Privacy Policy

§1The short version

Kyzen is a local-first wellness app available on iOS and on the web at kyzenos.com. Most of your data — sleep, food, water, workouts, dreams, calendar — stays on your device. We sync a small profile to our servers so you can sign in on a new device and so we can run premium features. We don't sell your data. We don't license it for AI training.

§2What we collect

• Account basics: your email, display name, optional avatar image, and chosen subscription tier.
• Wellness logs: what you tell Kyzen — meals, water, workouts, sleep records, dream notes, mood checks.
• App usage: anonymous crash reports, with no identifying info attached. Kyzen runs no product-analytics SDK, so we do not record your taps, your screen views, or how often you open a feature in order to study your behaviour. We do keep exactly one usage counter, and it is your AI allowance: each AI request you make — an assistant message, a food-photo estimate, a generated plan, an AI insight — increments a per-feature monthly count and a running cost figure on your account, so the meter in the app can show what you have left and so the allowance can reset each month. It exists to run your plan, not to profile you.
• Apple HealthKit data, only if you grant permission — see §3.
• Apple Calendar read access if you enable Calendar sync.
• Push notification token if you enable reminders.
• Photos you choose when you attach a progress shot, meal photo, or milestone card (only the specific photos you pick — Kyzen never scans your full library).
• Voice input if you dictate a journal entry, meal log, or note. Speech recognition runs on-device and the audio is not uploaded.
• Precise location (GPS) while you are actively recording a cardio session — a run, walk, hike, ride, or similar — including while the screen is locked or you are using another app, because iOS stops delivering GPS the moment Kyzen goes to the background without that permission. Recording begins only when you tap start on the Activity screen and ends when you finish or discard the session; Kyzen does not track your location at any other time, and you can deny or revoke the permission and still use everything else in the app. The route is saved on your device with the session, and because your workout records sync to your Kyzen account so you can recover them on a new device, a copy of the route's coordinates is stored on our servers as part of that record — deleting the session, or your account (§9), removes it. Route data is never used for advertising, never sold, and never shared with the ad SDK.
• Motion data from your device's motion coprocessor (on iOS) to estimate activity when wearable data is unavailable.
• Reminders write access if you enable hydration, bedtime, or planning alerts.

We do not collect your contacts or your full photo library (only the specific photos you attach). Kyzen itself runs no product-analytics SDK: we do not record your taps or your screen views to measure your behaviour, and the only feature counter we keep is the AI allowance meter described above. We do use a crash reporter (Sentry) to find and fix crashes, and its reports are scrubbed of personal data and tied only to a random per-install identifier, never to your account. The free tier is ad-supported by Google AdMob, which is a third-party advertising SDK: on iOS it asks your permission first, and if you decline it serves non-personalised ads and does not use your advertising identifier to track you. If you allow it, AdMob may use your advertising identifier, approximate (city-level) location, and your in-app ad interactions to personalise ads across apps and websites owned by other companies. Pro and Ultra remove ads.

§3HealthKit

If you grant HealthKit permission, Kyzen reads the following from Apple Health. Activity: steps, active energy, resting (basal) energy, walking and running distance, cycling distance, swimming distance, flights climbed, stand time, exercise time, time in daylight, VO2 max, and workouts. Heart: heart rate, resting heart rate, walking heart-rate average, heart-rate variability (HRV), and heart-rate recovery. Respiratory: blood oxygen and respiratory rate. Body: body mass (weight), height, body mass index, body fat percentage, lean body mass, body temperature, and wrist temperature while sleeping. Sleep and mindfulness: sleep analysis and mindful minutes. Nutrition: water and dietary energy (calories consumed) logged in Apple Health. Cycle tracking: menstrual flow. Characteristics: your biological sex and date of birth. That is every type Kyzen asks for. You can grant or deny each one individually in iPhone Settings, and Kyzen works without any of them. These values populate your dashboard, score your day, personalise your targets and readiness, and tune coaching suggestions. They are never used for advertising and are never sold. One exception you should know about: Kyzen AI (the assistant, food-photo estimates, AI workout plans and AI insights) is powered by OpenAI, and nothing is sent to OpenAI until you allow it in the Kyzen AI data-sharing prompt, which names OpenAI and lists what is shared. Once you allow it, each AI request includes these figures so the answer can reference your actual day instead of generic advice: steps, last night's sleep duration and sleep score, heart-rate variability (HRV), resting heart rate, and recovery score, each with the device it came from. The AI insight cards (Pro) also include your recent sleep sessions or workouts and, when advanced metrics are on, your latest health snapshot: steps, active energy, last night's sleep, heart rate, resting heart rate, HRV, blood oxygen, respiratory rate, body temperature, weight, VO2 max, Kyzen's sleep score and stress load with your HRV and resting-heart-rate baselines, and any scores a connected wearable provides. These figures are sent only to generate your reply, OpenAI does not use data sent through its API to train its models, and you can withdraw at any time in Settings → Kyzen AI. If you never allow it, no health data leaves your device except to your own Kyzen account.

