Claude Code 2.1.172

• [new] Added Artifact tool for rendering .html or .md files as interactive browser artifacts, with support for favicons, labels, and redeployment to existing URLs.
• [new] Added ShowOnboardingRolePicker tool and supporting types to surface role selection during onboarding flows.
• [new] Introduced artifact-related environment variables (CLAUDE_CODE_ARTIFACT_*) to control auto-open, direct upload, and MCP integration behavior.
• [new] Added CLAUDE_CODE_AUTO_MODE_* variables and supporting context handling for sibling context and temperature in auto mode.
• [changed] Updated SDK tool schemas (sdk-tools.d.ts) and manifest to include new input/output types for artifacts and the onboarding picker.
• [changed] Refined prompt instructions around Chrome browser tool loading, focus mode output visibility, and task reporting expectations.

Models & prompts

• Added prompt guidance for focus mode, which restricts visible output to final text messages only.
• Expanded instructions on artifact handling, DesignSync project syncing, and explicit consent rules for action parameters.
• Incorporated server-side fallback behavior under the server-side-fallback-2026-06-09 beta header, including fallback block formatting in responses.

Under the hood

• New backend routes for frame deployment and deployment lifecycle operations (/api/frame, /v1/deployments/*).
• Added CLAUDE_RUNNER environment variable group and related fetch depth control.
• Internal feature gates added for structured output retraction, reactive compaction, and credit clamping behaviors.

Upgrade notes

• Update any pinned optional dependencies in @anthropic-ai/claude-code to 2.1.172 when consuming via npm.