Your data, your device

Privacy

Biometric processing happens on your device. Raw heart-rate waveforms are never stored or transmitted — only per-session summaries, and only when you finish a session in-app.

What we keep (summary only)

id
protocol
durationSec
avgHrv
coherenceScore
cycles
source
startedAt

What we never keep: raw camera frames, the green-channel waveform, or the inter-beat-interval series. Those exist only in memory during a live session.

Export or delete

7 session summaries stored.

Export is the only way summary data leaves your device. There is no cloud account and no automatic sync.

On-device guarantee

privacy.audit

$ breath-coach audit --privacy
camera frames .......... in-memory only (discarded)
ppg waveform ........... in-memory only (discarded)
inter-beat intervals ... in-memory only (discarded)
session summaries ...... 7 stored on-device
network transmissions .. 0 (no cloud account)
export ................. user-initiated only
OK · no raw biometrics leave this device