Privacy Policy
Corpus is an endurance coaching app for iPhone, made by David Puchades (the developer). It reads your training and recovery data from Apple Health and uses an AI model to write and adjust your training plan through a conversation. This page explains what data the app handles, where it goes, and what stays on your phone.
What the app reads
With your permission, Corpus reads from Apple Health: workouts and their routes, heart rate and heart rate variability, resting heart rate, sleep, steps and walking distance, respiratory rate, blood oxygen, wrist temperature and VO₂ max. It reads only. It never writes to Apple Health.
You can grant or refuse each category in Health › Sharing › Apps › Corpus at any time. The app keeps working with whatever you allow.
What stays on your phone
Your health records, your daily scores, your notes, your training plan and your conversation with the coach are stored in a database on your device. Messages in the conversation are kept for 24 hours and then folded into a short summary that stays on the device. Deleting the app deletes all of it.
What is sent to the coach
When you talk to the coach, or when the app writes a session evaluation or a daily tip, it sends a request to our server, which forwards it to Anthropic, the company that runs the AI model. That request contains what the coach needs to answer: your message, a summary of your profile and plan, and the training and recovery numbers relevant to the question (for example, last night's sleep, a workout's pace and heart rate, or your weekly training load). Until your first plan is written, the conversation with the coach also carries the same summary of your last 30 days that the plan is built from (see "Building your plan" below), so the coach can start from what you already do. A request does not contain your name unless you entered one, or anything from outside the app.
Anthropic processes these requests to generate the reply and does not use them to train its models. Our server does not store the content of any request or reply. It records only that a request happened, which model answered, how long it took and how large it was.
Building your plan
Your training plan is the one thing written on our server rather than on your phone, because it takes minutes and you should be able to close the app while it happens. To build it we send the coach your interview answers and a summary of your last 30 days of Apple Health data — your weekly training volume and load, one line per workout (its date and time of day, type, duration, distance, pace, average heart rate, calories and effort rating where recorded), and your average resting heart rate, heart rate variability, sleep, breathing rate and steps, with your latest VO₂ max — and hold them on the server only while the plan is being written — they are deleted as soon as the build finishes. The finished plan is held encrypted in transit and at rest until the app fetches it, deleted the moment the app confirms it has received it, and deleted unconditionally 7 days after it was finished whether it was collected or not, so it is still there if you close the app while it is being written and come back later. A build that does not finish is deleted after 24 hours.
Sharing a workout
When you share a workout as a link, the app sends our server a copy of that workout as you choose to share it: its name, date and headline numbers (distance, time, pace, elevation), its splits and pace, and — only if you leave them switched on — its route, its heart rate and zones, the coach's write-up of it and how it compared with your plan. By default the first and last 200 metres of the route are removed so the page does not show where you started and finished, but a route that begins and ends at home still shows the area around it.
The server keeps that copy, and a small preview image of it, so that anyone you send the link to can open the page. The link is random and the page is hidden from search engines, but anyone who has the link can see it. The page and everything on it are deleted 7 days after you last shared it, or straight away if you tap Stop sharing. Sharing again within those 7 days refreshes the page and starts the 7 days again. When someone opens the page, their browser loads the map from Apple Maps; Apple sees the map area being viewed, not your health data. The preview picture a messaging app shows for the link is a map drawn by Apple Maps, so Apple receives the route line as shared (without the ends you chose to hide) to draw it, and nothing else about the workout.
Anonymous usage statistics
The app sends us anonymous usage events: which features are used, the app version, the iOS version, how long an action took and, if something failed, a short category such as "network error". A few events also carry one word from a fixed list, such as whether you connected Apple Health or allowed notifications while setting up the app. Each install is identified by a random identifier generated on your phone. It is not linked to your name, your Apple ID or your conversation, and we cannot use it to identify you.
One of those events describes, in coarse groups, what Apple Health held when you set up the app: whether your workouts of the last 30 days were recorded by an Apple Watch, by another watch or app (such as Garmin Connect or Strava), by the iPhone alone, or by nothing; whether they carry heart rate; whether any sleep is recorded; and how many sessions of your sport there were, as a range (none, 1 to 4, 5 to 12, or 13 or more). It never contains a number, an app name or a date. We use it to understand which kinds of athletes set up the app and where setup loses them.
What we never do
- We do not sell or share your data with anyone other than Anthropic, and only for the purpose of generating the coach's replies. A workout you share as a link is shared by you, with whoever you send it to.
- We do not track you across other apps or websites, and the app contains no advertising.
- We do not store the content of your conversation or your health data on our servers, beyond the hours a plan build takes, the 7 days a finished plan waits for the app to collect it, the 7 days a workout you chose to share stays online, and the coarse setup groups in our usage statistics, as described above.
Membership
Corpus Membership is a subscription sold through the App Store. Apple handles the payment and knows your Apple ID; we receive only an anonymous confirmation that a subscription is active. You can manage or cancel it in your Apple ID settings.
Your choices
- Withdraw Apple Health access at any time in the Health app.
- Take a shared workout offline before its 7 days are up with Stop sharing, in the workout's share panel.
- Delete the app to delete every piece of data it holds on your device.
- Email us to ask what anonymous usage data we hold, or to have it deleted.
Children
Corpus is not intended for anyone under 16.
Changes
If this policy changes, the new version is published here with a new date.
Contact
David Puchades · dvpuchades@gmail.com