Follow Discord
Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.265 ·

Resuming a session can reuse a precomputed compaction summary instead of recompacting

Session resume can now skip recomputing a conversation summary by reusing one precomputed ahead of time (feature-gated)

TierNothing to try yethow much it should matter to you
Useful3my rating, 1 to 5
Signal3worth watching, 1 to 5
AreaSessionswhat it touches
KindIn Developmentin v2.1.265,
Group of 4 Nothing to try yet

Session resume can now skip recomputing a conversation summary by reusing one precomputed ahead of time (feature-gated)

What

  • A new path lets the agent loop reuse a previously precomputed compaction summary, built ahead of time and cached by session id, model, and boundary, instead of running compaction fresh.
  • The cached summary is validated before use: its age, model match, and token growth are checked, with rejection reasons including session_mismatch, model_mismatch, bad_timestamp, too_old, grew_too_much, shrank_too_much, and preserve_uuid_missing. A successful reuse emits tengu_precomputed_compact_rehydrated.
  • The session-resume warning dialog now shows a "Resume from summary (instant, recommended)" label instead of the usual "Resume from summary (recommended)" when a precomputed summary is available (hasPrecomputedSummary).
  • The resume flow, gated by tengu_gleaming_fair_reuse (extending tengu_gleaming_fair), can skip recomputation entirely, or detect that a precomputed summary has gone stale.

Why Recomputing a full conversation summary on every resume is slow; reusing a precomputed one when it's still valid should make resuming a session noticeably faster. The feature is currently gated off.

Read from
Feature flag
tengu_gleaming_fair Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: off · compiled default in v2.1.265: off

tengu_gleaming_fair_reuse Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: off · compiled default in v2.1.265: off

Read once, for one account on one subscription tier, against v2.1.265. It isn't a statement about your account. What a flag value here can and cannot tell 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 doubtNo reading of any of these gates has been taken under this release, so their state in this version is unknown.
The name it cites is new in this buildNew in this build: tengu_gleaming_fair_reuse

See this entry in the whole of v2.1.265 →

Feedback