> For the complete documentation index, see [llms.txt](https://0x29a.gitbook.io/0x29a-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://0x29a.gitbook.io/0x29a-docs/introduction/first-script.md).

# Your first script

A simple script that draws a HUD and reacts to a hotkey:

```lua
-- Script state
local hud_enabled = true

-- INSERT already opens the overlay menu — we use F5 for our own toggle.
bind(input.KEY.F5, function()
    hud_enabled = not hud_enabled
end)

-- Runs once per frame, whenever the overlay is up.
_29a.on_frame(function()
    if not hud_enabled then return end

    local w, h = ui.get_io_display_size()
    local fps  = ui.framerate()

    render.text(12, 12, color(1, 1, 1, 1), string.format("FPS: %.0f", fps))
    render.rect(8, 8, 140, 22, color(0.5, 0.3, 1, 0.5))
end)

print("script loaded — F5 toggles the HUD")
```

Key points:

* `_29a.on_frame(fn)` registers a callback that runs every frame — this is how most scripts draw a HUD/ESP. See [Lifecycle](/0x29a-docs/introduction/lifecycle.md).
* `bind(vk, fn)` binds a key (`input.KEY.*`) to a function, with edge detection (fires once per press, not on repeat). See [Hotkeys](/0x29a-docs/introduction/hotkeys.md).
* `render.*` draws straight on screen in screen coordinates — no need to manage an ImGui window for a simple HUD.
* `print()` goes to the overlay's console (the **Console** tab).

## An example reading memory

```lua
local m = mem.module(nil)              -- the process's main module
print(string.format("base: 0x%X  size: 0x%X", m.base, m.size))

local hp_addr = sig.scan("48 8B 05 ? ? ? ? 8B 88 ? ? ? ?")
if hp_addr then
    local hp = mem.read_i32(mem.deref(hp_addr, 3))
    print("current hp:", hp)
else
    print("signature not found — did the game update?")
end
```

`sig.scan` searches for a byte pattern (with `?` as a wildcard) and returns the address where it shows up — the backbone of pretty much every script that survives game updates. See the full reference in [sig](/0x29a-docs/memory-and-analysis/sig.md) and [mem](/0x29a-docs/memory-and-analysis/mem.md).


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