Terms of service

These terms cover the Mathend editor and the optional hosted AI agent. By downloading the editor or buying credits you agree to them.

The editor

The editor is provided free of charge for personal and commercial use. You own the documents you create with it; we claim no rights over your content. Because your notes are stored only on your own device, keeping backups is your responsibility.

Bring your own API key

If you configure your own model provider key, your use of that model is governed by your agreement with that provider, and they bill you directly. We are not a party to it and cannot refund it.

Agent credits

• Credits are prepaid in packs of $5, $10 and $25 and are denominated in US dollars.
• Each request to the hosted agent is billed at the upstream model cost plus a per-model margin, and deducted from your balance. The current rate for every model is published on the pricing page.
• Rates can change when upstream model prices change. The rate in effect when you send a request is the rate you pay.
• Credits do not expire, and there is no subscription or seat count.
• Credits are not transferable between accounts and have no cash value outside the service.

Refunds

Unspent credit can be refunded on request within 14 days of purchase. Credit already consumed by requests cannot be refunded, because the upstream model cost has already been incurred. Purchases are processed by Polar as merchant of record, so refunds are issued through them. Email support@mathend.com to start one.

Acceptable use

Do not use the hosted agent to break the law, to attack or overload the service, to resell access, or in a way that violates the usage policies of the underlying model providers. We may suspend an account that does, and will refund any unspent balance if we do.

Availability and liability

The service is provided as is. The hosted agent depends on third party model providers, so we cannot guarantee uptime, latency, or the correctness of any model output — check mathematical results before relying on them. To the extent permitted by law, our total liability is limited to the amount you have paid us in the previous twelve months.

Changes

We may update these terms; the date at the top changes when we do. See also our privacy policy.