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Sweep 08 Oct 2026 · 18:53Z Build v2.1.295 516 read Stable v2.1.286 Latest v2.1.295 Next v2.1.295 Feeds RSS JSON llms.txt llms-full.txt Unofficial
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Claude Code v2.1.290 ·

Compaction usage reports now record which summary prompt was used

Usage reports about automatic conversation compaction now record the summary prompt variant and whether a scope warning was given

Under the hood Internal Changes
JSON All of v2.1.290
Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
TelemetryArea: what it touches
Internal ChangesKind: in v2.1.290,
Internal ChangesSection of the release

Unclear Where the summary prompt version is chosen is not known.

What

Compaction is when Claude Code summarizes a long conversation to free up space. The usage report Claude Code sends after a successful automatic compaction, tengu_reactive_compact_succeeded, now records two more things:

  • summaryPromptArm: which version of the summary prompt was used.
  • summaryScopeWarned: whether a warning about the summary's scope was raised.

The kind of compaction it reports can now also be taken directly from the compaction itself, rather than always being worked out from what triggered it.

Why

This makes it possible to compare different versions of the prompt that writes the compaction summary. Nothing changes in how compaction works for you.

How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhere the summary prompt version is chosen is not known.

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