Can I use an open-weight AI model commercially?

Not automatically. "Open weights" means you can download the weights, not that the license permits commercial use. And the license tag you see is often wrong: a model's terms inherit through its fine-tune lineage, so a model tagged permissive can really be a fine-tune of a non-commercial base two hops up. To use one safely, trace the lineage to the original base, read each license in the chain, and take the most restrictive term — not the tag.

0106the tag is a claim, not a contract

The tag is a claim, not a contract

The license field is metadata a human set, and on community fine-tunes it inherits wrong constantly. The binding terms are in the actual license files of the model and everything it's derived from.

0206licenses inherit through fine-tunes

Licenses inherit through fine-tunes

A fine-tune is a derivative of the base weights, so it carries the base's terms. A restriction does not wash out by fine-tuning — if the base is non-commercial, the fine-tune is too, whatever tag it wears.

0306how to clear a model before you ship

How to clear a model before you ship

Trace to the root, take the strictest term, check the dataset license too, read for use-based clauses (non-commercial, no-compete, field-of-use), and write down the result so an auditor or acquirer can see it was cleared.

0406common questions

Straight answers.

Does a fine-tuned model inherit its base's license?: Usually yes — it's a derivative of the base weights, so it's bound by the base's terms plus anything the fine-tuner adds. Relabelling it doesn't make it commercial.
Why does this matter for a company?: Discovering at a fundraise or acquisition that you shipped on a non-commercial model is expensive. Clearing the license costs an hour; ripping a mislicensed model out of a shipped product costs a quarter.
Are 'open' model licenses the same as open source?: Often no. Many add acceptable-use, no-commercial, or no-compete clauses a true OSI-open license never would. Read for them.