# ComfyUI MCP Server
> AI-powered image generation for game development via ComfyUI and the Model Context Protocol
[](https://github.com/purlieu-studios/comfyui-mcp/actions/workflows/ci.yml)
[](https://www.python.org/downloads/)
[](https://opensource.org/licenses/MIT)
[](https://github.com/astral-sh/ruff)
[](http://mypy-lang.org/)
## Overview
ComfyUI MCP Server is a **Model Context Protocol (MCP) server** that bridges [ComfyUI](https://github.com/comfyanonymous/ComfyUI)'s powerful workflow-based AI image generation with modern development workflows. Originally designed for [Godot](https://godotengine.org/) game development, it can be used with any MCP-compatible client to generate game assets, concept art, and visual content dynamically.
### Key Features
- **MCP Integration**: Expose ComfyUI workflows as standardized MCP tools
- **Python API Client**: Full-featured async ComfyUI API client with type safety
- **Workflow Templates**: Pre-built templates for common game assets (characters, items, environments)
- **Async Operations**: Non-blocking generation with real-time progress updates via WebSockets
- **Flexible Configuration**: TOML files, environment variables, or Python code
- **Type Safe**: Full type hints with strict mypy validation
- **Well Tested**: Comprehensive test coverage with pytest
- **Production Ready**: Retry logic, error handling, and logging built-in
### Use Cases
- **Character Generation**: NPC portraits, character sprites, concept art
- **Item Icons**: Unique item icons from text descriptions
- **Environment Art**: Background textures, tileable patterns, landscapes
- **Dynamic Content**: Procedural asset generation during gameplay
- **Concept Art**: Rapid visual prototyping and iteration
- **Batch Processing**: Generate multiple asset variations efficiently
---
## Table of Contents
- [Quick Start](#quick-start)
- [Installation](#installation)
- [Configuration](#configuration)
- [Usage](#usage)
- [MCP Server](#mcp-server-usage)
- [Python API Client](#python-api-client)
- [Workflow Templates](#workflow-templates)
- [Documentation](#documentation)
- [Examples](#examples)
- [Development](#development)
- [Troubleshooting](#troubleshooting)
- [Contributing](#contributing)
- [License](#license)
---
## Quick Start
### Prerequisites
1. **Python 3.10 or higher**
```bash
python --version # Should be 3.10+
```
2. **ComfyUI installed and running**
- Download: [ComfyUI GitHub](https://github.com/comfyanonymous/ComfyUI)
- Default URL: `http://localhost:8188`
- Verify: Open `http://localhost:8188` in your browser
3. **Stable Diffusion models**
- Download models and place in ComfyUI's `models/checkpoints/` directory
- Recommended: Stable Diffusion 1.5 or 2.1 for game assets
### Installation
```bash
# Clone the repository
git clone https://github.com/purlieu-studios/comfyui-mcp.git
cd comfyui-mcp
# Install the package
pip install -e .
# For development (includes testing and linting tools)
pip install -e ".[dev]"
# Verify installation
python -c "from comfyui_mcp import ComfyUIClient; print('Installation successful!')"
```
### Basic Configuration
**Option 1: Environment Variables (Recommended for getting started)**
```bash
# Required
export COMFYUI_URL="http://localhost:8188"
# Optional
export COMFYUI_TIMEOUT="120.0"
export COMFYUI_OUTPUT_DIR="./generated_images"
```
**Option 2: TOML Configuration File**
Create `comfyui.toml` in your project root:
```toml
[comfyui]
url = "http://localhost:8188"
timeout = 120.0
output_dir = "./generated_images"
```
See [docs/CONFIGURATION.md](docs/CONFIGURATION.md) for comprehensive configuration options.
