Add unit tests for lib

**Feature request**
It would be great to have logging for api.

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

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

The issue names no files or tests. Start by locating the API entry point, library configuration, and existing unit-test setup; determine where the enable_logging option belongs and how API output is currently handled. Done means the option defaults to false and tests cover the requested logging behavior.

Written by the indexing model from the issue text.