Bootstrapping Composer with Autoinstall
Cursor, Wednesday, May 6th, 2026
Cursor built Composer autoinstall, a system using earlier model versions to automatically set up RL training environments.
Cursor developed Composer autoinstall, a system that uses previous versions of their coding model to automatically configure working RL training environments from unconfigured repositories. The two-stage process involves one agent proposing setup commands and success criteria, while another agent executes those commands and mocks missing dependencies as needed.
This bootstrapping approach significantly improved Composer 2's performance on Terminal-Bench (61.7% vs 47.9% for Composer 1.5), demonstrating that using earlier model versions to prepare training environments creates better training signals. The system is inspired by Cursor's production cloud agent features and shows promise for future applications in run management, data preprocessing, and architecture tuning.