mirzapCursor Composer 2 is just Kimi K2.5 with RL
im pretty sure this is in violation of moonshot's ToS. this is going to be fun to watch unfold
They probably licensed it. Still a bit deceptive not to mention it on the model card/blog post, but companies whitelabel all the time without mentioning.
It goes against the ML community ethos to obscure it, but is common branding practice.
No they didn't [0][1]. With this leak they're probably negotiating as we speak, which could be why they've deleted the posts.
[0] https://chainthink.cn/zh-CN/news/113784276696010804
[1] https://pbs.twimg.com/media/HD2Ky9jW4AAAe0Y?format=jpg&name=...
Cursor「自研」Composer 2内藏Kimi K2.5，月之暗面公开指控：未遵守许可证、未支付费用 - 最新链上快讯 - ChainThink链智库
据 1M AI News 监测，开发者 @fynnso 在调试 Cursor API 请求时发现，Composer 2 的实际模型 ID 为 `kimi-k2p5-rl-0317-s515-fast`，字面即「Kimi K2.5 + RL」。月之暗面（Moonshot AI）预训练负责人杜羽伦（@Yulun_Du）随即发推，称团队测试 Composer 2 的 tokenizer 后发现「与我们的 Kimi tokenizer 完全一致」，「几乎可以确认这是我们的模型被进一步后训练的结果」，并直接 @ Cursor 联合创始人 Michael Truell，质问「为什么不尊重我们的许可证，也没有支付任何费用」。Cursor 3 月 19 日发布 Composer 2 时称，性能提升来自「首次对基座模型进行继续预训练，再结合强化学习」，但全程未提及 Kimi K2.5。两点并不矛盾：继续预训练和 RL 本就施加在某个基座之上，Cursor 只是未披露基座来源。Kimi K2.5 采用修改版 MIT 协议，明文规定：月活超 1 亿或月营收超 2000 万美元的商业产品，必须在用户界面显著标注「Kimi K2.5」。以 Cursor 293 亿美元估值及付费用户规模，月营收门槛几乎必然触发。截至发稿，Cursor 未公开回应。
I stand corrected, that is pretty scummy.
I bet Moonshot is going to make them open their wallets to avoid legal trouble.