Claude Code version 2.1.278 changes the default behavior for Claude API, Enterprise, Bedrock, Vertex, Foundry, and gateway users to use the server-side classifier in auto mode. This shift eliminates charges for classifier overhead, with a warning displayed if a billed fallback occurs.
- Auto mode now defaults to the server-side classifier for API, Enterprise, Bedrock, Vertex, Foundry, and gateway users.
- Users can opt out of this default on Bedrock, Vertex, Foundry, and gateways by setting CLAUDE_CODE_AUTO_MODE_SERVER=0.
- A new "Auto mode server" row has been added to the /status command to indicate whether the classifier is running on the server.