfigGetNumeric(RedisModuleCtx *ctx, const char *name, long long *res);

**Available since:** 8.2.0

Get the value of a numeric config.

If the config does not exist or is not a numeric config, `REDISMODULE_ERR` is
returned, else `REDISMODULE_OK` is returned and `res` is populated with the
value.

### `RedisModule_ConfigSet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configset "Copy link to clipboard"/index.html)

int RedisModule_ConfigSet(RedisModuleCtx *ctx, const char *name, RedisModuleString *value, RedisModuleString **err);

**Available since:** 8.2.0

Set the value of a config.

This function can be used to set the value of any config, regardless of its
type. If the config is multi-argument, the value must be a space-separated
string.

If the value failed to be set `REDISMODULE_ERR` will be returned and if `err`
is not NULL, it will be populated with an error message.

### `RedisModule_ConfigSetBool` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configsetbool "Copy link to clipboard"/index.html)

int RedisModule_ConfigSetBool(RedisModuleCtx *ctx, const char *name, int value, RedisModuleString **err);

**Available since:** 8.2.0

Set the value of a bool config.

See [`RedisModule_ConfigSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSet/index.html) for return value.

### `RedisModule_ConfigSetEnum` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configsetenum "Copy link to clipboard"/index.html)

int RedisModule_ConfigSetEnum(RedisModuleCtx *ctx, const char *name, RedisModuleString *value, RedisModuleString **err);

**Available since:** 8.2.0

Set the value of an enum config.

If the config is multi-argument the value parameter must be a space-separated
string.

See [`RedisModule_ConfigSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSet/index.html) for return value.

### `RedisModule_ConfigSetNumeric` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_configsetnumeric "Copy link to clipboard"/index.html)

int RedisModule_ConfigSetNumeric(RedisModuleCtx *ctx, const char *name, long long value, RedisModuleString **err);

**Available since:** 8.2.0

Set the value of a numeric config.
If the value passed is meant to be a percentage, it should be passed as a
negative value.
For unsigned configs pass the value and cast to (long long) - internal type
checks will handle it.

See [`RedisModule_ConfigSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSet/index.html) for return value.

## Key eviction API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#key-eviction-api "Copy link to clipboard"/index.html)

### `RedisModule_SetLRU` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_setlru "Copy link to clipboard"/index.html)

int RedisModule_SetLRU(RedisModuleKey *key, mstime_t lru_idle);

**Available since:** 6.0.0

Set the key last access time for LRU based eviction. not relevant if the
servers's maxmemory policy is LFU based. Value is idle time in milliseconds.
returns `REDISMODULE_OK` if the LRU was updated, `REDISMODULE_ERR` otherwise.

### `RedisModule_GetLRU` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getlru "Copy link to clipboard"/index.html)

int RedisModule_GetLRU(RedisModuleKey *key, mstime_t *lru_idle);

**Available since:** 6.0.0

Gets the key last access time.
Value is idletime in milliseconds or -1 if the server's eviction policy is
LFU based.
returns `REDISMODULE_OK` if when key is valid.

### `RedisModule_SetLFU` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_setlfu "Copy link to clipboard"/index.html)

int RedisModule_SetLFU(RedisModuleKey *key, long long lfu_freq);

**Available since:** 6.0.0

Set the key access frequency. only relevant if the server's maxmemory policy
is LFU based.
The frequency is a logarithmic counter that provides an indication of
the access frequencyonly (must be <= 255).
returns `REDISMODULE_OK` if the LFU was updated, `REDISMODULE_ERR` otherwise.

### `RedisModule_GetLFU` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getlfu "Copy link to clipboard"/index.html)

int RedisModule_GetLFU(RedisModuleKey *key, long long *lfu_freq);

**Available since:** 6.0.0

Gets the key access frequency or -1 if the server's eviction policy is not
LFU based.
returns `REDISMODULE_OK` if when key is valid.

## Miscellaneous APIs  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#miscellaneous-apis "Copy link to clipboard"/index.html)

### `RedisModule_GetModuleOptionsAll` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getmoduleoptionsall "Copy link to clipboard"/index.html)

int RedisModule_GetModuleOptionsAll(void);

**Available since:** 7.2.0

Returns the full module options flags mask, using the return value
the module can check if a certain set of module options are supported
by the redis server version in use.
Example:

int supportedFlags = RedisModule_GetModuleOptionsAll(); if (supportedFlags & REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS) { // REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS is supported } else{ // REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS is not supported }

### `RedisModule_GetContextFlagsAll` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getcontextflagsall "Copy link to clipboard"/index.html)

int RedisModule_GetContextFlagsAll(void);

**Available since:** 6.0.9

Returns the full ContextFlags mask, using the return value
the module can check if a certain set of flags are supported
by the redis server version in use.
Example:

int supportedFlags = RedisModule_GetContextFlagsAll(); if (supportedFlags & REDISMODULE_CTX_FLAGS_MULTI) { // REDISMODULE_CTX_FLAGS_MULTI is supported } else{ // REDISMODULE_CTX_FLAGS_MULTI is not supported }

### `RedisModule_GetKeyspaceNotificationFlagsAll` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getkeyspacenotificationflagsall "Copy link to clipboard"/index.html)

int RedisModule_GetKeyspaceNotificationFlagsAll(void);

**Available since:** 6.0.9

Returns the full KeyspaceNotification mask, using the return value
the module can check if a certain set of flags are supported
by the redis server version in use.
Example:

int supportedFlags = RedisModule_GetKeyspaceNotificationFlagsAll(); if (supportedFlags & REDISMODULE_NOTIFY_LOADED) { // REDISMODULE_NOTIFY_LOADED is supported } else{ // REDISMODULE_NOTIFY_LOADED is not supported }

### `RedisModule_GetServerVersion` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getserverversion "Copy link to clipboard"/index.html)

int RedisModule_GetServerVersion(void);

**Available since:** 6.0.9

Return the redis version in format of 0x00MMmmpp.
Example for 6.0.7 the return value will be 0x00060007.

