Claude Code Overhauls /fork and /resume for Background Sessions
Claude CodeAnthropic changed how /fork works in Claude Code: instead of spawning an in-session subagent, it now copies the current conversation into a brand-new background session with its own row in claude agents, letting a side investigation run independently while the original session keeps going. The old in-session forking behavior didn't disappear — it was renamed to /subtask. The same release also reworked /resume in the agent view so it opens a picker covering every past session, including ones deleted from the list, and reopens the chosen one as a background session.
Sources & Mentions
2 external resources covering this update
/fork Becomes a Background-Session Launcher
Claude Code's /fork command no longer branches a conversation inside the current session. Running /fork now copies the conversation into a new background session that appears as its own row in claude agents, so a developer can send a side investigation off to run independently — testing an alternate approach, digging into a tangent, or letting a long task run — without losing their place or tying up their terminal in the original session.
/subtask Takes Over In-Session Forking
The behavior /fork used to provide — spinning up a subagent that runs within the same session — has moved to a new command, /subtask. Anyone relying on the old in-session fork workflow needs to switch to /subtask going forward.
/resume Gets a Real Picker
The same release reworked /resume inside the agent view. Previously, interactive and background sessions lived in separate UIs, and once a background session's row was deleted from claude agents, there was no convenient way to find it again even though its transcript was still on disk. Typing /resume now opens a single picker across all past sessions — including ones removed from the list — and reopens whichever one is selected as a background session. A community-filed GitHub issue asking for exactly this behavior predates the fix.
Also in This Release
Version 2.1.212 shipped alongside several safety and reliability guards: a session-wide cap on WebSearch calls (200 by default, tunable via CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION) and a per-session cap on subagent spawns (also 200, via CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION) to stop runaway loops, plus automatic backgrounding of MCP tool calls that run longer than two minutes so a session doesn't stall.