Nylas API MCP Server

Implementation Reference

• src/tools/index.ts:232-354 (registration)

  Registration of the 'generate-endpoint-code' tool. Includes inline input schema and the main handler function that normalizes language, formats endpoint/params, selects template, fills with helper-generated code, and returns markdown code block.
  server.tool( "generate-endpoint-code", { language: z.enum(["node", "python", "java", "ruby", "curl"]), endpoint: z.string(), method: z.enum(["GET", "POST", "PUT", "DELETE"]).optional(), params: z.record(z.any()).optional() }, async ({ language, endpoint, method = "GET", params = {} }) => { const normalizedLanguage = normalizeLanguage(language); const endpointPath = endpoint.startsWith("/") ? endpoint : `/${endpoint}`; // Construct the endpoint with path parameters let formattedEndpoint = endpointPath; // Replace path parameters with values from params Object.keys(params).forEach(key => { if (formattedEndpoint.includes(`{${key}}`)) { formattedEndpoint = formattedEndpoint.replace(`{${key}}`, params[key]); delete params[key]; // Remove used path parameters } }); // Map of languages to their API code templates const templates: Record<string, string> = { "Node": ` // ${method} ${endpointPath} using Nylas Node.js SDK import 'dotenv/config'; import Nylas from '@nylas/nylas-js'; // Initialize the Nylas client const nylas = new Nylas({ apiKey: process.env.NYLAS_API_KEY }); async function callNylasApi() { try { ${generateNodeCode(method, formattedEndpoint, params)} console.log(response); return response; } catch (error) { console.error('Error calling Nylas API:', error); } } callNylasApi(); `, "Python": ` # ${method} ${endpointPath} using Nylas Python SDK from dotenv import load_dotenv load_dotenv() import os from nylas import Client # Initialize the Nylas client nylas = Client( api_key=os.environ.get('NYLAS_API_KEY') ) ${generatePythonCode(method, formattedEndpoint, params)} print(response) `, "Java": ` // ${method} ${endpointPath} using Nylas Java SDK import com.nylas.NylasClient; import com.nylas.models.*; public class NylasApiExample { public static void main(String[] args) { try { // Initialize the Nylas client NylasClient nylas = new NylasClient.Builder(System.getenv("NYLAS_API_KEY")).build(); ${generateJavaCode(method, formattedEndpoint, params)} System.out.println(response); } catch (Exception e) { System.err.println("Error calling Nylas API: " + e.getMessage()); } } } `, "Ruby": ` # ${method} ${endpointPath} using Nylas Ruby SDK require 'nylas' require 'dotenv/load' # Initialize the Nylas client nylas = Nylas::Client.new( api_key: ENV['NYLAS_API_KEY'] ) ${generateRubyCode(method, formattedEndpoint, params)} puts response `, "curl": ` # ${method} ${endpointPath} using curl ${generateCurlCode(method, formattedEndpoint, params)} ` }; // Get the template for the requested language, or provide an error message const template = templates[normalizedLanguage] || `Code generation is not available for ${language}. Available languages are: Node.js, Python, Java, Ruby, and curl.`; return { content: [ { type: "text", text: template } ] }; } );
• src/tools/index.ts:234-239 (schema)

  Zod input schema defining parameters for the tool: language (programming lang), endpoint (API path), optional method and params.
  { language: z.enum(["node", "python", "java", "ruby", "curl"]), endpoint: z.string(), method: z.enum(["GET", "POST", "PUT", "DELETE"]).optional(), params: z.record(z.any()).optional() },
• src/tools/index.ts:240-353 (handler)