### `RedisModule_GetTypeMethodVersion` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_gettypemethodversion "Copy link to clipboard"/index.html)

int RedisModule_GetTypeMethodVersion(void);

**Available since:** 6.2.0

Return the current redis-server runtime value of `REDISMODULE_TYPE_METHOD_VERSION`.
You can use that when calling [`RedisModule_CreateDataType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateDataType/index.html) to know which fields of
`RedisModuleTypeMethods` are gonna be supported and which will be ignored.

### `RedisModule_ModuleTypeReplaceValue` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_moduletypereplacevalue "Copy link to clipboard"/index.html)

int RedisModule_ModuleTypeReplaceValue(RedisModuleKey *key, moduleType *mt, void *new_value, void **old_value);

**Available since:** 6.0.0

Replace the value assigned to a module type.

The key must be open for writing, have an existing value, and have a moduleType
that matches the one specified by the caller.

Unlike [`RedisModule_ModuleTypeSetValue()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ModuleTypeSetValue/index.html) which will free the old value, this function
simply swaps the old value with the new value.

The function returns `REDISMODULE_OK` on success, `REDISMODULE_ERR` on errors
such as:

1. Key is not opened for writing.
2. Key is not a module data type key.
3. Key is a module datatype other than 'mt'.

If `old_value` is non-NULL, the old value is returned by reference.

### `RedisModule_GetCommandKeysWithFlags` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getcommandkeyswithflags "Copy link to clipboard"/index.html)

int *RedisModule_GetCommandKeysWithFlags(RedisModuleCtx *ctx, RedisModuleString **argv, int argc, int *num_keys, int **out_flags);

**Available since:** 7.0.0

For a specified command, parse its arguments and return an array that
contains the indexes of all key name arguments. This function is
essentially a more efficient way to do `COMMAND GETKEYS`.

The `out_flags` argument is optional, and can be set to NULL.
When provided it is filled with `REDISMODULE_CMD_KEY_` flags in matching
indexes with the key indexes of the returned array.

A NULL return value indicates the specified command has no keys, or
an error condition. Error conditions are indicated by setting errno
as follows:

- ENOENT: Specified command does not exist.
- EINVAL: Invalid command arity specified.

NOTE: The returned array is not a Redis Module object so it does not
get automatically freed even when auto-memory is used. The caller
must explicitly call [`RedisModule_Free()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Free/index.html) to free it, same as the `out_flags` pointer if
used.

### `RedisModule_GetCommandKeys` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getcommandkeys "Copy link to clipboard"/index.html)

int *RedisModule_GetCommandKeys(RedisModuleCtx *ctx, RedisModuleString **argv, int argc, int *num_keys);

**Available since:** 6.0.9

Identical to [`RedisModule_GetCommandKeysWithFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCommandKeysWithFlags/index.html) when flags are not needed.

### `RedisModule_GetCurrentCommandName` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getcurrentcommandname "Copy link to clipboard"/index.html)

const char *RedisModule_GetCurrentCommandName(RedisModuleCtx *ctx);

**Available since:** 6.2.5

Return the name of the command currently running

## Defrag API  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#defrag-api "Copy link to clipboard"/index.html)

### `RedisModule_RegisterDefragFunc` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerdefragfunc "Copy link to clipboard"/index.html)

int RedisModule_RegisterDefragFunc(RedisModuleCtx *ctx, RedisModuleDefragFunc cb);

**Available since:** 6.2.0

Register a defrag callback for global data, i.e. anything that the module
may allocate that is not tied to a specific data type.

### `RedisModule_RegisterDefragFunc2` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerdefragfunc2 "Copy link to clipboard"/index.html)

int RedisModule_RegisterDefragFunc2(RedisModuleCtx *ctx, RedisModuleDefragFunc2 cb);

**Available since:** 8.0.0

Register a defrag callback for global data, i.e. anything that the module
may allocate that is not tied to a specific data type.
This is a more advanced version of [`RedisModule_RegisterDefragFunc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterDefragFunc/index.html), in that it takes
a callbacks that has a return value, and can use [`RedisModule_DefragShouldStop`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragShouldStop/index.html)
in and indicate that it should be called again later, or is it done (returned 0).

### `RedisModule_RegisterDefragCallbacks` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_registerdefragcallbacks "Copy link to clipboard"/index.html)

int RedisModule_RegisterDefragCallbacks(RedisModuleCtx *ctx, RedisModuleDefragFunc start, RedisModuleDefragFunc end);

**Available since:** 8.0.0

Register a defrag callbacks that will be called when defrag operation starts and ends.

The callbacks are the same as [`RedisModule_RegisterDefragFunc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterDefragFunc/index.html) but the user
can also assume the callbacks are called when the defrag operation starts and ends.

### `RedisModule_DefragShouldStop` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragshouldstop "Copy link to clipboard"/index.html)

int RedisModule_DefragShouldStop(RedisModuleDefragCtx *ctx);

**Available since:** 6.2.0

When the data type defrag callback iterates complex structures, this
function should be called periodically. A zero (false) return
indicates the callback may continue its work. A non-zero value (true)
indicates it should stop.

When stopped, the callback may use [`RedisModule_DefragCursorSet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorSet/index.html) to store its
position so it can later use [`RedisModule_DefragCursorGet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorGet/index.html) to resume defragging.

When stopped and more work is left to be done, the callback should
return 1. Otherwise, it should return 0.

### `RedisModule_DefragCursorSet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragcursorset "Copy link to clipboard"/index.html)

int RedisModule_DefragCursorSet(RedisModuleDefragCtx *ctx, unsigned long cursor);

**Available since:** 6.2.0

Store an arbitrary cursor value for future re-use.

This should only be called if [`RedisModule_DefragShouldStop()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragShouldStop/index.html) has returned a non-zero
value and the defrag callback is about to exit without fully iterating its
data type.

This behavior is reserved to cases where late defrag is performed. Late
defrag is selected for keys that implement the `free_effort` callback and
return a `free_effort` value that is larger than the defrag
'active-defrag-max-scan-fields' configuration directive.

Smaller keys, keys that do not implement `free_effort` or the global
defrag callback are not called in late-defrag mode. In those cases, a
call to this function will return `REDISMODULE_ERR`.

The cursor may be used by the module to represent some progress into the
module's data type. Modules may also store additional cursor-related
information locally and use the cursor as a flag that indicates when
traversal of a new key begins. This is possible because the API makes
a guarantee that concurrent defragmentation of multiple keys will
not be performed.

