Darwin Privacy Policy

Effective July 14, 2026 · Applies to the Darwin iOS app (beta)

Darwin is built by an athlete, for athletes. The short version: your health data stays on your phone. We collect the minimum needed to run the service, we sell nothing, and we show no ads.

Health data stays on your device

With your permission, Darwin reads workouts, sleep, heart rate, heart rate variability, and resting heart rate from Apple Health. This data is processed entirely on your device to track your plan, compute your readiness score, and display your workout details. Raw health data, workout streams, GPS locations, and sleep records are never uploaded to our servers. Darwin does not write anything to Apple Health.

What does leave your device

Once per week, when you complete your Sunday Refresh, the app sends a small structured summary to our server so we can generate your plain-language weekly digest and understand beta engagement. That summary contains:

• Your adherence percentage and goal status (on track / at risk / off track)
• Three flags: low sleep, low feel, whether long sessions were fueled
• The adjustments the planning engine made, your event name, and week number
• Your first name and a random install identifier (not linked to your Apple ID, email, or device identifiers)

No workout data, heart rate values, sleep records, or location data are included.

How that summary is processed

The summary is stored on our backend (Supabase, hosted in the United States) and passed to Anthropic's Claude API solely to write your weekly digest text. It is not used to train AI models. Training decisions are never made by AI; a deterministic planning engine on your device makes every training-load decision.

What we never do

• No selling or sharing of your data with data brokers or advertisers
• No ads, no third-party analytics or tracking SDKs
• No reading of contacts, photos (except a profile photo you choose, which stays on device), or location

Retention and deletion

Weekly summaries are kept while you use the beta so your history works. Email justin@darwinendurance.com from any address with your first name and we will delete every record tied to your install within 7 days. Deleting the app removes all on-device data immediately.

Not medical advice

Darwin provides training guidance for healthy recreational athletes. It is not a medical device and its content is not medical advice. Consult a physician before beginning any training program.

Beta software

Darwin is distributed through Apple TestFlight during beta. Apple's own privacy terms apply to TestFlight itself. This policy may be updated as Darwin grows; material changes will be announced in the app.

Contact

Justin Ramirez · justin@darwinendurance.com