nREPL MCP Server

Instructions

Implementation Reference

• src/index.ts:188-211 (handler)

  Handler for the 'connect' tool: validates input arguments, closes existing connection if any, initializes a new NReplClient with the provided host and port, clones a session, and returns a success message.

  case 'connect': {
    const args = request.params.arguments;
    if (!args || typeof args.host !== 'string' || typeof args.port !== 'number') {
      throw new McpError(
        ErrorCode.InvalidParams,
        'host and port parameters are required'
      );
    }
  
    // Close existing connection if any
    if (this.nreplClient) {
      await this.nreplClient.close();
      this.nreplClient = null;
    }
  
    this.host = args.host;
    this.port = args.port;
    this.nreplClient = new NReplClient(this.port);
    await this.nreplClient.clone(); // Create initial session
  
    return {
      content: [{ type: 'text', text: `Connected to nREPL server at ${this.host}:${this.port}` }],
    };
  }

• src/index.ts:143-149 (schema)

  Input schema definition for the 'connect' tool, specifying host as string and port as number, both required.

  inputSchema: {
    type: 'object',
    properties: {
      host: { type: 'string', description: 'nREPL server host' },
      port: { type: 'number', description: 'nREPL server port' }
    },
    required: ['host', 'port']

• src/index.ts:140-151 (registration)

  Registration of the 'connect' tool in the ListToolsRequestSchema response, including name, description, and input schema.

    name: 'connect',
    description: 'Connect to an nREPL server.\n' +
      'Example: (connect {:host "localhost" :port 1234})',
    inputSchema: {
      type: 'object',
      properties: {
        host: { type: 'string', description: 'nREPL server host' },
        port: { type: 'number', description: 'nREPL server port' }
      },
      required: ['host', 'port']
    }
  },