Wikipedia MCP Server

A Model Context Protocol (MCP) server that provides comprehensive Wikipedia access for AI assistants. Built in TypeScript, deployed on Vercel, and fully compatible with the MCP Streamable HTTP transport (protocol version `2025-03-26`).

Features

• 🔍 Advanced Search — find articles with relevance ranking
• 📄 Full Article Access — plain text extracts or complete wikitext
• 📝 Smart Summaries — concise summaries tailored to a specific query
• 🗂️ Section Analysis — extract and summarize individual sections
• 🔗 Link Discovery — internal links and related articles
• 🌍 Multi-language — 50+ language codes, 140+ country codes, resolved automatically
• 🔀 Parallel Search — `multi_search_wikipedia` runs multiple queries simultaneously
• 🎯 Fact Extraction — structured key-fact lists from any article
• 📍 Coordinates — lat/lon for geographic articles
• ⚡ Streamable HTTP — full MCP transport support (POST + GET SSE + DELETE)
• 🔒 Security hardened — input sanitization, tiered rate limiting, no `Server` header
• 🚀 Vercel ready — stateless serverless deployment, zero cold-start friction

Quick Start

1. Deploy

git clone https://github.com/YOUR_USERNAME/wikipedia-mcp-vercel.git
cd wikipedia-mcp-vercel
vercel

Or use the Deploy with Vercel button above.

2. Connect your AI client

The server implements MCP Streamable HTTP transport (`2025-03-26`).

Both the POST channel (client → server) and the GET SSE channel (server → client) are supported.

MCP endpoint: `https://your-app.vercel.app/mcp`

Claude Desktop

{
  "mcpServers": {
    "wikipedia": {
      "type": "http",
      "url": "https://your-app.vercel.app/mcp"
    }
  }
}

Claude Code / CLI

claude mcp add wikipedia --transport http https://your-app.vercel.app/mcp

Any MCP client (generic)

Configure the client with transport type `streamable-http` and the endpoint URL above.

The server uses stateless mode (no `Mcp-Session-Id` header), which is correct and expected for serverless deployments.

3. Environment variables (optional)

Copy `.env.example` → `.env` for local development.

4. Verify

# Health check
curl https://your-app.vercel.app/health

# Test MCP initialize
curl -X POST https://your-app.vercel.app/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-03-26","capabilities":{},"clientInfo":{"name":"test","version":"1.0"}}}'

MCP Tools

All 13 tools accept optional `language` (e.g. `"ja"`) and `country` (e.g. `"JP"`) parameters. When set, the query is sent as-is to that language's Wikipedia endpoint (e.g. `ja.wikipedia.org`). Wikipedia's own search can often match a short English title phrase to the correct local article, but there is no translation layer in this server.

Tool reference

MCP Prompts

Three prompt templates are registered and available via `prompts/list` / `prompts/get`:

REST API

Standard HTTP endpoints for non-MCP usage:

GET  /health
GET  /search/:query?limit=10
GET  /article/:title
GET  /summary/:title
GET  /sections/:title
GET  /links/:title
GET  /coordinates/:title
GET  /related/:title?limit=10
GET  /summary/:title/query/:query/length/:maxLength
GET  /summary/:title/section/:section/length/:maxLength
GET  /facts/:title?topic=...&count=5
GET  /test-connectivity
GET  /supported-countries
POST /tools/:toolName

Architecture

src/
├── server.ts               # Express app wiring
├── routes/
│   ├── mcp.ts              # Streamable HTTP transport (POST + GET SSE + DELETE)
│   └── rest.ts             # REST endpoints
├── mcp-server.ts           # MCPServer helper — tool dispatch, language routing
├── handlers.ts             # Tool handler functions
├── toolRegistrations.ts    # SDK tool + prompt registration
├── toolDefinitions.ts      # JSON Schema definitions (for REST /mcp info)
├── prompts.ts              # Prompt template logic
├── wikipedia-client.ts     # Wikipedia Action API client
├── sanitize.ts             # Input sanitization
├── middleware.ts           # Rate limiting, Server header removal
├── utils.ts                # Shared helpers
└── types.ts                # TypeScript interfaces

Transport design

The server uses stateless Streamable HTTP — the correct mode for serverless platforms:

• `POST /mcp` — receives JSON-RPC messages, returns JSON or SSE stream
• `GET /mcp` — opens an SSE channel for server-initiated messages (clients reconnect on timeout)
• `DELETE /mcp` — session termination (acknowledged; no server-side sessions to clean up)

A fresh `McpServer` + `StreamableHTTPServerTransport` instance is created for each request. All Wikipedia logic is handled by the shared, stateless `MCPServer` helper.

Development

npm install
npm run dev       # tsx watch mode on port 8000
npm run build     # tsc → dist/
npm start         # node dist/server.js
vercel dev        # local Vercel simulation

Bot authentication

For higher Wikipedia API rate limits, create a bot password:

1. Log in to your Wikipedia account

2. Go to Special:BotPasswords

3. Create a new bot password

4. Set `WIKIPEDIA_BOT_USERNAME=YourAccount@BotName` and `WIKIPEDIA_BOT_PASSWORD=...`

License

MIT