Skip to main content
Redis functions act as a superset of Lua scripts. Instead of sending the script content with every request (like EVAL), you load the script once as a “library” and call the functions it registers.
Currently, LUA is the only supported engine.
The library source code must start with the #!lua name=<library_name> shebang. Inside the script, use redis.register_function to expose your functions. The registered functions can be called with the FCALL command.

​
Arguments

​
options
Object
required
The load options.

​
Response

The name of the loaded library.
const code = `#!lua name=mylib
  
  -- Simple function that returns a string
  redis.register_function(
    'helloworld',
    function() return 'Hello World!' end
  )

  -- Complex function that modifies data with logic
  local function my_hset(keys, args)
    local hash = keys[1]
    local time = redis.call('TIME')[1]
    return redis.call('HSET', hash, '_last_modified_', time, unpack(args))
  end

  redis.register_function('my_hset', my_hset)
`;

const libraryName = await redis.functions.load({ code, replace: true });

console.log(libraryName); // "mylib"