### Your First Generation
#### Using the Python API
```python
import asyncio
from comfyui_mcp import ComfyUIClient, ComfyUIConfig, WorkflowPrompt
async def generate_image():
# Configure the client
config = ComfyUIConfig(url="http://localhost:8188")
async with ComfyUIClient(config) as client:
# Check ComfyUI server health
if not await client.health_check():
print("ComfyUI server is not responding!")
return
# Create a simple workflow
workflow = WorkflowPrompt(
prompt={
"3": {
"class_type": "KSampler",
"inputs": {
"seed": 42,
"steps": 20,
"cfg": 7.0,
"sampler_name": "euler",
"scheduler": "normal",
"denoise": 1.0
}
}
}
)
# Submit and wait for completion
prompt_id = await client.submit_workflow(workflow)
print(f"Workflow submitted: {prompt_id}")
result = await client.wait_for_completion(
prompt_id=prompt_id,
poll_interval=1.0,
timeout=300.0
)
print(f"Generation complete! Result: {result}")
# Run the async function
asyncio.run(generate_image())
```
#### Using the MCP Server
**1. Configure MCP Server**
Add to your `.mcp.json`:
```json
{
"mcpServers": {
"comfyui-mcp": {
"command": "python",
"args": ["-m", "comfyui_mcp.server"],
"env": {
"COMFYUI_URL": "http://localhost:8188",
"COMFYUI_OUTPUT_DIR": "./generated_images"
}
}
}
}
```
**More Configuration Examples:**
Complete `.mcp.json` configuration examples are available in [`examples/mcp/`](examples/mcp/):
| Example | Description | Use Case |
|---------|-------------|----------|
| [`basic.mcp.json`](examples/mcp/basic.mcp.json) | Minimal configuration | Quick start, local development |
| [`development.mcp.json`](examples/mcp/development.mcp.json) | Development setup | Game project development |
| [`production.mcp.json`](examples/mcp/production.mcp.json) | Production deployment | Remote servers, teams |
| [`custom-templates.mcp.json`](examples/mcp/custom-templates.mcp.json) | Custom workflow templates | Game-specific workflows |
| [`multi-server.mcp.json`](examples/mcp/multi-server.mcp.json) | Multiple MCP instances | Large projects, asset categories |
| [`docker.mcp.json`](examples/mcp/docker.mcp.json) | Docker/container setup | Containerized deployment |
| [`windows.mcp.json`](examples/mcp/windows.mcp.json) | Windows environment | Windows development |
See [`examples/mcp/README.md`](examples/mcp/README.md) for detailed documentation of each configuration.
**2. Use via Claude Code or MCP Client**
```python
# Via MCP client (example)
result = await mcp.call_tool(
"generate_image",
{
"template": "character-portrait",
"prompt": "fantasy elf warrior with detailed armor and glowing sword",
"width": 512,
"height": 512,
"steps": 25,
"seed": 12345
}
)
```
---
## Installation
### From Source (Development)
```bash
# Clone the repository
git clone https://github.com/purlieu-studios/comfyui-mcp.git
cd comfyui-mcp
# Create virtual environment (recommended)
python -m venv venv
source venv/bin/activate # On Windows: venv\Scripts\activate
# Install in editable mode with dev dependencies
pip install -e ".[dev]"
# Install pre-commit hooks
pre-commit install
```
### From PyPI (Coming Soon)
```bash
pip install comfyui-mcp
```
### Dependencies
**Core:**
- Python 3.10+
- `aiohttp` - Async HTTP client for ComfyUI API
- `pydantic` - Data validation and settings management
- `tomli` - TOML configuration file parsing
- `websockets` - WebSocket support for real-time updates
**Development:**
- `pytest` - Testing framework
- `pytest-asyncio` - Async test support
- `pytest-cov` - Code coverage
- `mypy` - Static type checking
- `ruff` - Fast linting and formatting
- `pre-commit` - Git hooks for code quality
---
## Configuration
ComfyUI MCP Server supports three configuration methods:
### 1. TOML Configuration File (Recommended for Projects)
Create `comfyui.toml`:
```toml
[comfyui]
# Required: ComfyUI server URL
url = "http://localhost:8188"
# Optional: API key for authentication (8+ characters)
# api_key = "your-api-key-here"
# Optional: Request timeout in seconds (1.0 - 3600.0)
timeout = 120.0
# Optional: Output directory for generated images
output_dir = "./generated_images"
```
**Configuration file locations** (searched in order):
1. `./comfyui.toml` (current directory)
2. `~/.config/comfyui/comfyui.toml` (user config)
3. `/etc/comfyui/comfyui.toml` (system-wide)
### 2. Environment Variables (Recommended for Deployment)
```bash
export COMFYUI_URL="http://localhost:8188"
