Microsoft has built a billion-dollar AI business in China, selling OpenAI's GPT models through Azure to firms like ByteDance, Tencent, Ant Group and Meituan, even as OpenAI and Anthropic refuse to. ByteDance alone spends over $1 billion a year, making it Microsoft's biggest AI customer.

OpenAI has privately complained Microsoft isn't doing enough to stop Chinese firms copying its models, a process known as distillation.