Add unit tests for api

**Feature request**
It would be great to have backup for types.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_backup` with default `false`.

Start by locating the API configuration entry point and existing unit-test files. Clarify whether the goal is tests for the API or implementation of the `enable_backup` option; done should include coverage for its default `false` value and the requested backup behavior.

Written by the indexing model from the issue text.