The artifact publish action can offer a pin field, but it is refused outright in cloud sessions and otherwise depends on an env var or gate.
The artifacts/files tool's publish action now accepts a pin boolean parameter; when true, publishing also pins the artifact to the user's claude.ai sidebar, where it shows up the next time the sidebar loads. On success the tool reply includes a note that it was pinned to the sidebar; if pinning fails, the publish itself still succeeds and the reply appends a note that the pin didn't go through. This is wired into the publish tool's response builder at two call sites, gated by the tool's Zod schema still exposing a pin literal in its action shape.
Whether the field is even offered to the model is controlled by a check ($Ot()) that returns false outright for remote/cloud sessions (unless Jd()), otherwise reads the CLAUDE_CODE_ARTIFACT_PIN env var or falls back to a gate.
tengu_cobalt_plinth_holly Off in both readingsThe 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 v2.1.259: 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 v2.1.259. It isn't a statement about your account. What a flag value here can and cannot tell you
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.
Without the `thinking-binding-controls-2026-08-01` beta header the message also names that header. Keep the conversation history append-only, or send the beta header with `prefix_mismatch_behavior: "drop_block"` to drop the block and conti…api/errors see the edit
| `claude-science uninstall` | Windows only. Remove the app, its shortcuts, and its PATH entry while keeping your data; `--purge` also deletes the data directory. Quit Claude Science first. |claude-science/command-line-settings see the edit
Anthropic's documentation has since written up pin, on Command line settings.
New in this build: CLAUDE_CODE_ARTIFACT_PIN