Privacy policy
Last updated: 10 November 2026
Twillie is a free, invite-only coaching service for a small private group. This policy explains what data we collect, why, who processes it, how long we keep it and how you can control it. Some of this data is health related, so we only process it with your explicit consent.
Who is responsible
The data controller is Johann Arias, entrepreneur individuel (micro-entreprise), France. Contact for any privacy question or request: hello@twillie.io.
What we collect
Account data
- Your email address, used to sign you in and to send your daily brief.
Data from Garmin Connect, once you connect your account
- Sleep: duration, sleep stages, sleep score, sleep time window.
- Recovery and daily health: overnight HRV, resting heart rate, stress, Body Battery, respiration, pulse oximetry, steps.
- Activities: type, date, duration, distance, elevation, heart rate and heart rate zones, training load, training effect, and the activity file recorded by your device (which may include a GPS track).
- Body composition, if you record it in Garmin Connect (for example weight).
Data you give us
- Your goal, race dates, training history, injuries or constraints, and weekly availability.
- Messages you send to the coach, for example to move a session.
Why we use it
- To compute your daily training state (sleep, recovery, training load).
- To write your morning brief and adapt your training plan for the coming days.
- To send planned workouts to your Garmin Connect calendar, so they appear on your device.
- To show your history and plan on your dashboard and send you the brief by email.
We do not use your data for advertising, profiling for third parties, or any purpose unrelated to your coaching. We do not sell, rent or share your data. Your data is not used to train AI models.
Legal basis
We process health-related data on the basis of your explicit consent (GDPR art. 6(1)(a) and art. 9(2)(a)), given when you connect your Garmin account. You can withdraw it at any time by disconnecting, which stops all collection. Account data is processed to provide the service you asked for (art. 6(1)(b)).
Artificial intelligence
The brief and the plan are written with the Claude API from Anthropic. We send it summarized metrics (for example last night's sleep duration, HRV, recent training load and the list of recent sessions) together with your goal and constraints. We never send GPS tracks, your email address or your name. Under Anthropic's commercial terms, data sent through the API is not used to train their models.
Who processes your data
| Provider | Purpose | Location |
|---|---|---|
| Vercel Inc. | Application hosting and server functions | United States (Standard Contractual Clauses) |
| Supabase Inc. | Database storing your account and Garmin-sourced data | European Union |
| Anthropic PBC (Claude API) | Generates your daily brief and training plan from summarized metrics | United States (Standard Contractual Clauses) |
| Resend Inc. | Sends your daily brief by email | United States (Standard Contractual Clauses) |
No other third party receives your data.
How long we keep it
- While your account is active, we keep your Garmin-sourced data to compute trends (for example your usual HRV range).
- When you disconnect Garmin or delete your account, your Garmin-sourced data is deleted within 30 days, and Twillie's access to Garmin Connect is revoked.
- Backups are overwritten within 30 days.
Your rights
You can ask to access, correct, export or delete your data, object to its processing, or withdraw your consent at any time, by writing to hello@twillie.io. We answer within one month. You can also lodge a complaint with the French data protection authority, the CNIL (cnil.fr).
Security
Data is encrypted in transit. Access tokens to Garmin Connect are stored encrypted and are never shown in the interface. Access to the database is limited to the operator.
Cookies
Twillie only uses the cookie needed to keep you signed in. There are no analytics or advertising cookies.
Age
Twillie is intended for adults (18 and over).
Changes
If this policy changes in a way that affects how your data is used, we will tell you by email before the change applies.