Terms of Use

Effective October 12, 2026

These terms govern your use of the half-lyfe app for iPhone, Apple Watch and Mac (“the app”). By installing or using the app you agree to them. If you downloaded the app from the App Store, Apple’s Licensed Application End User License Agreement also applies, and where the two conflict, these terms apply to the extent permitted.

Not medical advice

half-lyfe uses a pharmacokinetic model seeded from your answers. Optional sleep observations, reaction checks and self-reports can make experimental model adjustments, but do not measure caffeine clearance, establish your actual half-life or validate predictions of focus or sleep. Daily limits, bedtime projections and intended-drink planning are general wellness estimates informed by population research, not tailored medical advice or guarantees. The app is not a medical device and provides no diagnosis or treatment. Ask a clinician about caffeine if you are pregnant or breastfeeding, under 18, have a heart condition, anxiety, a sleep disorder or high blood pressure, take medication, or have any health concern. Follow professional advice over app estimates. Do not use this app to decide whether it is safe to drive, operate machinery or perform another safety-critical activity.

Who can use the app

You must be at least 13 years old. If you are under 18, use the app with a parent or guardian’s permission.

half-lyfe Pro subscription

• Plans. half-lyfe Pro is offered as a yearly plan and a monthly plan, and occasionally at a promotional price. The exact price and period are shown in the app before you subscribe and may vary by country.
• Free trial. Apple determines eligibility. Any available trial, its length and the billing terms are shown before purchase. At the end of an applicable trial you are charged the displayed subscription price unless you cancel at least 24 hours before it ends. Any unused portion of a free trial is forfeited when you purchase a subscription.
• Auto‑renewal. Subscriptions renew automatically at the end of each period at the then‑current price unless cancelled at least 24 hours before the end of the current period. Your Apple Account is charged within 24 hours before renewal.
• Cancelling. You can cancel at any time in iPhone Settings → your name → Subscriptions, or in the app under Profile → Subscription → Manage Subscription. Cancellation takes effect at the end of the current period; you keep access until then.
• Refunds. Payments are processed by Apple, and all refund requests are handled by Apple under its policies at reportaproblem.apple.com. We cannot issue refunds directly.
• Price changes. If a price increases, Apple will notify you and, where required, ask for your consent before the new price applies.
• Restoring. Use the Restore control at Welcome, on the paywall or under Profile → Subscription to regain subscription access on a device signed in to the same Apple Account. Online features also require successful server verification of Apple-signed purchase or app information. A remote verification failure does not remove locally verified Pro access; online planning may require a retry. Restore does not restore drink history.

Earlier-version Groups

Groups let you share today’s caffeine numbers with people you invite, under a display name you choose. Choose a name that is not offensive, misleading or someone else’s, and do not use a group to harass anyone. Names are checked on your device against a word filter. Group owners can remove members, anyone can leave a group, and from the group’s menu you can block a member (they disappear from your leaderboards) or report them. Groups run on Apple’s iCloud and we cannot see them, so a report is handled by email with what you tell us; we respond to reports within 24 hours.

Your data

Tracking and local calendar planning stay on your device, with a direct paired-Watch companion. Optional AI ranking and connected-agent sharing use the separate data flows described in the Privacy Policy. Groups, iCloud tracking sync and referral collection remain unavailable in this update. Tracking files are excluded from automatic backups where supported; a subscription restore does not restore drink history. Export data you wish to keep. Delete account clears this device and attempts erasure of retained backend identities and known legacy iCloud data. Remote deletion can remain pending until authenticated confirmation; independent exports, other-device copies, Apple Health samples and external agents' own copies require separate management. See the Privacy Policy for retention, retry and recovery limits.

Optional online planning and connected agents

Where available in your build and account, AI planning is an optional ranking of generic schedule windows, not a measurement of your body or a medical recommendation. Local checks determine whether a proposed drink and time are eligible. Local planning remains available without AI sharing. Connected agents are separately authorized to read shared future plans and, if approved, suggest coffee. Review every draft in half-lyfe before approving it. Approval is a plan, not a record that you consumed a drink; suggestions never log intake automatically.

Online features require connectivity, configured services and any applicable subscription. Paid AI ranking permits up to 20 provider attempts per day per verified subscription owner, shared across linked installations. Additional short-term and service-wide capacity limits apply, and a failed provider attempt can still count against a limit. Online availability is not guaranteed. Agent availability and its own account requirements depend on the service you choose. Open half-lyfe to receive and validate agent drafts; an overnight suggestion is not guaranteed background delivery. Disconnecting stops future sharing from this phone, but server removal may remain pending and an agent may retain its own copies under its terms and privacy policy.

Café search and directions

Optional café searches and walking estimates use Apple MapKit; directions open Apple Maps. Search results, business details and travel times may change and are not guaranteed. Location access is requested only when you choose to use your location; the app does not track it in the background. Selected café details can be included in a future plan shared with an agent you connect. You remain responsible for choosing where to go and whether to consume a planned drink.

Acceptable use

You may use the app for personal, non‑commercial purposes on Apple devices you own or control. You may not reverse engineer, copy, resell, or interfere with the app or attempt to circumvent the subscription. Drink names, brands and caffeine figures in the app’s catalog are provided for identification and are the property of their respective owners; caffeine figures are typical values and may differ from what is in the drink in front of you.

Disclaimer and limitation of liability

The app is provided “as is” without warranties of any kind, express or implied, including fitness for a particular purpose and accuracy. To the fullest extent permitted by law, we are not liable for any indirect, incidental, special or consequential damages, or for any loss or injury arising from your reliance on the app’s estimates, limits, forecasts or suggestions. Our total liability for any claim is limited to the amount you paid for the app in the twelve months before the claim. Some jurisdictions do not allow these limitations, in which case they apply to the extent permitted.

Changes to the app or these terms

We may update the app or these terms. Material changes to the terms will be posted at this address with a new effective date. Continued use after a change means you accept it.

Contact

Email halflyfesupport@gmail.com.