JavaScript Basics

JavaScript is a modern alternative to Lua for FiveM scripting. FiveM runs JavaScript separately in client and server contexts. Keep shared data serializable, use runtime-specific natives only on the correct side, and avoid blocking loops so other resource callbacks continue to execute.

Variables


const name = 'John'
let age = 25
var isActive = true

Functions


function greet(name) {
  return `Hello, ${name}`
}
 
const message = greet('World')

Objects


const player = {
  name: 'John',
  age: 25,
  items: ['sword', 'shield'],
}
 
console.log(player.name) // "John"
console.log(player.items[0]) // "sword"

FiveM Functions


// Get the local player's ped (client)
const ped = PlayerPedId()
 
// Get ped coords
const coords = GetEntityCoords(ped)
 
// Trigger event
emit('myevent', { source: 'js-basics' })

Async/Await

Where fetch is available depends on the context. Client scripts have no browser or Node.js APIs (JavaScript runtime manual ). Server scripts default to Node.js 16, which has no global fetch; add node_version '22' to fxmanifest.lua or use PerformHttpRequest. NUI pages run in Chromium and have the browser fetch.


// Server script with node_version '22', or an NUI page
async function fetchData() {
  const response = await fetch('https://api.example.com/data')
  const data = await response.json()
  return data
}

Common Patterns

Debouncing


let lastTime = 0
function debouncedAction() {
  const currentTime = GetGameTimer()
  if (currentTime - lastTime < 1000) {
    return
  }
  lastTime = currentTime
  // Do action
}

Threading


setTick(() => {
  // Do something every frame
})