Last updated: 21 July 2026
This policy explains what personal data Cairn processes, why, and your rights under the GDPR. The free Basic edition works without an account and keeps your diagrams in your browser; this policy mainly concerns Cairn Pro.
| Data | Why |
|---|---|
| Account email and name | To create and secure your account and contact you about the service |
| Payment details | Processed by Stripe to take payment. We do not store your card number |
| AI prompts | The text you submit to generate a diagram is sent to our server and AI provider to produce a result |
| Usage records | Basic logs (for example, how many AI generations) to run and protect the service and to bill fairly |
| Your diagrams | Stored locally in your browser. We do not receive or store them on our servers |
We process account and billing data to perform our contract with you; usage and security data on the basis of our legitimate interest in running and protecting the service; and any optional data with your consent, which you can withdraw at any time.
We use trusted providers that act as our processors:
Some providers may process data outside the EU/EEA (for example, in the United States). Where they do, transfers are covered by appropriate safeguards such as the EU Standard Contractual Clauses or an adequacy decision.
We keep account and billing data for as long as your account is active and for any period required by law (for example, tax records). You can ask us to delete your account, after which we remove personal data that we are not legally required to keep.
You have the right to access, correct, delete, restrict or object to the processing of your data, and to data portability. To exercise any right, email wabackpackers@gmail.com. You can also complain to the Portuguese Data Protection Authority (CNPD, cnpd.pt) or your local authority.
Cairn uses your browser's local storage to keep your session and to save your diagrams on your device. We do not use advertising or tracking cookies.
Cairn is not directed at children under 16. We do not knowingly collect their data.
We may update this policy and will post the new version here with an updated date.
Privacy questions: wabackpackers@gmail.com.