Key Features

PowerShell Tool Preview: Added opt-in PowerShell tool for Windows, expanding Claude Code's terminal capabilities beyond bash. Users can enable this preview in the tools reference documentation.

MCP Server Improvements: MCP servers configured both locally and via claude.ai connectors are now automatically deduplicated, with local configuration taking priority. Server descriptions and instructions are now capped at 2KB to prevent context bloat from OpenAPI-generated servers.

Developer-Facing Changes

• New environment variables for model configuration: ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_SUPPORTS for overriding effort/thinking capability detection, and _MODEL_NAME/_DESCRIPTION for customizing the model picker
• New hook types: TaskCreated (fires when tasks are created) and WorktreeCreate with HTTP support
• CLAUDE_STREAM_IDLE_TIMEOUT_MS env var to configure streaming idle watchdog threshold (default 90s)
• Rules and skills paths: frontmatter now accepts YAML lists of globs
• x-client-request-id header added to API requests for debugging timeouts

Quality of Life Improvements

• Deep links (claude-cli://) now open in your preferred terminal instead of the first detected one
• Global system-prompt caching now works with ToolSearch enabled and MCP tools configured
• Interactive prompts that appear stuck for ~45 seconds now surface a notification
• Token counts ≥1M display as "1.5m" instead of "1512.6k"
• Voice push-to-talk no longer leaks characters into text input
• Fixed multiple keyboard shortcuts (Ctrl+U, arrow keys in multiline input)
• Terminal cursor now tracks text input caret for proper IME composition support
• Improved startup performance by ~30ms and reduced flickering in long sessions

Bug Fixes

Addressed critical issues including workflow subagents failing with JSON schema, MCP tool cache leaks, partial clone repositories triggering mass downloads, and transient keychain failures on macOS.