No new flags, no new surface — 2.1.220 is the kind of release you take without reading the notes. It follows 2.1.219, which the day before wired in Claude Opus 5 as the default and bumped nested subagents to depth 3, so this one is mostly the settling-out patch that tends to trail a model swap. Upgrade whenever your CLI next prompts you; there's nothing here that needs a second look.