Evidence record / claude-code

A dated record of one change, kept so the writing that cites it can be checked. Compiled from the sources listed below by the research run, not written for reading. The judgment lives in the signals and issues that cite it, below.

2026-09-21-claude-code-2-1-278-auto-mode-classifier-moves-server-side-by-default

2.1.273 (2026-09-15) set the local auto-mode classifier as default on Bedrock, Vertex and Foundry, with CLAUDE_CODE_AUTO_MODE_SERVER=1 to opt into the server classifier. 2.1.278 (2026-09-19) reversed that: auto mode for Claude API, Enterprise, Bedrock, Vertex, Foundry and gateways now defaults to the server-side classifier, which “does not charge for classifier overhead”, with CLAUDE_CODE_AUTO_MODE_SERVER=0 as the opt-out on the three clouds and gateways. A new docs page says the server performs the checks inside the session’s own model requests. When a gateway strips the safeguards request field or drops safeguard_results, Claude Code holds the action on a notice and Enter continues on the billed local classifier. The page calls the variable temporary. /status gains an Auto mode server row.

Channel: tagged-release (latest 2.1.278; not on stable 2.1.267). Half: both.

Operator consequence: Gateway operators must pass safeguards and safeguard_results through unchanged, or set CLAUDE_CODE_AUTO_MODE_SERVER=0 and keep paying for the local classifier. Otherwise the first checked action in every auto-mode session holds on a notice, including under -p. Record which classifier decided from /status or the stream-json system warning. A fleet that set =1 on 09-15 is now a no-op; one that never set it changed behavior on 09-19.

Receipt

Finding metadata

Confidence: high

Run: 2026-09-21-weekly-digest-2026-08-20_2026-09-21-frontier-v0

Finding ID: 2026-09-21-claude-code-2-1-278-auto-mode-classifier-moves-server-side-by-default

Accepted signals

Auto mode's judge moved to the server; the docs still list its isolation as none / 2026-09-21

Profile citations

Claude Code / claim / server-side-classifier-default

Source links

Primary links, including exact changelog lines when available.

Claude Code
github release2026-09-21-claude-code-2-1-278-auto-mode-classifier-moves-server-side-by-defaultanthropics/claude-code / v2.1.278 github release2026-09-21-claude-code-2-1-278-auto-mode-classifier-moves-server-side-by-defaultanthropics/claude-code / v2.1.273 official docs2026-09-21-claude-code-2-1-278-auto-mode-classifier-moves-server-side-by-defaultcode.claude.com/docs/en/auto-mode-classifier-billing

Versioned source: run artifact