How to create an API adapter in Angular?

Question

Angular

There is a service which is used by several components.
How to write an adapter - API layer for this service?
Or is this not necessary, while the service itself is already a kind of API?

Answer 1

Or is this not necessary, while the service itself is already a kind of API?
Yes.
Sometimes combined with a storage/caching service, sometimes not.
Good practice is one api family - one service. Type usersService, it has GET, POST, etc. users.
Additional manipulations with requests, insert the header there, redirect - in interceptors.