comfygenmcp

A Model Context Protocol (MCP) server that connects an AI assistant to a running ComfyUI instance. It fetches a workflow saved in ComfyUI, writes the prompt and seed into it, runs it, and returns the image inline in the chat — so it only works with text-to-image workflows that have a single prompt node and seed to inject into.

Install

Requires Python 3.10+ and a running ComfyUI.

git clone https://github.com/aschet/comfygenmcp.git
cd comfygenmcp
python -m venv .venv
.venv/bin/pip install -e .

That gives you the command .venv/bin/comfygenmcp, which a client launches for you — nothing to start by hand beyond ComfyUI itself.

Connecting a Client

Any MCP client works. By default the server speaks stdio, meaning the client launches .venv/bin/comfygenmcp itself and talks to it over the process pipes. With --transport http it instead listens on http://127.0.0.1:8000/mcp for clients that connect over the network — with no authentication, so don't expose it without one in front.

Add this mcpServers entry to the client's config. Flags go in an "args" array, e.g. "args": ["--comfy-url", "http://host:8188", "--timeout", "600"] — add the first if ComfyUI isn't on localhost, and raise the timeout if your workflows are slow or an agent chains several generations.

{
  "mcpServers": {
    "comfygen": {
      "command": "/path/to/comfygenmcp/.venv/bin/comfygenmcp"
    }
  }
}

• Claude Desktop: add it to claude_desktop_config.json. The image only shows inside the collapsed tool card — expand it, or use the URL instead.
• AnythingLLM: add it to anythingllm_mcp_servers.json (~/.config/anythingllm-desktop/storage/plugins/ on Linux), then start it from Settings → Agent Skills → MCP Servers and invoke with @agent. It renders no image at all, so tell the agent to always pass fetch_image: false.

Use

Ask the assistant what's available:

you:    which image workflows do I have?
claude: [list_workflows]
        Ready to generate with:
          Krea2
          Z-Image Turbo

        Present but not usable:
          Ideogram 4 -- needs models that are not installed:
          flux2-vae.safetensors, gemma4_e4b_it_fp8_scaled.safetensors,
          ideogram4_fp8_scaled.safetensors

Then generate with one of your own names:

you:    generate a red fox in deep snow using Krea2
claude: [image]  Done: generated with Krea2 · seed 12345 ·
        http://127.0.0.1:8188/view?filename=Krea2_turbo_00007_.png

Three tools are exposed:

Tool	Description
generate_image(prompt, workflow, seed?, fetch_image?)	Generate and return the image. Seeds are random unless you pass one, and every result reports the seed it used. fetch_image defaults to true; a client that cannot render one can pass false and get only the seed and URL.
list_workflows()	The workflows saved in ComfyUI, split into those ready to run and those that cannot.
comfy_status(workflow?)	Connection check; with a name, the nodes it would patch.

Limitations

• Only the prompt and seed change — no width, height, steps or sampler; those come from the workflow. A sampler set to "fixed" in ComfyUI is not honoured.
• Node detection can pick the wrong node when a workflow has several prompt boxes. comfy_status shows what it found; set a node's Title to MCP:prompt to override.
• Images are sent as JPEG, downscaled and compressed to fit a 1 MB limit, with transparency flattened onto white. The full-resolution original stays in ComfyUI's output folder.

Configuration

All settings are command-line flags.

Flag	Default	Description
--comfy-url	http://127.0.0.1:8188	Address of the ComfyUI server to generate on
--transport	stdio	stdio, or http to listen on a port
--listen	127.0.0.1:8000	Address this server binds to, with --transport http
--timeout	300	Seconds before giving up on a generation