Limits

The schedule is a target, not a promise

The scheduled export aims to send data typically within an hour of it arriving in Health. iOS decides when the app actually wakes, so there is no realtime delivery and no schedule in seconds or minutes. Build your dashboard for data that is usually recent, not for data that is always current.

What stops scheduled delivery

• Low Power Mode stops scheduled export outright while it is on.
• Swiping the app away in the app switcher stops it until you open the app again. No app can override this. Work that was queued is kept on the phone, not lost: it goes out after the app is opened. Delivery does not continue on its own while the app is swiped away.
• A locked phone. Health data cannot be read while the phone is locked. A background wake while locked can still deliver batches that are already queued; reading new samples waits until the phone is unlocked. An export started from a Shortcut while the phone is locked stops with “Couldn’t read from Health”.
• A restart before the first unlock. Until the phone has been unlocked once after a restart, a background wake does nothing and leaves everything as it was; the next wake after unlock does the work.

How long the app keeps trying

A failed batch is retried with backoff, from 15 minutes up to once an hour, for seven days. Pending work older than that is dropped, and the app does not go back for it. A batch your receiver answered with a status that is not retried (a 4xx such as 401 or 404, a redirect, a bare 413) is dropped at once. The only way back after either is a manual export over a range that covers the loss.

One export at a time

The button, the Shortcuts action and the scheduled export share one gate. A second export that starts while one is running is refused, not queued.

What version 1 of the payload cannot tell you

• Deletions. A sample deleted in Health after it was delivered stays in your copy. Your copy only grows; reconcile out of band if you need to.
• Coalescing. When Health replaces fine-grained historic samples with a combined one, you receive both, with no signal that the originals are gone. Sums over that span double-count.
• Backdated samples, on a manual or Shortcuts export. A range matches on a sample’s start, so a sample written today with last week’s date is not in a “Last 24 hours” export. The scheduled export does deliver it, on its next run, but no sample says when it was written.
• Workout routes. GPS traces are not sent and will not be added to version 1.

Time ranges

Manual and Shortcuts exports offer four fixed ranges — 3 hours, 24 hours, 7 days, 30 days, each ending now. There is no custom date range.