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 v2.1.275 ·

Artifacts: new 'source restore' read path and Artifact Types catalog

New backend support for restoring a published Artifact's source and reading Artifact Types

TierYou'll noticehow much it should matter to you
Useful3my rating, 1 to 5
Signal3worth watching, 1 to 5
AreaArtifactswhat it touches
KindImprovementsin v2.1.275,
You'll notice

New backend support for restoring a published Artifact's source and reading Artifact Types

What

A large new module adds the ability to read back the published source of an Artifact (a piece of generated content Claude Code can publish, such as a document or app) through a new artifact_source_restore path. It reports detailed reasons when this fails, including permission checks, blocked outbound network access, organization mismatches, read timeouts, version lag, and warnings when another writer has changed the content.

Alongside this, new plumbing supports "Artifact Types": reading a type's catalog entry, its instruction file, and the content of individual files within it via artifact_type_link_read. This is tied to a feature state called frozenArtifactTypes.

Why

This lays groundwork for Claude Code to fetch back and inspect previously published Artifacts and their type definitions, with clearer error messages when that read fails.

Read from
Feature flag
tengu_cobalt_plinth_moss On for this account, and not off by default

The flag server returned on for the one account this site reads, and nothing in this release compiles it off by default. The compiled default is shown below, and says which it is when we cannot read one: a fifth of gates compile in a string or a number rather than on or off, and most published releases have no gate table behind them at all. No client can see what the server returns for your account.

This account: on · anonymous baseline: on · compiled default in v2.1.275: on

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 v2.1.275. It isn't a statement about your account. What a flag value here can and cannot tell you

See this entry in the whole of v2.1.275 →