Tip: /cost Now Reports Per-Session Prompt Cache Hit Ratio, Misses, and Tokens Re-Cached

Claude Code Changelog·medium signalXBlueskyLinkedInCopy link

2.1.251 adds a per-session prompt-cache line to `/cost` showing hit ratio, misses, tokens re-cached, and warm versus cold, plus a matching `prompt_cache` object for status line scripts. This lands one release after the fix for Claude Code blowing its own cache hourly on OAuth token refresh, which is the point: cache behaviour was previously invisible, so a regression like that could run for weeks unnoticed. Pull `prompt_cache` into a status line and you get a standing tripwire instead of a surprise bill.