export COMFYUI_API_KEY="your-api-key-min-8-chars"
export COMFYUI_TIMEOUT="120.0"
export COMFYUI_OUTPUT_DIR="./generated_images"
```
### 3. Python Code (Programmatic Configuration)
```python
from comfyui_mcp import ComfyUIConfig, ComfyUIClient
# Direct instantiation
config = ComfyUIConfig(
url="http://localhost:8188",
api_key="your-api-key",
timeout=120.0,
output_dir="./generated_images"
)
# Load from environment
config = ComfyUIConfig.from_env()
# Use the config
async with ComfyUIClient(config) as client:
await client.health_check()
```
### Configuration Priority
When multiple methods are used:
1. **Python code** (highest priority)
2. **Environment variables**
3. **TOML configuration file**
4. **Default values** (lowest priority)
### Example Configuration Files
Complete example configuration files are available in `examples/config/`:
| File | Description | Use Case |
|------|-------------|----------|
| `comfyui.minimal.toml` | Minimal configuration with only required settings | Quick start, beginners |
| `comfyui.example.toml` | Standard configuration with common options | General development |
| `comfyui.dev.toml` | Development environment settings | Local development |
| `comfyui.prod.toml` | Production environment settings | Production deployment |
| `comfyui.test.toml` | Testing and CI/CD configuration | Automated testing |
| `comfyui.docker.toml` | Docker and Kubernetes deployment | Containerized environments |
| `comfyui.advanced.toml` | Comprehensive reference with all options | Complete documentation |
| `.env.example` | Environment variables template | Docker, CI/CD |
**Quick start:**
```bash
# Copy minimal config to get started
cp examples/config/comfyui.minimal.toml comfyui.toml
# Or use a specific environment
cp examples/config/comfyui.dev.toml comfyui.toml
```
See [docs/CONFIGURATION.md](docs/CONFIGURATION.md) for comprehensive configuration documentation.
---
## Usage
### MCP Server Usage
The MCP server exposes ComfyUI functionality as standardized MCP tools.
#### Available MCP Tools
| Tool | Description |
|------|-------------|
| `generate_image` | Generate images using workflow templates |
| `list_workflows` | List available workflow templates |
| `get_workflow_status` | Check generation progress and status |
| `cancel_workflow` | Cancel a running workflow |
| `load_workflow` | Load and use a custom workflow file |
#### Example: Generate Image Tool
```json
{
"tool": "generate_image",
"arguments": {
"template": "character-portrait",
"prompt": "cyberpunk hacker, neon lights, detailed face",
"negative_prompt": "blurry, low quality",
"width": 512,
"height": 768,
"steps": 30,
"cfg_scale": 7.5,
"seed": 42
}
}
```
#### Starting the MCP Server
```bash
# Via Python module
python -m comfyui_mcp.server
# Or with custom configuration
COMFYUI_URL="http://localhost:8188" python -m comfyui_mcp.server
```
### Python API Client
Direct programmatic access to ComfyUI API.
#### Basic Usage
```python
from comfyui_mcp import ComfyUIClient, ComfyUIConfig
async def main():
config = ComfyUIConfig(url="http://localhost:8188")
async with ComfyUIClient(config) as client:
# Health check
is_healthy = await client.health_check()
print(f"ComfyUI Status: {'Online' if is_healthy else 'Offline'}")
# Get system info
system_stats = await client.get_system_stats()
print(f"System: {system_stats}")
```
#### Submitting Workflows
```python
from comfyui_mcp import WorkflowPrompt
async def generate():
config = ComfyUIConfig.from_env()
async with ComfyUIClient(config) as client:
workflow = WorkflowPrompt(
prompt={
"1": {
"class_type": "CheckpointLoaderSimple",
"inputs": {"ckpt_name": "sd_v1-5.safetensors"}
},
"2": {
"class_type": "CLIPTextEncode",
"inputs": {
"text": "beautiful landscape, mountains, sunset",
"clip": ["1", 0]
}
}
# ... more nodes
}
)
# Submit workflow
prompt_id = await client.submit_workflow(workflow)
# Wait for completion (with polling)
result = await client.wait_for_completion(
prompt_id=prompt_id,
poll_interval=2.0, # Check every 2 seconds
timeout=300.0 # Timeout after 5 minutes
)
return result
```
#### Queue Management
```python
async def manage_queue():
async with ComfyUIClient(config) as client:
# Get queue status
queue = await client.get_queue()
print(f"Queue size: {queue['queue_running']}")
# Cancel specific workflow
await client.cancel_workflow(prompt_id="abc-123")
