{"version":"2.1.267","anchor":"precomputed-compaction-results","canonical_anchor":"precomputed-compaction-results","heading":"Precomputed compaction results","tier":"internal","area":"Compaction","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.267\/e\/precomputed-compaction-results","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.267","markdown":"### Precomputed compaction results\n\nConversation compaction can now apply precomputed summaries, with a dedicated error if one fails to settle\n\n**Unclear.** The finding doesn't explain what triggers precomputing a summary ahead of time or what a reader would notice differently during compaction.\n\n**What**\n\nWhen Claude Code compacts a conversation (compressing older history to save space), the result of applying a compaction swap now carries additional tracking data: a key, a flag indicating whether it was a replacement, and a `precomputedAtUuid` identifying when the summary was precomputed. There's also a new dedicated error type for when a precomputed summary fails to settle properly.\n\n**Why**\n\nThis points to compaction summaries now being computed ahead of time in some cases rather than only on demand, with better error handling and traceability if a precomputed summary doesn't finish correctly.\n\n- Area: Compaction\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5"}