Claude Code v2.1.212: /fork Becomes Background Session Copy + Runaway Loop Guards

Anthropic shipped Claude Code v2.1.212 with a behavioral change to /fork and new safeguards against runaway search and delegation loops. Here are the details.

Key Changes

• /fork now copies your conversation into a new background session (appears as its own row in claude agents). The old behavior — launching an in-session subagent — is now /subtask.
• Auto-mode reset: claude auto-mode reset restores the default auto-mode configuration. Use --yes to skip the confirmation prompt.
• WebSearch limit: New session-wide cap of 200 WebSearch tool calls (default). Tune via CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION.
• Subagent cap: Per-session limit of 200 subagent spawns. Override with CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION. Running /clear resets the budget.
• MCP auto-background: MCP tool calls exceeding 2 minutes automatically move to the background. Configure the threshold (in ms) or disable via CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS.
• Improved /resume: Typing /resume in the agent view opens a picker of past sessions — including deleted ones — and resumes your pick as a background session.

Notable Fixes

• Plan mode no longer auto-runs file-modifying bash commands (e.g., touch, rm) without permission prompt or SDK canUseTool callback.
• Fixed worktree creation following a repository-committed symlink at .claude/worktrees that could create files outside the repository.
• SIGTERM during a running Bash tool in print/SDK mode now aborts the turn, kills the process tree, and exits with code 143.
• Windows fix: /background and claude --bg no longer fail when Group Policy blocks PowerShell 5.1; the daemon now prefers PowerShell 7.
• Shell mode (!) now executes commands containing file paths even while the path autocomplete popup is open.
• /ultrareview now accepts PR references like #123, PR 123, and pasted URLs; error hints name the command you typed. It also fetches branches from origin and suggests closest branch name on typos.
• Hosted sessions no longer fail at startup when repository settings configure mTLS certs, extra CA bundles, or OAuth scopes — these transport settings are now ignored with a warning.
• Fixed diff previews losing line numbers and +/- markers in narrow layouts.
• Fixed false "Command timed out" on exit code 143.

Full details in the release notes.