Composer 2 Is Kimi K2.5

Remember Cursor's new coding model that beats Opus? Turns out it's not entirely theirs. Cursor had to admit that Composer 2 is actually built on Kimi K2.5 after the internet did some snooping. Cursor launched Composer 2 as a proprietary breakthrough - continued pre-training combined with reinforcement learning. What they didn't mention was the base model. Kimi K2.5's licence requires prominent attribution for any commercial product generating over twenty million dollars a month in revenue. This was discovered when a developer found the model declaration buried in an API response. Kinda awkward. Moonshot AI's response was diplomatic. They congratulated Cursor, confirmed there's an authorised commercial partnership, and called it a win for the open model ecosystem. Either way - the model's still good. But the marketing wasn't.