Cursor admits its new coding model was built on top of
Moonshot AI’s Kimi

AI coding company Cursor launched a new model this week called Composer 2, which it promoted as offering “frontier-level coding intelligence.” 

However, an X user posting under the name Fynn soon claimed that Composer 2 was “just Kimi 2.5” with additional reinforcement learning — Kimi 2.5 being an open source model recently released by Moonshot AI, a Chinese company backed by Alibaba and HongShan (formerly Sequoia China).