Module 07 · Bonus

Convars: server.cfg config you can read from Lua

A convar (configuration variable) is a key/value pair you set in server.cfg or at runtime, then read from Lua. Convars are how you externalize the things that change per server: a debug flag, a database name, a starting balance, an owner ID. You tune them without editing Lua and without rebuilding the resource. The catch that trips up everyone is replication: the prefix you use to declare a convar decides whether a client can ever read it. Get that wrong and your client silently reads the default forever. This lesson makes the difference visible.

You'll learn: The three convar prefixes (set, setr, sets), exactly who can read each, the four read functions, and why a client can only see a setr value.
You'll ship: A debug toggle and a configurable starting balance for the banking script: both flippable from server.cfg with no code redeploy.
Time: ~15 minutes
Why now: You finished the banking lesson with a hard-coded starting balance. Convars let you tune that per server.

BEFORE YOU START

Build it

Make the resource folder

The server has one folder for this lesson.

Inside your server's resources folder, create this folder:

code

resources/qu_convars_server_cfg

Create the files

Every file named in the manifest exists.

Create this exact file layout:

code

resources/qu_convars_server_cfg/
fxmanifest.lua
server.lua
client.lua

Write fxmanifest.lua

FiveM knows which files to load.

Open fxmanifest.lua and paste this:

code

fx_version 'cerulean'
game 'gta5'

server_script 'server.lua'
client_script 'client.lua'

Older tutorials add a lua54 'yes' line here. As of June 2025 that setting is deprecated and ignored: Lua 5.4 is now the only Lua runtime, so you leave it out.

Declare the convars in server.cfg

The server has two config values it can read.

Open server.cfg and add these two lines above the line that ensures this resource. You will add the ensure line in Step 6.

code

set qu_convars_cash 750
setr qu_convars_debug true

The two prefixes are not interchangeable. set is server-only. setr is replicated, which means it is also sent to every client. You will see in a moment why the client half of this lesson reads the setr one and not the set one.

Write the lesson code

The topic is now represented by runnable code.

Open server.lua and paste this:

code

RegisterCommand('cashcfg', function()
local cash = GetConvarInt('qu_convars_cash', 500)
print('[qu_convars_server_cfg] server reads cash ' .. cash)
end, false)

Keep reading the full lesson

Still ahead in this lesson

How it works
If something went wrong
What you can do now
Try it yourself

Build it

Make the resource folder

Create the files

Write fxmanifest.lua

Declare the convars in server.cfg

Write the lesson code

Keep reading the full lesson

Start and test it