### `RedisModule_DefragCursorGet` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragcursorget "Copy link to clipboard"/index.html)

int RedisModule_DefragCursorGet(RedisModuleDefragCtx *ctx, unsigned long *cursor);

**Available since:** 6.2.0

Fetch a cursor value that has been previously stored using [`RedisModule_DefragCursorSet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorSet/index.html).

If not called for a late defrag operation, `REDISMODULE_ERR` will be returned and
the cursor should be ignored. See [`RedisModule_DefragCursorSet()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorSet/index.html) for more details on
defrag cursors.

### `RedisModule_DefragAlloc` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragalloc "Copy link to clipboard"/index.html)

void *RedisModule_DefragAlloc(RedisModuleDefragCtx *ctx, void *ptr);

**Available since:** 6.2.0

Defrag a memory allocation previously allocated by [`RedisModule_Alloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Alloc/index.html), [`RedisModule_Calloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Calloc/index.html), etc.
The defragmentation process involves allocating a new memory block and copying
the contents to it, like `realloc()`.

If defragmentation was not necessary, NULL is returned and the operation has
no other effect.

If a non-NULL value is returned, the caller should use the new pointer instead
of the old one and update any reference to the old pointer, which must not
be used again.

### `RedisModule_DefragAllocRaw` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragallocraw "Copy link to clipboard"/index.html)

void *RedisModule_DefragAllocRaw(RedisModuleDefragCtx *ctx, size_t size);

**Available since:** 8.0.0

Allocate memory for defrag purposes

On the common cases user simply want to reallocate a pointer with a single
owner. For such usecase [`RedisModule_DefragAlloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragAlloc/index.html) is enough. But on some usecases the user
might want to replace a pointer with multiple owners in different keys.
In such case, an in place replacement can not work because the other key still
keep a pointer to the old value.

[`RedisModule_DefragAllocRaw`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragAllocRaw/index.html) and [`RedisModule_DefragFreeRaw`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragFreeRaw/index.html) allows to control when the memory
for defrag purposes will be allocated and when it will be freed,
allow to support more complex defrag usecases.

### `RedisModule_DefragFreeRaw` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragfreeraw "Copy link to clipboard"/index.html)

void RedisModule_DefragFreeRaw(RedisModuleDefragCtx *ctx, void *ptr);

**Available since:** 8.0.0

Free memory for defrag purposes

See [`RedisModule_DefragAllocRaw`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragAllocRaw/index.html) for more information.

### `RedisModule_DefragRedisModuleString` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragredismodulestring "Copy link to clipboard"/index.html)

RedisModuleString *RedisModule_DefragRedisModuleString(RedisModuleDefragCtx *ctx, RedisModuleString *str);

**Available since:** 6.2.0

Defrag a `RedisModuleString` previously allocated by [`RedisModule_Alloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Alloc/index.html), [`RedisModule_Calloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Calloc/index.html), etc.
See [`RedisModule_DefragAlloc()`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragAlloc/index.html) for more information on how the defragmentation process
works.

NOTE: It is only possible to defrag strings that have a single reference.
Typically this means strings retained with [`RedisModule_RetainString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RetainString/index.html) or [`RedisModule_HoldString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_HoldString/index.html)
may not be defragmentable. One exception is command argvs which, if retained
by the module, will end up with a single reference (because the reference
on the Redis side is dropped as soon as the command callback returns).

### `RedisModule_DefragRedisModuleDict` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_defragredismoduledict "Copy link to clipboard"/index.html)

RedisModuleDict *RedisModule_DefragRedisModuleDict(RedisModuleDefragCtx *ctx, RedisModuleDict *dict, RedisModuleDefragDictValueCallback valueCB, RedisModuleString **seekTo);

**Available since:** 8.0.0

Defragment a Redis Module Dictionary by scanning its contents and calling a value
callback for each value.

The callback gets the current value in the dict, and should update newptr to the new pointer,
if the value was re-allocated to a different address. The callback also gets the key name just as a reference.
The callback returns 0 when defrag is complete for this node, 1 when node needs more work.

The API can work incrementally by accepting a seek position to continue from, and
returning the next position to seek to on the next call (or return NULL when the iteration is completed).

This API returns a new dict if it was re-allocated to a new address (will only
be attempted when \*seekTo is NULL on entry).

### `RedisModule_GetKeyNameFromDefragCtx` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getkeynamefromdefragctx "Copy link to clipboard"/index.html)

const RedisModuleString *RedisModule_GetKeyNameFromDefragCtx(RedisModuleDefragCtx *ctx);

**Available since:** 7.0.0

Returns the name of the key currently being processed.
There is no guarantee that the key name is always available, so this may return NULL.

### `RedisModule_GetDbIdFromDefragCtx` [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#redismodule_getdbidfromdefragctx "Copy link to clipboard"/index.html)

int RedisModule_GetDbIdFromDefragCtx(RedisModuleDefragCtx *ctx);

**Available since:** 7.0.0

Returns the database id of the key currently being processed.
There is no guarantee that this info is always available, so this may return -1.

## Function index  [Copy link to clipboard](/content/docs/latest/develop/reference/modules/modules-api-ref/\#function-index "Copy link to clipboard"/index.html)

