Kimi K3 License: Commercial Use Is Allowed

Kimi K3 is extraordinarily open for a frontier model, but “open weights” does not mean “no strings attached.” The short answer is that most individuals, startups and enterprises can use, modify, fine-tune and redistribute Kimi K3 commercially. The important exceptions affect certain large Model-as-a-Service businesses and very large commercial products.

Moonshot AI released Kimi K3 under a custom Kimi K3 License, not a familiar MIT, Apache 2.0 or other standard open-source license. The distinction matters: the grant is broad, but Sections 2 and 3 add revenue-based conditions that can change the answer for high-scale commercial deployments.

Bottom line: Commercial use is generally allowed. Preserve the license notice, determine whether your product is “Model as a Service,” and check the two scale thresholds before launch. If the conditions could apply, have counsel review the license and contact Moonshot AI.

Related Kimi K3 coverage: Read the benchmark, specifications and pricing analysis, the official-weight download guide, and the hardware and local-deployment guide.

Kimi K3 commercial-use decision table

User	Can they use K3 commercially?	Important condition
Individual developer	Generally yes	Preserve the copyright and license notice in copies or substantial portions.
Startup building an embedded feature	Generally yes	Confirm the feature falls outside the license’s “Model as a Service” definition.
Internal enterprise deployment	Yes	Sections 2 and 3 are expressly exempted for qualifying internal use.
Large inference or API provider	Conditional	A separate Moonshot AI agreement may be required once the Section 2 test is met.
Massive consumer product	Conditional	Prominent “Kimi K3” attribution may be required in the user interface.

This table is a practical summary, not legal advice. The exact corporate structure, revenue calculation, deployment and product design can affect the result.

What the Kimi K3 license lets you do

The opening grant is unusually permissive for a frontier-scale model. It covers the model weights, parameters, configuration files, inference and training code, and associated documentation that Moonshot provides as the “Software.” Subject to the listed conditions, a licensee may:

use, copy, modify and merge the software;
run, deploy and fine-tune Kimi K3;
create derivative works;
publish, distribute, sublicense or sell copies; and
allow recipients to exercise those rights.

That is a real commercial grant, not a research-only release. The baseline obligation in Section 1 is to include Moonshot’s copyright notice and the permission notice in all copies or substantial portions, while complying with applicable laws and regulations.

Condition 1: the $20 million Model-as-a-Service threshold

Section 2 is the provision most likely to matter to inference hosts and API companies. It defines “Model as a Service” as giving a third party access to language-model inference or fine-tuning—an API is the license’s example—where that third party has meaningful control over inputs, parameters or training data.

The license then applies a two-part test:

The licensee or an affiliate operates a Model-as-a-Service business; and
The aggregate revenue of the licensee and its affiliates exceeds $20 million in total over any consecutive 12 months.

If both are true, the licensee must enter a separate agreement with Moonshot AI before using Kimi K3 or a derivative work for any commercial purpose. The wording refers to aggregate revenue across the licensee and its affiliates; it does not say the threshold is limited to revenue generated by K3.

What is not Model as a Service?

The definition excludes two useful categories:

Embedded end-user features: products in which model capabilities are confined to specific features or harnesses.
Mere relaying: passing requests to models hosted by someone else.

A writing assistant built into one workflow, for example, may look different from a general-purpose K3 inference API. The dividing line is fact-specific, so companies near the threshold should not rely on a product label alone.

Condition 2: attribution for very large products

Section 3 creates a separate scale trigger. If a commercial product or service using Kimi K3 or a derivative has either:

more than 100 million monthly active users; or
more than $20 million in monthly revenue,

then “Kimi K3” must be prominently displayed in that product or service’s user interface.

This is not the same as the Section 2 threshold. Section 2 looks at aggregate company-and-affiliate revenue across any consecutive 12 months and applies only when a Model-as-a-Service business is operated. Section 3 looks at the individual commercial product or service’s monthly users or monthly revenue and imposes attribution rather than a separate-license requirement.

Internal use and certified-partner exemptions

Section 4 switches off the requirements in Sections 2 and 3 for two categories:

Internal use: use that does not make the software, its outputs or its underlying capabilities available to third parties.
Official or certified access: use through Moonshot AI’s official products or certified inference partners.

That makes a private enterprise deployment materially simpler under the custom terms. But “internal” is narrower than “behind a login”: if customers, contractors or other third parties can access the outputs or capabilities, the exemption may not fit.

So, is Kimi K3 really open source?

The most accurate label is open-weight under a custom, broadly permissive license—not unconditionally open source. Moonshot itself calls Kimi K3 an “open-weight” model in the official model card, and Hugging Face identifies its license as the custom “kimi-k3” license rather than a standard identifier.

The Open Source Initiative’s Open Source AI Definition says an open-source AI system should be usable for any purpose without asking permission and should include the preferred form for modification, including detailed training-data information and training code. The K3 license’s separate-agreement requirement for certain large commercial users means the permission is not universal. Open weights alone also do not establish that the full system meets the OSI definition.

That does not make the release trivial. Developers can download the weights, self-host them, fine-tune them and redistribute derivatives under broad terms. It does mean “open source” should not be used as shorthand for “every commercial use is unconditional.”

Licensing is only half the deployment decision. See our Kimi K3 hardware requirements and local deployment guide for the 1.56 TB download, VRAM, cluster and API cost math.

Practical compliance checklist

Keep the notice. Include the copyright and permission notice in copies or substantial portions.
Map the deployment. Decide whether third parties control inputs, parameters or training data.
Classify the product. Document why it is an embedded feature, a relay, internal use or Model as a Service.
Calculate revenue broadly. For Section 2, include the licensee and affiliates and test every consecutive 12-month period.
Track product scale separately. Monitor monthly active users and monthly product or service revenue for Section 3.
Plan attribution early. If Section 3 may apply, reserve prominent UI space for “Kimi K3.”
Escalate before the threshold. Contact license@moonshot.ai and obtain legal advice before a commercial use falls within Section 2.

Kimi K3 license FAQ

Can I use Kimi K3 commercially?

Generally, yes. The license expressly grants rights to use, modify, deploy, fine-tune, distribute, sublicense and sell the covered software. Preserve the required notice and check the special conditions for large Model-as-a-Service operators and very large products.

Can I fine-tune and redistribute Kimi K3?

Yes, the grant expressly covers fine-tuning, derivative works and redistribution, subject to the license conditions.

Does every company above $20 million need a separate license?

No. The separate-agreement clause requires both an operated Model-as-a-Service business and aggregate licensee-and-affiliate revenue above $20 million over any consecutive 12 months. The internal-use and certified-partner exemptions can also remove Sections 2 and 3.

Do embedded Kimi K3 features count as Model as a Service?

Not automatically. The definition excludes end-user products whose model capabilities are solely embedded within specific features or harnesses. A general inference or fine-tuning API is more likely to fit the definition.

Is Kimi K3 licensed under MIT or Apache 2.0?

No. Kimi K3 has its own custom license. Do not assume the terms are identical to earlier Kimi releases or to a standard permissive software license.

Source check: July 27, 2026. This article summarizes the published license for general information and is not legal advice. Review the current license text and obtain professional advice for a specific deployment.

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