cosmocoder/mcp-web-docs

MCP Web Docs

Index Any Documentation. Search Locally. Stay Private.

A self-hosted Model Context Protocol (MCP) server that crawls, indexes, and searches documentation from any website. Unlike remote MCP servers limited to GitHub repos or pre-indexed libraries, web-docs gives you full control over what gets indexed — including private documentation behind authentication.

Features • Installation • Quick Start • Tools • Tips • Troubleshooting • Contributing

❌ The Problem

AI assistants struggle with documentation:

• ❌ Remote MCP servers only work with GitHub or pre-indexed libraries
• ❌ Private docs behind authentication can't be accessed
• ❌ Outdated indexes don't reflect your team's latest documentation
• ❌ No control over what gets indexed or when

✅ The Solution

MCP Web Docs crawls and indexes documentation from ANY website locally:

• ✅ Any website - Docusaurus, Storybook, GitBook, custom sites, internal wikis
• ✅ Private docs - Interactive browser login for authenticated sites
• ✅ Always fresh - Re-index anytime with one command
• ✅ Your data, your machine - No API keys, no cloud, full privacy

✨ Features

• 🌐 Universal Crawler - Works with any documentation site, not just GitHub
• 🔍 Hybrid Search - Combines full-text search (FTS) with semantic vector search
• 📂 Collections - Group related docs into named collections for project-based organization
• 🏷️ Tags & Categories - Organize docs with tags and filter searches by project, team, or category
• 📦 Version Support - Index multiple versions of the same package (e.g., React 18 and 19)
• 🔐 Authentication Support - Crawl private/protected docs with interactive browser login (auto-detects your default browser)
• 📊 Smart Extraction - Automatically extracts code blocks, props tables, and structured content
• ⚡ Local Embeddings - Uses FastEmbed for fast, private embedding generation (no API keys)
• 🗄️ Persistent Storage - LanceDB for vectors, SQLite for metadata
• 🔄 Real-time Progress - Track indexing status with progress updates

🚀 Installation

Prerequisites

• Node.js >= 22.19.0

Option 1: Install from NPM (Recommended)

npm install -g @cosmocoder/mcp-web-docs

Option 2: Run with npx

No installation required - just configure your MCP client to use npx (see below).

Option 3: Build from Source

# Clone the repository
git clone https://github.com/cosmocoder/mcp-web-docs.git
cd mcp-web-docs

# Install dependencies (automatically installs Playwright browsers)
npm install

# Build
npm run build

Configure Your MCP Client

{
  "mcpServers": {
    "web-docs": {
      "command": "npx",
      "args": ["-y", "@cosmocoder/mcp-web-docs"]
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "mcp-web-docs"
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "node",
      "args": ["/path/to/mcp-web-docs/build/index.js"]
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "npx",
      "args": ["-y", "@cosmocoder/mcp-web-docs"]
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "mcp-web-docs"
    }
  }
}

{
  "servers": {
    "web-docs": {
      "command": "npx",
      "args": ["-y", "@cosmocoder/mcp-web-docs"]
    }
  }
}

{
  "servers": {
    "web-docs": {
      "command": "mcp-web-docs"
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "npx",
      "args": ["-y", "@cosmocoder/mcp-web-docs"]
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "mcp-web-docs"
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "npx",
      "args": ["-y", "@cosmocoder/mcp-web-docs"],
      "disabled": false,
      "autoApprove": []
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "mcp-web-docs",
      "disabled": false,
      "autoApprove": []
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "npx",
      "args": ["-y", "@cosmocoder/mcp-web-docs"]
    }
  }
}

{
  "mcpServers": {
    "web-docs": {
      "command": "mcp-web-docs"
    }
  }
}

⚡ Quick Start

1. Index public documentation

Index the LanceDB documentation from https://lancedb.com/docs/

The AI assistant will call add_documentation and begin crawling.

2. Search for information

How do I create a table in LanceDB?

The AI will use search_documentation to find relevant content.

3. For private docs, authenticate first

I need to index private documentation at https://internal.company.com/docs/
It requires authentication.

A browser window will open for you to log in. The session is saved for future crawls.

🔨 Available Tools

add_documentation

Add a new documentation site for indexing.

add_documentation({
  url: "https://docs.example.com/",
  title: "Example Docs",              // Optional
  id: "example-docs",                 // Optional custom ID
  tags: ["frontend", "mycompany"],    // Optional tags for categorization
  version: "2.0",                     // Optional version for versioned packages
  auth: {                             // Optional authentication
    requiresAuth: true,
    // browser auto-detected from OS settings if omitted
    loginTimeoutSecs: 300
  }
})

search_documentation

Search through indexed documentation using hybrid search (FTS + semantic).

search_documentation({
  query: "how to configure authentication",
  url: "https://docs.example.com/",    // Optional: filter to specific site
  tags: ["frontend", "mycompany"],     // Optional: filter by tags
  limit: 10                            // Optional: max results
})

authenticate

Open a browser window for interactive login to protected sites. Your default browser is automatically detected from OS settings.

authenticate({
  url: "https://private-docs.example.com/",
  // browser auto-detected from OS settings - only specify to override
  loginTimeoutSecs: 300         // Optional: timeout in seconds
})

list_documentation

List all indexed documentation sites with their metadata including tags.

set_tags

Set or update tags for a documentation site. Tags help categorize and filter documentation.

set_tags({
  url: "https://docs.example.com/",
  tags: ["frontend", "react", "mycompany"]  // Replaces existing tags
})

list_tags

List all available tags with usage counts. Useful to see what tags exist across your indexed docs.

reindex_documentation

Re-crawl and re-index a specific documentation site.

get_indexing_status

Get the current status of indexing operations.

delete_documentation

Delete an indexed documentation site and all its data.

clear_auth

Clear saved authentication session for a domain.

