> 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/historical-data-and-backfill/cgm-glucose-body-payload-delivery-history.md).

# How do CGM glucose webhook payloads work?

**Payload structure:** each body payload contains all glucose samples for a given calendar date in the user's local timezone, and updates are supersets of previous payloads. Always **overwrite that day's samples with the latest** payload.

**History depth:** historical glucose data can be requested as far back as the user has data.

**Delivery delay:** webhooks typically arrive **5-10 minutes** after data reaches the provider's cloud, depending on the user's device and settings.