Data and security

Alpha status

Opti-U is in alpha testing with a small group of users. Where the alpha runs differently from how Opti-U will run at launch, this page says so.

Data the twin is built from

Every source below is optional apart from your account and what you choose to tell Opti-U when you start. The twin works with whatever you connect, and becomes more specific to you as more data arrives.

Health data from your phone

Through Android's Health Connect: steps, distance, calories, exercise, sleep and sleep stages, heart rate, resting heart rate, heart rate variability, breathing rate, blood oxygen and body temperature, with the app or device each reading came from. Apple Health support is in development.

Wearable files you import

For example a Garmin export that you choose to upload.

What you tell Opti-U

Your answers when you start, your daily check-ins, and what you write in reflections, worksheets and your journal.

Your calendar

Only if you connect Google, Microsoft or Apple. Opti-U reads your events to plan around them and adds your coaching sessions.

Account and technical data

Your email, name, date of birth, language and time zone, plus the app version and the server records of requests the app makes.

• Opti-U does not collect your precise location, contacts, photos, microphone or camera, and does not use advertising identifiers.

Your control

• Health data is read only after you connect a source and grant permission on your phone, one data type at a time. You can change those permissions in your phone's settings whenever you like.
• Disconnect on a source's card in the app stops new readings straight away.
• You can ask for a copy of your data or for your account and data to be deleted. During the alpha both are handled by request to info@opti-u.com, and a self-service option is planned for launch.
• Opti-U is for adults aged 18 and over. If the date of birth given at sign-up shows someone is under 18, the account and everything entered is deleted straight away.

Storage and location

• The Opti-U platform runs on Google Cloud in Europe. Your data is stored in Google Cloud's managed database, which is encrypted at rest and backed up automatically.
• Platform secrets, such as database credentials and encryption keys, are held in Google Secret Manager and never in source code.
• Account and service emails are sent through Postmark.

Protection on the platform

• All traffic between the app and the platform is encrypted in transit with HTTPS.
• On top of Google Cloud's encryption, the access tokens that connect Opti-U to your calendar and other integrations are encrypted by the platform itself with AES-256-GCM, using keys that can be rotated.
• Passwords are salted and hashed before storage. Opti-U never stores your password itself.
• Sign-in issues short-lived access tokens that expire after 30 minutes. Refresh tokens rotate on every use, and if an old refresh token is ever replayed, the platform treats it as theft and ends the session.
• Sign-in and token refresh are rate limited to slow down password guessing.
• Security-relevant events, such as changes to your account, are written to a hash-chained audit log, so any later alteration of a record breaks the chain and is detectable.
• The code is checked by automated security tooling, including static analysis, dependency vulnerability audits, container scanning and secret scanning.

Protection on your phone

• Your sign-in tokens are kept in the Android Keystore or iOS Keychain, never in plain app storage.
• Data the app keeps for offline use, and anything waiting to sync, is encrypted on the device with AES-256 using a key held in the Keystore or Keychain.
• An unsent draft stops being used after 7 days and is then deleted. Signing out clears what the app stored, apart from your choice of language.
• Crash reports, where enabled, are sent without screenshots and without personal identifiers, because health and coaching screens can contain sensitive data.

AI and your data

• The twin's baselines, forecasts, simulations and experiments are computed on Opti-U's own platform. Your health readings are not sent to an outside AI service.
• Coaching messages are written with the help of a large language model. To do that, the model receives only the text it needs: your starting answers, your check-ins and what you have written in your course. Your time zone is never sent.
• During the alpha, this language model is provided by Anthropic in the United States. Under Anthropic's commercial terms, data sent through its API is not used to train its models. Before launch, this processing moves to models hosted in the European Union.
• Every coaching message passes safety checks. If they find signs that you may be at risk, Opti-U may pause your course and shows crisis support lines, and you can ask for a person to review the decision.
• Opti-U is not a medical device, and its coaching is not medical advice.

Organisations

If your employer, club or team provides Opti-U, it sees aggregated results only. Results are shown only for groups at or above a minimum size, and figures for smaller groups are withheld so that no one can be singled out. Your organisation never sees your individual readings, your check-ins or what you write.

Retention

• Your data is kept for as long as you have an account, and deleted when you ask us to delete it. Automatic deletion periods are being set up and will be published here.
• Server request logs, which include the internet address each request came from, are kept for 30 days.
• Backups expire on their own rolling schedule.

What we never do

We do not sell your data, use it for advertising, or share your individual data with your employer.

Reporting a security issue

If you believe you have found a security vulnerability in Opti-U, email info@opti-u.com with the details. Please give us a reasonable chance to fix it before disclosing it publicly. We will acknowledge your report and keep you updated.