Privacy Policy

Who is responsible

Crux is operated by DByrd, an individual based in Alabama, United States. Privacy questions and requests: support@cruxlearn.app.

What we collect

We collect only what Crux needs to work:

• Your Whop user ID, and whether your Whop account has access to Crux Beta or Crux Pro. When you sign in, we ask Whop only to confirm who you are; we do not receive or store your Whop email address, name or payment details.
• What you add: the links you submit (YouTube or article addresses), the source’s title, the transcript or article text we fetch for it, and text you paste. Pasted text is kept only until your cards are made and is then deleted; we delete any leftover within about an hour.
• What Crux makes and tracks for you: your cards, review history and schedule, credits used, and settings such as your daily card cap and time zone.
• Service records: when each job ran, whether it succeeded, and what it cost us to run (for example, how many AI tokens it used). We keep our logs free of the content of your sources and your cards.
• Security data: sign-in and rate-limit records, including a one-way scrambled form of your IP address (not the address itself), kept for about a day to stop abuse.

Cookies

Crux uses only the cookies needed to keep you signed in and to complete a sign-in safely (a short-lived cookie during the Whop sign-in step). We do not use advertising or cross-site tracking cookies, and we do not run third-party analytics.

How we use it

To run Crux for you: sign you in, check your access, make and schedule your cards, enforce credits and limits, keep the service secure, fix problems, and understand our costs. We do not sell your information, use it for advertising, or share it with data brokers.

Who helps us run Crux

These providers process data on our behalf, only to provide their part of the service:

• Whop — sign-in, memberships and payments (Whop is the merchant of record for purchases).
• Supabase — our database, hosted in the United States.
• Vercel — hosts the Crux website.
• Trigger.dev — runs the background jobs that make your cards.
• Anthropic — the AI model that writes and checks your cards. We send it the text of the source you added; under Anthropic’s commercial terms, this data is not used to train its models.
• TranscriptAPI — fetches YouTube captions for videos you add.
• Resend — will send email reminders, only if you choose to turn them on.

Other sharing

We may disclose information if the law requires it, to protect people’s safety or Crux’s security, or as part of a transfer of Crux to a new owner, who would be bound by this policy for the data we hold.

How long we keep it

We keep your account data while your account exists. You can ask us to delete your account at any time by writing to support@cruxlearn.app; we will delete your account, sources, cards and review history within 30 days, and confirm when it is done. We may keep basic records of costs and payments, without your content, where we need them for accounting, tax or legal reasons.

Your choices and rights

You can ask us for a copy of your data, to correct it, or to delete it, by writing to support@cruxlearn.app. Depending on where you live (for example in the EU, the UK or some US states), you may have further rights, such as to object to or restrict processing, or to complain to a data-protection authority. We will not treat you differently for using these rights.

Security

Data travels over encrypted connections. Each learner’s data is kept separate in the database, so one learner cannot read another’s. Secret keys stay on our servers. No system is perfectly secure; if a breach affects your data, we will tell you as the law requires.

Children

Crux is not meant for children under 13, and we do not knowingly collect their information. If you believe a child under 13 has used Crux, contact us and we will delete their data.

International users

Crux is run from the United States, and your data is processed in the United States, where privacy laws may differ from those where you live.

Changes

We will update the date at the top when this policy changes, and tell you in Crux about material changes before they take effect.