Show HN: Tarmac – Know what Claude Code will cost before you run it

I built this because I kept getting surprised by Claude Code bills. A complex refactoring task that I expected to cost $2 would end up costing $15, and there was no way to know beforehand.

Tarmac analyzes your prompt and gives you a cost range before Claude Code starts working. It uses conformal prediction trained on 3,000 real SWE-bench tasks — hitting 81% in-range accuracy on an 80% target.

npm install -g tarmac-cost — fully open source, runs locally, no tracking, no accounts.

Would love feedback on estimate accuracy for your use cases - that's what I'm most focused on improving