- [`RedisModule_ACLAddLogEntry`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ACLAddLogEntry/index.html)
- [`RedisModule_ACLAddLogEntryByUserName`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ACLAddLogEntryByUserName/index.html)
- [`RedisModule_ACLCheckChannelPermissions`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ACLCheckChannelPermissions/index.html)
- [`RedisModule_ACLCheckCommandPermissions`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ACLCheckCommandPermissions/index.html)
- [`RedisModule_ACLCheckKeyPermissions`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ACLCheckKeyPermissions/index.html)
- [`RedisModule_ACLCheckKeyPrefixPermissions`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ACLCheckKeyPrefixPermissions/index.html)
- [`RedisModule_AbortBlock`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AbortBlock/index.html)
- [`RedisModule_AddACLCategory`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AddACLCategory/index.html)
- [`RedisModule_AddPostNotificationJob`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AddPostNotificationJob/index.html)
- [`RedisModule_Alloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Alloc/index.html)
- [`RedisModule_AuthenticateClientWithACLUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AuthenticateClientWithACLUser/index.html)
- [`RedisModule_AuthenticateClientWithUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AuthenticateClientWithUser/index.html)
- [`RedisModule_AutoMemory`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AutoMemory/index.html)
- [`RedisModule_AvoidReplicaTraffic`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_AvoidReplicaTraffic/index.html)
- [`RedisModule_BlockClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClient/index.html)
- [`RedisModule_BlockClientGetPrivateData`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientGetPrivateData/index.html)
- [`RedisModule_BlockClientOnAuth`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnAuth/index.html)
- [`RedisModule_BlockClientOnKeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeys/index.html)
- [`RedisModule_BlockClientOnKeysWithFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientOnKeysWithFlags/index.html)
- [`RedisModule_BlockClientSetPrivateData`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockClientSetPrivateData/index.html)
- [`RedisModule_BlockedClientDisconnected`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockedClientDisconnected/index.html)
- [`RedisModule_BlockedClientMeasureTimeEnd`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockedClientMeasureTimeEnd/index.html)
- [`RedisModule_BlockedClientMeasureTimeStart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_BlockedClientMeasureTimeStart/index.html)
- [`RedisModule_CachedMicroseconds`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CachedMicroseconds/index.html)
- [`RedisModule_Call`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Call/index.html)
- [`RedisModule_CallReplyArrayElement`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyArrayElement/index.html)
- [`RedisModule_CallReplyAttribute`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyAttribute/index.html)
- [`RedisModule_CallReplyAttributeElement`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyAttributeElement/index.html)
- [`RedisModule_CallReplyBigNumber`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyBigNumber/index.html)
- [`RedisModule_CallReplyBool`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyBool/index.html)
- [`RedisModule_CallReplyDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyDouble/index.html)
- [`RedisModule_CallReplyInteger`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyInteger/index.html)
- [`RedisModule_CallReplyLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyLength/index.html)
- [`RedisModule_CallReplyMapElement`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyMapElement/index.html)
- [`RedisModule_CallReplyPromiseAbort`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyPromiseAbort/index.html)
- [`RedisModule_CallReplyPromiseSetUnblockHandler`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyPromiseSetUnblockHandler/index.html)
- [`RedisModule_CallReplyProto`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyProto/index.html)
- [`RedisModule_CallReplySetElement`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplySetElement/index.html)
- [`RedisModule_CallReplyStringPtr`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyStringPtr/index.html)
- [`RedisModule_CallReplyType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyType/index.html)
- [`RedisModule_CallReplyVerbatim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CallReplyVerbatim/index.html)
- [`RedisModule_Calloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Calloc/index.html)
- [`RedisModule_ChannelAtPosWithFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ChannelAtPosWithFlags/index.html)
- [`RedisModule_CloseKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CloseKey/index.html)
- [`RedisModule_ClusterCanAccessKeysInSlot`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterCanAccessKeysInSlot/index.html)
- [`RedisModule_ClusterCanonicalKeyNameInSlot`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterCanonicalKeyNameInSlot/index.html)
- [`RedisModule_ClusterDisableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterDisableTrim/index.html)
- [`RedisModule_ClusterEnableTrim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterEnableTrim/index.html)
- [`RedisModule_ClusterFreeSlotRanges`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterFreeSlotRanges/index.html)
- [`RedisModule_ClusterGetLocalSlotRanges`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterGetLocalSlotRanges/index.html)
- [`RedisModule_ClusterKeySlot`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterKeySlot/index.html)
- [`RedisModule_ClusterKeySlotC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterKeySlotC/index.html)
- [`RedisModule_ClusterPropagateForSlotMigration`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ClusterPropagateForSlotMigration/index.html)
- [`RedisModule_CommandFilterArgDelete`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CommandFilterArgDelete/index.html)
- [`RedisModule_CommandFilterArgGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CommandFilterArgGet/index.html)
- [`RedisModule_CommandFilterArgInsert`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CommandFilterArgInsert/index.html)
- [`RedisModule_CommandFilterArgReplace`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CommandFilterArgReplace/index.html)
- [`RedisModule_CommandFilterArgsCount`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CommandFilterArgsCount/index.html)
- [`RedisModule_CommandFilterGetClientId`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CommandFilterGetClientId/index.html)
- [`RedisModule_ConfigGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigGet/index.html)
- [`RedisModule_ConfigGetBool`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigGetBool/index.html)
- [`RedisModule_ConfigGetEnum`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigGetEnum/index.html)
- [`RedisModule_ConfigGetNumeric`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigGetNumeric/index.html)
- [`RedisModule_ConfigGetType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigGetType/index.html)
- [`RedisModule_ConfigIteratorCreate`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorCreate/index.html)
- [`RedisModule_ConfigIteratorNext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorNext/index.html)
- [`RedisModule_ConfigIteratorRelease`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigIteratorRelease/index.html)
- [`RedisModule_ConfigSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSet/index.html)
- [`RedisModule_ConfigSetBool`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSetBool/index.html)
- [`RedisModule_ConfigSetEnum`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSetEnum/index.html)
- [`RedisModule_ConfigSetNumeric`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ConfigSetNumeric/index.html)
- [`RedisModule_CreateCommand`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateCommand/index.html)
- [`RedisModule_CreateDataType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateDataType/index.html)
- [`RedisModule_CreateDict`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateDict/index.html)
- [`RedisModule_CreateKeyMetaClass`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateKeyMetaClass/index.html)
- [`RedisModule_CreateModuleUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateModuleUser/index.html)
