Comfyui MCP server

comfyui-mcp

MCP server for ComfyUI. Generate images from natural language prompts in any MCP-compatible client.

Status

v0.2 ships the core tools plus upscale, an image proxy, and public-URL support. Current tool surface: generateimage, generatevariations, generatewithworkflow, refineimage, upscaleimage, listmodels, listworkflows, uploadimage, generatewithcontrolnet, generatewithipadapter, plus a workflow template registry. See Roadmap for what's next.

Install

npx (no install required)

npx @miller-joe/comfyui-mcp --comfyui-url http://your-comfyui-host:8188

npm

npm install -g @miller-joe/comfyui-mcp
comfyui-mcp --comfyui-url http://your-comfyui-host:8188

Docker

docker run -p 9100:9100 \
  -e COMFYUI_URL=http://your-comfyui-host:8188 \
  ghcr.io/miller-joe/comfyui-mcp:latest

Connect an MCP client

Claude Code:

claude mcp add --transport http comfyui http://localhost:9100/mcp

Or register the streamable HTTP endpoint with an MCP gateway (e.g. MetaMCP) to aggregate with other servers.

Configuration

All options can be set via CLI flag or environment variable:

Transports

The server speaks streamable HTTP by default (great for Claude Code, MetaMCP, raw fetch). Pass --stdio (or set MCP_TRANSPORT=stdio) to switch into stdio mode, which is what stdio-first clients like Claude Desktop and the MCP Inspector expect:

# Claude Desktop config (claude_desktop_config.json):
{
  "mcpServers": {
    "comfyui": {
      "command": "npx",
      "args": ["-y", "@miller-joe/comfyui-mcp", "--stdio", "--comfyui-url", "http://127.0.0.1:8188"]
    }
  }
}

Image URLs returned to clients

Generation tools return image URLs like /view?filename=…. If --comfyui-public-url is not set, URLs use the internal --comfyui-url value.

The server also exposes a proxy endpoint: GET /images/?subfolder=&type=output streams the image bytes through this server, which is useful when clients can reach the MCP server but not ComfyUI directly.

The default checkpoint must match a file in your ComfyUI models/checkpoints/ directory. Override via COMFYUIDEFAULTCKPT or pass checkpoint as a tool argument.

Tools

generate_image

Generate an image from a text prompt using ComfyUI's default txt2img workflow.

Parameters: prompt (required), negative_prompt, width, height, steps, cfg, seed, checkpoint.

generate_variations

Generate multiple variations of the same prompt by varying the seed. Returns all images at once.

Shortened. The full README is on GitHub.