# Godot MCP Runtime
A lightweight [MCP](https://modelcontextprotocol.io/) server that pairs comprehensive headless editing with full runtime control over a [Godot](https://godotengine.org/) 4.x project. Scene, node, autoload, and validation ops cover everything short of the most niche corners of the engine; the runtime bridge adds screenshots, input simulation, UI discovery, and live GDScript against the running scene tree.
The AI doesn't just write your game, it can check its work.
- **Headless editing** — scenes, nodes, scripts, signals, validation, no editor window
- **Runtime control** — screenshots, input simulation, UI discovery, and live GDScript against the running game
- **Zero footprint** — no Godot addon, no project commits, auto-cleanup on shutdown
**No addon required.** Most Godot MCP servers that offer runtime support ship as a Godot addon, something you install into your project, commit to version control, and manage as a dependency. Use npx and there's no install or setup needed.
Think of it as [Playwright MCP](https://github.com/microsoft/playwright-mcp), but for Godot. This does the same thing for games: run the project, take a screenshot, simulate input, read what's on screen, execute a script against the live scene tree. The agent closes the loop on its own changes rather than handing off to you to verify.
> [!NOTE]
> This is not a playtesting replacement. It doesn't catch the subtle feel issues that only a human notices, and it won't tell you if your game is fun. What it does is let an agent confirm that a scene loads, a button responds, a value updated, a script ran without errors. The ability to check work is crucial for AI driven workflows.
## Contents
- [What It Does](#what-it-does)
- [Quick Start](#quick-start)
- [Docs](#docs)
- [Acknowledgments](#acknowledgments)
- [License](#license)
## What It Does
**Built for agents.** Every tool is purpose-built and self-documenting. When something fails, the response tells the agent how to fix it; when something succeeds, it points toward the next step. The result is an AI that stays unstuck and self-corrects without needing you to nudge it along.
**Headless editing.** Create scenes, add nodes, set properties, attach scripts, connect signals, validate GDScript. All the standard operations, no editor window required.
**Runtime bridge.** When `run_project` or `attach_project` is called, the server injects `McpBridge` as an autoload. This opens a localhost-only TCP listener (both auto-select a free port when `bridgePort` is omitted; pass `bridgePort` to pin a specific port) and enables:
- **Screenshots:** Capture the viewport — by default returns a 960x540 preview inline plus the full PNG on disk; use `responseMode: 'full'` for pixel-perfect or `'path_only'` to skip the inline image
- **Input simulation:** Batched sequences of key presses, mouse clicks, mouse motion, UI element clicks by name or path, Godot action events, and timed waits
- **UI discovery:** Walk the live scene tree and collect every visible Control node with its position, type, text content, and disabled state
- **Live script execution:** Compile and run arbitrary GDScript with full SceneTree access while the game is running
**Background mode.** Pass `background: true` to `run_project` and the Godot window moves off-screen (positioned at `(-9999, -9999)`) with physical input blocked: borderless, unfocusable, mouse-passthrough. Programmatic input, screenshots, and all runtime tools work exactly the same. Useful for automated agent-driven testing where the window shouldn't be visible or interactive.
**Manual attach mode.** When something other than MCP launches the game (a CI pipeline, an external debugger, your own shell), call `attach_project` first. It injects the bridge and marks the project active without spawning Godot, so when you launch the game manually, runtime tools work against it. Use `detach_project` when done.
> [!IMPORTANT]
> `get_debug_output` is unavailable in attached mode. stdout and stderr only flow through processes MCP started itself, so when Godot is launched externally there's no captured output to return. Use `run_project` if you need the debug stream.
The bridge cleans itself up automatically when `stop_project` or `detach_project` is called. No leftover autoloads, no modified project files.
## Quick Start
### Prerequisites
- [Node.js](https://nodejs.org/) v20+
- [Godot 4.x](https://godotengine.org/)
That's it. No Godot addon, no project modifications.
### Configure Your MCP Client
Add the following to your MCP client config. Works with Claude Code, Claude Desktop, Cursor, or any MCP-compatible client.
**Zero-install via npx (recommended):**
```json
{
"mcpServers": {
"godot": {
"command": "npx",
"args": ["-y", "godot-mcp-runtime"],
"env": {
"GODOT_PATH": ""
}
}
}
}
```
**Or install globally:**
```bash
npm install -g godot-mcp-runtime
```
```json
{
"mcpServers": {
"godot": {
"command": "godot-mcp-runtime",
"env": {
"GODOT_PATH": ""
}
}
}
}
```
**Or clone from source:**
```bash
git clone https://github.com/Erodenn/godot-mcp-runtime.git
cd godot-mcp-runtime
npm install
npm run build
```
```json
{
"mcpServers": {
"godot": {
"command": "node",
"args": ["/godot-mcp-runtime/dist/index.js"],
"env": {
"GODOT_PATH": ""
}
}
}
}
```
> [!TIP]
> **Prefer pnpm?** All three install paths work with pnpm. Substitute `pnpm dlx godot-mcp-runtime` for `npx -y godot-mcp-runtime`, `pnpm add -g godot-mcp-runtime` for the global install, or `pnpm install && pnpm run build` for the source build. pnpm ships stronger defaults against npm supply-chain attacks; see [pnpm's supply chain security guide](https://pnpm.io/supply-chain-security).
If Godot is on your `PATH`, you can omit `GODOT_PATH` entirely. The server will auto-detect it. Set `"DEBUG": "true"` in `env` for verbose logging.
> [!IMPORTANT]
> **Windows path gotchas.** `GODOT_PATH` must point at the Godot executable itself, not its install folder. Backslashes in JSON must be escaped or replaced with forward slashes:
>
> ```json
> "GODOT_PATH": "D:\\Godot\\Godot_v4.4-stable_win64.exe"
> // or equivalently
> "GODOT_PATH": "D:/Godot/Godot_v4.4-stable_win64.exe"
> ```
>
> Setting the variable from a wrapper `.bat` does not propagate to the MCP server — the path must live in the client's `env` block above.
### Verify
Ask your AI assistant to call `get_project_info`. If it returns a Godot version string (e.g., `4.4.stable`), you're connected and working.
## Docs
- [`docs/tools.md`](docs/tools.md) — full tool reference, grouped by category
- [`docs/tool-authoring.md`](docs/tool-authoring.md) — standards for adding or modifying tools
- [`docs/architecture.md`](docs/architecture.md) — source layout, bridge sequence diagram, lifecycle steps, runtime artifact behavior
## Acknowledgments
Built on the foundation laid by [Coding-Solo/godot-mcp](https://github.com/Coding-Solo/godot-mcp) for headless Godot operations.
Developed with [Claude Code](https://claude.ai/code).
## License
[MIT](LICENSE)