Claude Code v2.1.166
Claude Code v2.1.166 was released on .
Summary
- Added fallbackModel setting to configure up to three fallback models tried in order when the primary model is overloaded or unavailable; --fallback-model now also applies to interactive sessions ...
Release Context
- This was the 131st Claude Code release of 2026 tracked by Havoptic.
- It shipped 1 day after Claude Code v2.1.165 (June 5, 2026).
Shipped around the same time
Within 3 days of this release, other AI coding tools also shipped:
- Kiro CLI v2.6.1 (June 8, 2026)
- Antigravity CLI v1.0.6 (June 6, 2026)
- Devin Desktop v3.0.28 (June 6, 2026)
- Gemini CLI v0.45.2 (June 5, 2026)
- GitHub Copilot CLI v1.0.60 (June 5, 2026)
Compare Claude Code: vs OpenAI Codex CLI · vs Cursor · vs Gemini CLI · vs Kiro CLI · vs GitHub Copilot CLI · vs Devin Desktop · vs Antigravity CLI
Release Notes
- Added fallbackModel setting to configure up to three fallback models tried in order when the primary model is overloaded or unavailable; --fallback-model now also applies to interactive sessions
- Added glob pattern support in deny rule tool-name position ("" denies all tools); allow rules reject non-MCP globs, and unknown tool names in deny rules warn at startup
- Hardened cross-session messaging: messages relayed via SendMessage from other Claude sessions no longer carry user authority — receivers refuse relayed permission requests, and auto mode blocks them
- MAXTHINKINGTOKENS=0, --thinking disabled, and the per-model thinking toggle now disable thinking on models that think by default via the Claude API (3P providers unchanged)
- Claude Code now retries a turn once on the fallback model when the API rejects an unexpected non-retryable error; auth, rate-limit, request-si
Other Recent Claude Code Releases
- v2.1.215 (July 19, 2026)
- v2.1.214 (July 18, 2026)
- v2.1.212 (July 16, 2026)
- v2.1.211 (July 15, 2026)
- v2.1.210 (July 14, 2026)
All Claude Code releases · All AI coding tool releases on Havoptic