Mistral open-sourced Large 4 and kept the one use that pays.Mistral 把 Large 4 开源了，却留下了唯一能赚钱的那种用法。

Mistral Large 4's weights went up free on Hugging Face on Oct 29 under a new Ecosystem Open-Weight license, a modified MIT. Download it, fine-tune it, ship it inside a product, all free. One carve-out: run it as a Model-as-a-Service and you need a separate paid license from Mistral.

Read the carve-out, not the headline. "Open" gave away the weights. It fenced off the single use that captures value at scale (reselling the model as an API), which happens to be the business Mistral still runs itself at $0.70 in and $2.10 out per million tokens. And serving a trillion-parameter mixture-of-experts needs GPUs most people downloading it will never own.

So the price did not vanish. It moved, off the weights and onto the right to serve them. For a solo builder self-hosting their own product, this is a real gift: frontier capability, actually free, and the service clause never touches you. For anyone hoping to resell it, the toll booth just slid down one layer.

When something powerful suddenly turns "free," find the clause that fences off the one use that prints money. That is where the asset still lives. Wrong if Mistral later drops the service condition and ships plain MIT, so watch the license on the repo.