ComfyUI MCP Server

A dynamic MCP (Model Context Protocol) server that lets you expose ComfyUI workflows as tools for LLMs. Ships with a web admin UI for configuring tools without writing any code.

Features

• Zero hardcoded tools — all tools are loaded dynamically from user-defined workflow configurations
• Web Admin UI — upload ComfyUI API workflows, name tools, map node inputs to parameters, configure output types
• Multi-media output — handles images, audio, video, and generic files
• Per-tool output delivery — choose between inline base64 binary or URL-based delivery for each tool
• Persistent configuration — tool definitions saved as JSON files, survive restarts
• Optional API key auth — protect the admin UI with a simple API key
• ComfyUI health monitoring — real-time connection status in the UI

Quick Start

# Install with uv
uv venv
uv pip install -e .

# Run the server
uv run comfyui-mcp

# Or with environment variables
COMFYUI_URL=http://localhost:8188 COMFYUI_API_KEY=your_key_here uv run comfyui-mcp

Open http://localhost:4206/ui to access the admin dashboard.

The MCP endpoint is available at http://localhost:4206/mcp.

Configuration

All configuration is via environment variables:

Variable	Default	Description
COMFYUI_URL	http://localhost:8188	ComfyUI HTTP API endpoint
COMFYUI_API_KEY	(empty)	Bearer token for ComfyUI auth
ADMIN_API_KEY	(empty)	API key for admin UI access
DATA_DIR	./data	Directory for persisted tool definitions
HOST	0.0.0.0	Server bind address
PORT	4206	Server port
MAX_WAIT_TIME	600	Default max wait for ComfyUI jobs (seconds)

How It Works

1. Export your ComfyUI workflow in API format (enable Dev Mode in ComfyUI → Save API Format)
2. Upload it via the admin UI at /ui
3. Name your tool and write a description (the LLM sees this)
4. Map parameters — click on any node input to expose it as a tool parameter
5. Configure output — set the output type (image/audio/video) and delivery method
6. Save — the tool is immediately available via MCP

MCP Client Configuration

Add this to your MCP client configuration:

{
  "mcpServers": {
    "comfyui": {
      "url": "http://localhost:4206/mcp"
    }
  }
}

Architecture

┌─────────────────────────────────────────┐
│            FastMCP Server               │
│  ┌───────────────────────────────────┐  │
│  │ Dynamic Tool Registry             │  │
│  │  tool1(prompt, steps) → ComfyUI   │  │
│  │  tool2(tags, lyrics) → ComfyUI    │  │
│  └───────────────────────────────────┘  │
│  ┌───────────────────────────────────┐  │
│  │ Admin UI (/ui)                     │  │
│  │  - Tool CRUD                       │  │
│  │  - Workflow upload                 │  │
│  │  - Parameter mapping               │  │
│  └───────────────────────────────────┘  │
│  ┌───────────────────────────────────┐  │
│  │ ComfyUI Client                     │  │
│  │  - HTTP submission                 │  │
│  │  - WebSocket tracking              │  │
│  │  - Output download                 │  │
│  └───────────────────────────────────┘  │
└─────────────────────────────────────────┘
         ↕ MCP Protocol (/mcp)
    ┌──────────┐
    │ LLM/Agent│
    └──────────┘

License

MIT