DuckDuckGo Search MCP

Instructions

Implementation Reference

• src/tools/monicaTool.js:26-58 (handler)

  The main execution handler for the 'monica-search' MCP tool. Extracts query from params, calls the searchMonica helper, and returns formatted text content or error response.

  /**
   * Monica AI search tool handler
   * @param {Object} params - The tool parameters
   * @returns {Promise<Object>} - The tool result
   */
  export async function monicaToolHandler(params) {
    const { query } = params;
    
    console.log(`Searching Monica AI for: "${query}"`);
    
    try {
      const result = await searchMonica(query);
      return {
        content: [
          {
            type: 'text',
            text: result || 'No results found.'
          }
        ]
      };
    } catch (error) {
      console.error(`Error in Monica search: ${error.message}`);
      return {
        isError: true,
        content: [
          {
            type: 'text',
            text: `Error searching Monica: ${error.message}`
          }
        ]
      };
    }
  }

• src/tools/monicaTool.js:3-24 (schema)

  The tool definition object including name, title, description, inputSchema for parameter validation, and annotations.

  /**
   * Monica AI search tool definition
   */
  export const monicaToolDefinition = {
    name: 'monica-search',
    title: 'Monica AI Search',
    description: 'AI-powered search using Monica AI. Returns AI-generated responses based on web content.',
    inputSchema: {
      type: 'object',
      properties: {
        query: {
          type: 'string',
          description: 'The search query or question.'
        }
      },
      required: ['query']
    },
    annotations: {
      readOnlyHint: true,
      openWorldHint: false
    }
  };

• src/index.js:49-61 (registration)

  In the MCP CallToolRequest handler, routes calls to 'monica-search' to the monicaToolHandler function.

  switch (name) {
    case 'web-search':
      return await searchToolHandler(args);
  
    case 'iask-search':
      return await iaskToolHandler(args);
  
    case 'monica-search':
      return await monicaToolHandler(args);
  
    default:
      throw new Error(`Tool not found: ${name}`);
  }

• src/index.js:14-18 (registration)

  Includes monicaToolDefinition in the list of tools returned by ListToolsRequestSchema handler.

  const availableTools = [
    searchToolDefinition,
    iaskToolDefinition,
    monicaToolDefinition
  ];

• src/utils/search_monica.js:196-242 (helper)

  The core helper function implementing the API interaction with Monica AI, including client instantiation, streaming request handling, response formatting, and comprehensive error management.

  /**
   * Search using Monica AI
   * @param {string} query - The search query
   * @returns {Promise<string>} The search results
   */
  export async function searchMonica(query) {
    // Input validation
    if (!query || typeof query !== 'string') {
      throw new Error('Invalid query: query must be a non-empty string');
    }
  
    console.log(`Monica AI search starting: "${query}"`);
  
    try {
      const client = new MonicaClient();
      const result = await client.search(query);
      
      if (result && result.trim()) {
        console.log(`Monica AI search completed: ${result.length} characters received`);
      } else {
        console.log('Monica AI search completed but returned empty result');
      }
      
      return result;
    } catch (error) {
      console.error('Error in Monica AI search:', error.message);
      
      // Enhanced error handling
      if (error.code === 'ENOTFOUND') {
        throw new Error('Monica network error: unable to resolve host');
      }
      
      if (error.code === 'ECONNREFUSED') {
        throw new Error('Monica network error: connection refused');
      }
      
      if (error.message.includes('timeout')) {
        throw new Error('Monica timeout: request took too long');
      }
      
      if (error.message.includes('network')) {
        throw new Error('Monica network error: service may be unavailable');
      }
      
      throw new Error(`Monica search failed for "${query}": ${error.message}`);
    }
  }