MCP Google Server

Instructions

Implementation Reference

• src/index.ts:127-175 (handler)

  Executes the 'search' tool: validates input, queries Google Custom Search API, maps results to SearchResult format, returns JSON stringified results or error message.

  if (request.params.name === 'search') {
    if (!isValidSearchArgs(request.params.arguments)) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'Invalid search arguments'
      );
    }
  
    const { query, num = 5 } = request.params.arguments;
  
    try {
      const response = await this.axiosInstance.get('', {
        params: {
          q: query,
          num: Math.min(num, 10),
        },
      });
  
      const results: SearchResult[] = response.data.items.map((item: any) => ({
        title: item.title,
        link: item.link,
        snippet: item.snippet,
      }));
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify(results, null, 2),
          },
        ],
      };
    } catch (error) {
      if (axios.isAxiosError(error)) {
        return {
          content: [
            {
              type: 'text',
              text: `Search API error: ${
                error.response?.data?.error?.message ?? error.message
              }`,
            },
          ],
          isError: true,
        };
      }
      throw error;
    }
  } else if (request.params.name === 'read_webpage') {

• src/index.ts:89-108 (registration)

  Registers the 'search' tool in the MCP server's listTools response, providing name, description, and input schema.

  {
    name: 'search',
    description: 'Perform a web search query',
    inputSchema: {
      type: 'object',
      properties: {
        query: {
          type: 'string',
          description: 'Search query',
        },
        num: {
          type: 'number',
          description: 'Number of results (1-10)',
          minimum: 1,
          maximum: 10,
        },
      },
      required: ['query'],
    },
  },

• src/index.ts:92-107 (schema)

  JSON Schema definition for the 'search' tool input parameters: query (required string), optional num (1-10).

  inputSchema: {
    type: 'object',
    properties: {
      query: {
        type: 'string',
        description: 'Search query',
      },
      num: {
        type: 'number',
        description: 'Number of results (1-10)',
        minimum: 1,
        maximum: 10,
      },
    },
    required: ['query'],
  },

• src/index.ts:36-42 (helper)

  Type guard helper function to validate 'search' tool arguments before execution.

  const isValidSearchArgs = (
    args: any
  ): args is { query: string; num?: number } =>
    typeof args === 'object' &&
    args !== null &&
    typeof args.query === 'string' &&
    (args.num === undefined || typeof args.num === 'number');

• src/index.ts:24-28 (schema)

  TypeScript interface defining the structure of each search result used in the handler.

  interface SearchResult {
    title: string;
    link: string;
    snippet: string;
  }