Legal
Privacy Policy
Last updated: July 31, 2026
This page is maintained by Kayyo to explain how Rest handles your information. It describes our current practices and is not a certification or an independent audit.
1.Introduction
Kayyo ("we," "our," or "us") operates the Rest by Kayyo mobile application and related services (collectively, the "Service"). This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use the Service.
Rest provides behavioral sleep support and CBT-I-inspired coaching. It is not a medical device and does not diagnose, treat, or cure any condition.
2.Information We Collect
- Personal information: name, email address, and account credentials when you create an account.
- Sleep intake and goals: the answers you give during onboarding about your schedule, sleep difficulties, and what you want to change.
- Sleep logs and journal entries: bedtimes, wake times, wind-down steps completed, caffeine entries, morning light, mood notes, and anything you write in the dream journal.
- Motion and sound data: accelerometer and microphone signals captured during a tracking session, used to estimate movement and sound events overnight (see Section 4).
- Coach conversations: the messages you send to the in-app sleep coach and the responses generated for you.
- Device information: device type, operating system, unique device identifiers, and app version.
- Usage data: how you interact with the Service, including sessions started, plans followed, streaks and milestones.
3.How We Use Your Information
- Build tonight's plan and adjust your sleep window over time.
- Estimate your sleep duration, restlessness and consistency from tracking sessions.
- Personalise coaching, reminders, and wind-down recommendations.
- Show your trends, sleep score, streaks and milestones.
- Communicate with you about updates, security notices and support.
- Analyse aggregated usage patterns to improve the Service.
- Comply with legal obligations and enforce our terms.
4.Sleep Tracking and Sound Analysis
What we capture
When you start a tracking session, Rest reads your phone's motion sensors and microphone for the duration of that session. You choose when a session starts and stops, and you can revoke microphone or motion permissions from your device settings at any time.
How it works
Audio is analysed to detect sound events such as movement, noise spikes and snoring-like patterns. We do not keep a continuous recording of your night — what is retained are the derived event markers and summary estimates.
Honest limits
Phone-based tracking estimates sleep duration, restlessness, consistency and sound events. It does not measure REM or deep sleep stages with clinical accuracy, and we do not present it as doing so.
Your rights
You can delete individual sessions, journal entries and your full tracking history from within the app.
5.Sleep Coach and AI Processing
What we send
When you chat with the sleep coach, your messages and a relevant summary of your recent sleep data (such as your sleep window, efficiency and adherence to your plan) are sent to a third-party AI provider to generate a response.
How it is handled
Data is transmitted securely over HTTPS. We ask providers not to use your content to train their models, and their own privacy terms govern their processing. Raw audio from tracking sessions is never sent to the AI provider.
Retention
Coach conversations are stored with your account so the coach has continuity across nights. You can clear your conversation history at any time.
6.Data Sharing and Disclosure
We do not sell your personal information. We share data only in limited circumstances:
- Service providers: hosting, database, authentication, crash reporting and the AI provider that powers the sleep coach — each under agreements limiting their use of your data.
- Legal requirements: when required by law, regulation or legal process.
- Business transfers: in connection with a merger, acquisition or sale of assets.
We do not share your sleep data with advertisers, data brokers, insurers or employers.
7.Data Security
We use encryption in transit, access-controlled storage and least-privilege access for our team. No method of electronic transmission or storage is completely secure, so we cannot guarantee absolute security.
8.Data Retention
We keep your sleep history for as long as your account is active, because trends over weeks are what make the coaching work. Derived summaries and analysis results are retained to show your progress. You may delete individual entries in the app, or request deletion of your account and all associated data at any time.
9.Your Rights
Depending on your jurisdiction, you may have the right to:
- Access, correct or delete your personal information.
- Object to or restrict certain processing activities.
- Receive your data in a structured, machine-readable format.
- Withdraw consent where processing is based on consent.
To exercise any of these, email us at the address in Section 12.
10.Children's Privacy
The Service is not intended for children under 13. We do not knowingly collect personal information from children under 13. If we become aware of such collection, we will delete the information promptly.
11.Health Notice
Rest offers behavioral sleep support and CBT-I-inspired coaching. It is not a substitute for professional medical advice, diagnosis or treatment. If you experience loud snoring, gasping or choking during sleep, or severe daytime sleepiness, please speak with a healthcare professional.
12.Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of material changes by posting the updated policy in the app or by email. Continued use of the Service after changes constitutes acceptance of the updated policy.
13.Contact Us
If you have questions about this Privacy Policy, please contact us at:
Kayyo
Email: hello@kayyo.co