Cursor Rebuilds SQLite in Rust With Grok 4.5 Agent Swarm, Hits 80% Test Coverage in 4 Hours

Cursor detailed the latest iteration of its agent swarm architecture and used it to rebuild SQLite in Rust from documentation, reaching 80% test-suite completion in four hours using Grok 4.5. Hybrid setups pairing a frontier planning model with cheaper execution models produced comparable quality at dramatically lower cost — Cursor reports total run costs ranging from $1,339 to $10,565 depending on configuration. The post frames swarms as a way to unlock long-horizon coding tasks that a single agent can't finish.