ComfyUI MCP Server

Research Preview: The ComfyUI MCP Server is currently in limited early access. Features, tools, and behavior may change as the project evolves. Interested? Sign up for the waitlist.

The ComfyUI MCP Server connects AI assistants — including Claude Desktop, Claude Code, and Cursor — to Comfy Cloud via the Model Context Protocol (MCP). It lets AI agents generate images, search models/nodes/templates, and run full ComfyUI workflows on cloud GPUs, with no local GPU required.

Quick Start

1. Get Your API Key

Visit https://platform.comfy.org/login and Log In

Please visit https://platform.comfy.org/login and log in with the corresponding account Visit Platform Login Page

Click `+ New` in API Keys to Create an API Key

Click + New in API Keys to create an API Key Create API Key

Enter API Key Name

(Required) Enter the API Key name,
Click Generate to create

Save the Obtained API Key

Since the API Key is only visible upon first creation, please save it immediately after creation. It cannot be viewed later, so please keep it safe. Please note that you should not share your API Key with others. Once it leaked, you can delete it and create a new one.

2. Connect Your Client

The ComfyUI MCP Server is hosted at https://cloud.comfy.org/mcp. No local installation or Node.js required — just point your MCP client at the server URL with your API key.

Claude Code
Claude Desktop
Cursor

claude mcp add comfyui-cloud \
  --transport http \
  https://cloud.comfy.org/mcp \
  -H "X-API-Key: your-api-key-here"

Add the following to your Claude Desktop config file:

OS	Config path
macOS	`~/Library/Application Support/Claude/claude_desktop_config.json`
Windows	`%APPDATA%\Claude\claude_desktop_config.json`
Linux	`~/.config/Claude/claude_desktop_config.json`

{
  "mcpServers": {
    "comfyui-cloud": {
      "url": "https://cloud.comfy.org/mcp",
      "headers": {
        "X-API-Key": "your-api-key-here"
      }
    }
  }
}

Add the following to your Cursor MCP config (.cursor/mcp.json in your project or global config):

{
  "mcpServers": {
    "comfyui-cloud": {
      "url": "https://cloud.comfy.org/mcp",
      "headers": {
        "X-API-Key": "your-api-key-here"
      }
    }
  }
}

See Cursor’s MCP documentation for more details.

After adding the server, restart your MCP client to pick up the new configuration.

Available Tools

Discovery

Tool	Description
`search_templates`	Search pre-built workflow templates from comfy.org by text, tag, media type, or model
`search_models`	Search model catalog by text, type, base model, or source
`search_nodes`	Search available nodes by text, category, or input/output types

Execution

Tool	Description
`submit_workflow`	Submit a ComfyUI API-format workflow for execution on Comfy Cloud
`upload_file`	Upload an input image or file for use in workflows (e.g. LoadImage)
`get_job_status`	Poll execution status of a submitted workflow
`get_output`	Retrieve output images, videos, or audio from a completed workflow
`use_previous_output`	Chain workflows by reusing the output of one as input to another
`cancel_job`	Cancel a pending or running job
`get_queue`	Check how many jobs are running and pending

Saved Workflows

Tool	Description
`list_saved_workflows`	Browse your saved workflows from Comfy Cloud
`get_saved_workflow`	Inspect a saved workflow’s nodes, inputs, and configuration

The server checks for a matching pre-built template before building a workflow from scratch, leading to better results and faster generation.

How It Works

┌──────────────┐    HTTPS/MCP    ┌─────────────────────────────────────────────┐
│  AI Agent    │◄───────────────►│            Comfy Cloud                      │
│  (Claude,    │   X-API-Key     │  cloud.comfy.org/mcp → Workflow Execution   │
│   Cursor)    │                 │                        on Cloud GPUs        │
└──────────────┘                 └─────────────────────────────────────────────┘

Your AI agent connects directly to the hosted MCP server at cloud.comfy.org/mcp. The server translates MCP tool calls into workflow executions on Comfy Cloud GPUs — no local server or GPU required. The AI agent uses the discovery tools to find templates and nodes, then constructs the ComfyUI API-format workflow JSON, submits it, and returns the results — just describe what you want in natural language.

Example Prompts

After installing, try these prompts in your AI assistant:

Generate an image of a cat astronaut floating in space, cartoon style

Find me workflow templates for text-to-video generation

Search for SDXL checkpoint models and tell me which ones are available

Generate a fantasy landscape with mountains and a glowing river at sunset

What nodes are available for image upscaling?

The agent will search for a matching template, build the ComfyUI workflow, submit it to Comfy Cloud, and return the generated image directly in the conversation.

Output Handling

Images are displayed inline in the conversation (Claude Code) or in the artifact side panel (Claude Desktop)
Video and audio outputs are returned as downloadable links
Animated images (GIF, WebP) are saved but not previewed inline to preserve animation
Inline image previews are resized to 1024px for efficient display; full-resolution outputs are always available via the get_output tool

Known Limitations

This is an early release. The following limitations are known and being actively worked on.

Workflows

Cannot run saved workflows by ID. You can browse and inspect saved workflows (list_saved_workflows, get_saved_workflow), but not execute them directly. Saved workflows use the ComfyUI graph format, which requires conversion to API format. The AI agent must reconstruct the workflow from scratch.
Generated assets have no workflow metadata. Images created via the MCP server don’t include workflow JSON in their metadata, so they won’t show the workflow when opened in ComfyUI.
Workflow accuracy depends on the AI. The agent constructs ComfyUI workflows from natural language. Complex multi-node workflows or unusual node configurations may require iteration.

File Handling

Upload size limits may apply depending on your MCP client.
Image previews are resized. Inline previews are limited to 1024px (JPEG). Full-resolution files are saved to disk.

Authentication

API key only. Authentication requires a Comfy Cloud API key passed via the X-API-Key header. Browser-based OAuth is not yet available.

Client-Specific

Claude Desktop — Generated images appear in the artifact side panel via HTML, not as native image artifacts.

Troubleshooting

MCP server not showing up

Restart your MCP client (close and reopen Claude Code, Claude Desktop, or Cursor). MCP servers are loaded at startup. Double-check that the server URL is exactly https://cloud.comfy.org/mcp in your config.

API key errors

Verify your API key is valid at platform.comfy.org/profile/api-keys. Make sure the key is passed in the X-API-Key header (not as a Bearer token). Generate a new key if needed and update your client config.

Connection errors

If the MCP client can’t reach the server, check that:

You have an active internet connection
Your firewall or proxy isn’t blocking cloud.comfy.org
You have an active Comfy Cloud subscription

ComfyUI Server

Cloud API

CLI

Develop Custom Nodes

Registry

Specifications

ComfyUI MCP Server

Quick Start

1. Get Your API Key

2. Connect Your Client

Available Tools

Discovery

Execution

Saved Workflows

How It Works

Example Prompts

Output Handling

Known Limitations

Troubleshooting

MCP server not showing up

API key errors

Connection errors

ComfyUI Server

Cloud API

CLI

Develop Custom Nodes

Registry

Specifications

​Quick Start

​1. Get Your API Key

​2. Connect Your Client

​Available Tools

​Discovery

​Execution

​Saved Workflows

​How It Works

​Example Prompts

​Output Handling

​Known Limitations

​Troubleshooting

​MCP server not showing up

​API key errors

​Connection errors

Quick Start

1. Get Your API Key

2. Connect Your Client

Available Tools

Discovery

Execution

Saved Workflows

How It Works

Example Prompts

Output Handling

Known Limitations

Troubleshooting

MCP server not showing up

API key errors

Connection errors