# Clear entire queue (careful!)
await client.interrupt()
```
#### Retrieving Generated Images
```python
async def download_images(prompt_id: str):
async with ComfyUIClient(config) as client:
# Get workflow result
history = await client.get_history(prompt_id)
# Extract image filenames
for node_id, output in history["outputs"].items():
if "images" in output:
for image in output["images"]:
# Download image
image_data = await client.download_image(
filename=image["filename"],
subfolder=image.get("subfolder", ""),
folder_type=image.get("type", "output")
)
# Save to file
with open(f"./output/{image['filename']}", "wb") as f:
f.write(image_data)
```
#### Error Handling
```python
from comfyui_mcp.exceptions import (
ComfyUIError,
ConnectionError,
WorkflowExecutionError,
TimeoutError
)
async def safe_generation():
try:
async with ComfyUIClient(config) as client:
result = await client.submit_workflow(workflow)
except ConnectionError as e:
print(f"Cannot connect to ComfyUI: {e}")
except WorkflowExecutionError as e:
print(f"Workflow failed: {e}")
except TimeoutError as e:
print(f"Generation timed out: {e}")
except ComfyUIError as e:
print(f"ComfyUI error: {e}")
```
See [docs/API.md](docs/API.md) for complete API documentation.
---
## Workflow Templates
Pre-built workflow templates for common game asset types.
### Available Templates
| Template | Description | Size | Use Case |
|----------|-------------|------|----------|
| `character-portrait` | Character portraits and avatars | 512x512 | RPG character art, NPC portraits |
| `item-icon` | Centered item icons | 512x512 | Inventory items, UI icons |
| `environment-texture` | Tileable environment textures | 1024x1024 | Backgrounds, terrain textures |
| `pixel-art` | Upscaled pixel art style | 256x256 | Retro games, pixel art assets |
### Using Templates
```python
from comfyui_mcp import WorkflowTemplateManager
# Load template manager
manager = WorkflowTemplateManager(templates_dir="./workflows")
# List available templates
templates = manager.list_templates()
for template in templates:
print(f"{template.name}: {template.description}")
# Load and customize template
template = manager.load_template("character-portrait")
workflow = template.instantiate(
prompt="fantasy wizard with blue robes",
seed=12345,
steps=25
)
# Submit to ComfyUI
async with ComfyUIClient(config) as client:
prompt_id = await client.submit_workflow(workflow)
```
### Creating Custom Templates
See [docs/workflow-templates.md](docs/workflow-templates.md) for template creation guide.
---
## Documentation
Comprehensive documentation is available in the `docs/` directory:
- **[API Reference](docs/API.md)** - Complete Python API documentation
- ComfyUIClient methods and parameters
- Pydantic models and data structures
- Exception handling
- Type hints and examples
- **[Configuration Guide](docs/CONFIGURATION.md)** - Configuration options and best practices
- TOML file format and schema
- Environment variables
- Configuration priority
- Example configurations
- **[ComfyUI API Integration](docs/COMFYUI_API.md)** - ComfyUI REST API patterns
- API endpoints and methods
- Workflow structure
- Queue management
- WebSocket integration
- **[MCP Tool Usage](docs/MCP_TOOLS.md)** - Complete MCP tool reference and usage guide
- All 5 MCP tools documented
- Integration patterns and examples
- Best practices and troubleshooting
- **[Workflow Creation Tutorial](docs/WORKFLOW_TUTORIAL.md)** - Comprehensive guide to creating ComfyUI workflows
- Understanding workflow structure and node system
