Events & Keyboard Controls

Learn how to run code continuously and detect player keyboard presses.

Mod Callbacks (Events)

The onTick() function is the heart of your mod. GTA IV calls it every single frame (around 60 times per second).

This is where you should check for key presses, draw HUD elements, or update game values:

function onTick()
    -- This code runs constantly while playing
end

Called when your mod is stopped or reloaded. Use it to clean up objects, delete spawned cars, or save settings:

function onUnload()
    log("Mod stopped!")
end

To check if a key is pressed, use is_key_down(key_code).

function onTick()
    if is_key_down(0x73) then -- F4
        log("F4 was pressed!")
    end
end

Here are the most useful Windows Virtual-Key (VK) codes to copy and paste:

Key	Hex Code	Decimal	Description
F1	`0x70`	112	Function Key 1
F2	`0x71`	113	Function Key 2
F3	`0x72`	114	Function Key 3
F4	`0x73`	115	Function Key 4 (Trainer standard)
F5	`0x74`	116	Function Key 5
F6	`0x75`	117	Reserved (Built-in In-Game Editor)
F7	`0x76`	118	Function Key 7
F8	`0x77`	119	Function Key 8
F9	`0x78`	120	Function Key 9
Shift	`0x10`	16	Left or Right Shift
Ctrl	`0x11`	17	Left or Right Control
Alt	`0x12`	18	Alt Key
Space	`0x20`	32	Spacebar
Enter	`0x0D`	13	Return / Enter
Escape	`0x1B`	27	Escape
Tab	`0x09`	9	Tab Key
Arrow Up	`0x26`	38	Up Arrow
Arrow Down	`0x28`	40	Down Arrow
Arrow Left	`0x25`	37	Left Arrow
Arrow Right	`0x27`	39	Right Arrow
E Key	`0x45`	69	Letter E
T Key	`0x54`	84	Letter T
X Key	`0x58`	88	Letter X
Z Key	`0x5A`	90	Letter Z
0 to 9	`0x30` - `0x39`	48 - 57	Top number row (0-9)
Numpad 0-9	`0x60` - `0x69`	96 - 105	Numeric Keypad