unity-api-mcp
An MCP server with accurate Unity API docs for Claude Code and Cursor: signatures, namespaces and deprecated methods
- 66 ★ on the repository
- Last commit
Extended access
Why this level
- The first run downloads a database from GitHub and writes it to the home folder
- The server only reads documentation and does not touch project files other than the version
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add mcp/unity-api-mcpDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- The first run downloads a database from GitHub and writes it to the home folder
- The server only reads documentation and does not touch project files other than the version
This is third-party code. Review the repository files before installing.
What it does
The server answers an agent's questions about the Unity API from a local SQLite database so code does not rely on invented signatures or outdated calls. Databases exist for Unity 6 (one per minor stream such as `6000.3`), Unity 2023 and Unity 2022 LTS. A Unity installation is not required. There are five tools: `search_unity_api` finds APIs by keyword, `get_method_signature` returns exact signatures with every overload, `get_namespace` supplies the right `using` directive, `get_class_reference` gives a class card with all methods, fields and properties, and `get_deprecation_warnings` shows that a method is obsolete and what replaces it. The server picks the version from the `UNITY_VERSION` variable or reads `ProjectSettings/ProjectVersion.txt` from the path in `UNITY_PROJECT_PATH`. On first run it downloads the database (about 20-30 MB) to `~/.unity-api-mcp/` and later checks its freshness against the release. UnityEngine and UnityEditor modules are covered, along with Input System, Addressables, uGUI, AI Navigation and Netcode.
Who it is for. Unity game developers whose agents mix up overloads, namespaces and deprecated calls.
Good fit when
- The agent writes Unity 6 code and signatures such as `SceneManager.LoadSceneAsync` must be checked
- It is unclear which `using` directive to add for a UnityEngine class
- You need to know whether the `WWW` call is obsolete and what replaces it
- The project runs on Unity 2022 LTS or 2023 and answers must match that exact branch
Not a fit when
- The question is about third-party assets such as DOTween, VContainer or Newtonsoft.Json: they are not in the database
- You need to drive the Unity editor itself: the server only answers from documentation
- Work happens in Unreal Engine or Godot: the database contains Unity only
Example request
Show every overload of `Physics.Raycast` for Unity 6 and tell me which `using` to add for `InputAction`MCP
- Transport
- stdio
- Authentication
- not required
Environment variables
UNITY_VERSION- Unity version to serve: 2022, 2023 or 6, auto-detected or 6 by default
UNITY_PROJECT_PATH- Path to a Unity project to read the version from ProjectSettings/ProjectVersion.txt
Limitations
The database covers the UnityEngine and UnityEditor modules and the Input System, Addressables, uGUI, AI Navigation and Netcode packages, while third-party assets stay with the project source. Unity 6, 2023 and 2022 LTS are supported and other versions are not served. On first run the server downloads the database from GitHub, so network access is needed, and it is then kept in `~/.unity-api-mcp/`. The agent sees the tools but may not know when to use them: the author recommends adding a snippet to `CLAUDE.md` or an instructions file. It runs through `uvx`, so `uv` and Python are required.
How to disable. Remove the `unity-api` entry from the client MCP configuration and optionally delete the `~/.unity-api-mcp/` database folder.
FAQ
How do I connect unity-api-mcp to Claude Code or Cursor?
Add a server to `.mcp.json` or the MCP settings with `command` `uvx`, `args` `["unity-api-mcp"]` and the `UNITY_VERSION` variable for the project version. No API key is needed.
Which Unity versions are supported?
Unity 6 (one database per stream, for example `6000.3`), Unity 2023 and Unity 2022 LTS. New Unity releases are detected and built automatically every week.
Does it need Unity installed?
No. The server works from its own database, downloaded on first run, and takes the version from `UNITY_VERSION` or from `ProjectSettings/ProjectVersion.txt`.
Why use it if the agent can already search code?
Exact overloads, namespaces and deprecations are not in project files. In the author's 25-question test the agent with this server answered 24 correctly and invented no APIs, while agents without it each invented an overload.
Does the server know third-party plugins such as DOTween?
No, the database holds only Unity modules and the listed packages. For DOTween, VContainer and Newtonsoft.Json the agent relies on project source.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| unity-api-mcp (this card) | no | not required | 66 | |
| MCP Unity | no | not required | 2,018 | a server that drives the Unity editor, whereas this one answers from API documentation |
| Unity Skills | no | 1,244 | a set of skills with Unity practices, whereas this is a signature reference database for checking code |
README in short
The README has a quick start, a description of version selection and database download, a tool table, the coverage list and results of a 25-question test. A snippet for the agent instructions file closes it.