Follow Discord
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 v2.1.280 ·

Artifact verify/preview tools merged into a single 'check' tool

Artifact verify and preview tools are merged into one 'check' tool with old verb names still accepted

Nothing to try yet In Development
JSON All of v2.1.280
Nothing to try yetTier: how much it should matter to you
4Useful: my rating, 1 to 5
4Signal: worth watching, 1 to 5
ArtifactsArea: what it touches
In DevelopmentKind: in v2.1.280,
What probably matters to youSection of the release
What

The separate artifact-verify and artifact-preview capabilities are combined into a single tool called check. Its search hint dynamically lists "preview a page locally" and/or "read viewers' runtime diagnostics" depending on which capabilities are enabled for a given session. An offersLegacyVerb mechanism maps the old verify and preview verbs back to the new tool for compatibility.

Why

This consolidates two related artifact tools into one, while offersLegacyVerb means existing usage of the old verb names should keep working.

Read from
Names in the bundlecheck
Feature flag
tengu_osier_pylon_trace 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: no value returned · compiled default in v2.1.280: off

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

tengu_cobalt_plinth_aspen 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: no value returned · compiled default in v2.1.280: off

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.280. It isn't a statement about your account. What a flag value here can and cannot tell you

Since it was published

The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.

Added since A small documentation edit on fast-mode touched a line naming check after this was published. Fast mode is not available on Claude Opus 4.6. Requests to `claude-opus-4-6` with `speed: "fast"` do not return an error: they run at standard speed and are billed at [standard rates](https://platform.claude.com/docs/en/about-claude/pricin… build-with-claude/fast-mode see the edit
Confirmed since Anthropic's documentation has since written up check, on Admin controls. | Organization and access > User provisioning (SCIM directory sync, Enterprise) | Supported in Claude Science | Provisioning and deprovisioning act on claude.ai membership, which Anthropic checks on every request the app makes, so a deprov… claude-science/admin-controls see the edit
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up check, on Admin controls.

See this entry in the whole of v2.1.280 →

Feedback