What water_intake measures
water_intake is the total volume of water logged as consumed during the local day, in litres.
| Field | water_intake |
|---|---|
| Unit | Litres |
| Reported | Daily total, on days with at least one log |
| Window | Midnight to midnight, profile local time |
| Wearable required | No |
| API | GET /api/v1/profile/biomarker/{externalId}?categories=nutrition&types=water_intake plus a date range |
| Webhook | BiomarkerCreatedIntegrationEvent. Entries update in place, upsert on id. |
Data sources
| Platform | Record | Notes |
|---|---|---|
| iOS, HealthKit | dietaryWater | WaterMinder and similar hydration apps, food loggers, Apple Watch water shortcuts, manual entry |
| Android, Health Connect | HydrationRecord | Hydration apps, food loggers, Samsung Health |
| Direct integrations | None | |
| Phone only | Manual entry, or entries your own app writes |
How Sahha calculates water_intake
- Pick one source for the day, for water. The source with the highest daily water total wins. This is decided independently of which app wins energy or any other nutrient.
- Sum the winning source’s entries with an end time inside the local day.
Absence means nothing was logged that day.
Interpreting the value
It measures logging, not hydration. Users log a glass and forget the next three. Treat the value as a lower bound and the logging habit as the behaviour.
Litres, not millilitres. A value of 1.75 is one and three-quarter litres. Convert for display.
Related scores and insights
Water intake is not a score factor and has no trend or comparison insight.
Use cases
A hydration goal that your app writes to. If your app lets users log water, write it to HealthKit or Health Connect and it comes back as this biomarker, merged with whatever other apps logged.
GET /api/v1/profile/biomarker/{externalId}?categories=nutrition&types=water_intake&startDateTime=2026-08-27&endDateTime=2026-09-03A hot-day or high-activity prompt. Pair a low logged total with a high active duration day for a reminder that has a reason behind it.
Limitations
- Logged only. No hydration app, no data.
- Absence is not zero.
Related guides
- Energy intake for how nutrition sources and per-nutrient selection work
- Caffeine intake for the other single-purpose intake
- Data dictionary in the developer docs