{"version":"2.1.260","anchor":"new-diagnostics-for-unexpected-prompt-cache-breaks","canonical_anchor":"new-diagnostics-for-unexpected-prompt-cache-breaks","heading":"New diagnostics for unexpected prompt-cache breaks","tier":"internal","area":"Elsewhere","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.260\/e\/new-diagnostics-for-unexpected-prompt-cache-breaks","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.260","markdown":"### New diagnostics for unexpected prompt-cache breaks\n\nA new diagnostic explains why the prompt-cache hit rate suddenly dropped.\n\nA new diagnostic analyzes why a prompt-cache hit rate suddenly dropped, checking causes like a changed system prompt, changed tools, TTL expiry, or a changed model. It logs a categorized 'causes' list at warn level with a `[PROMPT CACHE BREAK] ...` line, including source, call count, and cache read\/creation details.\n\n- Area: Elsewhere\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 1\/5"}