Claude Code 2.1.212: /fork Now Creates a True Background Session; /subtask Replaces the Old In-Session Delegate

Claude Code 2.1.212 ships today with a meaningful delegation model change: /fork now creates a persistent background session, not a fire-and-forget inline subagent.

/fork now copies your conversation into a fully independent background session — its own row in claude agents, visible in the web view, resumable later. The old in-session delegate behavior is now /subtask: runs inline, shares parent context, disappears when done. Use /fork for complex parallel work that might outlast your current focus; use /subtask for quick inline helpers.

The release also adds session-wide safety caps: WebSearch calls cap at 200 per session (tune with CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION), and subagent spawns cap at 200 (CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION). /clear resets both budgets. New: claude auto-mode reset restores default auto-mode if your CLAUDE.md rules have drifted.

Also: GitHub Copilot is deprecating Gemini 2.5 Pro and Gemini 3 Flash across all experiences on July 31. Migrate workflows to Gemini 3.1 Pro or Gemini 3.5 Flash before then.

Why it matters: The /fork → true background session change makes parallel branching significantly more durable. Forked sessions survive /clear and are resumable, making them proper persistent workers rather than disposable inline tasks.

Sources: Claude Code changelog v2.1.212 · GitHub Copilot Gemini deprecation (Jul 31)