Tilpas · Privacy policy
Last updated 30 October 2026
Tilpas is a personal training and health app that you run on your own computer. Your data stays there. The developer of Tilpas never receives, stores or sees it.
Who is behind Tilpas
Tilpas is open-source software written and published by Tim Madsen, Denmark (tim@datamadsen.dk). It is not a hosted service: there is no Tilpas server, no account to create and no database run by the developer. Each person installs their own copy, and everything that copy collects lives in a folder on their own machine.
What data Tilpas handles
| Data | Where it comes from | What it is used for |
|---|---|---|
| Activities and daily health data | Your Garmin Connect account: activities with distance, time, heart rate, route and laps; sleep, heart-rate variability, readiness, training status and load, steps, stress, blood-oxygen, VO₂ max, race predictions, fitness age, personal records. | Shown to you in the app, summarised by week and by period, and used to compute your own statistics: easy share, aerobic efficiency, best efforts, what kind of training the day calls for. |
| Weight, body composition, blood pressure | Your Withings account, if you connect one. | Shown next to your training data; a weight trend and a blood-pressure band as information, never a diagnosis. |
| Things you enter | Weekly targets, reminders and habits, a picture of yourself if you add one, questions you ask the coach. | Only what they are for: tracking your week, nudging you, the app icon, the coach's answer. |
| Weather during an activity | Open-Meteo, looked up for the hours and the start point of each outdoor activity. | Explaining heart rate and pace that were affected by heat, wind or rain. |
Where it is stored
In a data folder on the computer that runs Tilpas, as plain files you can read, copy and delete. The app keeps no copy anywhere else. If the app is made reachable from your phone, that happens over your own private network (for example Tailscale); it is not published on the internet. The browser stores only display preferences (language, theme, chosen colours) on the device itself. There are no accounts, no analytics, no advertising and no tracking cookies.
Who the app talks to
Your copy of Tilpas makes requests to these services, on your behalf and with your own credentials. Nothing goes through the developer.
| Service | What is sent | Why |
|---|---|---|
| Garmin | Your Garmin Connect login or an access token, and requests for your own data. | Fetching the activities and health data listed above. Tilpas only reads; it never writes to or changes your Garmin account. |
| Withings | An authorisation you grant once (OAuth), then requests for your own measurements. | Fetching weight, body composition and blood pressure, if you connect Withings. |
| Open-Meteo | The start point of an outdoor activity, rounded to about 100 metres, and its date. No name, no account, no identifier. | The weather during that activity. Open-Meteo is a free, non-commercial weather service. |
| OpenStreetMap | Requests for map tiles of the area a route is in, from your browser, when you open an activity with a route. | Drawing the route on a map. |
| Anthropic (Claude) | Only when you press "Ask": a summary of your training and health numbers for the period in question (dates, durations, heart rates, sleep, readiness, weight, blood pressure, the titles you gave your activities, your age) and your question. No name, e-mail address, account identifier, device identifier or GPS coordinates are included. The request is made with your own Anthropic account. | The "coach": written feedback on a session, a day or a period, and answers to your questions. |
About the coach, said plainly: the numbers that go to Anthropic are health data about you, and because the request is sent from your own Anthropic account, Anthropic can associate it with that account. Tilpas does not add anything that identifies you, and it strips coordinates, but it cannot make the data anonymous towards the provider you are logged in with. What Anthropic does with the content is governed by your agreement with them and your settings there. The coach is optional; nothing is sent until you ask.
Garmin data in particular
Data obtained from Garmin is used solely to show you your own activities and health data in the app and to compute your own statistics from them. It is not shared with anyone, not sold, not used for advertising, profiling of other people or training of any model, and not combined with data about other people. It is deleted when you delete the app's data folder, and you can stop the app's access at any time by disconnecting it in your Garmin account.
Your rights and control
- See everything: the data folder holds all of it, as readable files.
- Delete everything: delete the data folder. Nothing remains anywhere else on the developer's side, because nothing was ever there.
- Disconnect a source: revoke the app's access in your Garmin or Withings account, or remove its credentials from the app's configuration.
- Questions: write to tim@datamadsen.dk. As the developer holds no personal data, there is nothing for him to export or erase on your behalf, but he will help you do it on your copy.
Changes to this policy
This page is updated when the app starts talking to a new service or handling a new kind of data. The date at the top says when.