JavaScript Snippets

Common JavaScript patterns for FiveM resources. Treat these snippets as focused building blocks. Rename events and callbacks, handle rejected promises, validate messages crossing the NUI boundary, and move authoritative gameplay decisions to server-side handlers before production use. Log failures with enough context to reproduce them without exposing secrets.

NUI to Client

fetch(`https://${GetParentResourceName()}/callback`, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    type: 'action',
    data: data,
  }),
})

Client to NUI

// In NUI
window.addEventListener('message', (event) => {
  const data = event.data
  if (data.type === 'showMenu') {
    // Show menu
  }
})

Async Function

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() {
  try {
    const response = await fetch('https://api.example.com/data')
    const data = await response.json()
    return data
  } catch (error) {
    console.error('Error:', error)
  }
}