Compare sources

Wear a ring and a watch, carry a phone, and they never agree on your steps or your sleep. Since Open Health Sync keeps every source with its provenance, you can see by how much.

python3 recipes/compare-sources.py                     # steps, last 14 days
python3 recipes/compare-sources.py --metric sleep      # also resting_hr, hrv
python3 recipes/compare-sources.py --metric resting_hr --days 30

steps (steps), 2 sources

Day             apple_health            oura
2026-10-08              9507            8661
2026-10-09              9471            9505
2026-10-10              9937           10231
2026-10-11              9470            8752

apple_health vs oura: 14 days, typical gap 534 steps (6%), apple_health reads 436 steps higher on average

How it worksCopy Anchor Link

Every record the API returns carries provider, the integration it came through. The recipe reads one figure per provider and day from GET /v1/users/{id}/daily (steps, resting heart rate, HRV) or from GET /v1/users/{id}/sleep (hours per night), then compares each pair of sources on the days both measured: the typical gap, and which one reads higher.

Why it mattersCopy Anchor Link

For you, it says which device to trust for which number. For a developer, it is the question every multi-device product meets: show one value per day, and know how much the choice moves it. Studies and coaches use the same comparison to calibrate one device against another.