Events

[!Summary] Signals let you respond to runtime events by connecting callbacks to a Signal. Use :Connect to listen for updates, :Once or :Wait for one-time handling, and disconnect listeners when they are no longer needed.

Signals

Events are represented by Signal values. Connect a callback with :Connect, keep the returned Connection, and disconnect it when the listener is no longer needed.

local connection = game:GetService("RunService").Heartbeat:Connect(function(deltaTime)
    print(deltaTime)
end)

connection:Disconnect()

Once and Wait are also available. ConnectParallel is not exposed.

Delivery limits

Manual Signal:Fire(...) delivery works for standalone signals and other supported signals. Some instance change signals are only partially implemented: they can be connected, but do not fire when the corresponding property or attribute is changed. Part.Changed, user input, Humanoid health-related signals, and remote-event signals each need to be treated according to their documented runtime behavior.

Do not treat a connectable signal as proof that a producer exists. Confirm that the specific event delivers in the context where your code runs.