Claude Code v2.1.299-v2.1.302: idle compaction, configurable auto-mode model, fork subagents on by default

Anthropic

Tools official 1 src. ~1 min

Anthropic shipped four Claude Code releases in the window: v2.1.299-v2.1.302 (Oct 14-16). v2.1.299 introduces idle compaction, compacting 200K+ token conversations idle for roughly 54 minutes before the 1-hour prompt cache expires (CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS). v2.1.301 adds % motion in vim mode and otel tool_decision events; v2.1.302 adds CLAUDE_CODE_AUTO_MODE_MODEL for choosing the client-side auto-mode classifier and turns on fork subagents by default in claude -p, the Agent SDK, desktop, and VS Code.

Why it matters

Idle compaction attacks the recurring cost of re-establishing prompt cache on long sessions, and fork subagents going default changes how parallel Claude Code runs behave.

Importance: 3/5

notable release (major version, significant open-weights drop, or regulatory shift)

coding-agent cli

Sources

official anthropics/claude-code releases