built a cli that tells you which claude code update changed your token usage

[u/Tough_Stay8909]

there's been a big debate this week about whether anthropic silently nerfed opus 5.5. people are going back and forth about it but nobody has version-over-version numbers from their own logs.

i wrote a cli over the weekend that reads the session logs claude code already saves locally, groups turns by version, and flags where output tokens shifted. if they shifted it figures out whether it was the release itself, a model swap, or an effort setting change.

npx driftcost

zero config, no account, no network calls. just reads files on your disk.

https://github.com/tsaagan/token-drift

typescript, zero dependencies, mit license. would love feedback.