You may be interested in https://docs.postgrest.org/en/v12/ an automatic way of creating a REST API from the database. It even uses the database to do authentication which is very rarely seen in production (CREATE ROLE, GRANT SELECT, etc). And you create functions in the database to customize things including implementing custom RPC methods when the standard REST is insufficient.

Many devs however would consider creating functions and stored procedures a bridge too far to cross.