Artifacts gain full pin and unpin actions, wired end to end but off by default behind a gate with an env override.
Artifacts gain full pin/unpin support, wired end-to-end but gated off by default behind a growthbook gate (overridable by an env var). The artifacts tool's action enum now includes pin and unpin alongside publish, list, read, and others, and the action list conditionally exposes these two verbs based on a new capability flag. The list/read schemas gain a pinned field and a pins_enabled flag.
Pinning an artifact you didn't create triggers an approval prompt; pinning your own session's artifact or unpinning is auto-allowed. The UI renders "pinned to the sidebar" / "unpinned" for these actions, and tool-use rendering now has a dedicated branch for action === "pin" or "unpin" that prints the resolved title and address. The tool description gains the line "(then pins it to the user's own sidebar - private, reversible)", and accounts lacking the capability see "(Pinning isn't available for this account: 'pin' and 'unpin' will not work.)" Cloud sessions refuse the action with "Pinning artifacts isn't available in this cloud session yet...", and pin state is tracked via new store fields including frozenArtifactPins.
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.
The following example sends one request with an unpinned toolset, copies the returned list into the toolset's `tools` field, and sends the request again. The second response has no `mcp_tool_listing` block, because the API doesn't ask the …agents-and-tools/mcp-connector see the edit
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: tengu_cobalt_plinth_holly