Add TypeScript types for utils

**Feature request**
It would be great to have monitoring for handlers.

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

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

The issue names no files, tests, or entry points. First clarify whether the work concerns TypeScript utility types or handler monitoring and the `enable_monitoring` configuration option; then locate the relevant utilities or handler configuration and define tests for the chosen scope and default behavior.

Written by the indexing model from the issue text.