Webby MCP Server

Instructions

Implementation Reference

• src/performance/gtmetrix.ts:57-119 (handler)

  The main handler function `analyzeGTmetrix` that creates a GTmetrix test, fetches the API, and returns performance metrics including scores and timings.
  export async function analyzeGTmetrix( url: string, options: GTmetrixOptions ): Promise<GTmetrixResult> { try { if (!options.apiKey) { throw new Error('GTmetrix API key is required. Get one at https://gtmetrix.com/api/'); } // Start test const testResponse = await fetch('https://gtmetrix.com/api/2.0/tests', { method: 'POST', headers: { 'Authorization': `Basic ${Buffer.from(options.apiKey + ':').toString('base64')}`, 'Content-Type': 'application/vnd.api+json', }, body: JSON.stringify({ data: { type: 'test', attributes: { url, location: options.location || 'vancouver-canada', browser: options.browser || 'chrome', }, }, }), }); if (!testResponse.ok) { throw new Error(`GTmetrix API error: ${testResponse.status} ${testResponse.statusText}`); } const testData: GTmetrixResponse = await testResponse.json(); const testId = testData.data.id; // Poll for results (simplified - returns immediately with test ID) // For complete implementation, would poll until state === 'completed' return { tool: 'gtmetrix', success: testData.data.attributes.state !== 'error', url, test_id: testId, status: testData.data.attributes.state as any, lighthouse_score: testData.data.attributes.lighthouse_score, pagespeed_score: testData.data.attributes.pagespeed_score, yslow_score: testData.data.attributes.yslow_score, fully_loaded_time: testData.data.attributes.fully_loaded_time, page_bytes: testData.data.attributes.page_bytes, page_elements: testData.data.attributes.page_elements, report_url: testData.data.attributes.report_url, error: testData.data.attributes.error, raw: testData, }; } catch (error) { return { tool: 'gtmetrix', success: false, url, status: 'error', error: error instanceof Error ? error.message : String(error), }; } }
• src/performance/gtmetrix.ts:34-49 (schema)

  TypeScript interface defining the output schema/result structure for GTmetrix analysis.
  export interface GTmetrixResult { tool: 'gtmetrix'; success: boolean; url: string; test_id?: string; status: 'queued' | 'started' | 'completed' | 'error'; lighthouse_score?: number; pagespeed_score?: number; yslow_score?: number; fully_loaded_time?: number; page_bytes?: number; page_elements?: number; report_url?: string; error?: string; raw?: GTmetrixResponse; }
• index.ts:40-45 (schema)

  Zod schema for input argument validation of the GTmetrix tool.
  const GTmetrixArgsSchema = z.object({ url: z.string().url(), apiKey: z.string(), location: z.string().optional(), browser: z.string().optional(), });
• index.ts:144-157 (registration)

  Tool registration in the MCP tools array, including name, description, and input schema.
  { name: 'validate_performance_gtmetrix', description: 'Analyze website performance using GTmetrix. Requires API key (free tier available).', inputSchema: { type: 'object', properties: { url: { type: 'string' }, apiKey: { type: 'string', description: 'GTmetrix API key (required)' }, location: { type: 'string', description: 'Test location (e.g., vancouver-canada)' }, browser: { type: 'string', description: 'Browser type (e.g., chrome)' }, }, required: ['url', 'apiKey'], }, },
• index.ts:331-339 (registration)

  Switch case in the tool call handler that invokes the analyzeGTmetrix function after validation.
  case 'validate_performance_gtmetrix': { const validatedArgs = GTmetrixArgsSchema.parse(args); const result = await analyzeGTmetrix(validatedArgs.url, { apiKey: validatedArgs.apiKey, location: validatedArgs.location, browser: validatedArgs.browser, }); return { content: [{ type: 'text', text: JSON.stringify(result, null, 2) }] }; }