Why does /activity return invalid user id after auth?

An invalid user id error on a user that looks authenticated usually means the request credentials belong to a different environment than the user.

An invalid user id error on a user that looks authenticated usually means the request credentials belong to a different environment than the user.

A user is only visible to credentials from the same environment they were created in. So make sure both your dev-id and x-api-key headers come from the same environment (e.g. production) as the user.

With those aligned, /activity and /plannedWorkout will resolve the user correctly.