- [`RedisModule_CreateString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateString/index.html)
- [`RedisModule_CreateStringFromCallReply`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromCallReply/index.html)
- [`RedisModule_CreateStringFromDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromDouble/index.html)
- [`RedisModule_CreateStringFromLongDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromLongDouble/index.html)
- [`RedisModule_CreateStringFromLongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromLongLong/index.html)
- [`RedisModule_CreateStringFromStreamID`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromStreamID/index.html)
- [`RedisModule_CreateStringFromString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromString/index.html)
- [`RedisModule_CreateStringFromULongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringFromULongLong/index.html)
- [`RedisModule_CreateStringPrintf`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateStringPrintf/index.html)
- [`RedisModule_CreateSubcommand`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateSubcommand/index.html)
- [`RedisModule_CreateTimer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_CreateTimer/index.html)
- [`RedisModule_DbSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DbSize/index.html)
- [`RedisModule_DeauthenticateAndCloseClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DeauthenticateAndCloseClient/index.html)
- [`RedisModule_DefragAlloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragAlloc/index.html)
- [`RedisModule_DefragAllocRaw`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragAllocRaw/index.html)
- [`RedisModule_DefragCursorGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorGet/index.html)
- [`RedisModule_DefragCursorSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragCursorSet/index.html)
- [`RedisModule_DefragFreeRaw`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragFreeRaw/index.html)
- [`RedisModule_DefragRedisModuleDict`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragRedisModuleDict/index.html)
- [`RedisModule_DefragRedisModuleString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragRedisModuleString/index.html)
- [`RedisModule_DefragShouldStop`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DefragShouldStop/index.html)
- [`RedisModule_DeleteKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DeleteKey/index.html)
- [`RedisModule_DictCompare`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictCompare/index.html)
- [`RedisModule_DictCompareC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictCompareC/index.html)
- [`RedisModule_DictDel`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictDel/index.html)
- [`RedisModule_DictDelC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictDelC/index.html)
- [`RedisModule_DictGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictGet/index.html)
- [`RedisModule_DictGetC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictGetC/index.html)
- [`RedisModule_DictIteratorReseek`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorReseek/index.html)
- [`RedisModule_DictIteratorReseekC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorReseekC/index.html)
- [`RedisModule_DictIteratorStart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStart/index.html)
- [`RedisModule_DictIteratorStartC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStartC/index.html)
- [`RedisModule_DictIteratorStop`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictIteratorStop/index.html)
- [`RedisModule_DictNext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictNext/index.html)
- [`RedisModule_DictNextC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictNextC/index.html)
- [`RedisModule_DictPrev`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictPrev/index.html)
- [`RedisModule_DictPrevC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictPrevC/index.html)
- [`RedisModule_DictReplace`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictReplace/index.html)
- [`RedisModule_DictReplaceC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictReplaceC/index.html)
- [`RedisModule_DictSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictSet/index.html)
- [`RedisModule_DictSetC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictSetC/index.html)
- [`RedisModule_DictSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DictSize/index.html)
- [`RedisModule_DigestAddLongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DigestAddLongLong/index.html)
- [`RedisModule_DigestAddStringBuffer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DigestAddStringBuffer/index.html)
- [`RedisModule_DigestEndSequence`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_DigestEndSequence/index.html)
- [`RedisModule_EmitAOF`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_EmitAOF/index.html)
- [`RedisModule_EventLoopAdd`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_EventLoopAdd/index.html)
- [`RedisModule_EventLoopAddOneShot`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_EventLoopAddOneShot/index.html)
- [`RedisModule_EventLoopDel`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_EventLoopDel/index.html)
- [`RedisModule_ExitFromChild`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ExitFromChild/index.html)
- [`RedisModule_ExportSharedAPI`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ExportSharedAPI/index.html)
- [`RedisModule_Fork`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Fork/index.html)
- [`RedisModule_Free`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Free/index.html)
- [`RedisModule_FreeCallReply`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeCallReply/index.html)
- [`RedisModule_FreeClusterNodesList`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeClusterNodesList/index.html)
- [`RedisModule_FreeDict`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeDict/index.html)
- [`RedisModule_FreeModuleUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeModuleUser/index.html)
- [`RedisModule_FreeServerInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeServerInfo/index.html)
- [`RedisModule_FreeString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeString/index.html)
- [`RedisModule_FreeThreadSafeContext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_FreeThreadSafeContext/index.html)
- [`RedisModule_GetAbsExpire`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetAbsExpire/index.html)
- [`RedisModule_GetBlockedClientHandle`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetBlockedClientHandle/index.html)
- [`RedisModule_GetBlockedClientPrivateData`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetBlockedClientPrivateData/index.html)
- [`RedisModule_GetBlockedClientReadyKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetBlockedClientReadyKey/index.html)
- [`RedisModule_GetClientCertificate`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClientCertificate/index.html)
- [`RedisModule_GetClientId`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClientId/index.html)
- [`RedisModule_GetClientInfoById`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClientInfoById/index.html)
- [`RedisModule_GetClientNameById`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClientNameById/index.html)
- [`RedisModule_GetClientUserNameById`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClientUserNameById/index.html)
- [`RedisModule_GetClusterNodeInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClusterNodeInfo/index.html)
- [`RedisModule_GetClusterNodesList`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClusterNodesList/index.html)
- [`RedisModule_GetClusterSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetClusterSize/index.html)
- [`RedisModule_GetCommand`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCommand/index.html)
- [`RedisModule_GetCommandKeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCommandKeys/index.html)
- [`RedisModule_GetCommandKeysWithFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCommandKeysWithFlags/index.html)
- [`RedisModule_GetContextFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetContextFlags/index.html)
- [`RedisModule_GetContextFlagsAll`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetContextFlagsAll/index.html)
- [`RedisModule_GetContextUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetContextUser/index.html)
- [`RedisModule_GetCurrentCommandName`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCurrentCommandName/index.html)
- [`RedisModule_GetCurrentUserName`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetCurrentUserName/index.html)
- [`RedisModule_GetDbIdFromDefragCtx`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDbIdFromDefragCtx/index.html)
