Company-lua is a company-mode completion backend for Lua.

We use api files from ZeroBrane Studio as source for the completion candidates. Right now only Lua 5.1, 5.2, 5.3 and LÖVE are supported.

Add company-lua to the load-path:

(add-to-list 'load-path "path/to/company-lua")

Add the following to your init.el:

(require 'company)
(require 'company-lua)

Since this backend only gives completion results for lua keywords it might be good to use company-lua in combination with other backends instead adding it to company-backends as single backend.

(defun my-lua-mode-company-init ()
  (setq-local company-backends '((company-lua
                                  company-etags
                                  company-dabbrev-code
                                  company-yasnippet))))
(add-hook 'lua-mode-hook #'my-lua-mode-company-init)

See documentation of company-backends.