Privacy Policy

The Service is operated by 3Days. You can reach us about privacy at the contact address that will be published on this page.

Information you give us

• Account: your email address. If you sign up with a password, it is stored only as a secure hash by our login provider, never in readable form. If you continue with Google, Google shares your email address and basic profile (name and picture) with us.
• Learning activity: your goals, Day 0 diagnostic answers and confidence ratings, answers to questions and exercises, final projects, role-play answers, messages to the AI tutor, your learning plan, gap list and progress.
• Optional context: if you tell us your role or describe your job, we use it to tailor your goal and examples.
• Topics you ask for: what you type in "What do you want to learn?", the direction you choose and any changes you ask for in a course outline.

Information collected automatically

• AI usage records: for each AI request, the feature used, the model, the number of tokens and the cost. We use these to keep the Service affordable and to prevent abuse.
• Approximate location: the country (and, for a few countries, the region) your connection comes from, worked out from your IP address. We use it only to check that the Service is available where you are; we don't store your IP address with your account.
• Technical logs: our hosting provider keeps short-lived server logs (such as request times and errors) to keep the Service running and secure.
• On your device: we store your progress in your browser's local storage so you can learn without an account, and a login cookie when you are logged in. We don't use advertising cookies.

We do not collect payment details yet. When paid plans launch, payments will be handled by a payment provider and this policy will be updated before then.

• To provide the Service: teach, grade your answers, give feedback, build courses you ask for and keep your progress in sync across your devices.
• To personalise your learning: your goal, diagnostic results, role and gaps shape your route, examples and tutor replies.
• To keep the Service safe, available and affordable: enforce topic boundaries and regional availability, prevent abuse and control AI costs.
• To improve the Service: for example, by checking which lessons cause confusion and fixing them.

We do not sell your personal information, we do not share it for cross-context behavioural advertising, and we do not use it for advertising.

The Service uses AI models provided by Anthropic (Claude). When you use an AI feature, the relevant part of your input (for example your answer, your message to the tutor or the topic you typed), together with the lesson context, is sent to Anthropic to generate a response. Under Anthropic's commercial terms, inputs and outputs sent through its API are not used to train its models by default. AI-generated content can be wrong; see our Terms of Service.

When you ask the Service to build a course, the course itself (its outline, lessons, questions and the concepts it teaches) becomes part of our shared course library. Other learners may see and learn from it, and parts of it may be reused in other courses.

Your personal information is never added to the library: not your email, your role or job description, your answers, your chats with the tutor or your progress. They only shape your own experience. Please don't type personal or confidential information into the topic box, because the topic wording may inform the course that is built.

We share personal information only with service providers that help us run the Service, under contracts that limit how they can use it:

We may also disclose information if the law requires it, to protect the rights and safety of our users or others, or as part of a merger or acquisition (in which case this policy would continue to apply to your information). If we add a provider (for example for payments or product analytics), we will update this list.

Our providers may process information in the United States and other countries. Where the law requires it, we rely on appropriate safeguards (such as standard contractual clauses) for these transfers.

• Account and learning data: until you delete your account.
• AI usage records: until you delete your account (they are deleted with it).
• Courses you asked us to build: they stay in the shared library after you delete your account, without any link to you.
• Server logs: a short period set by our hosting provider.
• Data stored on your device: until you clear it or remove it from your browser.

• Download your data: on your Account page, you can download your learning data and AI usage records as a file.
• Delete your account: on your Account page, you can delete your account; your learning data and usage records are deleted with it.
• Use the Service without an account: you can learn the free parts without logging in; your progress then stays only in your browser.

Depending on where you live (for example in the European Economic Area, the United Kingdom or California), you may also have the right to access, correct, delete or port your information, to object to or restrict some processing, and to complain to your data protection authority. We will not treat you differently for using these rights. To use a right that the Account page doesn't cover, contact us at the contact address that will be published on this page.

Where the GDPR applies, we rely on: performing our contract with you (to provide the Service), our legitimate interests (to keep it safe, affordable and improving) and, where we ask for it, your consent.

The Service is not intended for children under 16, and we do not knowingly collect information from them. If you believe a child has given us information, contact us and we will delete it.

The Service is not offered in some countries and regions, for example because the AI services we rely on are not available there. Visitors from those places see a notice instead of the Service.

We use reasonable technical and organisational measures to protect your information, such as encrypted connections, access controls and row-level security in our database. No service can be completely secure.

We may update this policy. If we make significant changes, we will let you know through the Service or by email before they take effect.

Questions or requests: the contact address that will be published on this page.