Claude Code v2.1.302: Auto Mode Classifier Model Setting, Idle Compaction Toggle, and Fork Subagents On by Default

Claude Code v2.1.302 is a large release with 63 changelog entries. It adds CLAUDE_CODE_AUTO_MODE_MODEL for choosing the client-side auto mode classifier’s model and an Idle compaction row in /config, and it changes defaults for fork subagents, subagent background and foreground runs, and the starting permission mode of claude -p sessions, along with a new limit on hook concurrency. Fixes cover compaction, providers, plugins, MCP, cloud sessions, and a long list of Claude Tag items.

What’s New

Choose the Auto Mode Classifier Model

The new CLAUDE_CODE_AUTO_MODE_MODEL variable chooses the model the client-side auto mode classifier uses; it does not change the model for server-side auto mode. Separately, auto mode with the server-side classifier now compacts a conversation that is too long for the safety check, instead of denying every checked tool call.

Idle Compaction Toggle in `/config`

/config has a new Idle compaction row for turning idle compaction off or back on. The notices shown after an idle compaction now also say how to turn it off.

Fork Subagents On by Default in More Places

Fork subagents (subagent_type: "fork") are now on by default in claude -p, the Agent SDK, the desktop app and VS Code, as they already were in the terminal. CLAUDE_CODE_FORK_SUBAGENT=0 turns them off, and claude mcp serve never offers them.

Subagent Background and Foreground Defaults

The desktop app and VS Code now always run the main conversation’s subagents in the background, as the terminal does, rather than letting Claude choose. A subagent’s own Agent calls in claude -p, the Agent SDK, the desktop app and VS Code now run in the foreground by default.

Default Permission Mode for `claude -p` and the Agent SDK

claude -p and Agent SDK sessions with no permission mode now start in default mode on third-party providers, with telemetry off or on a fresh install. --permission-mode auto keeps auto mode.

Hook Concurrency Limit

Prompt and agent hooks now run at most 12 of one event at a time; the rest wait their turn.

Claude Design Closing Notice

/design-sync and /design-login now show a notice that standalone Claude Design (claude.ai/design) closes by December 14, 2026.

Fixes and Improvements

Compaction: Stopping a turn while the conversation is being compacted no longer causes a “Prompt is too long” error.
Providers: Requests no longer fail with “diagnostics: Extra inputs are not permitted” after switching to Vertex or Bedrock mid-session.
Read tool: The Read tool no longer loads an image file of any size, or a pipe or device named like an image, entirely into memory; image sources over 128 MB are now refused.
Plugins: claude plugin and other subcommands no longer sometimes exit before a queued settings or config write finishes, which could lose the change or leave a .tmp file behind. Plugin marketplaces no longer re-clone on every refresh, and newly installed git plugins no longer show version “unknown”, when git defaults to the reftable ref format. The PowerShell tool now finds commands in a plugin’s bin/ folder.
Startup: Startup is faster with many plugins enabled, since plugin command and agent files now take far fewer file system calls to load, most of all on Windows.
MCP: MCP servers no longer show no tools, or fail every tool call, when the server negotiates protocol version 2026-07-28 but omits resultType, ttlMs or cacheScope.
OpenTelemetry: classifier_category is no longer missing from tool_decision events for most auto mode classifier blocks, and new tool_decision attributes no longer push out tool_use_id, tool_source and tool_parameters when OTEL_LOGRECORD_ATTRIBUTE_COUNT_LIMIT is low.
Usage credits: Prompt suggestions no longer spend usage credits on models your plan pays for only with credits; they are now skipped after a reply billed to credits.
Worktrees: Worktree isolation no longer refuses to create or resume worktrees under git 2.56 or later when a stray .git file points at a directory that doesn’t exist.
Windows: File writes are no longer all refused or asked about for projects on exFAT or FAT32 drives, including in sessions started with --plugin-dir.
Cloud sessions: “Rewind to here” now works on messages other than the newest (self-hosted runners need Claude Code v2.1.246 or later). A scheduled routine run that failed partway is no longer run again from the start an hour or more later, which could repeat work such as posting the same report twice. A routine’s page now shows a banner explaining why its last run didn’t start.
Remote Control: A subagent’s pane no longer spins forever after your computer goes offline; it now says Remote Control is disconnected.
Claude Tag: HEIC, SVG, TIFF and BMP images attached in Slack now reach Claude as files in its working files. Claude in Slack no longer sometimes answers a direct message with “DMs are temporarily unavailable” and drops it when a single Slack lookup stalls; it now retries first. Claude Tag admin settings now organize Claude’s access into four tabs: Bundles, Connectors, Skills and plugins, and Channels.
VS Code: MCP server sign-in from the panel no longer opens a broken authorization page when the server URL contains a query string, and the @browser banner no longer says “Browser connected” when no browser with the Claude extension can be reached.

The release contains 63 changes in total; see the full changelog for every item.

How to Update

Check your installed version: claude --version
Update in place: claude update
If you run claude -p or the Agent SDK without a permission mode on a third-party provider, with telemetry off or on a fresh install, sessions now start in default mode; pass --permission-mode auto to keep auto mode.