Terms of Service

Last updated 19 October 2026

These terms are an agreement between you and [[LEGAL NAME]] ("we", "us") about your use of Sonnet at multichatstem.com and app.multichatstem.com (the "Service"). By signing in you accept them.

1. Your account

You sign in with a Google account. You must be at least 16 years old and keep your account to yourself. You are responsible for what happens under it.

2. What the Service does

Sonnet lets you chat with AI models and hold separate side conversations about parts of an answer. Replies are produced by third-party AI models and sent through us. We may add, change or remove models and features, and we may change which models are available on each plan.

3. AI output can be wrong

AI replies can be inaccurate, incomplete or out of date, including in mathematics and science. Check anything that matters before you rely on it. Sonnet is not a substitute for professional advice (medical, legal, financial or otherwise), and you are responsible for how you use what it produces.

4. Your content

What you type, upload and receive ("your content") stays yours. You give us permission to store it, process it and send it to the AI providers we use, only as needed to run the Service for you. Do not upload anything you have no right to share.

5. Acceptable use

Do not use the Service to break the law, to harm or harass anyone, to create malware or other abuse, or to infringe other people's rights. Do not try to get around limits or billing, probe or attack the Service, share your access, or resell it. We may suspend an account that does.

6. Plans, usage and billing

• Free includes a small allowance of AI usage each month, no card needed.
• Pro costs $20 per month (US dollars) and includes $10 of AI usage each month. Payment is taken by Stripe and renews every month until you cancel.
• Usage is measured by what each reply costs us at the model's list price, so larger models use your allowance faster. Unused allowance does not carry over. Allowances reset on the 1st of each month (UTC).
• When you reach your allowance, requests that need an AI model stop until the next reset. You do not pay extra.
• You can cancel any time from your account page (app.multichatstem.com/billing). Cancelling stops future charges; Pro continues until the end of the period you paid for.
• We will tell you at least 30 days before changing the price of Pro. Taxes, where they apply, are added at checkout.
• Refunds are covered in our refund policy.

7. Availability

The Service is provided "as is" and "as available". We work to keep it running and your data safe, but we do not promise it will be uninterrupted or error-free, and we may change or stop it. Keep your own copy of anything you cannot afford to lose.

8. Ending your account

You can stop using the Service at any time and ask us to delete your data (see the privacy policy). We may suspend or end an account that breaks these terms or puts the Service at risk, and we will refund any unused part of a Pro payment if we end your account without that being your fault.

9. Liability

To the fullest extent the law allows, we are not liable for indirect or consequential loss, lost profits or lost data, and our total liability to you for anything arising from the Service is limited to the amount you paid us in the 12 months before the claim (or $50 if you paid nothing). Nothing here limits liability that cannot be limited by law, and your rights as a consumer under the law where you live are not affected.

10. Changes and law

We may update these terms; if a change matters we will tell you in the app or by email before it applies, and continuing to use the Service afterwards means you accept it. These terms are governed by the laws of [[COUNTRY]], and disputes go to its courts, except where the law where you live gives you the right to use your local courts.

11. Contact

[[LEGAL NAME]] · [[CONTACT EMAIL]]