Release · Claude Code · Anthropic

Claude Code v2.1.278

What's new in Claude Code v2.1.278, released Sep 19, 2026 (). Newer: v2.1.310 (Oct 23, 2026)

Release notes

Claude Code v2.1.278

What's changed

  • Changed auto mode for Claude API and Enterprise users, and on Bedrock, Vertex, Foundry and gateways, to default to the server-side classifier, which does not charge for classifier overhead (CLAUDE_CODE_AUTO_MODE_SERVER=0 opts out on Bedrock, Vertex, Foundry and gateways); warns on billed fallback. See https://code.claude.com/docs/en/auto-mode-classifier-billing
  • Added an Auto mode server row to /status showing whether this session's auto mode classifier runs on the server