nestjs-guards-interceptors

NestJS interceptors handle data transformation by modifying responses before they are sent to the client, ensuring consistent API output. They bind extra logic to route handlers for mapping and formatting response data across your application.

NestJS guards handle authorization by evaluating permissions before a route handler executes, returning a boolean or throwing an exception to block access. This mechanism secures endpoints using role-based or permission-based access control logic.

Use NestJS guards when you need to evaluate authorization and authentication before a request reaches the handler. Use interceptors to transform response data or apply logging after the handler executes, managing different cross-cutting concerns.

You need knowledge of NestJS and TypeScript to implement guards and interceptors for cross-cutting concerns like authentication, logging, and data transformation. Familiarity with JWT, RBAC, and API key patterns is also beneficial.

This Skill covers implementing JWT, session, and API key authentication, role-based access control, advanced logging, response data transformation, caching strategies, timeout handling, and error management for NestJS applications.