Terms
Terms of service
These cover the hosted service at contextbill.vercel.app. The command line tool is separate and is covered by its MIT licence. Last updated August 26, 2026.
What the service is
contextbill estimates what your Claude Code usage cost, by reading transcripts you point it at and pricing them against a published rate table. It is a free service provided as is.
Estimates, not invoices
Every figure is an estimate produced from your transcripts and a rate table with a date on it. It is not a bill, it is not issued by any model provider, and it will not match your invoice. Three limits are worth naming, largest first. Figures are priced at Anthropic's published first-party API rates, so if you work on a subscription you paid a flat fee and these dollars value the usage rather than restate what you were charged; Bedrock and Vertex are priced separately again and are not modelled. A transcript records how many tokens were written to cache but not which cache lifetime was charged, so contextbill assumes the cheaper one and therefore tends to understate. And the startup-prefix figure is a model of how a session's fixed overhead is apportioned, not a line item anyone billed you. Do not use these numbers as the sole basis for a financial decision, a chargeback or a dispute.
Your account
You are responsible for keeping your credentials secure and for what happens under your account. Tell us if you think it has been compromised. One person or organisation per account.
What you may not do
- Upload anything you do not have the right to analyse, including someone else's transcripts.
- Try to reach another user's data, or probe the service for ways to do so. If you find one, report it rather than using it.
- Automate against the service in a way that degrades it for other people.
- Use it to break the law, or to breach your agreement with a model provider.
Your content
The aggregates you save stay yours. We do not claim any rights over them and we do not use them to train anything. We need permission to store and display them back to you, and that is the whole of it.
Availability
There is no uptime guarantee. The service may change or stop. Because it is free and open source, keep your own copy of anything that matters. The command line tool produces the same numbers offline and does not depend on this site existing.
Liability
The service is provided without warranties of any kind. To the extent the law allows, we are not liable for indirect or consequential loss, or for any decision made on the basis of an estimate the service produced. Nothing here limits liability that cannot lawfully be limited.
Ending it
Stop using the service whenever you like, and ask for your data to be deleted as described in the privacy policy. We may suspend an account that breaks these terms.
Changes
If these terms change, the date at the top changes with them, and the history is public in the repository.
Contact
Open an issue on GitHub.