Unity Manual MCP

Local MCP server (stdio) that serves a local Unity documentation install to your AI assistant.

The documentation folder is usually located in your Unity Editors install directory, under Data\Documentation\en.

• Manual/ — how-to articles, organized in chapters (~3.5k pages)
• ScriptReference/ — full scripting API reference, one page per class / property / method (~42k pages)

On first start the server builds a SQLite full-text index of every page (Mozilla-Readability-style extraction of the article body, boilerplate stripped, code examples preserved) and caches it in the OS temp dir. Subsequent starts reuse it; it is rebuilt automatically if the docs file count changes.

Requirements

• uv
• Python 3.10+ — declared in pyproject.toml (required by fastmcp 3.x). uv reuses any already-installed Python that meets this and only downloads a new one if no compatible interpreter exists.

Setup

• Clone the repository
• Open a terminal inside the cloned repository
• Run

  uv sync
  

Creates .venv and installs the dependencies from pyproject.toml.

Run

uv run server.py "C:\Program Files\Unity\Hub\Editor\<ver>\Editor\Data\Documentation\en"

The en folder is auto-detected if you point at ...\Documentation or ...\Editor\Data instead.

Flags:

• --selftest — build the index and run sample queries, then exit (no MCP server; good for verifying a fresh setup)
• --rebuild — force rebuilding the index
• --prune — drop stale cache entries (db file missing) from the manifest
• UNITY_DOCS_PATH env var — alternative to the positional argument <br>

ℹ Run the server manually once after a fresh install to pre-index the docs and avoid waiting during first use

uv run server.py --selftest "C:\Program Files\Unity\Hub\Editor\<ver>\Editor\Data\Documentation\en"

Adding the MCP Server

This is a stdio server, so any client that can launch a local process works. Each client runs the same command:

uv run --directory "<repo>" server.py "<docs path>"

where <repo> is this repo's folder and <docs path> is your Unity docs en folder (auto-detected if you point at ...\Documentation or ...\Editor\Data instead). uv run creates and syncs the .venv environment automatically, so the client only needs uv on the PATH.

Claude Desktop

claude_desktop_config.json (substitute your own paths):

{
  "mcpServers": {
    "unity-manual": {
      "command": "uv",
      "args": ["run", "--directory", "<repo>", "server.py", "<docs path>"]
    }
  }
}

Claude Code

claude mcp add unity-manual -- uv run --directory "<repo>" server.py "<docs path>"

OpenCode

opencode.json in the project, or the global config (~/.config/opencode/opencode.json):

{
  "mcp": {
    "unity-manual": {
      "type": "local",
      "command": ["uv", "run", "--directory", "<repo>", "server.py", "<docs path>"],
      "enabled": true
    }
  }
}

Codex

codex mcp add unity-manual -- uv run --directory "<repo>" server.py "<docs path>"

Or edit ~/.codex/config.toml (shared with the ChatGPT desktop app and IDE extension; a project-scoped .codex/config.toml works in trusted projects):

[mcp_servers.unity-manual]
command = "uv"
args = ["run", "--directory", "<repo>", "server.py", "<docs path>"]

Tools

All read-only (readOnlyHint):

Tool	Purpose
search_unity_docs	Full-text search (all / manual / api)
get_page	Read one page as clean text (path from search results)
list_sections	Browse manual chapters, or pages inside a chapter
find_api	Find a class / member API page by C# name

Index cache

%TEMP%\unity-manual-mcp\ holds one db file per editor (e.g. <hash>.db) plus a manifest.json mapping each docs path to its db file. Switching editors reuses the cached index; it is validated by HTML file count. Delete a db file (or use --rebuild) to force a rebuild. --selftest reports stale entries (db file missing) and orphaned entries (docs folder gone, db still there); --prune drops the stale ones.

Credits

Fully written by Qwen 3.8 27b 🙂