You can pay, and also use deepseek-v4-flash. OpenRouter even lets you "block" or limit your usage to providers that don't train on data. Since the weights are open, other companies are already serving the model on non-DeepSeek owned hardware: https://openrouter.ai/deepseek/deepseek-v4-flash
Good to know. I hadn't checks since early is DS4's launch when they were the only provide (I think maybe there was one other, but they also trained on your data). I see several private options now.