{"version":"2.1.323","anchor":"compaction-ignores-custom-instructions-passed-in","canonical_anchor":"compaction-ignores-custom-instructions-passed-in","heading":"Compaction no longer uses instructions passed to it directly","tier":"notice","area":"Compaction","scope":"individual","heads_up":true,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323\/e\/compaction-ignores-custom-instructions-passed-in","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323","markdown":"### Compaction no longer uses instructions passed to it directly\n\nCompaction now ignores custom instructions given to it directly and uses only instructions returned by a PreCompact hook\n\n**Unclear.** It is unclear whether text typed after `\/compact` still reaches the summary by another route.\n\n**What**\n\nCompaction is when Claude Code summarizes a long conversation so it fits in the model's working space. Compaction used to read custom instructions from what it was given and pass them on to the summary and to hooks. It no longer does.\n\nA hook is a command you set up to run at certain moments. The PreCompact hook, which runs before compaction, now receives no custom instructions. Only instructions the hook sends back are used.\n\n**Why**\n\nIf you add focus text after `\/compact` to steer the summary, check whether your summaries still follow it. Instructions supplied through a PreCompact hook still apply.\n\n- Flag `tengu_compact_cache_prefix`: Off in both readings (read for one account on one subscription tier against v2.1.323; this account: off, anonymous baseline: off, compiled default: on) These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.\n- Area: Compaction\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: yes"}