Request & Response

Every MyCroCloud function receives a request object as its argument and must return a response object. This page documents both.

Handler Signature

function handler(request) {
  // process the request...

  return {
    statusCode: 200,
    body: 'Hello, world!'
  };
}

Request Object

The request object contains the following properties:

Property	Type	Description
method	string	HTTP method in uppercase (e.g., "GET", "POST")
path	string	Request path (e.g., "/api/users/123")
params	Record<string, string>	Route parameters extracted from the path
query	Record<string, string>	Query string parameters
headers	Record<string, string>	HTTP request headers
body	any	Parsed request body (null if no body was sent)

method

The HTTP method of the incoming request, always uppercase (e.g., "GET", "POST", "PUT", "DELETE").

If your route is configured with the ANY method, it matches all HTTP methods. You can use request.method to distinguish between them in your handler:

function handler(request) {
  if (request.method === 'GET') {
    return { statusCode: 200, body: 'Reading data' };
  }
  if (request.method === 'POST') {
    return { statusCode: 201, body: 'Created' };
  }
  return { statusCode: 405, body: 'Method not allowed' };
}

path

The URL path of the incoming request, without the query string.

function handler(request) {
  console.log(request.path); // "/api/users/123"
  return { statusCode: 200, body: 'OK' };
}

params

An object containing route parameters. When you define a route like /users/{id}, the matched value is available as request.params.id.

// Route: /users/{id}
function handler(request) {
  const userId = request.params.id;
  return {
    statusCode: 200,
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify({ userId })
  };
}

query

An object containing query string parameters as key-value pairs.

// Request: /search?q=hello&page=2
function handler(request) {
  const searchTerm = request.query.q;     // "hello"
  const page = request.query.page;        // "2" (always a string)
  return {
    statusCode: 200,
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify({ searchTerm, page: Number(page) })
  };
}

note

Query parameter values are always strings. Use Number(), parseInt(), or parseFloat() to convert numeric values.

headers

An object containing the HTTP request headers as key-value pairs.

function handler(request) {
  const contentType = request.headers['Content-Type'];
  const auth = request.headers['Authorization'];

  if (!auth) {
    return { statusCode: 401, body: 'Unauthorized' };
  }

  return { statusCode: 200, body: 'OK' };
}

body

The parsed request body. The body is automatically parsed as JSON. If the request has no body, body is null.

// POST /users with body: {"name": "Alice", "email": "alice@example.com"}
function handler(request) {
  const { name, email } = request.body;
  console.log('Creating user:', name);

  return {
    statusCode: 201,
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify({ name, email, created: true })
  };
}

tip

Since the body is parsed as JSON automatically, you don't need to call JSON.parse() yourself. Access fields directly with request.body.fieldName.

Response Object

Your handler must return an object with the following properties:

Property	Type	Required	Description
statusCode	number	Yes	HTTP status code (e.g., 200, 404, 500)
headers	Record<string, string>	No	Response headers as key-value pairs
body	string	Yes	Response body as a string

statusCode

The HTTP status code to send back to the client.

return { statusCode: 200, body: 'OK' };
return { statusCode: 404, body: 'Not found' };
return { statusCode: 500, body: 'Internal error' };

headers

An optional object of response headers. Header values can be strings, numbers, or booleans. null values are ignored.

return {
  statusCode: 200,
  headers: {
    'content-type': 'application/json',
    'cache-control': 'max-age=3600',
    'x-request-id': '12345'
  },
  body: JSON.stringify({ message: 'Hello' })
};

body

The response body as a string. For JSON responses, use JSON.stringify().

// Plain text
return { statusCode: 200, body: 'Hello, world!' };

// JSON
return {
  statusCode: 200,
  headers: { 'content-type': 'application/json' },
  body: JSON.stringify({ message: 'Hello' })
};

// HTML
return {
  statusCode: 200,
  headers: { 'content-type': 'text/html' },
  body: '<h1>Hello, world!</h1>'
};

Full Example

// Route: /api/greet/{name}
function handler(request) {
  console.log(request.method + ' ' + request.path);

  if (request.method !== 'POST') {
    return { statusCode: 405, body: 'Method not allowed' };
  }

  const name = request.params.name;
  const lang = request.query.lang || 'en';
  const { title } = request.body || {};

  const greetings = {
    en: 'Hello',
    es: 'Hola',
    fr: 'Bonjour'
  };

  const greeting = greetings[lang] || greetings.en;
  const fullName = title ? title + ' ' + name : name;

  return {
    statusCode: 200,
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify({ message: greeting + ', ' + fullName + '!' })
  };
}