What
New detailed logging when prompt caching breaks, helping identify why cache misses occur.
Details
- Logs when cache breaks due to: model changes, system prompt changes (with character delta), tool schema changes
- Format:
[PROMPT CACHE BREAK] system prompt changed (+123 chars) [source=X, call #Y, cache read: A → B, creation: C] - Useful for debugging unexpected cache misses in long sessions
Evidence
Logging at line 266957 (contains "[PROMPT CACHE BREAK]", "system prompt changed", "tools changed", "model changed")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.