Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.242 Home All releases olderv2.1.241 v2.1.243newer
Claude Code v2.1.242

The Artifact tool can browse published types, but not in this build

Not switched on
Useful2 Signal4
Artifacts Notable not in their notes

Claude could browse published artifact types to start from, but both actions are switched off.

list_types and describe_type are implemented behind CLAUDE_CODE_ARTIFACT_TYPE_CATALOG and a flag that defaults false.

Feature flag
tengu_cobalt_plinth_rowan Off in both readings

The flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.

This account: off · anonymous baseline: off · compiled default in v2.1.242: not a boolean we can read

Read once, for one account on one subscription tier, against v2.1.242. It isn't a statement about your account. What a flag value here can and cannot tell you

CLAUDE_CODE_ARTIFACT_TYPE_CATALOG
What

Two read-only actions are added to the Artifact tool: list_types takes a type_query and returns published types this account could start a new Artifact from (title, url, description, tier), and describe_type takes a type_url and returns that type's files, instructions file, capabilities and whether it is creatable. Both are switched off here. Availability is read from CLAUDE_CODE_ARTIFACT_TYPE_CATALOG, falling back to the flag tengu_cobalt_plinth_rowan, whose built-in value is false, and neither exists in the previous build.

Details
  • The value is computed once when the tool's schema is built and frozen for the session, and the wider artifact-types feature must also be on.
  • With it off, the actions do not appear in the tool's action list, the paragraph of the prompt that advertises them is omitted, and calls answer with an unavailable message or "artifact types not available to this account".
  • Permission text warns that titles and descriptions in these listings are written by their publishers and are read into the conversation.
  • Results render as "listed N artifact types" and "described artifact type ... (N files ... ships instructions)", and a not-found reply points you at using a type_url from list_types.
Evidence

describing an Artifact type is not available in this session, artifact types not available to this account, if (i) c.push("list_types", "describe_type");, list published artifact types (read-only; titles and descriptions written by their publishers)

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.242 →