> 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/data-model-fields-and-units/field-definitions-and-enum-lookup.md).

# Where do I find field definitions and enum values?

Full field-by-field definitions for every payload type are in the API reference [data models](https://docs.tryterra.co/reference/health-and-fitness-api/data-models) section, and enum values like `ActivityType` are listed there too.

A few specifics:

* Sample arrays (`hr_samples`, `calorie_samples`, `activity_levels_samples`, etc.) contain timestamped individual measurements, a granular time series rather than summaries.
* The `data_provided` field is an array of data-type enum values describing what the device contributed.
* As an example, `user_max_hr_bpm` is the user's maximum heart rate based on age and other factors, as determined by the provider.

Use the dashboard **payload simulator** to generate example payloads and inspect exact shapes.