- Creating workflows from scratch
- Parameter substitution and templates
- Advanced techniques (LoRA, ControlNet, batching)
- Integration with MCP server
- Complete examples for characters, items, and environments
- **[Workflow Template System](docs/WORKFLOW_TEMPLATES.md)** - Complete workflow template system documentation
- Template structure and file format
- Creating and using templates
- Built-in templates (character, item, environment, pixel art)
- Parameter substitution engine
- WorkflowTemplateManager usage
- Best practices and advanced topics
- Complete examples and troubleshooting
- **[Godot Integration](docs/godot-integration.md)** *(coming soon)* - Godot plugin and examples
---
## Examples
Practical examples are available in the `examples/` directory:
### Example Projects
- **[Character Portrait Generation](examples/character_portrait.py)** - Generate RPG character portraits
- **[Item Icon Batch Generation](examples/item_icons.py)** - Batch generate inventory icons
- **[Environment Textures](examples/environment_textures.py)** - Create tileable background textures
- **[Real-time Godot Integration](examples/godot/)** - Live generation in Godot engine
- **[Procedural Sprite Variation](examples/sprite_variation.py)** - Generate sprite variations
### Running Examples
```bash
# Set configuration
export COMFYUI_URL="http://localhost:8188"
# Run character portrait example
python examples/character_portrait.py
# Run batch item icon generation
python examples/item_icons.py --count 10 --prompt "fantasy sword"
```
---
## Development
### Setup Development Environment
```bash
# Clone repository
git clone https://github.com/purlieu-studios/comfyui-mcp.git
cd comfyui-mcp
# Create virtual environment
python -m venv venv
source venv/bin/activate # Windows: venv\Scripts\activate
# Install with development dependencies
pip install -e ".[dev]"
# Install pre-commit hooks
pre-commit install
```
### Running Tests
```bash
# Run all tests
pytest tests/ -v
# Run with coverage report
pytest tests/ -v --cov=comfyui_mcp --cov-report=term-missing
# Run specific test file
pytest tests/test_client.py -v
# Run tests matching pattern
pytest tests/ -v -k "test_workflow"
```
### Code Quality Checks
```bash
# Type checking (strict mode)
mypy src/
# Linting
ruff check src/ tests/
# Format code
ruff format src/ tests/
# Run all quality checks
pre-commit run --all-files
```
### Project Structure
```
comfyui-mcp/
├── src/
│ └── comfyui_mcp/ # Main package
│ ├── __init__.py # Public API exports
│ ├── server.py # MCP server implementation
│ ├── comfyui_client.py # ComfyUI API client
│ ├── models.py # Pydantic data models
│ ├── config.py # Configuration management
│ ├── exceptions.py # Custom exceptions
│ └── utils.py # Utility functions
├── tests/ # Test suite
│ ├── test_client.py # Client tests
│ ├── test_models.py # Model validation tests
│ ├── test_config.py # Configuration tests
│ └── fixtures/ # Test fixtures
├── examples/ # Example scripts
│ ├── character_portrait.py
│ ├── item_icons.py
│ └── godot/ # Godot integration
├── workflows/ # Workflow templates
│ ├── character-portrait.json
│ ├── item-icon.json
│ └── environment-texture.json
├── docs/ # Documentation
│ ├── API.md
│ ├── CONFIGURATION.md
│ └── COMFYUI_API.md
├── .github/workflows/ # CI/CD
│ └── ci.yml
├── pyproject.toml # Package configuration
├── README.md # This file
├── CLAUDE.md # AI assistant context
└── LICENSE # MIT License
```
### Contributing
We welcome contributions! Please see [CONTRIBUTING.md](CONTRIBUTING.md) for guidelines.
