Session Data
A SessionData object describes a single user's biometric state. It is used both for the current_session and each entry in past_sessions.
To explore how to structure the input data, see Input Data.
Biometric time series
These four fields are arrays of numeric samples, representing the biometric data over time. The number of samples depends on your wearable's sampling rate. Please be sure to pass all samples you have for the relevant window, not the averages.
| Field | Window | Unit |
|---|---|---|
HR_day_1h | 1 hour before prediction | bpm |
RR_day_1h | 1 hour before prediction | breaths/min |
HR_night | Full sleep window | bpm |
RR_night | Full sleep window | breaths/min |
Denser time series (e.g., 1-minute resolution) generally yield better predictions than sparse ones (e.g., 10-minute resolution). If your wearable provides high-resolution data, we recommend passing it all.
Sleep architecture
Sleep fields describe the structure of the previous night's sleep. These typically come directly from a wearable or by a sleep-tracking API.
Duration fields
sleepTimeSeconds Total time in the sleep window (including awake time)
deepSleepSeconds Time in slow-wave (N3) sleep
remSleepSeconds Time in REM sleep
lightSleepSeconds Time in light (N1 + N2) sleep
awakeSleepSeconds Time awake during the sleep window
Demographics
| Field | Type | Notes |
|---|---|---|
age | integer | Years |
height_cm | integer | Centimetres |
weight_kg | float | Kilograms |
sex | string or null | "M" or "F". Pass null if unknown. |
Demographics are used to population-normalize the output scores. Omitting or misreporting them will degrade the quality of normalization.