Privacy Policy — Cysta

Last updated: September 15, 2026

The short version

Cysta has no accounts and no third-party ads, and does not track you. Your meals, symptoms, cycle and supplement logs are stored on your device and, if iCloud is enabled, in your personal iCloud database that only you can access — never on our servers.

What the app stores

Food entries, symptom logs, cycle logs, supplement check-ins, water intake and your profile (name, height, weight, goals) are stored locally on your device. If you're signed into iCloud, Apple syncs them through your private CloudKit database. We cannot read this data.

AI features (OpenAI)

Two optional features send data off your device, and only after you have given permission in the app (Cysta asks before the first use; you can withdraw permission any time in Profile → AI features):

• What is sent: for AI photo logging, the meal photo you choose; for Chat with Luna, the messages you type. Each request also carries a random app-generated identifier used only to limit daily usage. Your name, profile, symptom, cycle, supplement and water logs, and Apple Health data are never sent.
• Who receives it: our server, hosted on Cloudflare, forwards the photo or messages to OpenAI (OpenAI, L.L.C., USA), whose model analyzes the photo or writes the reply.
• How it is used: solely to produce the result you asked for. We do not store photos or messages on our server beyond the request; we keep only the daily usage count per identifier. Under OpenAI's API terms, data sent through the API is not used to train OpenAI's models. See OpenAI's privacy policy and OpenAI's API data commitments.

Please don't include personal details you'd rather keep private in photos or chats. If you decline AI features, manual, search and barcode logging keep working.

Purchases

Subscriptions are processed by Apple. To validate purchases we use RevenueCat, which receives an anonymous purchase receipt and a random app-generated identifier — never your name, email or Apple ID. See RevenueCat's privacy policy.

Analytics and tracking

The app contains no third-party analytics or advertising SDKs and does not track you across apps or websites.

Not medical advice

Cysta is a tracking tool, not a medical device, and does not provide medical advice, diagnosis or treatment.

Contact

Questions? Email [email protected].