Which parts run on my device?

On an iPhone that supports Apple Intelligence, the course plan itself and the running “journey so far” narrative that carries it forward are both generated on the device by Apple Foundation Models. On other devices, or if the on-device model cannot run them, they are generated in the cloud instead. The long-form session script is always written in the cloud. Either way, what leaves your phone is a short list of derived labels, each capped at 64 characters, and never the text of your journal entries.