FiveM NUI Development

Best practices for FiveM NUI development — fullscreen UIs, NUI callbacks, messaging, and UI integration. Use this skill whenever you are dealing with FiveM user interfaces to obtain domain-specific knowledge.

When to use

• User asks how to create a UI for FiveM.
• Creating or editing HTML/CSS/JS files for FiveM resources.
• Setting up ui_page in fxmanifest.lua.
• Questions about NUI callbacks, SendNUIMessage, or SetNUIFocus.
• Need to look up natives → point to https://docs.fivem.net/natives/.

How to use

Read individual rule files for detailed explanations and examples:

• rules/setup.md — Setting up NUI in a resource: ui_page, files entry, folder structure.
• rules/fullscreen-nui.md — Creating fullscreen NUI pages: SEND_NUI_MESSAGE, SET_NUI_FOCUS, developer tools, referencing assets.
• rules/nui-callbacks.md — NUI callbacks: RegisterNUICallback, fetch requests, data handling, security.
• rules/best-practices.md — Best practices: performance, security, communication patterns, error handling.
• rules/reference-links.md — Official docs and natives reference.