Posted by Alumni from TechCrunch
March 23, 2026
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). It was a surprising revelation, since Cursor is a well-funded U.S. startup that raised a $2.3 billion round last fall at a $29.3 billion valuation, and is reportedly exceeding $2 billion in annualized revenue. Also, the company didn't mention anything about Moonshot AI or Kimi in its announcement. However, Cursor's vice president of developer education Lee Robinson soon acknowledged, 'Yep, Composer 2 started from an open-source base!' But he said, 'Only ~1/4 of the compute spent on the final model came from the base, the rest is from our training.' As a result, he said Composer 2's performance on various benchmarks is 'very different' from Kimi's. Robinson also insisted that Cursor's use of Kimi was... learn more