Privacy
Yarrow is built for quiet. We collect as little as possible, and we don't track you.
What stays on your device
Your questions, your cast hexagrams, your journal entries, and your app preferences are stored on your iPhone using Apple's standard local storage (SwiftData and UserDefaults). They never leave your device unless you ask for an AI reading.
What goes to our server when you ask for an AI reading
When you tap "Cast the Hexagram" and request an AI interpretation, the following is sent to our Cloudflare Worker at yarrow-oracle.shaozhengkun.workers.dev:
- Your question text
- The hexagram you cast and any moving lines
- A locally-generated random device identifier (a UUID stored only on your phone — used to enforce a daily request quota, not linked to your identity)
- Your iOS locale (e.g. "en", "zh") so we return the right language
The Worker forwards this to an Anthropic-compatible language model API. The model's reply is sent back to your phone and is not stored on our servers.
What we do not collect
- No name, email, phone, or account.
- No analytics SDKs. No third-party trackers.
- No advertising identifiers.
- No precise location.
Daily quota state
To prevent abuse, the Worker keeps a counter per device-UUID, per day (e.g. uuid:20260525 → 7). This counter auto-expires after about 36 hours. It is not joined with any other data.
Data retention
On-device data persists until you delete the app. Server-side quota counters expire automatically as described above. We do not log request bodies.
Children
Yarrow is rated 4+ but is not specifically designed for children under 13 and does not request consent under COPPA. Parents are responsible for their child's use.
Contact
Questions or requests: privacy@yarrow.pages.dev.