- [`RedisModule_GetDbIdFromDigest`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDbIdFromDigest/index.html)
- [`RedisModule_GetDbIdFromIO`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDbIdFromIO/index.html)
- [`RedisModule_GetDbIdFromModuleKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDbIdFromModuleKey/index.html)
- [`RedisModule_GetDbIdFromOptCtx`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDbIdFromOptCtx/index.html)
- [`RedisModule_GetDetachedThreadSafeContext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetDetachedThreadSafeContext/index.html)
- [`RedisModule_GetExpire`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetExpire/index.html)
- [`RedisModule_GetInternalSecret`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetInternalSecret/index.html)
- [`RedisModule_GetKeyMeta`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyMeta/index.html)
- [`RedisModule_GetKeyNameFromDefragCtx`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyNameFromDefragCtx/index.html)
- [`RedisModule_GetKeyNameFromDigest`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyNameFromDigest/index.html)
- [`RedisModule_GetKeyNameFromIO`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyNameFromIO/index.html)
- [`RedisModule_GetKeyNameFromModuleKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyNameFromModuleKey/index.html)
- [`RedisModule_GetKeyNameFromOptCtx`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyNameFromOptCtx/index.html)
- [`RedisModule_GetKeyspaceNotificationFlagsAll`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetKeyspaceNotificationFlagsAll/index.html)
- [`RedisModule_GetLFU`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetLFU/index.html)
- [`RedisModule_GetLRU`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetLRU/index.html)
- [`RedisModule_GetModuleOptionsAll`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetModuleOptionsAll/index.html)
- [`RedisModule_GetModuleUserACLString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetModuleUserACLString/index.html)
- [`RedisModule_GetModuleUserFromUserName`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetModuleUserFromUserName/index.html)
- [`RedisModule_GetMyClusterID`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetMyClusterID/index.html)
- [`RedisModule_GetNotifyKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetNotifyKeyspaceEvents/index.html)
- [`RedisModule_GetOpenKeyModesAll`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetOpenKeyModesAll/index.html)
- [`RedisModule_GetRandomBytes`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetRandomBytes/index.html)
- [`RedisModule_GetRandomHexChars`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetRandomHexChars/index.html)
- [`RedisModule_GetSelectedDb`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetSelectedDb/index.html)
- [`RedisModule_GetServerInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetServerInfo/index.html)
- [`RedisModule_GetServerVersion`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetServerVersion/index.html)
- [`RedisModule_GetSharedAPI`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetSharedAPI/index.html)
- [`RedisModule_GetThreadSafeContext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetThreadSafeContext/index.html)
- [`RedisModule_GetTimerInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetTimerInfo/index.html)
- [`RedisModule_GetToDbIdFromOptCtx`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetToDbIdFromOptCtx/index.html)
- [`RedisModule_GetToKeyNameFromOptCtx`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetToKeyNameFromOptCtx/index.html)
- [`RedisModule_GetTypeMethodVersion`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetTypeMethodVersion/index.html)
- [`RedisModule_GetUsedMemoryRatio`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_GetUsedMemoryRatio/index.html)
- [`RedisModule_HashFieldMinExpire`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_HashFieldMinExpire/index.html)
- [`RedisModule_HashGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_HashGet/index.html)
- [`RedisModule_HashSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_HashSet/index.html)
- [`RedisModule_HoldString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_HoldString/index.html)
- [`RedisModule_InfoAddFieldCString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldCString/index.html)
- [`RedisModule_InfoAddFieldDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldDouble/index.html)
- [`RedisModule_InfoAddFieldLongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldLongLong/index.html)
- [`RedisModule_InfoAddFieldString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldString/index.html)
- [`RedisModule_InfoAddFieldULongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddFieldULongLong/index.html)
- [`RedisModule_InfoAddSection`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoAddSection/index.html)
- [`RedisModule_InfoBeginDictField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoBeginDictField/index.html)
- [`RedisModule_InfoEndDictField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_InfoEndDictField/index.html)
- [`RedisModule_IsBlockedReplyRequest`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsBlockedReplyRequest/index.html)
- [`RedisModule_IsBlockedTimeoutRequest`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsBlockedTimeoutRequest/index.html)
- [`RedisModule_IsChannelsPositionRequest`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsChannelsPositionRequest/index.html)
- [`RedisModule_IsIOError`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsIOError/index.html)
- [`RedisModule_IsKeysPositionRequest`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsKeysPositionRequest/index.html)
- [`RedisModule_IsModuleNameBusy`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsModuleNameBusy/index.html)
- [`RedisModule_IsSubEventSupported`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_IsSubEventSupported/index.html)
- [`RedisModule_KeyAtPos`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KeyAtPos/index.html)
- [`RedisModule_KeyAtPosWithFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KeyAtPosWithFlags/index.html)
- [`RedisModule_KeyExists`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KeyExists/index.html)
- [`RedisModule_KeyType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KeyType/index.html)
- [`RedisModule_KillForkChild`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_KillForkChild/index.html)
- [`RedisModule_LatencyAddSample`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LatencyAddSample/index.html)
- [`RedisModule_ListDelete`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ListDelete/index.html)
- [`RedisModule_ListGet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ListGet/index.html)
- [`RedisModule_ListInsert`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ListInsert/index.html)
- [`RedisModule_ListPop`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ListPop/index.html)
- [`RedisModule_ListPush`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ListPush/index.html)
- [`RedisModule_ListSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ListSet/index.html)
- [`RedisModule_LoadConfigs`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadConfigs/index.html)
- [`RedisModule_LoadDataTypeFromString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadDataTypeFromString/index.html)
- [`RedisModule_LoadDataTypeFromStringEncver`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadDataTypeFromStringEncver/index.html)
- [`RedisModule_LoadDefaultConfigs`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadDefaultConfigs/index.html)
- [`RedisModule_LoadDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadDouble/index.html)
- [`RedisModule_LoadFloat`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadFloat/index.html)
- [`RedisModule_LoadLongDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadLongDouble/index.html)
- [`RedisModule_LoadSigned`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadSigned/index.html)
- [`RedisModule_LoadString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadString/index.html)
- [`RedisModule_LoadStringBuffer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadStringBuffer/index.html)
- [`RedisModule_LoadUnsigned`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LoadUnsigned/index.html)
- [`RedisModule_Log`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Log/index.html)
- [`RedisModule_LogIOError`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_LogIOError/index.html)
- [`RedisModule_MallocSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocSize/index.html)
