What broke and was undone

In version 2.1.265, the undocumented environment variable <code>CLAUDE_CODE_USE_GATEWAY</code> began forcing Cloud gateway sign-in when it appeared on its own. That affected environments using an API key, an <code>apiKeyHelper</code>, or custom authentication headers. The result was a <code>Not signed in to the Cloud gateway</code> error on every request, even when the configuration was not meant to use that sign-in flow.

Why this matters in real work

For companies running Claude Code behind an internal gateway, a corporate proxy, or a cost-control layer, this kind of regression is not a minor detail. It interrupts automations, blocks sessions, and can look like a credential, network, or identity problem. The larger cost is operational: teams spend hours changing variables that worked until the previous update.

My read

Update quickly if you use a gateway, proxy, or authentication outside Anthropic’s standard login. If you run Claude Code directly, the practical impact is close to zero. The counterpoint is that a one-fix release does not prove broad tool maturity. It shows something narrower but important: Anthropic identified a break introduced in its own release cycle and restored the expected behavior without requiring a configuration workaround.

Sources

Official GitHub release: https://github.com/anthropics/claude-code/releases/tag/v2.1.266. Official metadata and publication date: https://api.github.com/repos/anthropics/claude-code/releases/tags/v2.1.266. Independent registry record for the distributed package: https://registry.npmjs.org/@anthropic-ai%2fclaude-code/2.1.266. Gateway and authentication documentation: https://code.claude.com/docs/en/llm-gateway-connect.