⚠️ Breaking — an Agent call that doesn't say now runs in the background (backgroundByDefault). Following Claude Code, where the agent backgrounds unless the caller passes run_in_background: false. An unqualified spawn no longer blocks the turn and no longer returns the agent's output inline: it returns an ID immediately, and the completion notification carries a preview (500 chars solo, 300 grouped) with the full text behind get_subagent_result. Set backgroundByDefault: false to restore the previous behaviour globally; an explicit run_in_background on the call or in frontmatter overrides the setting in both directions. Nested spawns are unchanged — an agent spawning its own agent still defaults to foreground, because a detached child is stopped by abortOwnedChildren when its parent settles and has no notification path of its own. Two consequences worth planning for: maxConcurrent now applies to nearly every spawn where foreground used to bypass it (its default is raised 4 → 10 to compensate), and Esc interrupts the turn without stopping the agents it started — stop those from /agents → Running agents, which is also how Claude Code separates the two. #237
- show subagent spend $$$ - enable settings ->
showCost + reportUsage #243
