Composer-2

Cursor Composer 2 is Anysphere’s first in-house frontier AI model, released March 19, 2026, built specifically for autonomous project-scale coding inside Cursor IDE. Priced at $0.50/M input tokens — 86% cheaper than its predecessor — it outperforms Claude Opus 4.6 on Terminal-Bench 2.0 while being the only frontier coding model that runs exclusively inside an IDE rather than as an external API. What Is Cursor Composer 2? Cursor Composer 2 is the first proprietary AI model built by Anysphere (Cursor’s parent company), released March 19, 2026, marking a fundamental shift from being a model-agnostic IDE to owning the full AI stack. Unlike general-purpose models accessed via API, Composer 2 was trained end-to-end for autonomous coding workflows inside Cursor — with native understanding of file trees, shell sessions, browser control, and multi-step diffs. The model ships with a 200K token context window, a Mixture-of-Experts (MoE) architecture for fast inference, and a novel compaction-in-the-loop reinforcement learning technique that reduces context memory errors by 50%. This is Cursor’s third Composer generation in just five months — v1 launched October 2025, v1.5 in February 2026, v2 in March 2026 — signaling an aggressive model development timeline rarely seen outside OpenAI or Anthropic. The practical result: Composer 2 handles workflows that require hundreds of sequential actions without losing thread, applying real file diffs rather than just suggesting code snippets. ...