Closing the Parallelism Tap by Default — How Claude Code v2.1.217 Put a 20-Agent Cap, Nesting-Off, and a Budget Net Around Subagents
Claude Code v2.1.217 caps concurrently running subagents at 20 by default, turns nesting off by default, and applies the cost ceiling to background subagents too. We read this update — where a tool that has steadily expanded autonomy pulls its parallelism defaults toward the safe side — through the