RapidChart MCP Server

Model Context Protocol (MCP) server for RapidChart - Generate and manage diagrams directly from Cursor IDE.

Features

🎨 Generate diagrams from code (Class, ER, Sequence, Architecture, etc.)
🔄 Update existing diagrams with new code
📁 Organize diagrams in workspaces and folders
🤖 Support for multiple AI models (GPT-5, Claude, Gemini)
🔐 Secure Bearer token authentication
💳 Respects your RapidChart credits and API keys

Installation

pip install rapidchart-mcp

Or install from source:

git clone https://github.com/Samicostox/rapidchart-mcp.git
cd rapidchart-mcp
pip install -e .

Configuration

1. Generate API Token

Go to RapidChart Settings
Navigate to "API Tokens"
Click "Generate New Token"
Copy the token (starts with rc_)

2. Configure Cursor

Add to your Cursor MCP settings (~/.cursor/mcp.json or workspace .cursor/mcp.json):

{
  "mcpServers": {
    "rapidchart": {
      "command": "python",
      "args": ["-m", "rapidchart_mcp"],
      "env": {
        "RAPIDCHART_API_TOKEN": "rc_your_token_here",
        "RAPIDCHART_API_URL": "https://fastuml-0bb6938ba599.herokuapp.com",
        "RAPIDCHART_DEFAULT_TYPE": "general",
        "RAPIDCHART_FEW_PROMPTS": "false",
        "RAPIDCHART_GUIDELINES": "true"
      }
    }
  }
}

Usage

In Cursor

Once configured, you can use natural language:

User: "Generate a class diagram from src/models.py"
→ Cursor reads the file and calls RapidChart MCP
→ Returns diagram URL

User: "List my available AI models"
→ Shows models with your credit status

User: "Update diagram abc123 with new code from src/models.py"
→ Updates the diagram with context awareness

Available Tools

list_models - Show available AI models and your credits
list_workspaces - List your workspaces
list_folders - List folders in a workspace
list_diagrams - Browse your diagrams
create_diagram - Generate diagram from code
get_diagram - Get specific diagram details
update_diagram - Update diagram with new code
delete_diagram - Delete a diagram
move_diagram - Move diagram to different folder/workspace

Environment Variables

Variable	Required	Default	Description
`RAPIDCHART_API_TOKEN`	✅ Yes	-	Your RapidChart API token
`RAPIDCHART_API_URL`	No	Production URL	API base URL
`RAPIDCHART_DEFAULT_TYPE`	No	`general`	Default diagram type
`RAPIDCHART_DEFAULT_MODEL`	No	Auto	Default AI model ID
`RAPIDCHART_FEW_PROMPTS`	No	`false`	Enable multi-step thinking
`RAPIDCHART_GUIDELINES`	No	`true`	Include diagram guidelines
`RAPIDCHART_TIMEOUT`	No	`300`	Request timeout (seconds)

Development

# Clone the repo
git clone https://github.com/rapidchart/rapidchart-mcp.git
cd rapidchart-mcp

# Install in development mode
pip install -e .

# Run tests
pytest

# Run the server directly
python -m rapidchart_mcp

Known Issues

503 Timeout on Diagram Creation

Symptom: You get a 503 Service Unavailable error, but the diagram is created successfully.

Cause: Heroku has a 30-second router timeout. Complex diagrams can take 30-60+ seconds to generate.

Solution:

The diagram IS being created despite the error
Run list_diagrams to see your newly created diagram
This is a Heroku limitation, not a bug in RapidChart

Workaround: Use simpler code or smaller diagrams for faster generation.

License

MIT

Support

📧 Email: hello@rapidchart.com
🐛 Issues: GitHub Issues
📖 Docs: docs.rapidchart.com