{"version":"2.1.281","anchor":"prompt-cache-prefix-match-next-message-hash-is-checked-befo","canonical_anchor":"prompt-cache-prefix-match-next-message-hash-is-checked-befo","heading":"Prompt-cache prefix match: next message hash is checked before comparing","tier":null,"area":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281\/e\/prompt-cache-prefix-match-next-message-hash-is-checked-befo","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281","markdown":"### Prompt-cache prefix match: next message hash is checked before comparing\n\nThe check for reusing cached conversation history now looks at the next message first before comparing earlier ones\n\n**Unclear.** The finding does not say whether this changes which requests reuse the cache or only how quickly a mismatch is found.\n\n**What**\n\nClaude Code can reuse the start of a conversation already sent to the model, which is called the prompt cache. To do this, it tracks a fingerprint of each message sent. It now checks the next message against its recorded fingerprint first. If they differ, it stops and reports no match before comparing the earlier messages.\n\n**Why**\n\nA mismatch on the next message is now found straight away, without first going through all the earlier ones."}