Terms, Privacy and Health Notice
Last updated October 2026Terms of use
Who can use Kestrel. You must be 13 or older. If you are under 18, a parent or guardian must know you use Kestrel and agree to these terms. If you are under 13, do not create an account.
What Kestrel is. Kestrel is a free, open-source tool for logging runs, planning training and estimating race times. Everything it shows, including plans, paces, predictions, readiness scores and AI replies, is general information and an estimate. It is not professional coaching, medical, nutrition or legal advice, and it does not know everything about you.
Your responsibility. You choose whether and how to train. You are responsible for your own safety, for checking that any plan suits your health and ability, and for following instructions from your school, coach, doctor and local laws. Do not run through pain, illness or in dangerous heat, traffic or darkness.
Your content. You keep what you enter. You give Kestrel permission to store and process it to run the service for you and your teams. Do not post anything unlawful, abusive or private about someone else.
Accounts. Keep your sign-in secure. We can remove accounts or content that break these terms or put others at risk.
No warranty. Kestrel is provided “as is” and “as available”, without warranties of any kind, express or implied, including accuracy, fitness for a particular purpose and uninterrupted service. The code is released under the MIT licence, which has the same disclaimer.
Limit of liability. To the fullest extent the law allows, Kestrel's creators and contributors are not liable for any injury, illness, loss, lost data or indirect or consequential damages arising from your use of Kestrel or from reliance on its plans, predictions or AI output. Nothing in these terms limits liability that cannot be limited by law, such as for fraud.
Third parties. Garmin, COROS, Strava, intervals.icu, Google, Supabase, OpenAI, Anthropic and other names are trademarks of their owners. Kestrel is not affiliated with or endorsed by them. Their services have their own terms, which you accept when you use them.
Changes. We may update these terms. Using Kestrel after a change means you accept it.
Privacy
What we store. Your sign-in email and name, the profile details you give (birth year, sex, grade, height, weight, goals), your training log, plans, personal records, health and body-map notes, shoes, and your team memberships. If you connect a watch through intervals.icu, your intervals.icu key (encrypted), your runs and, when you open a run, its GPS route.
Who sees what. Only you (and your AI coach) see your training, health, body map, predictions and GPS routes. Teammates see your name, colour, availability and RSVPs. Your team roster shows name, jersey number, grade and events; your age is shown only to you, the team owner and team captains. Your weekly miles appear on the team mileage board only if you switch that on; team totals count everyone's miles without naming people. Team owners and captains do not get a view of anyone's training log or health.
Who processes it. Supabase handles sign-in, Cloudflare hosts the app and database, and Google (Gemini) or Cloudflare Workers AI answers when you use the free Kestrel AI. When you use your own AI provider, your messages go straight from your browser to that provider and are covered by their policy; your API key stays in your browser. We do not sell your data or show ads.
Kids and teens. Kestrel is for ages 13 and up and never asks for a home address or phone number. Parents and guardians can ask for an account to be deleted.
Your choices. You can change or delete your details at any time. In You → Settings, “Delete my Kestrel data” removes your account, log, plans, models and memberships. Backups age out within a short period. To ask us anything about your data, open an issue on the project's GitHub page.
Health and safety
Kestrel's readiness scores, injury and illness flags and body map are prompts to take care, not diagnoses. If you are injured, sick, dizzy, have chest pain or trouble breathing, or pain that lasts or gets worse, stop and see a coach, parent or doctor. Kestrel does not give advice about medication, diet or weight loss. Heat and hills affect everyone differently: use the guidance as a rough guide only.
AI
Kestrel AI can be wrong. It may misread your data or write a plan that does not suit you. Check what it suggests, and trust your body, your coach and your doctor over it. Plan changes pass fixed safety limits (for example no big mileage jumps), but those limits cannot make a plan safe for every person. Do not put secrets or other people's private information into chats.
Teams
Team owners and captains are ordinary Kestrel users, not employees of Kestrel. A training plan they publish is theirs, not Kestrel's, and Kestrel does not check it for suitability. Athletes should follow their school or club coach for decisions about their team and can leave a team at any time. School and club leaders are responsible for their own duty of care, consent and any rules about collecting information from minors.
This page is a plain-language summary written for an open-source project and is not legal advice. If you run Kestrel for an organisation, have a lawyer review it for your location.