MCP Mermaid

Generate mermaid diagram and chart with AI MCP dynamically. Also you can use mcp-server-chart to generate chart, graph, map.

✨ Features

Fully support all features and syntax of Mermaid.
Support configuration of backgroundColor and theme, enabling large AI models to output rich style configurations.
Support exporting to png, svg, and mermaid formats, with validation for Mermaid to facilitate the model's multi-round output of correct syntax and graphics.

🤖 Usage

To use with Desktop APP, such as Claude, VSCode, Cline, Cherry Studio, and so on, add the MCP server config below. On Mac system:

{
  "mcpServers": {
    "mcp-mermaid": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-mermaid"
      ]
    }
  }
}

On Window system:

{
  "mcpServers": {
    "mcp-mermaid": {
      "command": "cmd",
      "args": [
        "/c",
        "npx",
        "-y",
        "mcp-mermaid"
      ]
    }
  }
}

Also, you can use it on aliyun, modelscope, glama.ai, smithery.ai or others with HTTP, SSE Protocol.

🚰 Run with SSE or Streamable transport

Option 1: Global Installation

Install the package globally:

npm install -g mcp-mermaid

Run the server with your preferred transport option:

# For SSE transport (default endpoint: /sse)
mcp-mermaid -t sse

# For Streamable transport with custom endpoint
mcp-mermaid -t streamable

Option 2: Local Development

If you're working with the source code locally:

# Clone and setup
git clone https://github.com/hustcc/mcp-mermaid.git
cd mcp-mermaid
npm install
npm run build

# Run with npm scripts
npm run start:sse        # SSE transport on port 3033
npm run start:streamable # Streamable transport on port 1122

Access Points

Then you can access the server at:

SSE transport: http://localhost:3033/sse
Streamable transport: http://localhost:1122/mcp (local) or http://localhost:3033/mcp (global)

🎮 CLI Options

You can also use the following CLI options when running the MCP server. Command options by run cli with -h.

MCP Mermaid CLI

Options:
  --transport, -t  Specify the transport protocol: "stdio", "sse", or "streamable" (default: "stdio")
  --port, -p       Specify the port for SSE or streamable transport (default: 3033)
  --endpoint, -e   Specify the endpoint for the transport:
                    - For SSE: default is "/sse"
                    - For streamable: default is "/mcp"
  --help, -h       Show this help message

🔨 Development

Install dependencies:

npm install

Build the server:

npm run build

Start the MCP server

Using MCP Inspector (for debugging):

npm run start

Using different transport protocols:

# SSE transport (Server-Sent Events)
npm run start:sse

# Streamable HTTP transport
npm run start:streamable

Direct node commands:

# SSE transport on port 3033
node build/index.js --transport sse --port 3033

# Streamable HTTP transport on port 1122
node build/index.js --transport streamable --port 1122

# STDIO transport (for MCP client integration)
node build/index.js --transport stdio

📄 License

MIT@hustcc.