> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/data-api-sdk/provider-coverage-and-per-provider-data-availability/session-only-devices-no-daily-sleep.md).

# Why does Polar Verity Sense send no daily or sleep data?

Some Polar devices, like the Verity Sense, are **session-only sensors rather than all-day trackers**, so they do not produce daily or sleep summaries.

Empty `daily`/`sleep` arrays for such devices are **expected behaviour, not an integration fault**.