Kimi K3 License: Modified MIT & Commercial Use

The Kimi K3 license is a Modified MIT license, and Moonshot plans to release the full weights on July 27, 2026. That's the confirmed part, reported by Decrypt and Yahoo Finance over the weekend of July 18–19. The exact clause text isn't published yet, so anyone telling you precisely what you can and can't do commercially is guessing ahead of the document. This page separates what's known from what's inferred so procurement teams aren't reading tea leaves.

Here's the honest state of things. Three things are confirmed, a few more are reasonable to expect based on how Moonshot licensed the K2 family, and one big category stays unknown until the license file actually ships. Blur those together and you get the confident-sounding-but-wrong writeups that already exist. Keep them apart and you can actually plan.

What Is the Kimi K3 License?

The Kimi K3 license is a Modified MIT license, per reporting from Decrypt and Yahoo Finance during the July 18–19 weekend reveal. Moonshot has said the weights land July 27, 2026. What nobody has yet, including Moonshot publicly, is the clause-by-clause text. Until that file appears next to the model, "Modified MIT" is a name, not a contract you can read.

So treat the whole topic in three buckets and never let them merge. Below is the summary table that the rest of this page expands on.

If you're evaluating K3 for anything that touches legal review, that middle bucket is the one people keep mislabeling as fact. It isn't. The K2 precedent is a good prior, not a promise.

Kimi K3 Modified MIT: What's Confirmed So Far

Start with what a plain MIT license actually is, because "Modified MIT" only makes sense against that baseline. Plain MIT is about as permissive as open licensing gets: you can use, copy, modify, merge, publish, distribute, sublicense, and sell the covered work, commercially or not, as long as you keep the copyright notice and the license text with it. No copyleft, no share-alike, no field-of-use limits. The OSI-approved MIT text is short enough to read in a minute, and it's the reference point everyone means when they say "MIT."

"Modified MIT" signals that Moonshot started from that permissive base and added something. The word modified is doing the work. It could be a light attribution requirement, an acceptable-use rider, a scale threshold, or a name-and-logo clause; the K2 family, for context, layered an attribution condition on top for very large commercial deployments. What we don't have for K3 is which modifications made it in. Decrypt and Yahoo Finance reported the license name; they didn't publish a diff against MIT, because there isn't one to publish yet.

That gap matters more than it sounds. A Modified MIT that adds a footnote-level attribution line behaves, for 99% of users, exactly like MIT. A Modified MIT that adds a usage-scale gate or an acceptable-use policy behaves like a source-available license with extra reading. Same two words, very different procurement outcome. Which is why the next section is careful about the word almost.

Kimi K3 Commercial Use: Can You Use It Commercially?

Almost certainly yes at normal scale, if K3 follows the K2 precedent. That's the honest answer, and the italics are load-bearing.

Here's the reasoning, kept explicit so you can audit it. Moonshot's K2-family weights shipped under Modified MIT with an attribution condition that only bit at very large commercial deployment scale; ordinary commercial use (building a product on top, running the model behind a paid API, fine-tuning it for internal tooling) sat inside the permissive part. That's the pattern. If K3's "Modified MIT" mirrors it, most companies can use Kimi K3 commercially without special permission, keeping the license notice and any required attribution.

But "follows precedent" is an assumption, not the July 27 text. A few things would change the answer, and any one of them can turn up in the actual file:

• An attribution trigger that sits lower than K2's, so a mid-size deployment crosses it.
• An acceptable-use policy that carves out specific domains (the kind of clause several open-weight releases have added since 2025).
• A name-and-logo or "powered by" display requirement for commercial products.
• Anything that gates a specific variant. Recall that K3 access tiers already differ; the 1M-context and HighSpeed features are membership-gated on the hosted service, which is a service-tier matter rather than a weights-license matter, but it shows Moonshot does tier things.

If you're in a regulated industry, the practical move is boring and correct: don't sign anything, don't ship anything license-dependent, until you've read the real clause on the 27th. For everyone else, the K2 precedent is a reasonable bet; just label it a bet in your own notes.

Kimi K3 Self-Hosting: What the License Enables

A permissive license plus published weights is what makes self-hosting legally possible in the first place, and that combination is exactly what's coming July 27. If the Modified MIT text lands roughly where the K2 precedent sits, you'll be allowed to download the weights, run them on your own hardware, fine-tune them, and keep every token of your data inside your own perimeter. For teams that can't send prompts to a third-party API for compliance reasons, that's the whole point of an open-weight release.

