GameCodex

Free and open source game dev AI assistant — MCP server.

GameCodex gives any AI coding assistant permanent, structured game development knowledge: 950+ curated docs across 29 engines — design patterns, architecture guides, engine-specific implementation details — delivered through MCP so your AI never loses context on how to build games.

Works with Claude Code, Claude Desktop, Cursor, Windsurf, Cline, and any MCP-compatible tool.

The Problem

Every game dev using AI hits the same wall: your assistant starts strong, then forgets your architecture mid-session. It suggests deprecated APIs. It doesn't know the difference between a state machine and a behavior tree. It writes Unity 5 code when you're on Unity 6.

GameCodex solves this by giving your AI a persistent, searchable knowledge base of curated game dev expertise — not raw docs, but structured implementation guidance that actually helps you build.

Status

v1.0.0 — free and open source, MIT licensed. All tools, all docs, no tiers, no accounts, no license keys.

Active feature development has stopped. The project is in maintenance mode — bug fixes and doc corrections welcome, but no new feature work is planned. Fork freely.

What's Inside

957 docs. 18MB of curated knowledge. 29 engine modules.

Quick Start

npx gamecodex

That's it. No install required. Add it to your MCP config and your AI has instant game dev knowledge.

Claude Code

claude mcp add gamedev -- npx -y gamecodex

Claude Desktop / Cursor / Windsurf / Cline

Add to your MCP config file:

{
  "mcpServers": {
    "gamedev": {
      "command": "npx",
      "args": ["-y", "gamecodex"]
    }
  }
}

Config file locations:

• Claude Desktop: claude_desktop_config.json
• Cursor: .cursor/mcp.json
• Windsurf: ~/.windsurf/mcp.json
• Cline: VS Code settings > Cline MCP Servers

Engine Modules

GameCodex uses a modular architecture. Core knowledge (design, patterns, algorithms) is always available. Engine-specific modules add implementation guides for your stack.

Plus core with 52 engine-agnostic docs on game design, architecture, programming patterns, and project management.

Modules are auto-discovered. To filter which modules load:

{
  "env": {
    "GAMEDEV_MODULES": "monogame-arch,godot-arch"
  }
}

Without GAMEDEV_MODULES, all available modules load automatically.

MCP Tools

GameCodex consolidates everything into 5 tools — one per domain, with an action parameter for routing. Minimal schema overhead, maximum utility.

Context-Efficient by Design

Unlike tool-heavy MCP servers that dump 50K+ tokens of schemas into your context window, GameCodex is built for precision:

• 5 focused tools — Minimal schema overhead, maximum utility. Compare to Godot MCP servers with 95+ tools burning half your context on schema alone
• Section extraction — docs { action: "get", id: "G64", section: "Knockback" } returns just the knockback section, not the full 52KB doc
• maxLength param — Cap any response to fit your context budget
• stdio transport — No network exposure, no attack surface (MCP security is a real concern)

MCP Prompts

Workflow entry points that chain multiple tool calls:

What Makes This Different

There are 14,000+ MCP servers out there. Here's why this one matters for game dev:

• Knowledge, not integration. Godot-MCP, Unity-MCP, and Unreal-MCP give your AI buttons to press in the editor. This gives your AI understanding of how to architect and build games. They're complementary — use both.
• Cross-engine. One server, 29 engines. Learn a pattern once in core theory, then get the engine-specific implementation. No need to install separate MCPs per engine.
• Curated, not scraped. Every doc is hand-written with AI code generation in mind — typed examples, anti-pattern warnings, decision trees, and "when to use" guidance. This isn't a docs mirror.
• Secure by design. stdio-only transport — no network exposure, no open ports, no attack surface. While 7,000+ MCP servers sit exposed on the internet, this runs entirely local.

Genre Coverage

The design tool's patterns action maps any genre to its required systems with implementation priorities:

Platformer, Metroidvania, Roguelike, Tower Defense, Survival, RPG, Bullet Hell, Top-Down Shooter, Side-Scrolling, Fighting, Puzzle

Each genre profile includes: required systems, optional enhancements, suggested doc reading order, and a starter checklist.

Development

git clone https://gitlab.com/shawn-benson/GameCodex.git
cd GameCodex
npm install
npm run build
npm test          # Node.js built-in test runner
npm run dev       # Watch mode

Doc Structure

docs/
├── core/                    # Engine-agnostic (always loaded, 52 docs)
│   ├── game-design/         # Genre profiles, game feel, balancing
│   ├── programming/         # Patterns, principles, data structures
│   ├── concepts/            # Camera, physics, pathfinding, networking, particles
│   ├── project-management/  # Scope, sprints, pipelines
│   ├── ai-workflow/         # AI code generation best practices
│   └── session/             # Session workflow prompts
├── monogame-arch/           # MonoGame (131 docs)
├── godot-arch/              # Godot 4.4+ (116 docs)
├── unity-arch/              # Unity 6 (81 docs)
├── unreal-arch/             # Unreal Engine 5 (81 docs)
├── bevy-arch/               # Bevy ECS (37 docs)
├── ...                      # 24 more engine modules
└── [engine]-arch/           # Each module: architecture/, guides/, reference/

MCP Resources

Docs are also available as MCP resources for clients that support them:

• gamedev://docs/{module}/{id} — Any doc by module and ID
• gamedev://prompts/session — Session workflow prompt
• gamedev://prompts/code-rules — AI code generation rules

Security

GameCodex uses stdio-only transport — no HTTP server, no open ports, no network exposure. While 7,000+ MCP servers sit exposed on the internet, this runs entirely local. Read-only by design: it serves knowledge, never modifies your project files.

Vector search is opt-in. The @huggingface/transformers package (for ML-based semantic search) is an optional dependency. Without it, the server uses TF-IDF keyword search — fast and effective for most use cases. To enable vector search: npm install @huggingface/transformers.

See SECURITY.md for our full security policy and vulnerability reporting process.

Contributing

Found a bug? Have a doc correction? Open an issue. The project is in maintenance mode — bug fixes and small improvements are welcome; larger feature work is not being actively merged.

License

MIT — see LICENSE.

Built for game devs who use AI. Free, open source, and yours to fork.