Cursor Composer 1.5 (cursor.com)

The recent release of Composer 1.5 marks a significant advancement in agentic coding models, following the initial launch of Composer 1. This upgraded version balances speed and intelligence, achieved by scaling reinforcement learning 20 times on the pretrained model, with post-training computations surpassing those of the base model's pretraining. The enhanced capabilities have resulted in notable performance improvements, especially on complex coding tasks, as shown by internal benchmarks indicating that Composer 1.5 rapidly outperforms its predecessor. Notably, Composer 1.5 incorporates a novel "thinking model" approach, generating reasoning tokens during interactions to effectively analyze user codebases and strategize next steps, which is crucial for tackling challenging problems. The model is designed to efficiently respond to simpler queries while engaging in deeper reasoning for more difficult tasks. Additionally, the self-summarization feature enables Composer 1.5 to maintain accuracy even as context length varies, allowing it to explore solutions even when losing context. This release not only demonstrates the potential for increasingly intelligent coding models through scaled reinforcement learning but also confirms the model's suitability for interactive daily use in coding.