- [`RedisModule_MallocSizeDict`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocSizeDict/index.html)
- [`RedisModule_MallocSizeString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocSizeString/index.html)
- [`RedisModule_MallocUsableSize`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MallocUsableSize/index.html)
- [`RedisModule_Microseconds`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Microseconds/index.html)
- [`RedisModule_Milliseconds`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Milliseconds/index.html)
- [`RedisModule_ModuleTypeGetType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ModuleTypeGetType/index.html)
- [`RedisModule_ModuleTypeGetValue`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ModuleTypeGetValue/index.html)
- [`RedisModule_ModuleTypeReplaceValue`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ModuleTypeReplaceValue/index.html)
- [`RedisModule_ModuleTypeSetValue`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ModuleTypeSetValue/index.html)
- [`RedisModule_MonotonicMicroseconds`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_MonotonicMicroseconds/index.html)
- [`RedisModule_NotifyKeyspaceEvent`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_NotifyKeyspaceEvent/index.html)
- [`RedisModule_NotifyKeyspaceEventWithSubkeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_NotifyKeyspaceEventWithSubkeys/index.html)
- [`RedisModule_OpenKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_OpenKey/index.html)
- [`RedisModule_PoolAlloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_PoolAlloc/index.html)
- [`RedisModule_PublishMessage`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_PublishMessage/index.html)
- [`RedisModule_PublishMessageShard`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_PublishMessageShard/index.html)
- [`RedisModule_RandomKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RandomKey/index.html)
- [`RedisModule_RdbLoad`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RdbLoad/index.html)
- [`RedisModule_RdbSave`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RdbSave/index.html)
- [`RedisModule_RdbStreamCreateFromFile`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RdbStreamCreateFromFile/index.html)
- [`RedisModule_RdbStreamFree`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RdbStreamFree/index.html)
- [`RedisModule_Realloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Realloc/index.html)
- [`RedisModule_RedactClientCommandArgument`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RedactClientCommandArgument/index.html)
- [`RedisModule_RegisterAuthCallback`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterAuthCallback/index.html)
- [`RedisModule_RegisterBoolConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterBoolConfig/index.html)
- [`RedisModule_RegisterClusterMessageReceiver`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterClusterMessageReceiver/index.html)
- [`RedisModule_RegisterCommandFilter`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterCommandFilter/index.html)
- [`RedisModule_RegisterDefragCallbacks`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterDefragCallbacks/index.html)
- [`RedisModule_RegisterDefragFunc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterDefragFunc/index.html)
- [`RedisModule_RegisterDefragFunc2`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterDefragFunc2/index.html)
- [`RedisModule_RegisterEnumConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterEnumConfig/index.html)
- [`RedisModule_RegisterInfoFunc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterInfoFunc/index.html)
- [`RedisModule_RegisterNumericConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterNumericConfig/index.html)
- [`RedisModule_RegisterStringConfig`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RegisterStringConfig/index.html)
- [`RedisModule_ReleaseKeyMetaClass`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReleaseKeyMetaClass/index.html)
- [`RedisModule_Replicate`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Replicate/index.html)
- [`RedisModule_ReplicateVerbatim`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplicateVerbatim/index.html)
- [`RedisModule_ReplySetArrayLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplySetArrayLength/index.html)
- [`RedisModule_ReplySetAttributeLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplySetAttributeLength/index.html)
- [`RedisModule_ReplySetMapLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplySetMapLength/index.html)
- [`RedisModule_ReplySetSetLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplySetSetLength/index.html)
- [`RedisModule_ReplyWithArray`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithArray/index.html)
- [`RedisModule_ReplyWithAttribute`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithAttribute/index.html)
- [`RedisModule_ReplyWithBigNumber`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithBigNumber/index.html)
- [`RedisModule_ReplyWithBool`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithBool/index.html)
- [`RedisModule_ReplyWithCString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithCString/index.html)
- [`RedisModule_ReplyWithCallReply`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithCallReply/index.html)
- [`RedisModule_ReplyWithDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithDouble/index.html)
- [`RedisModule_ReplyWithEmptyArray`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithEmptyArray/index.html)
- [`RedisModule_ReplyWithEmptyString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithEmptyString/index.html)
- [`RedisModule_ReplyWithError`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithError/index.html)
- [`RedisModule_ReplyWithErrorFormat`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithErrorFormat/index.html)
- [`RedisModule_ReplyWithLongDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithLongDouble/index.html)
- [`RedisModule_ReplyWithLongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithLongLong/index.html)
- [`RedisModule_ReplyWithMap`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithMap/index.html)
- [`RedisModule_ReplyWithNull`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithNull/index.html)
- [`RedisModule_ReplyWithNullArray`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithNullArray/index.html)
- [`RedisModule_ReplyWithSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithSet/index.html)
- [`RedisModule_ReplyWithSimpleString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithSimpleString/index.html)
- [`RedisModule_ReplyWithString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithString/index.html)
- [`RedisModule_ReplyWithStringBuffer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithStringBuffer/index.html)
- [`RedisModule_ReplyWithVerbatimString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithVerbatimString/index.html)
- [`RedisModule_ReplyWithVerbatimStringType`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ReplyWithVerbatimStringType/index.html)
- [`RedisModule_ResetDataset`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ResetDataset/index.html)
- [`RedisModule_RetainString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_RetainString/index.html)
- [`RedisModule_SaveDataTypeToString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveDataTypeToString/index.html)
- [`RedisModule_SaveDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveDouble/index.html)
- [`RedisModule_SaveFloat`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveFloat/index.html)
- [`RedisModule_SaveLongDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveLongDouble/index.html)
- [`RedisModule_SaveSigned`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveSigned/index.html)
- [`RedisModule_SaveString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveString/index.html)
- [`RedisModule_SaveStringBuffer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveStringBuffer/index.html)
- [`RedisModule_SaveUnsigned`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SaveUnsigned/index.html)
- [`RedisModule_Scan`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Scan/index.html)
- [`RedisModule_ScanCursorCreate`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanCursorCreate/index.html)
- [`RedisModule_ScanCursorDestroy`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanCursorDestroy/index.html)
- [`RedisModule_ScanCursorRestart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanCursorRestart/index.html)
- [`RedisModule_ScanKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ScanKey/index.html)
- [`RedisModule_SelectDb`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SelectDb/index.html)