With your permission Kyzen also writes ONE type back to Apple Health: workouts you complete in Kyzen, so your rings close and the rest of your health stack stays in sync. Nothing else is ever written. You can disable write-back independently of read access in iPhone Settings.

Apple-mandated commitments:

• We never use HealthKit data for advertising or marketing.
• We never sell HealthKit data, share it with data brokers, or license it to third parties.
• We never disclose HealthKit data to anyone without your explicit consent — except as required by law.

You can revoke HealthKit access at any time in iPhone Settings → Privacy → Health → Kyzen.

§4Why we use this data

• To run features you asked for (track sleep, log meals, etc.).
• To sync your profile across your devices.
• To send the reminders you enable.
• To calculate streaks and KY currency for in-app rewards.
• To diagnose crashes and fix bugs.
• To enforce these Terms (e.g., detecting fraud against the KY economy).

§5Local-first storage

Wellness logs, calorie entries, dream notes, and similar personal content are stored on your device first using your platform's secure storage (Apple's secure storage on iOS, your browser's local storage on the web). We sync a slim profile and snapshot to our servers so that you can recover your data on a new device, but the canonical copy lives on your device.

§6What we never do

• We never sell your personal information.
• We never license your content to train third-party generative-AI models.
• The only third-party advertising SDK in Kyzen is Google AdMob, used on the free tier. iOS asks your permission before it may use your advertising identifier; decline and you still get the app, just non-personalised ads. Paid tiers have no ads at all.
• We never share your wellness logs with employers or insurers.

§7Subprocessors

We use these third-party services strictly to operate Kyzen. Each is bound by a data-processing agreement and only sees the minimum data needed for their function:

• Apple App Store / StoreKit, or Stripe — handle subscription billing. Which one applies depends on where you subscribed: subscriptions bought inside an app on Apple's platforms (not currently offered in the Kyzen iOS app) are billed by Apple and managed in iPhone Settings, and subscriptions bought on kyzenos.com are billed by Stripe and managed in your account's billing portal. Your receipt says which.
• Supabase — hosts the encrypted server-side profile snapshot and authentication tokens.
• Apple Push Notification service — delivers the reminders you enable.
• Resend — sends transactional email (account verification codes, security notices) to the email address on your account. Resend sees only your email address, your first name, and the contents of the email itself.
• OpenAI — powers Kyzen's AI features: the Kyzen assistant, food-photo calorie estimates, AI workout plans, turning a planning note into a flowchart, and AI insights. Nothing is sent to OpenAI until you allow it in the Kyzen AI data-sharing prompt, which names OpenAI and lists what is shared; you can withdraw at any time in Settings → Kyzen AI, and our servers refuse AI requests for any account that has not allowed it. Once you allow it, each request sends what that feature needs: your message and the conversation so far, the meal photo you scan, the planning note, or the choices you make for a plan; your goals and targets, units, weight, height and age, your active workout plan, your Kyzen AI preferences and the facts Kyzen has saved for you; today's logged calories, protein, water and workouts and your streak; the Apple Health and wearable figures described in §3; and what Kyzen looks up to answer you — when your question needs it, the assistant reads the relevant calendar events (including ones imported from Google or Apple Calendar), planning boards and tasks, earlier meals, water, sleep and workouts, weekly totals, goals, meal prep and grocery list, and sends what it found to OpenAI to write the reply. Requests are sent when you use a feature — with one exception: the AI insight cards (Pro) refresh their analysis on their own when you open the Workout or Sleep page. If you have not allowed it, those cards send nothing and offer a button to turn it on. The data is used only to generate your reply, and under OpenAI's API terms, data sent through the API is not used to train OpenAI's models. We never send your email or account identifiers with these requests. Kyzen AI's replies are also checked by OpenAI's moderation service before they reach you. Separately, OpenAI's moderation service can screen what you share with other people so objectionable content stays out of shared spaces — but only if you allow it in the content-screening prompt, which names OpenAI and appears before the first photo you share with other people; you can change it at any time in Settings → Kyzen AI. With your permission it checks your profile photo; photos on posts, shared activities, shared events and community foods; and the text of posts, your profile bio and status, events you share with friends, kudos messages, community foods, and the names and comments on shared planning boards. Without it, nothing you share is sent to OpenAI: that text is checked by Kyzen's own word filter on our servers instead, and photos cannot be shared with other people (a shared activity shows a stock image instead of your photo). Private events and private activities are never screened.
• RevenueCat — manages subscription entitlements across the App Store and our web checkout (card payments on the web are processed by Stripe through RevenueCat's billing). RevenueCat sees an anonymized account identifier and your purchase history, never your card number.
• PayPal — if you enroll in the affiliate program, PayPal processes your commission payouts and sees the payout email address you provide.
• Google AdMob — serves the ads on the free tier. On iOS we ask your permission first. If you decline, AdMob serves non-personalised ads and does not use your advertising identifier to track you. If you allow it, AdMob may use your advertising identifier, approximate (city-level) location derived from your IP address, and your in-app ad interactions to personalise ads across apps and websites owned by other companies. AdMob never receives your health data, your food photos, or your assistant conversations. Pro and Ultra remove ads, so this one does not apply to paying subscribers.
• Sentry — receives crash reports so we can find and fix crashes quickly. A report contains the error, the screen it happened on, and the app version. It is scrubbed of emails, tokens, and other personal data before it leaves your device, and is tied only to a random per-install identifier that is not your account. Sentry never receives your health data, your food photos, or your assistant conversations.