**Quick contribution checklist:**
1. Fork the repository
2. Create a feature branch (`git checkout -b feature/amazing-feature`)
3. Write tests for your changes
4. Ensure all tests pass (`pytest tests/`)
5. Run type checking (`mypy src/`)
6. Run linting (`ruff check src/ tests/`)
7. Format code (`ruff format src/ tests/`)
8. Commit changes (`git commit -m 'feat: add amazing feature'`)
9. Push to branch (`git push origin feature/amazing-feature`)
10. Open a Pull Request
---
## Troubleshooting
### Common Issues
#### ComfyUI Server Connection Failed
**Problem:** `ConnectionError: Cannot connect to ComfyUI server at http://localhost:8188`
**Solutions:**
1. Verify ComfyUI is running: Open `http://localhost:8188` in browser
2. Check URL configuration: Ensure `COMFYUI_URL` is correct
3. Check firewall settings: Allow connections on port 8188
4. Try explicit localhost: Use `http://127.0.0.1:8188` instead of `http://localhost:8188`
```python
# Test connection
from comfyui_mcp import ComfyUIClient, ComfyUIConfig
async def test_connection():
config = ComfyUIConfig(url="http://127.0.0.1:8188")
async with ComfyUIClient(config) as client:
is_healthy = await client.health_check()
print(f"Connection: {'✓' if is_healthy else '✗'}")
```
#### Workflow Execution Timeout
**Problem:** `TimeoutError: Workflow execution exceeded timeout of 120.0 seconds`
**Solutions:**
1. Increase timeout in configuration:
```toml
[comfyui]
timeout = 300.0 # 5 minutes
```
2. Reduce workflow complexity (fewer steps, lower resolution)
3. Check ComfyUI server logs for errors
4. Ensure models are downloaded and accessible
#### Module Import Errors
**Problem:** `ModuleNotFoundError: No module named 'comfyui_mcp'`
**Solutions:**
1. Reinstall package: `pip install -e .`
2. Activate virtual environment: `source venv/bin/activate`
3. Check Python path: `echo $PYTHONPATH`
#### Type Checking Errors
**Problem:** `mypy` reports type errors
**Solutions:**
1. Update type stubs: `pip install --upgrade types-all`
2. Check mypy configuration in `pyproject.toml`
3. Use `# type: ignore` for false positives (sparingly)
### Debug Mode
Enable debug logging:
```python
import logging
logging.basicConfig(
level=logging.DEBUG,
format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
# Now all ComfyUI MCP operations will log debug information
```
### Getting Help
- **GitHub Issues**: [Report bugs or request features](https://github.com/purlieu-studios/comfyui-mcp/issues)
- **GitHub Discussions**: [Ask questions and share ideas](https://github.com/purlieu-studios/comfyui-mcp/discussions)
- **Documentation**: [Read the docs](docs/)
---
## Roadmap
See [GitHub Milestones](https://github.com/purlieu-studios/comfyui-mcp/milestones) for upcoming features.
### Planned Features
- **Phase 1: Foundation** (Current)
- ✅ ComfyUI API client
- ✅ MCP server implementation
- ✅ Basic workflow templates
- ✅ Configuration system
- ✅ Comprehensive documentation
- **Phase 2: Advanced Features** (Next)
- [ ] WebSocket support for real-time progress
- [ ] Advanced workflow template system
- [ ] Image post-processing pipeline
- [ ] Generation caching
- [ ] Batch processing optimization
- **Phase 3: Godot Integration** (Future)
- [ ] Godot GDScript helper library
- [ ] Godot plugin for ComfyUI integration
- [ ] Editor tools for workflow testing
- [ ] Asset pipeline integration
- **Phase 4: Production Enhancements** (Future)
- [ ] Authentication and API key support
- [ ] Rate limiting and queue management
- [ ] Monitoring and metrics
- [ ] Docker containerization
- [ ] Kubernetes deployment support
---
## License
This project is licensed under the **MIT License** - see the [LICENSE](LICENSE) file for details.
---
## Acknowledgments
- **[ComfyUI](https://github.com/comfyanonymous/ComfyUI)** - Powerful workflow-based Stable Diffusion UI by comfyanonymous
- **[Godot Engine](https://godotengine.org/)** - Open-source game engine
- **[Model Context Protocol](https://modelcontextprotocol.io/)** - Universal AI integration standard by Anthropic
- **[Pydantic](https://docs.pydantic.dev/)** - Data validation using Python type hints
- **[Ruff](https://github.com/astral-sh/ruff)** - Fast Python linter and formatter
---
## Support
- **Issues**: [GitHub Issues](https://github.com/purlieu-studios/comfyui-mcp/issues)
- **Discussions**: [GitHub Discussions](https://github.com/purlieu-studios/comfyui-mcp/discussions)
- **Documentation**: [docs/](docs/)
---
**Status**: Alpha - Active Development
Built with ❤️ by [Purlieu Studios](https://purlieu.studio)
