unreal-api-mcp: Unreal Engine API reference
unreal-api-mcp
Unreal Engine C++ API reference over MCP: exact signatures, include paths and deprecated functions, no engine source reads
- 99 ★ on the repository
- Last commit
- MIT
Minimal access
Why this level
- The server reads only a local API database and downloads it on first run; it has no access to the project or secrets
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add mcp/unreal-api-mcpDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewMinimal accessThe tool runs nothing and makes no network calls.
- The server reads only a local API database and downloads it on first run; it has no access to the project or secrets
This is third-party code. Review the repository files before installing.
What it does
unreal-api-mcp gives an agent Unreal Engine API facts from a local SQLite database, one per engine version. It targets a common agent mistake in Unreal C++: an invented function signature, a wrong `#include` path or a call to a deprecated method. There are five tools. `search_unreal_api` finds functions and classes by keyword, `get_function_signature` returns the exact signature with parameters and return type, `get_include_path` resolves the `#include` for a type, `get_class_reference` returns a class card with its member list, and `get_deprecation_warnings` suggests a replacement for an obsolete call. The database covers the Engine Runtime, Editor and Developer modules, built-in plugins such as Enhanced Input, Gameplay Abilities, Common UI, Niagara and Chaos, and Blueprint internals: 158 UK2Node subclasses plus the BlueprintGraph, KismetCompiler and GraphEditor modules. An installed Unreal Engine is not required. On first run the server downloads the database for the chosen version to `~/.unreal-api-mcp/` and checks for updates at startup.
Who it is for. Unreal Engine C++ developers who write code with Claude Code, Cursor or Windsurf and want the agent to check API facts against a reference.
Good fit when
- The agent proposes a function and you need its signature and return type verified
- You need the exact `#include` for a class such as `ACharacter`
- Your project runs Unreal 5.5 or 5.7 and you need to know whether a call is deprecated there
- You write custom K2 nodes or editor tooling and need Blueprint classes
- You want to save tokens and avoid feeding huge engine files to the agent
Not a fit when
- You need third-party plugins and Marketplace assets: the server does not know them, so rely on the project source
- You want to follow logic inside an engine file, such as a function body: the database holds signatures, comments and member lists
- You work in Unity or Godot: the server describes Unreal only
Example request
What is the signature of AActor::GetActorLocation, and which include does ACharacter need in Unreal 5.5?MCP
- Transport
- stdio
- Authentication
- not required
Environment variables
UNREAL_VERSION- Unreal Engine version, for example 5.5 or 5.7.3
UNREAL_PROJECT_PATH- Project path; the version is read from EngineAssociation in the .uproject file
Limitations
Coverage follows the databases in the release list; if no database exists for a patch version, the server falls back to the minor version, for example 5.7 for 5.7.3. Without `UNREAL_VERSION` or `UNREAL_PROJECT_PATH` the server answers for Unreal 5.7. The first run needs network access to download the database. Third-party plugins and Marketplace assets are not included. The author advises adding a short snippet to `CLAUDE.md` about when to call the tools: without it the agent may not think of them. The benchmark in the README comes from the author, with 14 questions on two testbeds, so check it against your own project.
How to disable. Remove the `unreal-api` block from the MCP configuration and, if you like, the `~/.unreal-api-mcp/` folder with the downloaded databases.
FAQ
How do I connect unreal-api-mcp to Claude Code or Cursor?
Add a server to `.mcp.json` or the MCP settings with the command `uvx` and the argument `unreal-api-mcp`, and set `UNREAL_VERSION` in env, for example 5.5. No separate Unreal Engine install is needed.
Which Unreal Engine versions are supported?
The list of databases is on the db-v1 release page in the repository, and CI detects and builds new versions every Monday. For a patch version without its own database the server uses the minor version.
Does the server see my project and plugins?
No. It answers from a shared database of the engine and built-in plugins; your project code and third-party plugins are not in it. For those the agent reads project sources.
Do I need Unreal Engine installed for the server to work?
No. The server uses its own SQLite database downloaded to `~/.unreal-api-mcp/`; an installed engine is not required.
What if the agent does not call the tools?
Add the README snippet to `CLAUDE.md` or an equivalent rules file, telling the agent when to call which tool. The author notes that without it the agent may forget the server.
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 |
|---|---|---|---|---|
| unreal-api-mcp: Unreal Engine API reference (this card) | no | not required | 99 | |
| UnrealClaude | no | not required | 1,031 | drives the Unreal editor from Claude Code |
| Flopperam Unreal Engine MCP | no | API key | 1,117 | automation of the Unreal editor and scene |
README in short
The quick start reduces setup to one configuration block, engine version selection and the five tools. It then lists the database by record type (classes, structs, enums, functions, properties), query latencies in milliseconds and a benchmark with its method. A separate section gives a snippet for `CLAUDE.md`.