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AI coding company Cursor launched a new model this week called Composer 2, which it promoted<\/a> as offering \u201cfrontier-level coding intelligence.\u201d\u00a0<\/p>\n However, an X user posting under the name Fynn soon claimed<\/a> that Composer 2 was \u201cjust Kimi 2.5\u201d with additional reinforcement learning \u2014 Kimi 2.5 being an open source model recently released by Moonshot AI<\/a>, a Chinese company backed by Alibaba and HongShan (formerly Sequoia China).\u00a0<\/p>\n As evidence, Fynn pointed to code that seemed to identify Kimi as the model.<\/p>\n \u201c[A]t least rename the model ID,\u201d they scoffed.<\/p>\n It was a surprising revelation, since Cursor is a well-funded U.S. startup that raised a $2.3 billion round last fall<\/a> at a $29.3 billion valuation, and is reportedly exceeding $2 billion in annualized revenue<\/a>. Also, the company didn\u2019t mention anything about Moonshot AI or Kimi in its announcement.<\/p>\n However, Cursor\u2019s vice president of developer education Lee Robinson soon acknowledged<\/a>, \u201cYep, Composer 2 started from an open-source base!\u201d But he said, \u201cOnly ~1\/4 of the compute spent on the final model came from the base, the rest is from our training.\u201d As a result, he said Composer 2\u2019s performance on various benchmarks is \u201cvery different\u201d from Kimi\u2019s.<\/p>\n Robinson also insisted that Cursor\u2019s use of Kimi was consistent with the terms of its license, a point the Kimi account on X repeated in a subsequent post congratulating Cursor<\/a>, where it said the Cursor used Kimi \u201cas part of an authorized commercial partnership\u201d with Fireworks AI.<\/p>\n Techcrunch event<\/p>\n \n\t\t\t\t\t\t\t\t\tSan Francisco, CA<\/span> \u201cWe are proud to see Kimi-k2.5 provide the foundation,\u201d the Kimi account said. \u201cSeeing our model integrated effectively through Cursor\u2019s continued pretraining & high-compute RL training is the open model ecosystem we love to support.\u201d<\/p>\n So why not acknowledge Kimi upfront? Beyond any potential embarrassment in not creating a model from scratch, building on top of a Chinese model might feel particularly fraught right now, with the so-called AI \u201carms race\u201d often framed as an existential battle between United States and China<\/a>. (See, for example, Silicon Valley\u2019s apparent panic after Chinese company DeepSeek released a competitive model<\/a> early last year.)<\/p>\n Cursor co-founder Aman Sanger acknowledged<\/a>, \u201cIt was a miss to not mention the Kimi base in our blog from the start. We\u2019ll fix that for the next model.\u201d<\/p>\n<\/div>\n
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\n\t\t\t\t\t\t\t\t\t\t\t\t\tOctober 13-15, 2026<\/span>\n\t\t\t\t\t\t\t<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/div>\n