This week, two U.S. coding assistants—Cursor and Windsurf—were caught running on Chinese foundation models. Cursor’s “Composer” speaks Chinese when it thinks. Windsurf’s “SWE-1.5” traces back to Zhipu AI’s GLM. The real story here isn’t deception. Training foundation models from scratch costs tens of millions. Fine-tuning open-source models is the rational path. And Chinese models are now the best option. Qwen leads global downloads on Hugging Face. Chinese models dominate trending charts. Third-party benchmarks show they match or beat Western alternatives on reasoning and speed. Silicon Valley has spent years worrying about China “catching up” in AI. That framing is obsolete. Chinese open-source models aren’t just competitive—they’re infrastructure. Western developers build on them because they work, they’re free, and they’re good enough. The global AI stack is converging. Right now, much of it runs on code from Beijing.