What
The artifact type catalog lets Claude browse published artifact types. Its flag, tengu_cobalt_plinth_larch, now falls back to on instead of off when the server sends no value. A flag is a switch Anthropic's server can turn on remotely.
CLAUDE_CODE_ARTIFACT_TYPE_CATALOGandCLAUDE_CODE_ARTIFACT_TYPESfall back to true.CLAUDE_CODE_ARTIFACT_TYPE_CLOUD_CREATEstill falls back to false.- In all three cases, setting the environment variable overrides the flag. An environment variable is a setting passed to a program when it starts.
- The Artifact prompt builder now passes a
typeReachvalue of none, quickstart or create.
The flag server returned on for this site's account and off for an anonymous baseline. It switched on since the previous reading and was first seen on 2026-10-22. No reading has been taken under this release yet.
Why
Without a server value, the type-selection text in the Artifact tool's instructions is now included. To turn it off, set CLAUDE_CODE_ARTIFACT_TYPE_CATALOG.
tengu_cobalt_plinth_larch On for this account, and not off by defaultThe 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: off · compiled default in v2.1.310: not a boolean we can read
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 v2.1.310. It isn't a statement about your account. What a flag value here can and cannot tell you