Unreal Engine API Documentation
Wire Claude Code or Cursor to grounded Unreal Engine 5 C++ API lookups so gameplay and plugin code does not rely on invented signatures or headers.
Overview
Unreal API MCP is a Build-phase MCP server that serves version-accurate UE5 C++ API documentation to coding agents to reduce hallucinated signatures and includes.
What is this MCP server?
- Serves version-scoped UE5 C++ API documentation to MCP clients over stdio (PyPI package unreal-api-mcp, runtimeHint uvx)
- Targets hallucination-prone areas: function signatures, includes, and API surface for AI-generated Unreal code.
- UNREAL_VERSION supports 5.5, 5.6, and 5.7 with default auto-detect or 5.7.
- UNREAL_PROJECT_PATH reads EngineAssociation from a .uproject for automatic engine version selection.
- Server schema version 0.2.0 aligned with MCP server.schema.json 2025-12-11.
- Server version 0.2.0
- Supports UE versions 5.5, 5.6, and 5.7
- Stdio transport via PyPI identifier unreal-api-mcp
Community signal: 83 GitHub stars.
What problem does it solve?
LLMs routinely invent Unreal C++ APIs and headers, breaking compiles and wasting solo builders' limited engine time.
Who is it for?
Solo or small-team UE5 C++ work where an AI agent writes gameplay, subsystem, or editor code and you need docs matched to 5.5–5.7.
Skip if: Blueprints-only workflows, non-Unreal stacks, or teams that do not run MCP in their agent IDE.
What do I get? / Deliverables
Your agent can query grounded UE5 API facts for the engine version tied to your project or UNREAL_VERSION instead of guessing from stale training cutoffs.
- MCP-accessible UE5 C++ API documentation scoped to your engine version
- Reduced bad includes and signatures in agent-generated Unreal C++ patches
- Auto-detected engine minor when UNREAL_PROJECT_PATH points at a valid .uproject
Recommended MCP Servers
Journey fit
Canonical shelf is Build because the server exists to support active UE5 C++ implementation and agent-assisted coding, not early market research or post-launch ops. Agent-tooling fits an MCP doc bridge that feeds coding agents accurate types and includes while you write or refactor game code.
How it compares
Versioned API reference MCP for Unreal, not a general web search skill or Blueprint visual scripting tutor.
Common Questions / FAQ
Who is unreal-api-mcp for?
Unreal Engine 5 developers using AI coding agents who need C++ API answers tied to a specific engine minor (5.5, 5.6, or 5.7).
When should I use unreal-api-mcp?
Use it during active C++ implementation whenever the agent proposes Unreal classes, macros, or includes and you want MCP-backed lookups before merging generated code.
How do I add unreal-api-mcp to my agent?
Register the stdio server from PyPI package unreal-api-mcp (uvx), then set UNREAL_VERSION and optionally UNREAL_PROJECT_PATH to your .uproject path in your Claude Code or Cursor MCP config.