Why is Apple Watch Sleep Score null?

Apple's Sleep Score currently appears only on the watch/device and is not synced into Apple Health, so it isn't readable through HealthKit and comes through as…

Apple's Sleep Score currently appears only on the watch/device and is not synced into Apple Health, so it isn't readable through HealthKit and comes through as null. It's on-device-only display data, kept from third parties.

A few things worth knowing:

• Other providers differ. Garmin, for example, does include a sleep score in its sleep payloads.

• If Apple later exposes the score to Apple Health, support can be added.