kvleak finds 20.7% of Claude Code input spend lost to cache rebuilds

What the research found

kvleak is an open-source, no-API-key CLI (pip install kvleak) that audits Claude Code, Codex CLI, Gemini CLI and OpenCode session files and finds that a 95.4% cache hit rate hid 20.7% of input spend lost to cache rebuilds, mostly from idle gaps outliving the cache TTL.

Claims and how well the evidence supports them

1. Claude Code cache hit rate was 95.4% while 20.7% of input spend went to cache rebuilds in the maintainer's sample 98%
2. kvleak installs with pip install kvleak or pipx run and needs no API key, config or network calls 98%
3. Idle gap outlived the cache TTL caused 69.2% of leaked cost in the maintainer's sample 98%

Evidence

• github.com https://github.com/shangliy/kvleak

Actionability rated medium.