Add TypeScript types for data

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

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

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

No files, tests, or entry points are named. Start by locating the handler configuration and the data type definitions referenced by the issue, then trace how configuration options reach handlers. Done means the requested filtering behavior and the `enable_filtering` option are defined clearly, including its default, with relevant tests or validation.

Written by the indexing model from the issue text.