Claude Code 2.1.219 nests subagents 3 deep and can seal the sandbox
Opus 5 becomes the default, /fast drops Opus 4.7, a DirectoryAdded hook fires on /add-dir, and claude -p stops eating answers on mid-stream errors.
Copy markdown
Subagents now nest three deep
Subagents can spawn nested subagents up to depth 3 by default, up from 1 — real recursive task decomposition instead of a single flat layer. Set CLAUDE_CODE_MAX_SUBAGENT_SPAWN_DEPTH=1 to turn nesting back off.
A sandbox allowlist that fails closed
The new sandbox.network.strictAllowlist setting denies any non-allowlisted host for sandboxed commands without prompting, so an agent can't quietly reach an unexpected endpoint. Pair it with your allowlist for tighter network isolation.
Opus 5 is default; 4.7 leaves /fast
claude-opus-5 (1M context, fast mode at $10/$50 per Mtok) is now the default Opus model. /fast now applies to Opus 5 and 4.8, Opus 4.7 was removed from fast mode, and the claude-api skill defaults to Opus 5 with a 4.8 migration path.
claude -p stops eating your answer
A fix stops claude -p text output from dropping an answer it already produced when the turn dies on a mid-stream API error — scripted headless calls no longer silently return empty. mcp_server_errors now also lists skipped --mcp-config entries in the stream-json init event.
A DirectoryAdded hook for /add-dir
A new DirectoryAdded hook fires after /add-dir or the SDK's register_repo_root registers a working directory mid-session — a spot to auto-load per-repo context or config. Nested subagents at depth 2+ now also forward text in stream-json under --forward-subagent-text.