Borrowing it
Nothing to install: this file belongs to IvanMurzak/Unreal-MCP. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/IvanMurzak/Unreal-MCP/main/CLAUDE.mdgit clone --depth 1 https://github.com/IvanMurzak/Unreal-MCPWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/ivanmurzak/unreal-mcp/claude-md)<a href="https://agentmods.dev/instructions/ivanmurzak/unreal-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/ivanmurzak/unreal-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/ivanmurzak/unreal-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/ivanmurzak/unreal-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.07108 | $0.07108 |
| Opus 5 | $0.03554 | $0.03554 |
| Sonnet 5 | $0.01422 | $0.01422 |
| Haiku 4.5 | $0.00711 | $0.00711 |
Grade A, and why
Unreal-MCP CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 319 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md — Unreal-MCP
Unreal-MCP bridges LLMs (Claude, Cursor, Copilot, …) with Unreal Engine
via the Model Context Protocol — the Unreal-engine sibling of
Unity-MCP and Godot-MCP. It works in two modes: an editor mode (the default — drive the Unreal
Editor: spawn actors, edit levels, author/compile Blueprints, edit/compile C++, capture screenshots,
…) and an opt-in in-game runtime mode (drive a running PIE / Standalone / packaged Development
build so an AI can operate your live game). Status: beta — the plugin, the .NET sidecar, the
unreal-mcp-cli, the AI Game Developer editor UI, and 61 built-in editor tools across 7 families
(plus 3 §2.4 system tools)
have shipped and are covered by CI. The unreal-mcp-cli is published on npm (the Fab / Epic
Marketplace listing for the precompiled plugin is coming soon). The local MCP server is the shared,
engine-agnostic GameDev-MCP-Server
(binary gamedev-mcp-server) — no server source lives in this repo.
The authoritative design is docs/ARCHITECTURE.md (defer to it on any
conflict). Read the relevant section before implementing anything non-trivial — it locks the IPC
protocol (§1), dynamic tool registration (§2), schema generation (§3), the game-thread dispatcher (§4),
extensions (§5), sidecar lifecycle (§6), UI (§7), config (§8), repo/versioning/CI (§9), the tool-family
roadmap (§10), risks (§11), runtime (in-game) support (§12), and custom prompts & resources (§A).
The user-facing entry point is README.md; the release runbook is
docs/RELEASING.md; the extension author guide is
docs/EXTENSIONS.md; the in-game operator walkthrough is
docs/RUNTIME-E2E.md.
Architecture in one screen
Unlike Unity/Godot (C# engines that host the .NET McpPlugin/ReflectorNet/SignalR stack in-process),
Unreal's editor and runtime are C++ and cannot host that .NET stack. So the McpPlugin host runs as an
auto-managed .NET 9 sidecar process (unreal-mcp-bridge, bridge/) that is a local child of
whichever host loads the plugin — the Editor in dev, or the game process itself in an opt-in
packaged build. It is never remote: the C++ plugin listens on a loopback TCP port and the sidecar
dials it, authenticating with a one-shot token delivered over stdin (never argv — §1.4). The
sidecar relays IPC ⇄ SignalR to the MCP server (cloud ai-game.dev by default, or a local
gamedev-mcp-server). See the §0 system-overview diagram.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 10d ago First seen · 319 lines · 7,108 tokens per session scan A 920f7773d4a5
Unreal-MCP CLAUDE.md is an instructions file published in the GitHub repository IvanMurzak/Unreal-MCP (28 stars, last pushed yesterday), licensed Apache-2.0. It adds 7,108 tokens to every session, about $0.0355 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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