HexDocs MCP server

This MCP server enables AI agents to search documentation in HexDocs, giving them access to official Elixir and Hex package documentation. It works with AI assistants like Claude or Cursor to provide accurate technical information from the HexDocs ecosystem.

Prerequisites

• Node.js (v18 or later)
• npm

Installation

Follow these steps to set up the HexDocs MCP server:

1. Clone the repository:

git clone https://github.com/v0idpwn/hexdocs-mcp.git

2. Install dependencies:

npm install

3. Build the TypeScript code:

npm run build

4. Set up the MCP in your AI agent. For Claude, use:

claude mcp add hexdocs node /path/to/hexdocs-mcp/dist/index.js

Usage

Searching Documentation

Once installed, your AI assistant can access HexDocs documentation. The MCP enables searching through:

• Official Elixir documentation
• Any package published on Hex.pm with documentation

Example Queries

You can ask your AI assistant questions about Elixir or Hex packages:

• "Look up the String.split function in Elixir"
• "Find documentation for Phoenix LiveView"
• "How do I use Ecto changesets?"

The assistant will use the MCP to search HexDocs and retrieve the relevant documentation.

Advanced Usage

For more specific searches, you can specify the package and version:

• "Find the documentation for Ecto 3.10 Query API"
• "Show me the Phoenix.Controller module from Phoenix 1.7"

This allows you to access documentation for specific versions of packages when needed.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "hexdocs" '{"command":"node","args":["/path/to/hexdocs-mcp/dist/index.js"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

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

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

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

3. Restart Claude Desktop for the changes to take effect