{"name":"CLAUDE_CODE_ARTIFACT_OPEN_ACTION","slug":"claude-code-artifact-open-action","family":"env","title":"Environment variables","noun":"environment variable","description":"Whether an artifact auto-opens in a local browser is now behind a new env var, off by default.","description_source":"entry","described_by":{"version":"2.1.257","anchor":"artifact-open-action-behavior-gated-behind-a-new-flag-def"},"presence":{"first_seen":"2.1.257","removed_in":null,"in_current_build":true,"newest_mined":"2.1.322","builds":59,"mined_builds":161,"first_cited":{"version":"2.1.257","released_at":"2026-09-01 17:15:33","spans":2}},"aliases":[],"entries":[{"version":"2.1.257","anchor":"artifact-open-action-behavior-gated-behind-a-new-flag-def","heading":"Artifact 'open action' behavior gated behind a new flag, default off","line":"Whether an artifact auto-opens in a local browser is now behind a new env var, off by default.","released_at":"2026-09-01 17:15:33","reason":"found in this entry's text, named in this entry"},{"version":"2.1.257","anchor":"new-env-vars-added-to-the-passthrough-allowlist","heading":"New env vars added to the passthrough allowlist","line":"Three new env vars are preserved and passed through to subprocesses and sandboxes.","released_at":"2026-09-01 17:15:33","reason":"found in this entry's text, named in this entry"}],"entries_total":2,"docs":[],"docs_total":0,"gates":[],"related":[{"name":"CLAUDE_CODE_ARTIFACT_OPENING_PREFETCH","slug":"claude-code-artifact-opening-prefetch","description":"Off switch for the artifact opening prefetch: only an explicit false value (`0`, `false`, `no` or `off`) has an effect, and it turns the prefetch off. The prefetch runs only when `CLAUDE_CODE_ENTRYPOINT` is `remote_cowork` and the artifact REPL tool or quickstart is on. Before the first assistant reply, if the opening user message names a newly created empty artifact, Claude Code reads that artifact type's instructions file ahead and attaches it to the turn as context."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-code-artifact-open-action","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}