Claude MCP Server

A Model Context Protocol (MCP) server that provides a bridge to Anthropic's Claude CLI. This allows MCP-compliant clients (like Claude Desktop or Gemini) to interact with the Claude CLI to start new chat sessions or continue existing ones.

Features

• Start New Sessions: Initiate a new conversation with a specific Claude model.

• Continue Sessions: Reply to existing sessions using their Session ID.

• Session Management: Automatically continues the latest session if no Session ID is provided.

• Model Selection: Supports specifying different Claude models (e.g., sonnet, opus, haiku).

• System Prompt: Native support for custom system prompts.

• Working Directory: Specify custom working directory for CLI execution.

Related MCP server: MCP Server Example

Prerequisites

• Node.js 18+

• Claude CLI installed and authenticated

# Install Claude CLI
npm install -g @anthropic-ai/claude-code

# Authenticate
claude setup-token

Installation

Global Installation

npm install -g @2lab.ai/claude-mcp-server

Run directly with npx

npx @2lab.ai/claude-mcp-server

Usage

Running the server

After global installation:

claude-mcp-server

Or with npx:

npx @2lab.ai/claude-mcp-server

Testing with MCP Inspector

You can test and debug the server using the MCP Inspector:

npx @modelcontextprotocol/inspector npx @2lab.ai/claude-mcp-server

Or if globally installed:

npx @modelcontextprotocol/inspector claude-mcp-server

Claude Desktop Configuration

Add the following to your Claude Desktop configuration file:

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

{
  "mcpServers": {
    "claude-cli": {
      "command": "npx",
      "args": ["-y", "@2lab.ai/claude-mcp-server"]
    }
  }
}

Or if globally installed:

{
  "mcpServers": {
    "claude-cli": {
      "command": "claude-mcp-server"
    }
  }
}

Claude Code Configuration

Add to your Claude Code settings:

{
  "mcpServers": {
    "claude-cli": {
      "command": "npx",
      "args": ["-y", "@2lab.ai/claude-mcp-server"]
    }
  }
}

Available Tools

chat

Start a new Claude session with a prompt.

Parameters:

• prompt (required): The prompt to start the session with

• model (optional): The model to use (e.g., 'sonnet', 'opus', 'haiku')

• systemPrompt (optional): System prompt to set the assistant's behavior

• cwd (optional): Working directory for the claude CLI execution

Returns: Response text and new Session ID in _meta.sessionId

chat-reply

Continue an existing Claude session.

Parameters:

• prompt (required): The prompt to continue the conversation

• sessionId (optional): The session ID to continue. If not provided, continues the most recent session

• model (optional): The model to use for this turn

• systemPrompt (optional): Additional system prompt to append for this turn

• cwd (optional): Working directory for the claude CLI execution

Returns: Response text and Session ID in _meta.sessionId

Development

# Clone the repository
git clone https://github.com/2lab-ai/claude-mcp-server.git
cd claude-mcp-server

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# Run locally
npm start

# Test with MCP Inspector
npm run inspect

CI/CD

This project uses GitHub Actions to automatically publish to npm when changes are pushed to the main branch.

To enable automatic publishing:

1. Generate an npm access token from npmjs.com

2. Add the token as a secret named NPM_TOKEN in your GitHub repository settings

3. Bump the version in package.json before pushing to trigger a publish

License

ISC