We'll update this list — and notify you in-app under §14 — before adding any new subprocessor.

§8How long we keep data

Your data stays as long as your account is active. If you delete your account, we delete server-side personal data within 30 days, except where we're required to keep records for legal or fraud-prevention reasons (e.g., proof-of-purchase). On-device data is deleted when you delete the app (iOS) or clear your browser's site data (web).

§9Your controls

• Export: open Settings → Sync and privacy → Exports and tap JSON export or CSV export to download a copy of your Kyzen data to your device.
• Delete your account (in-app, permanent): open Settings → Account → Delete account permanently, type DELETE to confirm, and we will purge your profile, posts, friend connections, subscription record, and push notification tokens from our servers immediately. This satisfies Apple App Store Review Guideline 5.1.1(v). If anything goes wrong, email privacy@kyzen.app and we will complete the deletion described in §8 within 30 days.
• Delete on this device only: Settings → Account → Delete local account data only wipes Kyzen's data from this device and returns you to onboarding while leaving your server-side account intact. Useful when you want to sign out of this device without destroying your account.
• HealthKit: revoke access in iPhone Settings → Privacy → Health → Kyzen.
• Push notifications: control granularly in Settings → Notifications, or globally in iPhone Settings → Notifications → Kyzen.

§10California residents (CCPA / CPRA)

If you live in California you have the right to (a) know what personal information we've collected about you, (b) delete that information, (c) correct inaccurate information, and (d) opt out of any "sale" or "sharing" of personal information.

We do not sell or share personal information. To exercise any other right, email privacy@kyzen.app from the address tied to your account.

§11EU / UK residents (GDPR)

If you live in the European Economic Area, the United Kingdom, or Switzerland you have the rights of access, rectification, erasure, restriction, portability, and objection under the GDPR / UK GDPR. The legal basis for processing is performance of our contract with you (running the app), your consent (for HealthKit, push, Calendar, and location), and our legitimate interest (fraud prevention, security, and diagnosing crashes).

Email privacy@kyzen.app to exercise any of these rights. You also have the right to lodge a complaint with your local data-protection authority.

§12Children

Kyzen is not directed at children under 13 (under 16 in the EEA, UK, and Switzerland). We do not knowingly collect data from children. If you believe a child has created an account, email privacy@kyzen.app and we'll delete it.

§13Security

We encrypt data in transit with TLS and at rest using industry-standard AES-256. No system is perfectly secure, so we can't promise zero risk — if you suspect a breach of your account, change your password and email support@kyzenos.com.

§14Changes to this policy

If we change this Privacy Policy in a material way (new category of data, new subprocessor, new use), we'll notify you in-app and bump the effective date above. Continuing to use Kyzen after the effective date means you accept the updated policy.

§15Contact

Questions or requests? Email privacy@kyzen.app.