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RegisterNUICallback

FiveM client native documentation with a Lua example.

Summary

Registers a Lua handler the NUI (JS) can call via fetch. The way the UI sends actions back to the game (button clicks, form submits).

Returns

void

Parameters

namestringThe callback name.
handlerfunctionfunction(data, cb) — call cb(result) to respond.

Example

RegisterNUICallback('buy', function(data, cb)
  -- data.item, data.amount from the UI
  cb({ ok = true })
end)

-- JS: fetch(`https://${GetParentResourceName()}/buy`, {method:'POST', body: JSON.stringify({item})})

Common pitfalls

  • Always call cb(...) or the fetch on the JS side hangs.
  • Validate NUI data — treat it like any untrusted input, especially before server actions.

Related natives

SendNUIMessageSetNuiFocus

Related guides

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