[fahrradflucht]

License: https://huggingface.co/moonshotai/Kimi-K3/blob/main/LICENSE

> If the Licensee or any of its affiliates operates a Model as a Service business, and the aggregate revenue of the Licensee and its affiliates exceeds 20 million US dollars (or the equivalent in other currencies) in total over any consecutive 12 months, the Licensee must enter into a separate agreement with Moonshot AI before using the Software or its derivative works for any commercial purpose.

+ the existing 100 million monthly active users, or more than 20 million US dollars for commercial products have to name Kimi clause

[simonw]

Kimi 2.6 had the same janky license: https://huggingface.co/moonshotai/Kimi-K2.6/blob/main/LICENS... - looks like they've been doing that at least as far back as K2.

The models they released in 2025 - https://huggingface.co/moonshotai/models - were clean MIT. They started doing the "modified MIT" thing in January 2026 with moonshotai/Kimi-K2-Thinking

[zozbot234]

To be clear, the restriction on "Model as a Service" past $20M yearly revenue is new to K3. K2.x had the attribution requirement for any commercial use with more than $20M monthly revenue.

[simonw]

Good catch, thanks.

[lossolo]

In what way was the license "janky"? Moonshot isn't a trillion dollar US behemoth. If these terms allow it to release near frontier models with open weights, so startups and anyone with enough hardware can use them, while charging only companies with more than $20 million in revenue or 100 million users, that seems like a reasonable trade off.

[simonw]

I use the term "janky" for any time someone releases something under a supposedly open source license that doesn't comply with the OSI definition.

"Modified MIT" is the perfect example of that.

I'm not saying it's unreasonable, or that you can't release under such a license - it's your software, use whatever license you like!

I'll call it "janky" when you do.

[lossolo]

So it's more like your personal definition, not the normal meaning of the word. Ok, because "janky" is informal slang also meaning poor quality, unreliable etc. I understand that you're using janky as shorthand for not OSI compliant. I just think that can blur two separate issues: whether a license qualifies as open source under the OSI definition, and whether the license itself is unreasonable/badly designed.

[simonw]

I'm trying to make fetch happen.

[bilbo0s]

Reasonable for people at the bottom of the tech pyramid. Certainly for startup guys this is heaven sent.

For people at the top of the tech pyramid, I could totally see why they'd want to put an end to all this "Open Source LLM" stuff.

[ericpauley]

What is it a license for, though? Copyright? Are model weights even copyrightable?

[cosmojg]

These are the right questions. IANAL, but I am of the opinion that model weights are not copyrightable. See my sibling comment: https://news.ycombinator.com/item?id=49073127

[cosmojg]

It's worth noting that the weights of machine learning models are not subject to copyright in the United States as they are the product of an automated optimization process (e.g., stochastic gradient descent, expectation maximization, genetic algorithms) rather than human authorship. Granted, this has yet to be fully tested in court and going to court is expensive, so it's likely that your employer would prefer to err on the side of caution and respect such attempts at model licensing anyway. Nonetheless, this was partially tested last year in Thaler v. Perlmutter which affirmed that copyright requires human authorship, reading the Copyright Act's provisions on ownership, duration, and transferability as presupposing a human author[1].

If you want to assess the position of the U.S. Copyright Office for yourself, the relevant text can be found in the Compendium of U.S. Copyright Office Practices § 313.2, "Works That Lack Human Authorship"[2], which states:

> […] the Copyright Act protects “original works of authorship.” 17 U.S.C. § 102(a) (emphasis added). To qualify as a work of “authorship” a work must be created by a human being. See Burrow-Giles Lithographic Co., 111 U.S. at 58. Works that do not satisfy this requirement are not copyrightable.

> […] the Office will not register works produced by a machine or mere mechanical process that operates randomly or automatically without any creative input or intervention from a human author. The crucial question is “whether the ‘work’ is basically one of human authorship, with the computer [or other device] merely being an assisting instrument, or whether the traditional elements of authorship in the work (literary, artistic, or musical expression or elements of selection, arrangement, etc.) were actually conceived and executed not by man but by a machine.” U.S. COPYRIGHT OFFICE, REPORT TO THE LIBRARIAN OF CONGRESS BY THE REGISTER OF COPYRIGHTS 5 (1965).

