Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
CompactionArea: what it touches
Internal ChangesKind: in v2.1.321,
Internal ChangesSection of the release
What
Compaction is when Claude Code shortens a long conversation by replacing older messages with a summary. When a session is resumed after this, Claude Code checks that the saved conversation fits together. These checks used to give only a yes or no about whether something started behind the compaction. They now name what it was: one of your prompts, or a hidden message. They also count command entries that were left out. When a remote switch is on, saved messages that are only partly missing are treated as acceptable.
Why
This changes how sessions resumed after compaction are checked.