Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.269 ·

New added-cost timestamp field on comment thread framing

New readAtMs timestamp tracks when an artifact comment thread was last read

TierUnder the hoodhow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaArtifactswhat it touches
KindInternal Changesin v2.1.269,
Under the hood

New readAtMs timestamp tracks when an artifact comment thread was last read

What

A new small data structure combines a commentsEmpty flag with a readAtMs timestamp (validated to be a positive number within a plausible date range) for artifact comment threads.

Why

This timestamp likely lets Claude Code know when a comment thread's contents were last read, which can inform decisions about whether comments are stale or should be dropped from context.

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 doubtThe finding does not confirm exactly how readAtMs is used, only that it is likely for staleness or elision decisions.

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