In this article, we will explore how to implement a custom response interceptor in a NestJS application to format all API responses in a standardized structure. This is particularly useful for maintaining consistency across APIs, making it easier for front-end developers and other consumers of the API to parse and understand the responses.
What Is an Interceptor in NestJS?
In NestJS, interceptors are a powerful feature that allow you to:
- Transform data before sending it to the client.
- Manipulate the request/response.
- Perform logging, analytics, or caching.
- Add custom headers or structure the API response consistently.
Interceptors are executed before and/or after the route handler, giving you the flexibility to transform the incoming request or the outgoing response.
