Add unit tests for api

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

**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, tests, or entry points. Start by locating the API middleware and configuration handling, then determine where unit tests belong; done means middleware logging is controlled by enable_logging and the option defaults to false.

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