MCP Server

Overview

jscpd-server implements the Model Context Protocol (MCP), allowing AI assistants like Claude Desktop, Cursor, and Copilot to detect code duplication directly from the editor — no CLI invocation needed.

Starting the Server

# Install and start
npm install -g jscpd-server
jscpd-server /path/to/project

# With custom port
jscpd-server /path/to/project --port 3000

Note: The jscpd-server is still Node.js based. The CLI detection engine (jscpd command) is Rust-based in v5, but the server uses the v4 engine.

Configuration

Add to your MCP client config (e.g. Claude Desktop):

{
  "mcpServers": {
    "jscpd": {
      "type": "streamable-http",
      "url": "http://localhost:3000/mcp"
    }
  }
}

Available MCP Tools

check_duplication

Checks a provided code snippet for duplications against the codebase currently being served by jscpd-server.

Arguments:

• code (string, required): The source code snippet to analyze
• format (string, required): The format of the code (e.g. "javascript", "typescript")
• recheck (boolean, optional): If true, triggers a re-scan of the current directory before checking the snippet

get_statistics

Retrieves the overall project duplication statistics.

Arguments: None

Returns total lines, sources, clones, and duplication percentage broken down by format.

check_current_directory

Triggers a re-scan of the current working directory for duplications and returns the updated statistics.

Arguments: None

Resources

The server exposes the following resource:

• jscpd://statistics: Returns the current duplication statistics in JSON format

How It Works

1. Start jscpd-server against your project directory — it scans and indexes the codebase
2. Your AI assistant connects to the MCP endpoint
3. When you ask your assistant to check for duplications, it calls check_duplication or get_statistics
4. Results are returned directly in the assistant's context — no manual CLI needed

Tips

• Check /api/health to verify the server has finished its initial scan
• The server accepts request bodies up to 10MB