Our Indoorbike.app (Open Source bike smart trainer) now has a public URL-based API:
https://indoorbike.app/api/
Any app can now generate workouts and open it directly in the indoorbike.app editor. The user can then just ride the workout.
No user data ever leaves the source system. No user data, or workout data is ever stored on our servers. Full privacy interoperability.
Here's an example how VertMatch uses the API. It generates an alternative workout based on your history.