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Sweep 25 Sep 2026 · 19:33Z Build v2.1.283 504 read Stable v2.1.274 Latest v2.1.283 Next v2.1.283 Feeds RSS JSON llms.txt llms-full.txt Unofficial

Claude Code v2.1.282 ·

Feature flags can now be targeted by an atis pin

Claude Code now sends an atisPin value for feature-flag evaluation and re-fetches flags when it changes, behind the new tengu_serene_teacup switch

Group of 3 Under the hood Internal Changes
JSON All of v2.1.282
Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
InternalsArea: what it touches
Internal ChangesKind: in v2.1.282,
Internal ChangesSection of the release

What

Claude Code asks a feature-flag service (GrowthBook) which features are switched on for a session, and sends it some attributes describing that session. This release adds one:

  • A new attribute, atisPin, is sent whenever a stored atis value is present. If the value looks like v1.<pin>.x.y.z (five dot-separated parts), only the second part is sent; otherwise the whole string is sent.
  • atisPin is added to the list of attribute keys and to cacheKeyAttributes, so cached flag values are kept separately for each pin.
  • A new refreshAtisPin() compares the current pin with the one the flag client has and fetches flags again when they differ. It runs after the start-up data (bootstrap) has been fetched, and only when the new switch tengu_serene_teacup passes.

tengu_serene_teacup falls back to on when the server sends no value. Nothing has been read about this switch yet.

Why

For anyone who has an atis value, which features a session gets can now depend on that pin, and flag values are refreshed when the pin changes.

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 doubtIt is not clear where the "atis" value comes from or what it stands for.

See this entry in the whole of v2.1.282 →

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