Redot guide

What you'll learn: how to add an editor MCP server, and why that is the opposite of in-game play.

Editor MCP and in-game play point opposite ways. This page is lich connecting to an editor. NPC control, vetoes, and the game master are the game connecting to lich: the webhook and examples/game_bridge. That contract is the Godot guide. A game master is another persona, not an editor tool.

The client is general, the same shape as Hermes and Claude: a named list you extend when you need a server. Redot is a catalog entry on that client, not a hard-wired spawner. lich does not ship the engine and does not download an addon.

Client

mcp_servers is a closed record. Omit it and no MCP tools register. Each name is snake_case. Each value is either stdio or loopback HTTP. enabled defaults to false. Unknown keys are rejected.

{
  "mcp_servers": {
    "notes": {
      "enabled": true,
      "command": "/usr/local/bin/notes-mcp",
      "args": ["--stdio"]
    }
  }
}

stdio is a local binary you named, plus args, plus optional env. The process is spawned with those argv, never a shell. Config validation refuses common downloader basenames (npx, npm, bunx, uvx, curl, wget), a URL in the command, and shell metacharacters — a footgun guard, not a sandbox (wrappers like bash -c or env npx are not covered). Treat an enabled server as trusted code. lich does not run npx -y or fetch an addon. Values in env are passed to the process and are never logged. lich mcp add has no flag for env; set that key in the file if you need it. On Bun, the spawned child is not unref'd, so one-shot and other short-lived runs wait for the MCP answer instead of exiting while the child is still working; Agent.close() (every CLI mode calls it) kills the child.

HTTP is { "url": "http://127.0.0.1:9/mcp" }. The host must be 127.0.0.1 or localhost. 0.0.0.0 and any other host are refused. There is no remote MCP in v1.

On connect the client sends initialize, then notifications/initialized, then tools/list. tools/call runs only when the model invokes a registered tool. Registered names are mcp_<server>_<tool>, so two servers cannot collide. They appear only when that server is enabled and tools_enabled is "all" or lists the prefixed name. tools_enabled: [] drops them even when the server is enabled, and does not connect. A list applies to plugin tools too, so list each plugin tool you want exposed. The commander persona lists only its three game_bridge tools — persona_config does not copy mcp_servers.

This client has shipped since 0.7.0 (lich mcp, mcp_servers; current package 0.8.0). From a clone, use bun src/cli.ts mcp ....

Add a server

Paste an entry, call catalog_client_entry, or use the CLI. None of these start a process. New entries stay disabled until you enable them.

lich mcp add redot --project-path /home/me/game
lich mcp enable redot
lich mcp list
lich mcp disable redot
lich mcp remove redot

lich mcp add redot --project-path /home/me/game writes a disabled entry whose command is redot and whose args are --headless --mcp-server --path plus that directory. PATH lookup happens at connect, not at add.

lich mcp add notes --command /usr/local/bin/notes-mcp --arg --stdio is a custom stdio server. --url must be loopback. The command writes through the existing config writer and leaves providers, plugins, and gateway untouched. lich mcp list reads this work dir's .lich/config.json. A missing mcp_servers prints nothing and exits 0.

import { catalog_client_entry } from "@moikapy/lich";

catalog_client_entry("redot", { project_path: "/home/me/game" });

That returns a disabled stdio entry. Unknown names and the Godot catalog return an explanation instead of a spawn plan. Catalog files live in optional-mcps/<name>/manifest.json. A new server is a new manifest plus a config entry. It is not a new client.

Redot

Official Redot 26.1+ only. The catalog command is the local redot binary. The args are exactly:

redot --headless --mcp-server --path <project>

Basename must be redot. A missing binary tells you to install official Redot 26.1+ from redotengine.org. lich does not download a build.

{
  "mcp_servers": {
    "redot": {
      "enabled": true,
      "command": "/usr/local/bin/redot",
      "args": ["--headless", "--mcp-server", "--path", "/home/me/game"]
    }
  }
}

tools/list is what registers. The official server lists five controllers. The client drops a listed tool named execute (exclude_tools). It does not hard-allowlist those five names: any other listed tool is registered. Existing .gd files stay normal file edits (edit_file / write_file). Scene edits go through the scene tool. Do not rewrite .tscn as text.

Registered name	Use it for
mcp_redot_scene_action	.tscn edits: nodes, properties, instances, signals
mcp_redot_resource_action	.tres files and asset import metadata
mcp_redot_code_intel	GDScript validation and engine docs
mcp_redot_project_config	Input map, autoloads, settings, run and stop
mcp_redot_game_control	Screenshots, clicks, and the live scene tree

Play is the other direction

These tools build and inspect the project. They do not queue combat orders. NPC and game-master play still use one POST /message per round, then drain work_dir/.lich/game/orders.jsonl and refresh state.json. Do not call lich per frame.

Godot has no official MCP server. lich does not spawn a community godot-mcp and does not download an Asset Library addon. If you later point a different server name at a local binary you already have, that is a normal stdio entry. The catalog name godot writes no spawn plan. Play for both editors stays the Godot guide.