Claude Code v2.1.278

The status panel Claude Code shows (the one listing things like Model, MCP servers, and theme) now includes a row for the current permission mode, driven by a new permissionMode value passed into that panel.

A new diagnostics helper builds a status row labeled "Auto mode server" that reports either "Enabled" or "Disabled", based on a check of whether the auto-mode classifier resolves to server-side ("arbiter") mode and whether the current model is excluded from it.

In the SDK's startup-exit diagnostic logging, the code path for a permanently-closed transport (the connection used to talk to the SDK) was writing its message into the wrong variable, so that reason likely never actually showed up in the printed SDKStartup: exiting without result diagnostic line. This has been corrected.

When the new classifier billing notice dialog is showing and the user presses Escape to decline, the tool call that triggered the notice is denied outright, with the reason recorded as "Cancelled at the classifier billing notice."

In headless usage, such as -p/print mode or when output is set to stream-json, there's no interactive screen to show a pop-up dialog on. In those cases, the same classifier billing notice message is instead written to stderr, or emitted as a stream-json warning event when --verbose stream-json output is being used.

The main function that decides whether a tool call needs permission in auto mode was restructured to check for the new billing-notice/fallback condition before calling the local classifier, and a new "no result" handler is now threaded through both the fast-path check (used in acceptEdits mode) and the main classification path.

When Claude Code runs in a mode without an interactive display, such as with --output-format stream-json --verbose (a mode that streams structured JSON events instead of a normal terminal view, with --verbose showing full turn-by-turn output), a billing notice that would normally appear as a dialog is now delivered differently. It's emitted as a warning event in the stream-json output, or written directly to standard error (stderr) otherwise, before normal output begins.

A new feature flag, tengu_quiet_lantern, has been added to control whether auto mode's server-side ("arbiter") classifier falls back to local classification specifically when the server returns no result or reports the feature as unsupported.

Claude Code now remembers, for the rest of a session, if the server says it won't run server-side auto-mode classification (or silently drops the answer). The first time that happens, it's logged as a warning and a session-long flag is set so every later classification check goes straight to the local classifier instead of trying the server again.

Claude Code has internal logic for routing certain requests based on an apiRefusalCategory value (a label describing why a response was refused). A new function now only keeps that route active when the refusal category is cyber or frontier_llm, and only if a few other conditions also hold: the visible route wasn't already declined, an internal check (JB()) passes, and a feature or permission check (G$()) also passes.

The internal object that tracks per-session request state (exposed as host.requestLatches) changed how it stores some of its data. Two fields that used to be Maps (key-value lookup structures) are now a plain boolean and two new placeholder fields, alongside other existing maps used for different purposes. This structure backs several internal checks, including ones related to server classifier fallback choices and observed gateways.

Claude Code has an internal debugging feature called dumpPrompts that keeps track of state per agent (per subagent, a separate Claude instance handling part of a task). New helper functions let this state be cleared for a single agent or wiped out entirely.

Claude Code's internal per-session state object gained new tracking for the auto-mode server classifier fallback:

• which inference gateway was observed for the session
• whether a fallback choice was made when the server-side classifier is unavailable, and what that choice was
• a one-shot flag for announcing that fallback to the user (so the announcement only happens once)
• whether the third-party server classifier was refused for this session

The internal map that registers which component implements which UI dialog was restructured: a previously merged entry now uses a different pairing of helper functions, and two new entries were added to the end of the list. This affects dialogs including the Slack Connect consent prompt and the Slack sign-in offer prompt.

A new helper function returns the hostname from ANTHROPIC_BASE_URL in the specific case where the session is still classified as first-party but the base URL isn't api.anthropic.com, and no unix socket is in use.

The function that gates whether the server-side auto-mode classifier is usable changed its handling of third-party providers: it now checks a new predicate on the resolved provider, and calls a different negated function than before when deciding availability.

Claude Code keeps internal state (called request latches) tracking things about the current session's requests. Two small new helpers can now check whether that state indicates a request for 'thinking resumption' or 'thinking highlights' was refused.

This group of changes is purely the build version metadata (version number, build time, and git commit hash) being updated from 2.1.277 to 2.1.278, repeated across the many copies of that metadata embedded throughout the bundled code.