Claude Code 2.1.265–266: folder plugins, then a gateway hotfix

Teams that run Claude Code through an LLM gateway or proxy should treat 2.1.266 as the build to install. Later the same day as 2.1.265, Anthropic published a hotfix for a sign-in regression that broke API-key and custom-header setups when the undocumented CLAUDE_CODE_USE_GATEWAY variable was set on its own.

v2.1.266, published 8 September 2026 at 23:55 UTC, undoes that 2.1.265 change. The variable had previously been ignored unless ANTHROPIC_BASE_URL and ANTHROPIC_AUTH_TOKEN were both set. In 2.1.265 it began forcing Cloud-gateway sign-in by itself, 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. Do not treat this as a second launch.

The product drop is still 2.1.265, published 8 September 2026 at 20:37 UTC. --plugin-dir can now point at a folder of plugins: each child folder with a manifest loads, and children added or removed while running are picked up. Tool results saved to disk are capped at 1 GB, and the in-conversation preview says when a saved file was truncated.

The same release adds user.email and user.groups to the telemetry Claude Desktop and Cowork send through a Claude apps gateway, matching terminal sessions. It also fixes resuming a foreground-spawned subagent changing its tool list and system prompt prefix, which had broken prompt-cache reuse for that agent.

If you already pulled 2.1.265, update to 2.1.266, then point --plugin-dir at a plugins folder and watch child manifests load as you add or remove them.

Sources