- [`RedisModule_SendChildHeartbeat`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SendChildHeartbeat/index.html)
- [`RedisModule_SendClusterMessage`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SendClusterMessage/index.html)
- [`RedisModule_ServerInfoGetField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetField/index.html)
- [`RedisModule_ServerInfoGetFieldC`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetFieldC/index.html)
- [`RedisModule_ServerInfoGetFieldDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetFieldDouble/index.html)
- [`RedisModule_ServerInfoGetFieldSigned`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetFieldSigned/index.html)
- [`RedisModule_ServerInfoGetFieldUnsigned`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ServerInfoGetFieldUnsigned/index.html)
- [`RedisModule_SetAbsExpire`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetAbsExpire/index.html)
- [`RedisModule_SetClientNameById`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetClientNameById/index.html)
- [`RedisModule_SetClusterFlags`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetClusterFlags/index.html)
- [`RedisModule_SetCommandACLCategories`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetCommandACLCategories/index.html)
- [`RedisModule_SetCommandInfo`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetCommandInfo/index.html)
- [`RedisModule_SetContextUser`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetContextUser/index.html)
- [`RedisModule_SetDisconnectCallback`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetDisconnectCallback/index.html)
- [`RedisModule_SetExpire`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetExpire/index.html)
- [`RedisModule_SetKeyMeta`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetKeyMeta/index.html)
- [`RedisModule_SetLFU`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetLFU/index.html)
- [`RedisModule_SetLRU`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetLRU/index.html)
- [`RedisModule_SetModuleOptions`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetModuleOptions/index.html)
- [`RedisModule_SetModuleUserACL`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetModuleUserACL/index.html)
- [`RedisModule_SetModuleUserACLString`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SetModuleUserACLString/index.html)
- [`RedisModule_SignalKeyAsReady`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SignalKeyAsReady/index.html)
- [`RedisModule_SignalModifiedKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SignalModifiedKey/index.html)
- [`RedisModule_StopTimer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StopTimer/index.html)
- [`RedisModule_Strdup`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Strdup/index.html)
- [`RedisModule_StreamAdd`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamAdd/index.html)
- [`RedisModule_StreamDelete`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamDelete/index.html)
- [`RedisModule_StreamIteratorDelete`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamIteratorDelete/index.html)
- [`RedisModule_StreamIteratorNextField`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamIteratorNextField/index.html)
- [`RedisModule_StreamIteratorNextID`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamIteratorNextID/index.html)
- [`RedisModule_StreamIteratorStart`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamIteratorStart/index.html)
- [`RedisModule_StreamIteratorStop`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamIteratorStop/index.html)
- [`RedisModule_StreamTrimByID`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamTrimByID/index.html)
- [`RedisModule_StreamTrimByLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StreamTrimByLength/index.html)
- [`RedisModule_StringAppendBuffer`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringAppendBuffer/index.html)
- [`RedisModule_StringCompare`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringCompare/index.html)
- [`RedisModule_StringDMA`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringDMA/index.html)
- [`RedisModule_StringPtrLen`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringPtrLen/index.html)
- [`RedisModule_StringSet`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringSet/index.html)
- [`RedisModule_StringToDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringToDouble/index.html)
- [`RedisModule_StringToLongDouble`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringToLongDouble/index.html)
- [`RedisModule_StringToLongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringToLongLong/index.html)
- [`RedisModule_StringToStreamID`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringToStreamID/index.html)
- [`RedisModule_StringToULongLong`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringToULongLong/index.html)
- [`RedisModule_StringTruncate`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_StringTruncate/index.html)
- [`RedisModule_SubscribeToKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEvents/index.html)
- [`RedisModule_SubscribeToKeyspaceEventsWithSubkeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToKeyspaceEventsWithSubkeys/index.html)
- [`RedisModule_SubscribeToServerEvent`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_SubscribeToServerEvent/index.html)
- [`RedisModule_ThreadSafeContextLock`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ThreadSafeContextLock/index.html)
- [`RedisModule_ThreadSafeContextTryLock`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ThreadSafeContextTryLock/index.html)
- [`RedisModule_ThreadSafeContextUnlock`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ThreadSafeContextUnlock/index.html)
- [`RedisModule_TrimStringAllocation`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_TrimStringAllocation/index.html)
- [`RedisModule_TryAlloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_TryAlloc/index.html)
- [`RedisModule_TryCalloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_TryCalloc/index.html)
- [`RedisModule_TryRealloc`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_TryRealloc/index.html)
- [`RedisModule_UnblockClient`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnblockClient/index.html)
- [`RedisModule_UnlinkKey`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnlinkKey/index.html)
- [`RedisModule_UnregisterCommandFilter`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnregisterCommandFilter/index.html)
- [`RedisModule_UnsubscribeFromKeyspaceEvents`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnsubscribeFromKeyspaceEvents/index.html)
- [`RedisModule_UnsubscribeFromKeyspaceEventsWithSubkeys`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_UnsubscribeFromKeyspaceEventsWithSubkeys/index.html)
- [`RedisModule_ValueLength`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ValueLength/index.html)
- [`RedisModule_WrongArity`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_WrongArity/index.html)
- [`RedisModule_Yield`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_Yield/index.html)
- [`RedisModule_ZsetAdd`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetAdd/index.html)
- [`RedisModule_ZsetFirstInLexRange`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetFirstInLexRange/index.html)
- [`RedisModule_ZsetFirstInScoreRange`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetFirstInScoreRange/index.html)
- [`RedisModule_ZsetIncrby`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetIncrby/index.html)
- [`RedisModule_ZsetLastInLexRange`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetLastInLexRange/index.html)
- [`RedisModule_ZsetLastInScoreRange`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetLastInScoreRange/index.html)
- [`RedisModule_ZsetRangeCurrentElement`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetRangeCurrentElement/index.html)
- [`RedisModule_ZsetRangeEndReached`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetRangeEndReached/index.html)
- [`RedisModule_ZsetRangeNext`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetRangeNext/index.html)
- [`RedisModule_ZsetRangePrev`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetRangePrev/index.html)
- [`RedisModule_ZsetRangeStop`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetRangeStop/index.html)
- [`RedisModule_ZsetRem`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetRem/index.html)
- [`RedisModule_ZsetScore`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule_ZsetScore/index.html)
- [`RedisModule__Assert`](/content/docs/latest/develop/reference/modules/modules-api-ref/#RedisModule__Assert/index.html)

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