Oh, and there's also a bit in the following Section 313.3, "Works That Do Not Constitute Copyrightable Subject Matter"[2], which explicitly excludes mathematical principles, formulas, algorithms, and equations, along with DNA sequences and other genetic or chemical compounds, regardless of whether they are produced by humans or by nature. If one takes the perspective that machine learning models are algorithms, the conclusions on copyrightability are pretty clear.

[1] https://media.cadc.uscourts.gov/opinions/docs/2025/03/23-523...

[2] https://www.copyright.gov/comp3/chap300/ch300-copyrightable-...

[embedding-shape]

Hah, so much for "open weights" :D Fair enough, they're at least downloadable, shame they didn't end up being actually open, nor open source, the community had really high hopes for this. But again, still available for download, so better than nothing else I suppose.

[jhonof]

Open source projects frequently have separate commercial licenses no? This isn't abnormal.

[embedding-shape]

No, I don't know a single project I'd call "open source" (as understood by the FOSS community) that restricts what you can do with it, that'd make it very much "not open source" as you're discriminating against specific persons/groups/fields of endeavor.

[parodysbird]

GPL licenses also restrict what you can do with it...

[embedding-shape]

Beyond reciprocity which is the entire point of that license, what restrictions does it come with? I guess you could say that it has a restriction of adding new restrictions, but surely that's not what you're talking about?

[parodysbird]

Copyleft licenses have restrictions. Now, those restrictions are definitely in promotion of the normative ethics that the FOSS community holds, but they are nonetheless restrictions.

[throwaway27448]

I wonder how they'll figure out who to target for litigation when this license is violated.

[paxys]

How many companies host and serve models via API and have a $20M+ revenue? Going to be pretty straightforward to catch offenders.

[throwaway27448]

Demonstrating a company is using this model in court seems non-trivial, no? Or am I interpreting this post incorrectly.

[amazingamazing]

Not at all. It is easy to bake in a specific response to a given prompt in the model.

[throwaway27448]

It is trivial to contrive a distinct model that behaves the same, no?

Regardless, most uses of a model won't provide direct interaction. This entire line of thought seems starved of use. Unless we're talking about LLM providers themselves... but that is a separate topic entirely

[amazingamazing]

no, because you don't know what the "secret prompt" is. there could be hundreds such prompts

[ayewo]

Yep. Cursor’s Composer 2 model is a good example, though it is not clear if they entered into an agreement with Moonshot before they got found out in March this year [1] or after.

1: https://x.com/fynnso/status/2034706304875602030

[bityard]

Software licenses aren't enforced through litigation as much as they are enforced through the _threat_ of litigation and legal risk. In other words, pretty much every company pays lawyers to minimize legal risk. Those lawyers inevitably look at all the contracts, agreements, and software licenses, and tell the C-suite what to do in order to keep their legal exposure as low as possible. "Don't violate other companies' IP," is pretty low-hanging fruit in those conversations.

It is a very rare (and ballsy, and perhaps incompetent) company that ignores their lawyers' recommendations to adhere to the letter of all of the software licenses they are bound to.

[DennisP]

Normal software is copyrighted. Model weights don't seem to be copyrighted, as another comment pointed out here: https://news.ycombinator.com/item?id=49073127

If weights aren't copyrighted then there's no IP to license, other than the bit of software that runs the whole thing and it's probably not too hard to write that yourself. There might even be open source reimplementations soon.

Lots of companies are willing to push the boundaries of IP when there's a gray area. One example is Google's implementation of a Java API when they made Android, for which they got sued, and won their case. Another example is the AI companies training their models on copyrighted material.

[throwaway27448]

I'm at a bit of a loss here—is copyright formed around semantics rather than text? What are the constraints of matching these semantics?

[DennisP]

From the other comment:

> this was partially tested last year in Thaler v. Perlmutter which affirmed that copyright requires human authorship

Model weights are not authored by humans. Neither is AI output, which is why that's not copyrighted either. In another realm, a famous photo taken by a monkey was deemed by the courts to be free of copyright.

[ffsm8]

They haven't litigated the last public non-compliance... Despite that one being extremely public. So probably not at all for now.

[JumpCrisscross]

> They haven't litigated the last public non-compliance

What was it?

[drawnwren]

Cursor was thought to be but they were later found to be using an authorized provider [1]

1 - https://x.com/Kimi_Moonshot/status/2035074972943831491?lang=...

[Iolaum]

Maybe because a non public agreement was in place?

[mike_hearn]

They have certainly trained in some secret call/response pairs that would uniquely identify Kimi serving.