Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
ElsewhereArea: what it touches
Internal ChangesKind: in v2.1.309,
Internal ChangesSection of the release
What
Compaction is how Claude Code shortens a long conversation so it fits, keeping some messages and summarizing the rest. Each compaction leaves a boundary in the conversation.
The tracker for running turns now records the IDs of the messages kept at each compaction boundary, through a new keptAtTheLastBoundary input. One tracker field is set only when a setting equals 'on'.
The handler for compact_boundary now passes the conversation to the boundary hook.
The terminal interface now calls onMainRequestStart, which marks the main request to Claude as announced.
Why
These are internal bookkeeping changes for compaction and resuming. Nothing here changes what you see or type.
