Claude Code v2.1.266

Claude Code v2.1.266 was released on .

Summary

Claude Code 2.1.266 resolves a critical authentication issue that broke proxy and gateway setups in the previous version. We've restored the proper behavior so your existing configurations work seamlessly again without any changes needed. Check the full notes to see what else ...

Release Context

  • This was the 211th Claude Code release of 2026 tracked by Havoptic.
  • It shipped the same day as Claude Code v2.1.265 (September 8, 2026).
  • Claude Code: ships every 1 days — 28 releases in the last month.

Why it matters: Proxy setups work again without configuration changes.

Shipped around the same time

Within 3 days of this release, other AI coding tools also shipped:

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 · vs Grok Build

Release Notes

- Fixed a 2.1.265 regression affecting LLM-gateway and proxy setups: the undocumented CLAUDECODEUSEGATEWAY environment variable, previously ignored unless ANTHROPICBASEURL and ANTHROPICAUTHTOKEN were both set, began forcing Cloud-gateway sign-in on its own in 2.1.265, so configurations that set it alongside an API key, apiKeyHelper, or custom auth headers failed every request with "Not signed in to the Cloud gateway". The variable on its own is ignored again; no configuration change is needed

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