What
While CLAUDE_CODE_EVAL_ARTIFACT_STUB_DIR is set, published artifacts resolve to local stub URLs of the form eval-stub://artifact/<slug> and the /artifacts browse command is hidden, since there is no remote gallery to browse. The plugin eval CLI sets the variable for the sessions it spawns.
Evidence
eval-stub://artifact/
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundleCLAUDE_CODE_EVAL_ARTIFACT_STUB_DIR/artifacts
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 Connect Claude Code to an LLM gateway touched a line naming /artifacts after this was published.
| `400` errors on every request, in the gateway's own words rejecting a tool's input schema or its `pattern`, on Claude Code v2.1.265 through v2.1.267 | In a gradual rollout on those versions, the [Artifact tool](/docs/en/artifacts#availab…llm-gateway-connect see the edit
Confirmed since
Anthropic's documentation has since written up /artifacts, on Error reference.
Claude tried to publish an [artifact](/docs/en/artifacts) from a file whose bytes don't decode as text, or whose text already contains the replacement character `U+FFFD`, so Claude Code refused the publish before uploading anything. The me…errors see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up /artifacts, on Error reference.