Summary
Claude Agent SDK TypeScript 0.3.238 adds is_backgrounded and spawn_depth to subagent task events, plus a terminal refused state for cross-session messages rejected by policy. It also fixes hook reinitialisation and exposes more reliable branch and prompt-suggestion events.
Why it matters
Explicit lifecycle state lets agent hosts distinguish background work, nesting and policy refusal instead of reconstructing those conditions from missing events.
Related coverage
- GitHub’s Copilot Cloud Agent status visibility degraded for hours
- OpenCode v1.18.20 makes subagent failures resumable and provider retries explicit
- Cline CLI v3.0.56 carries skills, images and hook state into agent sessions