Claude Code 2.1.266 undoes a 2.1.265 gateway sign-in break for proxy setups.

v2.1.266: undocumented CLAUDE_CODE_USE_GATEWAY, which in 2.1.265 forced Cloud-gateway sign-in alone, is ignored again. API-key / apiKeyHelper / custom-header setups that set it were failing every request with "Not signed in to the Cloud gateway". No config change after the pin.¹

2.1.265 (same window): folder --plugin-dir, 1 GB tool-result cap, subagent/resume cache fixes, MCP HTTP→SSE fallback, Windows AppContainer Read/Write/Edit. Skip 2.1.265 on gateway/proxy; pin ≥2.1.266. npm latest/next 2.1.266, stable 2.1.236.²³