Now the hardware reality check, because "you can self-host" and "you should self-host" are different sentences. K3 is a roughly 2.8T-parameter mixture-of-experts model (896 experts). MoE means only a fraction of those parameters activate per token, so the compute-per-token is far below what 2.8T total suggests, but you still have to hold the full weight set in memory across your serving cluster. That's a serious GPU footprint. Realistically, most teams that want K3 won't stand up their own inference cluster; they'll rent it, hit a hosted endpoint, or route through a managed layer. The license permits full self-hosting. Your ops budget decides whether you use that permission.

If the goal is data control without owning the infrastructure headache, you can run K3 through an agent instead of standing up your own serving stack — MoClaw's Kimi K3 integration is one managed path for that. Read the July 27 license first; it governs self-hosting rights either way.

Kimi K3 Open Source License vs the Alternatives

Where does K3 sit against the other big open-weight releases? Broadly, in the permissive camp, though "permissive" spans a real range and the exact K3 clauses are still pending. The table below positions K3 by license style, not by clauses we can't yet quote. Where a competitor's exact terms aren't something we can source cleanly, the entry describes the category, not a specific line.

The takeaway isn't "K3 is more open than X." It's that MIT-derived licenses like K3's sit at the loose end of the spectrum, while community licenses like Llama's carry a usage-scale gate and an acceptable-use policy baked in. K3's expected position is closer to the MIT end than the Llama end, but until the file drops, that's a placement based on the family's history, not a reading of K3's own terms.

What to Verify on July 27 Before You Commit

When the weights drop, don't skim the README and call it diligence. Pull the actual license file and check, in order:

• Exact clause text. Confirm it's genuinely MIT-derived and read every added sentence. The word "modified" hides the entire risk surface.
• Attribution triggers. Is there a deployment-scale or revenue threshold that flips on an attribution or notice requirement? If so, where's the line, and are you above it?
• Acceptable-use terms. Some open-weight releases attach a usage policy (restricted domains, no-weapons clauses, etc.). Check whether one rides along.
• Model card + knowledge cutoff. As of July 21 there's no model card and the knowledge cutoff is undisclosed. If those still aren't published on the 27th, that's a data-provenance gap regulated adopters should log.
• Tech report. A missing tech report doesn't affect the license, but it affects how well you can defend the model choice in an audit.

For regulated industries specifically: treat July 27 as the start of evaluation, not the finish. The license text is the document your legal team signs off against, and it doesn't exist until then.

FAQ: Kimi K3 License

Is Kimi K3 open source?

It's open-weight, which isn't quite the same as OSI-approved open source. The distinction: OSI open source means the license meets the Open Source Initiative's definition (no field-of-use restrictions, among other criteria). "Open weight" means the model parameters are published under some license, which might be OSI-approved or might not. Plain MIT is OSI-approved. A Modified MIT might or might not still qualify, depending on what was modified. Until the K3 clause text is out on July 27, the accurate statement is "open-weight, license Modified MIT, OSI-status to be confirmed," not a flat "yes, it's open source."

Can I fine-tune Kimi K3?

Almost certainly, once the weights are public on July 27 and if the license follows the permissive K2 precedent, since fine-tuning is a normal permitted use under MIT-derived terms. Verify against the actual license file before shipping a fine-tuned model commercially, since that's exactly where an attribution or acceptable-use rider would apply.

Does Modified MIT allow commercial use?

Plain MIT explicitly allows commercial use, including selling the work. "Modified MIT" starts from that and adds conditions, so the base answer is yes, with whatever the modifications require layered on top. For K3 the K2 precedent suggests those conditions are light at normal scale, but the confirmed terms only arrive with the July 27 text.

When exactly do the weights drop?

July 27, 2026. That's the date Moonshot has given for the full weights release, and it's when the license file, the document this whole page is waiting on, becomes readable.

To go deeper on the surrounding picture: what is Kimi K3 covers the model itself, Kimi K3 free access walks the ways to try it before self-hosting is an option, and Kimi K3 limitations covers the open questions the license reveal doesn't answer. The Kimi K3 license story isn't finished until the July 27 text ships, and this page gets rewritten with the confirmed clauses the day it does.