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Is Kimi K3 open source? The weights are public. The licence is not Apache.

Published 16 Oct 2026. Updated 16 Oct 2026. Researched 16 Oct 2026.

Moonshot’s own pages say Kimi K3 is open source. The licence text is more specific, and it is the text that matters.

The grant, from the licence file: you may use, copy, modify, and distribute the weights, and you may run and fine-tune them, subject to conditions. Condition 2 is the one companies miss. If you or your affiliates run a “model as a service” business and aggregate revenue exceeds 20 million US dollars in any consecutive 12 months, you need a separate agreement with Moonshot before commercial use. The licence defines that service as giving a third party inference or fine-tuning with meaningful control over inputs, parameters, or training data. It says the definition does not include an end-user product where the model is only embedded in a feature, and it does not include merely relaying requests to someone else’s host.

Condition 3: if a commercial product using the weights has more than 100 million monthly active users, or more than 20 million dollars of monthly revenue, the interface must display “Kimi K3”. Internal use, and use through Moonshot’s own products or certified partners, is carved out of those two conditions.

That is not the MIT licence and not Apache-2.0. “Open weights” is fair. “Do anything Apache allows” is not.

The model card calls it a 2.8T model with a 1 million token context. Local hosting is a data-center question. The local guide is for smaller Qwen files. The API price, which is a different topic, is $3 / $15 at Moonshot and is explained in the K3 guide.