  Handler function: processes inputs, normalizes language, formats endpoint by substituting path params, generates language-specific code templates using helper functions, returns as text content.
  async ({ language, endpoint, method = "GET", params = {} }) => { const normalizedLanguage = normalizeLanguage(language); const endpointPath = endpoint.startsWith("/") ? endpoint : `/${endpoint}`; // Construct the endpoint with path parameters let formattedEndpoint = endpointPath; // Replace path parameters with values from params Object.keys(params).forEach(key => { if (formattedEndpoint.includes(`{${key}}`)) { formattedEndpoint = formattedEndpoint.replace(`{${key}}`, params[key]); delete params[key]; // Remove used path parameters } }); // Map of languages to their API code templates const templates: Record<string, string> = { "Node": ` // ${method} ${endpointPath} using Nylas Node.js SDK import 'dotenv/config'; import Nylas from '@nylas/nylas-js'; // Initialize the Nylas client const nylas = new Nylas({ apiKey: process.env.NYLAS_API_KEY }); async function callNylasApi() { try { ${generateNodeCode(method, formattedEndpoint, params)} console.log(response); return response; } catch (error) { console.error('Error calling Nylas API:', error); } } callNylasApi(); `, "Python": ` # ${method} ${endpointPath} using Nylas Python SDK from dotenv import load_dotenv load_dotenv() import os from nylas import Client # Initialize the Nylas client nylas = Client( api_key=os.environ.get('NYLAS_API_KEY') ) ${generatePythonCode(method, formattedEndpoint, params)} print(response) `, "Java": ` // ${method} ${endpointPath} using Nylas Java SDK import com.nylas.NylasClient; import com.nylas.models.*; public class NylasApiExample { public static void main(String[] args) { try { // Initialize the Nylas client NylasClient nylas = new NylasClient.Builder(System.getenv("NYLAS_API_KEY")).build(); ${generateJavaCode(method, formattedEndpoint, params)} System.out.println(response); } catch (Exception e) { System.err.println("Error calling Nylas API: " + e.getMessage()); } } } `, "Ruby": ` # ${method} ${endpointPath} using Nylas Ruby SDK require 'nylas' require 'dotenv/load' # Initialize the Nylas client nylas = Nylas::Client.new( api_key: ENV['NYLAS_API_KEY'] ) ${generateRubyCode(method, formattedEndpoint, params)} puts response `, "curl": ` # ${method} ${endpointPath} using curl ${generateCurlCode(method, formattedEndpoint, params)} ` }; // Get the template for the requested language, or provide an error message const template = templates[normalizedLanguage] || `Code generation is not available for ${language}. Available languages are: Node.js, Python, Java, Ruby, and curl.`; return { content: [ { type: "text", text: template } ] }; }
• src/tools/index.ts:516-533 (helper)

  Helper: normalizes input language string to template keys (e.g., 'node' -> 'Node').
  function normalizeLanguage(language: string): string { const langMap: Record<string, string> = { 'node': 'Node', 'nodejs': 'Node', 'javascript': 'Node', 'js': 'Node', 'python': 'Python', 'py': 'Python', 'java': 'Java', 'ruby': 'Ruby', 'rb': 'Ruby', 'curl': 'curl', 'api': 'curl', 'rest': 'curl' }; return langMap[language.toLowerCase()] || language; }
• src/tools/index.ts:538-616 (helper)

  Helper: Generates Node.js SDK code snippet for calling the specified Nylas API endpoint/method with params.
  function generateNodeCode(method: string, endpoint: string, params: Record<string, any>): string { const parts = endpoint.split('/'); let resourceType = ''; let functionName = ''; let grantId = 'process.env.NYLAS_GRANT_ID'; let resourceId = ''; // Try to determine the resource type and function name if (parts.length >= 3) { if (parts[1] === 'v3' && parts[2] === 'grants') { if (parts.length >= 5) { resourceType = parts[4]; // like 'messages', 'events', etc. if (parts.length >= 6) { resourceId = parts[5]; if (parts.length >= 7 && parts[6] === 'send') { functionName = 'send'; } } } } } // Handle different HTTP methods switch (method) { case 'GET': if (resourceId) { // Get a specific resource return `const response = await nylas.${resourceType}.find({ identifier: ${grantId}, ${resourceType.slice(0, -1)}Id: "${resourceId}", ${Object.entries(params).map(([key, value]) => `${key}: ${JSON.stringify(value)}`).join(',\n ')} });`; } else { // List resources return `const response = await nylas.${resourceType}.list({ identifier: ${grantId}, ${Object.keys(params).length > 0 ? `queryParams: { ${Object.entries(params).map(([key, value]) => `${key}: ${JSON.stringify(value)}`).join(',\n ')} }` : ''} });`; } case 'POST': if (functionName === 'send') { // Send a draft return `const response = await nylas.${resourceType}.send({ identifier: ${grantId}, ${resourceType.slice(0, -1)}Id: "${resourceId}" });`; } else { // Create a resource return `const response = await nylas.${resourceType}.create({ identifier: ${grantId}, ${Object.entries(params).map(([key, value]) => `${key}: ${JSON.stringify(value)}`).join(',\n ')} });`; } case 'PUT': // Update a resource return `const response = await nylas.${resourceType}.update({ identifier: ${grantId}, ${resourceType.slice(0, -1)}Id: "${resourceId}", ${Object.entries(params).map(([key, value]) => `${key}: ${JSON.stringify(value)}`).join(',\n ')} });`; case 'DELETE': // Delete a resource return `const response = await nylas.${resourceType}.destroy({ identifier: ${grantId}, ${resourceType.slice(0, -1)}Id: "${resourceId}" });`; default: return `// No code generation available for this endpoint const response = "Please refer to the Nylas API documentation for this endpoint.";`; } }