Claude Code Prompt Cache Fix: Long Sessions No Longer Bleed Full-Price Tokens from Tool Schema Drift and CLAUDE.md Re-Injection

Claude Code Docs·high signal

Two bugs were silently inflating token costs in long Claude Code sessions: tool schema bytes changing mid-session caused prompt cache misses (every turn sent uncached), and nested CLAUDE.md files were being re-injected dozens of times as more files were read. Both fixed in v2.1.94-97. Additionally, Pro users now see a footer hint when prompt cache has expired showing uncached token count for the next turn. A separate v2.1.69 regression causing --resume sessions to miss cache hits entirely was also patched.