MCP Server Builder

A Model Context Protocol (MCP) server for searching MCP protocol documentation. Built with TypeScript using the official MCP SDK.

Features

• BM25 Search - High-quality ranked search using BM25 algorithm with Porter stemming
• Fast Startup - Indexes document titles at startup, fetches content on-demand
• Markdown Aware - Weights headers, code blocks, and links for better relevance
• stdio Transport - Runs as a local process for easy integration

Installation

npm install
npm run build

Usage

Testing with MCP Inspector

The easiest way to test the server is with the MCP Inspector:

# Build first
npm run build

# Run inspector with compiled JS
npx @modelcontextprotocol/inspector node dist/index.js

# Or run with tsx for development (no build needed)
npx @modelcontextprotocol/inspector npx tsx src/index.ts

As an MCP Server

Add to your MCP client configuration (e.g., Claude Desktop, Kiro):

{
  "mcpServers": {
    "mcp-server-builder": {
      "command": "node",
      "args": ["/path/to/mcp-builder-ts/dist/index.js"]
    }
  }
}

Or using tsx for development:

{
  "mcpServers": {
    "mcp-server-builder": {
      "command": "npx",
      "args": ["tsx", "/path/to/mcp-builder-ts/src/index.ts"]
    }
  }
}

Development

# Run in development mode
npm run dev

# Run tests
npm test

# Type check
npm run typecheck

# Build
npm run build

# Test with MCP Inspector (after build)
npm run inspect

# Test with MCP Inspector (development, no build needed)
npm run inspect:dev

Tools

search_mcp_docs

Search MCP protocol documentation with ranked results.

Parameters:

• query (string, required): Search query string
• k (number, optional): Maximum results to return (default: 5). Returns fewer if fewer documents match.

Example:

{
  "query": "transports",
  "k": 5
}

Returns:

[
  {
    "url": "https://modelcontextprotocol.io/specification/2025-11-25/basic/transports.md",
    "title": "Transports",
    "score": 15.725,
    "snippet": "MCP uses JSON-RPC to encode messages..."
  }
]

fetch_mcp_doc

Fetch full document content by URL.

Parameters:

• uri (string, required): Document URL from modelcontextprotocol.io

Example:

{
  "uri": "https://modelcontextprotocol.io/specification/2025-11-25/server/tools.md"
}

Returns:

{
  "url": "https://modelcontextprotocol.io/specification/2025-11-25/server/tools.md",
  "title": "Tools",
  "content": "# Tools\n\nTools enable servers to expose executable functionality..."
}

Architecture

src/
├── index.ts          # MCP server entry point
├── config.ts         # Configuration
├── tools/
│   └── docs.ts       # search_mcp_docs, fetch_mcp_doc
└── utils/
    ├── cache.ts      # Document caching
    ├── doc-fetcher.ts # HTTP fetching & HTML parsing
    ├── indexer.ts    # BM25 search index
    ├── logger.ts     # Logging utilities
    ├── stopwords.ts  # Stop words list
    ├── text-processor.ts # Text utilities
    └── url-validator.ts  # URL validation

Search Algorithm

The search uses BM25 (Best Matching 25) with enhancements:

• Porter Stemming - Matches word variants (e.g., "running" → "run")
• Bigrams - Captures phrase matches (e.g., "tool input")
• Weighted Scoring:
  • Title matches: 3-8x boost
  • Header matches: 4x weight
  • Code blocks: 2x weight
  • Link text: 2x weight
• Domain Term Preservation - Technical terms like "mcp", "json", "stdio" are not stemmed

License

MIT