Vibe Coding
Claude Code 2.1.280 fixes two silent prompt-cache busters in model switching and resumed fork subagents
The changelog lists two cache fixes. Switching models from a host app (Claude Desktop, VS Code, SDK) while Claude was working caused a cache miss on the next prompt, and resumed fork subagents rebuilt their tool list instead of re-sending the original one, which broke caching for that agent. `/cost` now also names thinking-mode and thinking-display changes as cache-miss causes. If your cache-hit rate dropped on multi-agent runs, update before blaming your prompts. Opus 5.5 cache reads cost $0.20/Mtok, so each miss is now 25x more expensive than a hit.
↳ Follow the thread