Cassie: Terms of Use
Last updated: 18 October 2026
These terms cover the Cassie web app, website and browser extension. By using Cassie you
agree to them. Please also read the Privacy Policy.
Who can use Cassie
- Anyone can use Cassie on their own device without an account.
- Cassie is for learners of every age: from nursery and grade school to
high school, college and working people, for educational purposes, with or without an
account. Children should use Cassie, and make an account, with a parent's, guardian's or
teacher's permission and help.
What Cassie is for
- Cassie is a study aid: explanations, practice, reviewers and notes.
- Don't use Cassie during tests, quizzes or other graded work, or to hand
in work that isn't your own.
- Cassie uses AI, and AI can be wrong. Check important answers, especially for grades,
health, money or legal matters. Cassie is not a doctor, lawyer or counsellor; in an
emergency, contact local emergency services.
Your files and pictures
- Only attach files you're allowed to use. Cassie reads them only to answer you, then
lets them go: our server keeps no copy and never writes them in a log. She doesn't publish
them or show them to other people.
- Pictures Cassie makes are for your own study and projects.
Fair use
Free use without your own API key has daily limits so everyone gets a fair share.
Don't try to get around limits (for example with throwaway emails or many accounts),
misuse Cassie to harm others, or use it for anything illegal. We may block accounts
or devices that do.
API keys and other services
Cassie uses AI. To answer you, she sends your questions, and any file, photo or voice you
add, to AI services run by other companies (or to Cassie's server, which passes them on).
The Privacy Policy names each one and what it is for. If you add
your own Groq or Google Gemini key, your use of those services also follows their terms.
Paid plans
Cassie is free today. When paid plans launch, the price, how often you're billed, that
the plan renews automatically until you cancel, and how to cancel will be
shown right next to the subscribe button before you pay. You'll be able to cancel any
time; your plan then stays active until the end of the period you paid for.
- Cancelling never takes more steps than subscribing. You can cancel
yourself in the app, from Settings, without emailing anyone or answering
questions first.
- A reminder before every renewal. If your plan renews automatically,
we remind you before each renewal, in the app and by email, about a week before it and
never less than 3 days before. Yearly plans also get a reminder a month before. The
reminder says the date, the amount, and how to cancel.
- A Semester pass (the Pasado Pass) is one payment and never renews. It
lasts 5 months, and we tell you in the app and by email about a week before it ends. You
won't be charged again unless you choose to buy another plan.
- 7 days to change your mind. If you're not happy with the first payment
for any plan, email [email protected] within 7 days of paying and
you get all of it back. No questions asked.
- Founding price. A Monthly or Yearly plan keeps the price you started
with for as long as it keeps renewing, even if our prices go up. If you cancel and come
back later, the price at that time applies.
No guarantee
Cassie is provided "as is". We work to keep it running and accurate, but we can't promise
it will always be available or error-free.
Changes
If these terms change, the date above changes. Continuing to use Cassie means you accept
the updated terms.
Contact
Questions? Contact the developer at [email protected], or use
Settings → Report a problem in the app.