comfyui-mcp

An MCP server that drives a local ComfyUI - including the workflow you have open in the browser.

English | Русский

Point your assistant at ComfyUI and it can list your workflows, work out what parameters each one takes, run them, watch the progress, and show you the result. With the optional bridge node installed it can also read and edit the canvas on screen, unsaved changes and all.

you: run the ideogram workflow at 1.5 megapixels, portrait
     -> describe_workflow  finds `megapixels` and `aspect_ratio` and where they land
     -> run_workflow       submits, streams progress, returns the file
     -> show_image         you look at it

Why the bridge is the interesting half

ComfyUI's HTTP API knows about files, models and the queue. It knows nothing about the workflow being edited: that lives in litegraph, inside the page, and the only copy of its unsaved state is in the tab's memory.

The bridge turns the WebSocket ComfyUI already holds open to every client into a request/response channel, so an assistant can read the live graph, change widget values, rewire links, tidy the layout, take a screenshot of the canvas, and queue the workflow the same way the Queue button does.

Everything else works without it, and the tools say plainly which of the two setup steps is missing rather than failing vaguely.

Related MCP server: ComfyPilot

Requirements

• ComfyUI - a portable build or any local install.

• Nothing else. The installer fetches uv, which then builds an isolated .venv with the right Python. No global Python, no system packages.

• An MCP client. Eleven are supported out of the box; see below.

Install

Windows

install.bat

Linux and macOS

./install.sh

Five steps: fetch uv, build the .venv, seed .env from the template, check the server imports, run the test suite. Safe to run again - each step checks whether it is already done.

Prefer a menu to remembering names? launcher.bat / ./launcher.sh opens one window over every script in the folder, and installs first if there is no .venv yet.

Tell it where ComfyUI is

configure_comfy.bat        ./configure_comfy.sh

Root folder, port, launch script, the model and export directories, the download token. The installer opens this window by itself if it cannot resolve COMFYUI_ROOT. Everything it writes goes to .env; see .env.example for the full list of settings.

Connect your MCP client

configure_clients.bat      ./configure_clients.sh

Generates a ready config for Claude Code, Cursor, Kilo Code, OpenCode, LM Studio, Cherry Studio, MiMo Code, OpenClaw, Hermes, Codex and llama.cpp - the right shape, the right container key, the right file format, with the absolute paths into this checkout already filled in. An existing config is merged rather than replaced, and a file with comments in it is never rewritten.

Install the bridge node

install_node.bat           ./install_node.sh
uninstall_node.bat         ./uninstall_node.sh

A directory junction (symlink on Unix) into custom_nodes, so there is no second copy to drift. No administrator rights needed.

Restart ComfyUI afterwards - custom nodes are imported once at startup. After that, opening a tab is all it takes; workspace_status says whether both halves are in place.

What the 44 tools cover

Not all of them have to be offered. configure.bat writes one line to .env that narrows the set - a switched-off tool is not registered at all, so its schema never reaches the model's context. What is off is reported by comfy_status, so the assistant does not conclude the server cannot do it.

Workflows

Workflow files live in workflows/ and must be API format - Workflow -> Export (API) in ComfyUI. A UI-format export is refused with an explanation rather than half-read.

A workflow may ship a same-named .md beside it: an instruction file for whoever fills the parameters in, served verbatim by get_workflow_guide. Some graphs need input in a shape the node list cannot express, and prose gets you nowhere.

Two languages

Every window, the installer and .env.example speak English or Russian. COMFYUI_LANG decides; left empty it asks the machine. --lang=en opens any window in the other language for one run.

The tool descriptions the model reads stay English throughout, deliberately: they describe an interface to a program.

When something is wrong

• A node type cannot be found, or a pack behaves as though half of it is missing: read get_comfy_log. A custom node whose import failed is simply absent from /object_info, and absent looks exactly like never installed.

• A node is on the canvas but behaves wrongly: read get_console_log. The frontend catches an extension's import error and only logs it to the browser console, so that is the only place it exists.

• A workspace tool fails: workspace_status names which of the two things is missing - the node, or an open tab. Neither is worth retrying.

Licence

GPL-3.0. ComfyUI itself is GPL-3.0, and the bridge half of this project is a custom node that runs inside it, so the same terms are the honest fit: use it, change it, distribute it - and pass the source and the credit along with it.

Copyright (C) 2026 pytraveler