Consider deprecating old api API

**Feature request**
It would be great to have serialization for routes.

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

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

Start by locating the route handling and configuration entry points in the repository, then inspect how routes are currently represented and whether any serialization support exists. Confirm the intended serialized format and how the enable_serialization option should affect production deployments; done means the option is documented and route serialization works when enabled without changing the default behavior.

Written by the indexing model from the issue text.