Legal, Privacy & Regulatory Information

I. Nature and Purpose of Tau.

Tau. is a mobile application that reads health and biometric data stored on the user's device via Apple HealthKit, displays it in structured summaries and trend visualizations, provides access to third-party AI assistants for personal data exploration, and generates exportable reports.

II. Regulatory Status — Not a Medical Device

Tau. is not a medical device. It has not been certified, cleared, or approved under any medical device regulatory framework, including but not limited to:

European Union: Tau. does not bear the CE marking and has not been evaluated or certified under Regulation (EU) 2017/745 (Medical Device Regulation — MDR) or any prior directive.
United States: Tau. has not been cleared or approved by the U.S. Food and Drug Administration (FDA) under Section 510(k), the De Novo pathway, or any Premarket Approval (PMA) process. It is not listed as a registered medical device with the FDA.
Other jurisdictions: Tau. has not received regulatory clearance or approval from any national or regional health authority worldwide.

Tau. is not intended to diagnose, treat, cure, mitigate, or prevent any disease or medical condition. It is not intended to replace, supplement, or override the professional judgment of any qualified healthcare provider.

Users should not rely on Tau. as a medical device, and should not make any clinical, therapeutic, or diagnostic decision based solely on Tau.'s output without independent clinical assessment.

III. Privacy Policy

This policy explains how the Tau. iOS app handles your data. Tau. has no server: Liminal Pictures never receives, sees or stores your health data, your conversations or your API key. The contact form of this website is covered by the site's Privacy Policy.

Data read from Apple Health. With your permission, Tau. reads the health and fitness data stored in Apple Health (HealthKit): for example activity, workouts, heart, sleep, nutrition, body measurements and clinical symptoms. You choose which categories to share in the iOS Health permissions and can change this at any time in Settings → Privacy & Security → Health → Tau.
Processing on your device. Every figure, trend, chart and report is computed on your iPhone. Your health data, conversation history and settings stay on your device.
What is sent to the AI, and only when you ask. Nothing is sent to an AI provider unless you use the AI Chat and send a message. The request then goes directly from your iPhone to the provider you selected, without passing through any Liminal Pictures server. It contains your message, the conversation so far, and the figures computed on your device that your question needs: an overview of your record (the metrics you have, their units, date ranges and source devices, all-time highs and lows, and the last seven days in full), then the days, periods and statistics the model asks for. Reports and exports leave your device only when you share them yourself, with the recipient you choose.
AI providers. Depending on your choice, your requests are processed by Google (Gemini), Mistral AI, OpenAI (ChatGPT) or Anthropic (Claude). You use your own API key, so this processing is governed by your agreement with that provider and by its privacy policy, including how long requests are kept and whether they may be used to train models (free API tiers may allow this). Some of these providers process data outside the European Union, notably in the United States. See the Google Privacy Policy, the Mistral AI Privacy Policy, the OpenAI Privacy Policy and the Anthropic Privacy Policy.
Consent for each provider. Health data is sensitive data (Article 9 GDPR). It is only sent to an AI provider with your explicit consent, given separately for each provider in the app. You can withdraw it at any time in the app's settings, and disconnect your API key from the ⋯ menu of the AI Chat. Withdrawing consent stops any further sending; it does not delete what the provider has already received (see “Deleting your data”).
API key. Your API key is stored only in the iOS Keychain on your device. It is sent only to the provider that issued it, to authenticate your requests.
Reproductive health: off by default. Periods, ovulation and pregnancy tests, contraception, cervical mucus, sexual activity and lactation are never sent to any AI provider unless you turn this setting on. You can turn it off again at any time.
No server, no tracking. Tau. has no server and no account, and contains no analytics, advertising or tracking SDK.
Deleting your data. Starting a new chat (pencil button) permanently deletes the current conversation; the ⋯ menu lets you disconnect your API key. Uninstalling Tau. removes all of its data from your iPhone; your Apple Health data itself is not affected. To delete data already sent to an AI provider, use that provider's tools or contact it directly. You can also revoke Tau.'s access to Apple Health at any time in the iOS Settings.
Questions and complaints. For any question about this policy, write to liminal.pictures.prod@gmail.com. You may also lodge a complaint with the CNIL, the French data protection authority (cnil.fr).

IV. Medical Disclaimer and Limitation of Liability

Tau. is provided free of charge, for personal and informational use only. Its figures, charts and AI-generated answers may be incomplete or inaccurate: AI models can make mistakes, and results depend on the data recorded in Apple Health. To the extent permitted by applicable law, Liminal Pictures cannot be held liable for:

Decisions about your health made on the basis of Tau.'s figures or AI answers without consulting a healthcare professional;
Errors, omissions or inaccuracies in AI-generated answers, which are produced by third-party providers;
The processing of your data by the AI provider you choose, which is governed by that provider's own terms;
Costs charged by the AI provider for the use of your API key;
Temporary unavailability, technical malfunctions or data loss;
Unauthorized access to your device, or misuse of the data stored on it.

Tau. does not replace a doctor or any other healthcare professional. For any question about your health, consult a qualified professional; in an emergency, call your local emergency number (112 in Europe). Nothing in this notice limits the rights you have as a consumer under mandatory law, nor any liability that cannot be excluded by law.

V. Applicable Law and Jurisdiction

This Legal Notice and any dispute arising from the use of Tau. or this website are governed by French law. In the event of a dispute and failing an amicable resolution, the matter will be brought before the competent French courts.

VI. Modifications

Liminal Pictures reserves the right to update this legal information at any time. Users are encouraged to review this page periodically. Continued use of Tau. after any modification constitutes acceptance of the updated terms.