How do I turn off fork subagents in Claude Code 2.1.302?

Claude Code 2.1.302 enables fork subagents by default in claude -p, the Agent SDK, the desktop app and VS Code. Setting the environment variable CLAUDE_CODE_FORK_SUBAGENT=0 turns them off. The release notes also say that claude mcp serve never offers fork subagents, so MCP server mode is not affected by the new default.

When does standalone Claude Design close?

Claude Code 2.1.302 adds a notice to the /design-sync and /design-login commands saying that standalone Claude Design at claude.ai/design closes by December 14, 2026. The release notes do not describe a replacement, so users who depend on the standalone site should plan around that date and watch Anthropic's official channels.

Can I disable idle compaction in Claude Code?

Claude Code 2.1.302 adds an Idle compaction row to the /config menu for turning idle compaction off or back on. The notices shown after an idle compaction now also explain how to turn it off. Idle compaction itself arrived in version 2.1.299 to save long sessions before the prompt cache expires.

What changed for auto mode in Claude Code 2.1.302?

Claude Code 2.1.302 adds CLAUDE_CODE_AUTO_MODE_MODEL to choose the model the client-side auto mode classifier uses; it does not change server-side auto mode. With the server-side classifier, a conversation too long for the safety check is now compacted instead of every checked tool call being denied.

Anthropic · 2026-10-16 · major

Claude Code 2.1.302 — fork subagents on by default in the SDK and apps

Claude Code 2.1.302 turns fork subagents on by default in claude -p, the Agent SDK, the desktop app and VS Code. It adds a /config switch for idle compaction and warns that standalone Claude Design closes by December 14, 2026.

Claude Code 2.1.302 brings terminal-style subagent behavior to the SDK and apps and makes idle compaction easy to switch off.

Quick facts

Version	v2.1.302
Maker	Anthropic
Released	2026-10-16
New setting	CLAUDE_CODE_AUTO_MODE_MODEL (client-side auto mode classifier)
Default change	Fork subagents on in claude -p, Agent SDK, desktop, VS Code
Deprecation	Standalone Claude Design (claude.ai/design) closes by 2026-12-14

What is it?

Fork subagents (subagent_type: "fork") are now on by default in Claude Code 2.1.302 for 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. The release also adds an Idle compaction row to /config so users can turn that feature off or back on.

How does it work?

In the desktop app and VS Code, the main conversation's subagents now always run in the background, while a subagent's own Agent calls in claude -p, the SDK and the apps run in the foreground by default. A new CLAUDE_CODE_AUTO_MODE_MODEL variable picks the model for the client-side auto mode classifier, and with the server-side classifier a conversation too long for the safety check is now compacted instead of every checked tool call being denied.

Why does it matter?

Agent SDK and headless users get the same subagent behavior as terminal users without extra flags. Claude Design users get notice that the standalone claude.ai/design site closes by December 14, 2026. The patch also stops the Read tool from loading huge image files into memory (sources over 128 MB are refused) and fixes several prompt cache misses and lost config writes.

Who is it for?

Claude Code and Agent SDK users, teams on auto mode, Claude Design users

Frequently asked questions

How do I turn off fork subagents in Claude Code 2.1.302?: Claude Code 2.1.302 enables fork subagents by default in claude -p, the Agent SDK, the desktop app and VS Code. Setting the environment variable CLAUDE_CODE_FORK_SUBAGENT=0 turns them off. The release notes also say that claude mcp serve never offers fork subagents, so MCP server mode is not affected by the new default.
When does standalone Claude Design close?: Claude Code 2.1.302 adds a notice to the /design-sync and /design-login commands saying that standalone Claude Design at claude.ai/design closes by December 14, 2026. The release notes do not describe a replacement, so users who depend on the standalone site should plan around that date and watch Anthropic's official channels.
Can I disable idle compaction in Claude Code?: Claude Code 2.1.302 adds an Idle compaction row to the /config menu for turning idle compaction off or back on. The notices shown after an idle compaction now also explain how to turn it off. Idle compaction itself arrived in version 2.1.299 to save long sessions before the prompt cache expires.
What changed for auto mode in Claude Code 2.1.302?: Claude Code 2.1.302 adds CLAUDE_CODE_AUTO_MODE_MODEL to choose the model the client-side auto mode classifier uses; it does not change server-side auto mode. With the server-side classifier, a conversation too long for the safety check is now compacted instead of every checked tool call being denied.

Try it

npm i -g @anthropic-ai/[email protected]