The github seems to be a better source, since it supports JavaScript and python https://github.com/chopratejas/headroom (4 points, 16 days ago) https://news.ycombinator.com/item?id=48155888

But we also seem to have a couple of Show HN from another of the contributors.. extraheadroom.com which uses this library, but bundles it further:

Show HN: Headroom – Get 2x Claude Code usage by optimizing input data (2 points, 60 days ago) https://news.ycombinator.com/item?id=47602591