Your own tools and UIs

Speak the wire protocol directly — a Python client and a working browser panel, each under 50 lines.

The CLI is one client of a boring, stable wire: JSON-RPC 2.0 over a local WebSocket hosted by the editor addon. Anything that can open a WebSocket can be a Godot tool — a script, a test rig, a web UI. Three facts cover the whole protocol:

Find the port in <project>/.godot/godot-mcp.json — the addon writes it on bind (auto range 9080-9095).
Send {"jsonrpc": "2.0", "id": 1, "method": "<group>.<command>", "params": {…}} as a text frame, and match the response by id — frames without your id (heartbeats) are ignored.
Errors come back as {"error": {"code", "message", "data"}} with JSON-RPC-style codes — see How it works.

A Python client

# pip install websockets
import asyncio, json, pathlib, sys
import websockets

def port(project="."):
    f = pathlib.Path(project) / ".godot" / "godot-mcp.json"
    return json.loads(f.read_text())["port"] if f.exists() else 9080

async def call(method, params=None, project="."):
    async with websockets.connect(f"ws://127.0.0.1:{port(project)}") as ws:
        await ws.send(json.dumps(
            {"jsonrpc": "2.0", "id": 1, "method": method, "params": params or {}}))
        async for raw in ws:
            msg = json.loads(raw)
            if msg.get("id") == 1:            # heartbeat frames carry no id: skip them
                if "error" in msg:
                    raise RuntimeError(msg["error"]["message"])
                return msg["result"]

if __name__ == "__main__":
    params = json.loads(sys.argv[2]) if len(sys.argv) > 2 else None
    print(json.dumps(asyncio.run(call(sys.argv[1], params)), indent=2))

python godot.py scene.tree
python godot.py node.add '{"type": "Sprite2D", "name": "Player", "parent_path": "."}'

A browser panel

A WebSocket from a page needs no server and no CORS exception — this single file is a working Godot control panel:

<!doctype html>
<meta charset="utf-8">
<title>godot-mcp panel</title>
<style>
  body { font: 14px ui-monospace, monospace; background: #12151a; color: #e8eaed; padding: 2rem; }
  input { width: 26rem; } input, button { font: inherit; padding: .35rem .6rem; }
  pre { white-space: pre-wrap; color: #7ecbff; }
</style>
<input id="m" value="scene.tree" placeholder="group.command">
<input id="p" value="{}" placeholder="params JSON">
<button id="go">run</button>
<pre id="out"></pre>
<script>
  const ws = new WebSocket("ws://127.0.0.1:9080"); // or read the port from godot-mcp.json
  let id = 0;
  const pending = new Map();
  ws.onmessage = (e) => {
    const msg = JSON.parse(e.data);
    if (!pending.has(msg.id)) return;              // heartbeats and strays: ignore
    pending.get(msg.id)(msg.error ?? msg.result);
    pending.delete(msg.id);
  };
  go.onclick = () => {
    const reqId = ++id;
    pending.set(reqId, (r) => (out.textContent = JSON.stringify(r, null, 2)));
    ws.send(JSON.stringify({ jsonrpc: "2.0", id: reqId, method: m.value, params: JSON.parse(p.value || "{}") }));
  };
</script>

The exchange above is verified against a live editor. Grow it in any direction — the live dashboard that ships with the CLI is exactly this pattern taken further: one persistent connection polling stats.snapshot, an htmx UI, embedded in the Go binary.

Or skip the socket

Shell out to the CLI and parse JSON or TSV — see Scripting and CI.
Speak MCP: godot-mcp serve exposes every command as a typed tool for AI clients — see Use with an AI client.
Generate from the catalog: engine commands --docs returns every command with typed params — enough to build forms, bindings, or a command-palette UI without hardcoding a single command name.

A Python client#

A browser panel#

Or skip the socket#

A Python client

A browser panel

Or skip the socket