Claude Code release notes: 2.1.302 runs subagents in the background

Claude Code 2.1.302 now runs the main conversation's subagents in the background in the desktop app and VS Code. Previously, Claude could choose in those interfaces; the terminal already used background execution. A subagent is a separate agent assigned part of a task by the main agent.

Source: Anthropic's Claude Code 2.1.302 release notes.

Claude Code changes subagent defaults

Version 2.1.302 also enables fork subagents by default in claude -p, the Agent SDK, the desktop app and VS Code. The Agent SDK is Anthropic's development toolkit for building applications with Claude agents. The terminal already had this default.

• The environment variable CLAUDE_CODE_FORK_SUBAGENT=0 disables fork subagents.
• claude mcp serve never offers them.
• When a subagent itself calls the Agent tool, that nested task now runs in the foreground by default in claude -p, the Agent SDK, the desktop app and VS Code.

Background execution for the main conversation's subagents therefore does not mean every level of delegated work runs in the background.

Source: Claude Code 2.1.302: changed defaults.

Version and availability

These changes arrived in 2.1.302 on October 16. When checked on October 19, 2.1.303 was the latest version on GitHub and npm. The later version's changelog lists only bug fixes and reliability improvements; the features above come from 2.1.302.

Sources: Claude Code 2.1.302. Claude Code 2.1.303. Anthropic's package in the npm registry.