Originally published on NextFuture Cursor shipped Composer 2 in March 2026 as the centerpiece of the Cursor 2.0 overhaul. The model runs on Cursor's own code-only architecture — no Claude or GPT-4 proxy underneath — at $0.50/1M input tokens. The headline number is real, but the KV cache economy behind it is what changes your monthly bill on agentic coding workloads. What changed Custom code-only model : Composer 2 is trained exclusively on coding data via continued pre-training and reinforcement learning. Prior Cursor versions routed all Composer requests to Claude Sonnet or GPT-4 through the Anthropic and OpenAI APIs. $0.50/1M input tokens : That's 6× cheaper than Claude Sonnet 3.7 ($3/1M) and 16× cheaper than GPT-4o ($8/1M) — the two models Cursor previously proxied for Composer tasks. Aggressive KV cache on repo context : Cursor stores repo embeddings in a shared KV cache between agentic requests.…