Agent swarms and the new model economics

Cursor's agent swarm architecture uses a tree-based decomposition where planner agents (powered by frontier models) split tasks and delegate to worker agents (using cheaper models), achieving 80% on a SQLite-from-scratch Rust build in 4 hours with Grok 4.5 versus the old swarm's failure. The design avoids context drift by keeping planners free of low-level detail and workers focused on narrow execution, enabling 1,000 commits per second versus the prior 1,000 per hour. Cost varied enormously across model mixes while quality remained similar, suggesting significant optimization potential.

Wilson Lin