FCALL

FCALL runs a function registered by a library loaded with FUNCTION LOAD. Like a script, the function runs atomically. It receives the numkeys key names after numkeys as its first argument and the remaining arguments as its second. Function names are not case-sensitive.

Unlike scripts, function libraries are part of the dataset: they are saved with snapshots and the AOF, and are copied to replicas, so they survive a restart and do not need to be reloaded by clients. See Functions for the full guide.

The function’s flags (set with redis.register_function) decide where it may run, as for scripts: a function without no-writes is refused on a read-only replica, and one without allow-oom when the server is over maxmemory.

Return value

The function’s return value, converted as described for EVAL.

Errors:

• ERR Function not found when no loaded library registers that name.
• ERR Number of keys can't be greater than number of args and ERR Number of keys can't be negative for a bad numkeys.
• The BUSY, read-only and out-of-memory errors described for EVAL.

Examples

127.0.0.1:6379> FUNCTION LOAD "#!lua name=counters\nredis.register_function('bump', function(keys, args) return redis.call('INCRBY', keys[1], args[1]) end)"
"counters"
127.0.0.1:6379> FCALL bump 1 hits 10
(integer) 10
127.0.0.1:6379> FCALL BUMP 1 hits 5
(integer) 15
127.0.0.1:6379> FCALL nosuch 0
(error) ERR Function not found

Compatibility

Same as Redis 7 and Valkey 8.

See also

FCALL_RO, FUNCTION LOAD, FUNCTION LIST, EVAL