@middy/util

What is @middy/util?

@middy/util is a utility package that provides a set of helper functions and middlewares to simplify the development of AWS Lambda functions. It is part of the Middy middleware engine, which allows you to compose reusable middleware for your Lambda functions.

What are @middy/util's main functionalities?

createError

The `createError` function helps in creating HTTP errors with a specified status code and message. This is useful for handling errors in a standardized way in your Lambda functions.

const { createError } = require('@middy/util');

const error = createError(400, 'Bad Request');
console.log(error);

jsonSafeParse

The `jsonSafeParse` function safely parses a JSON string into an object. If the string is not valid JSON, it returns `null` instead of throwing an error.

const { jsonSafeParse } = require('@middy/util');

const jsonString = '{"key": "value"}';
const parsedObject = jsonSafeParse(jsonString);
console.log(parsedObject);

normalizeHttpResponse

The `normalizeHttpResponse` function ensures that the HTTP response object conforms to the expected format, making it easier to handle responses in a consistent manner.

const { normalizeHttpResponse } = require('@middy/util');

const response = { statusCode: 200, body: 'Success' };
const normalizedResponse = normalizeHttpResponse(response);
console.log(normalizedResponse);

Other packages similar to @middy/util

aws-lambda-middleware

The `aws-lambda-middleware` package provides a collection of middleware functions for AWS Lambda. It offers similar functionalities to @middy/util, such as error handling and response normalization, but it is not as comprehensive in terms of utility functions.

lambda-middleware

The `lambda-middleware` package is another alternative that provides middleware for AWS Lambda functions. It focuses on simplifying common tasks like input validation, error handling, and response formatting, similar to @middy/util.

lambda-api

The `lambda-api` package is designed to help build RESTful APIs using AWS Lambda. It includes middleware support and offers functionalities like routing, error handling, and response formatting, making it a good alternative to @middy/util for API development.

README

Middy Utilities

Util component of the middy middleware, the stylish Node.js middleware engine for AWS Lambda

You can read the documentation at: https://middy.js.org/docs/intro/utilities

License

Licensed under MIT License. Copyright (c) 2017-2025 Luciano Mammino, will Farrell, and the Middy team.