Mermaid ValidatorSAFE

A Model Context Protocol server that validates and renders Mermaid diagrams. This server enables LLMs to validate and render Mermaid diagrams.

Usage

Quick Start

You can configure your MCP client to use the Mermaid Validator by adding it to your mcp servers file:

{
"mcpServers": {
"mermaid-validator": {
"command": "npx",
"args": [
"-y",
"@rtuin/mcp-mermaid-validator@latest"
]
}
}
}

Architecture

High-Level Architecture

This project is structured as a simple TypeScript Node.js application that:

1. Main Application: A Node.js service that validates Mermaid diagrams and returns rendered PNG output
2. MCP Integration: Uses the Model Context Protocol SDK to expose functionality to MCP-compatible clients
3. Mermaid CLI Integration: Leverages the Mermaid CLI tool to perform diagram validation and rendering

Code Structure

mcp-mermaid-validator/
├── dist/                   # Compiled JavaScript output
│   └── main.js             # Compiled main application
├── src/                    # TypeScript source code
│   └── main.ts             # Main application entry point
├── node_modules/           # Dependencies
├── package.json            # Project dependencies and scripts
├── package-lock.json       # Dependency lock file
├── tsconfig.json           # TypeScript configuration
├── eslint.config.js        # ESLint configuration
├── .prettierrc             # Prettier configuration
└── README.md               # Project documentation

Component Functionality

MCP Server (Main Component)

The core functionality is implemented in src/main.ts. This component:

1. Creates an MCP server instance
2. Registers a validateMermaid tool that accepts Mermaid diagram syntax
3. Uses the Mermaid CLI to validate and render diagrams
4. Returns validation results and rendered PNG (if valid)
5. Handles error cases with appropria