{"version":"2.1.257","anchor":"new-mid-conversation-toolsystem-prompt-diffing-sent-to-the","canonical_anchor":"new-mid-conversation-toolsystem-prompt-diffing-sent-to-the","heading":"New mid-conversation tool\/system-prompt diffing sent to the model","tier":"notice","area":"System Prompt","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.257\/e\/new-mid-conversation-toolsystem-prompt-diffing-sent-to-the","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.257","markdown":"### New mid-conversation tool\/system-prompt diffing sent to the model\n\nWhen a tool description or prompt section changes mid-conversation, Claude is now sent a diff saying the newer version is in effect.\n\nA new sent-prefix ledger, tracked per conversation, compares each outgoing request against what was previously committed to detect a model switch, a declared boundary, or a violation. When a tool description, `input_schema`, or system-prompt section has changed since it was first sent, it synthesizes a diff block for the model prefaced with: \"The following changed since it was first sent in this conversation. The earlier text above stays as sent; where they differ, the current version below is the one in effect.\"\n\n- Area: System Prompt\n- Tier: You'll notice\n- Useful: 4\/5\n- Signal: 4\/5"}