Collection Tools

Collections let you group related documentation sites together for project-based organization. Unlike tags (which categorize individual docs), collections create named workspaces like "My React Project" containing React + Next.js + TypeScript docs.

create_collection

Create a new collection to group documentation sites.

create_collection({
  name: "My React Project",
  description: "React, Next.js, and TypeScript docs for my project"  // Optional
})

add_to_collection

Add indexed documentation sites to a collection.

add_to_collection({
  name: "My React Project",
  urls: [
    "https://react.dev/",
    "https://nextjs.org/docs/",
    "https://www.typescriptlang.org/docs/"
  ]
})

search_collection

Search within a specific collection. Uses the same hybrid search as search_documentation but limited to docs in the collection.

search_collection({
  name: "My React Project",
  query: "server components data fetching",
  limit: 10  // Optional
})

list_collections

List all collections with their document counts.

get_collection

Get details of a specific collection including all its documentation sites.

get_collection({
  name: "My React Project"
})

update_collection

Rename a collection or update its description.

update_collection({
  name: "My React Project",
  newName: "Frontend Stack",           // Optional
  description: "Updated description"   // Optional
})

remove_from_collection

Remove documentation sites from a collection. The sites remain indexed, just removed from the collection.

remove_from_collection({
  name: "My React Project",
  urls: ["https://old-library.dev/docs/"]
})

delete_collection

Delete a collection. The documentation sites in the collection are not deleted, only the collection grouping.

delete_collection({
  name: "Old Project"
})

💡 Tips

Crafting Better Search Queries

The search uses hybrid full-text and semantic search. For best results:

1. Be specific - Include unique terms from what you're looking for

   • Instead of: "Button props"
   • Try: "Button props onClick disabled loading"

2. Use exact phrases - Wrap in quotes for exact matching

   • "authentication middleware" finds that exact phrase

3. Include context - Add related terms to narrow results

   • API docs: "GET /users endpoint authentication headers"
   • Config: "webpack config entry output plugins"

Auto-Invoke with Rules

To avoid typing search instructions in every prompt, add a rule to your MCP client:

Cursor (Cursor Settings > Rules):

When I ask about library documentation or need code examples,
use the web-docs MCP server to search indexed documentation.

Windsurf (.windsurfrules):

Always use web-docs search_documentation when I ask about
API references, configuration, or library usage.

Scoping Searches

If you have multiple sites indexed, filter by URL or tags:

// Filter by specific site URL
search_documentation({
  query: "routing",
  url: "https://nextjs.org/docs/"
})

// Filter by tags (searches all docs with matching tags)
search_documentation({
  query: "Button component",
  tags: ["frontend", "mycompany"]  // Only docs tagged with BOTH tags
})

Organizing with Tags

Tags help organize documentation when you have multiple related sites. Add tags when indexing:

// Index frontend package docs
add_documentation({
  url: "https://docs.mycompany.com/ui-components/",
  tags: ["frontend", "mycompany", "react"]
})

// Index backend API docs
add_documentation({
  url: "https://docs.mycompany.com/api/",
  tags: ["backend", "mycompany", "api"]
})

Later, search across all frontend docs:

search_documentation({
  query: "authentication",
  tags: ["frontend"]  // Searches all frontend-tagged docs
})

You can also add tags to existing documentation with set_tags.

Using Collections for Project Organization

Collections provide a higher-level grouping than tags — they let you organize documentation by project or context, making it easy to switch between different work contexts.

Create a collection for your project:

create_collection({
  name: "E-commerce Backend",
  description: "All docs for the backend rewrite project"
})

Add relevant documentation:

add_to_collection({
  name: "E-commerce Backend",
  urls: [
    "https://fastapi.tiangolo.com/",
    "https://docs.sqlalchemy.org/",
    "https://redis.io/docs/"
  ]
})

Search within your project context:

search_collection({
  name: "E-commerce Backend",
  query: "connection pooling best practices"
})

Collections vs Tags:

You can use both together — a document can have tags AND belong to multiple collections.

Versioning Package Documentation

When indexing documentation for versioned packages (React, Vue, Python libraries, etc.), you can specify the version to track which version you've indexed:

// Index React 18 docs
add_documentation({
  url: "https://18.react.dev/",
  title: "React 18 Docs",
  version: "18"
})

// Index React 19 docs (different URL)
add_documentation({
  url: "https://react.dev/",
  title: "React 19 Docs",
  version: "19"
})

The version is displayed in list_documentation output and preserved when re-indexing. Version formats are flexible — use whatever makes sense for your package (e.g., "18", "v6.4", "3.11", "latest").

Note: Version is optional and mainly useful for software packages with multiple versions. For internal documentation, wikis, or single-version products, you can skip the version field.

🚨 Troubleshooting

npx playwright install

Data Storage

All data is stored locally in ~/.mcp-web-docs/:

~/.mcp-web-docs/
├── docs.db           # SQLite database for document metadata
├── vectors/          # LanceDB vector database
├── sessions/         # Saved authentication sessions
└── crawlee/          # Crawlee datasets (cached crawl data)

📄 License

MIT License - see for details.

🙏 Acknowledgments

• Model Context Protocol - The protocol specification
• Crawlee - Web scraping and browser automation
• LanceDB - Vector database
• FastEmbed - Local embedding generation
• Playwright - Browser automation