Cursor Composer 2: The Cache Economy Behind a 10x Cheaper Coding Agent

Cursor's Composer 2 shipped in March 2026 as the centerpiece of the Cursor 2.0 overhaul. The headline numbers—$0.50/1M input tokens, outperforming frontier models on SWE-bench Multilingual—look like marketing. The cache read mechanism is where the real story is. Why a Specialized Model at All Prior Cursor versions proxied Claude or GPT-4. Composer 2 is trained exclusively on coding data via continued pre-training and reinforcement learning. The obvious question is: what's cut? Every...