They should have disclosed it though. If they didn't it's a bad look for sure.
Seems like cursor is trying to build a "thicker wrapper" beyond the harness. Either to protect against Anthropic shutting them off or increase margins.
Cursor is killed for this market.
Ollama is also doing this.
There is so much money to be made repackaging open source these days.
So funny to see Twitter go wild saying "a 50 person team just beat Anthropic" blah blah.
[0] https://chainthink.cn/zh-CN/news/113784276696010804 - may have originally been https://x.com/apples_jimmy/status/2034920082602864990
[1] https://pbs.twimg.com/media/HD2Ky9jW4AAAe0Y?format=jpg&name=...
Their moat looks pretty thin. A VSCode fork with an open-source LLM fork on top. In the fast-moving coding-agent market, it’s not obvious they keep their massive valuation forever.
Are there any open models that come close? Why doesnt OAI or Anthropic dedicate some resources to blowing Cursor's model out of the water? Cursor's completion model is a sticking point for a lot of users.
I mean I guess this is what businesses do all the time. There's a term for it even, it's called white-labeling.
But is this all that Cursor have? They pass of VS Code as their own, they pass off Kimi as their own... What do Cursor even do? What do I need them for?
Why? As I said before, Anthropic mentions Moonshot AI (Maker of the Kimi models) as one of the AI labs that were part of this alleged "distillation attack" [0] campaign and will use that reason to cut off Cursor, Just like they did to OpenAI, xAI and OpenCode.
Let's see if the market thinks Composor 2 is really that good without the Claude models helping Cursor. (If Anthropic cuts them off).
[0] https://www.anthropic.com/news/detecting-and-preventing-dist...
It's a bit more than that. They have plenty of data to inform any finetunes they make. I don't know how much of a moat it will turn out to be in practice, but it's something. There's a reason every big provider made their own coding harness.
"Is Kimi K2.5 open source?"
"Yes, Kimi K2.5 is an open source AI model. Developers and researchers can explore its architecture, build new solutions, and experiment openly. Model weights and code are publicly available on Hugging Face and the official GitHub repository."
Their value is in the data they've collected and are collecting. Usage, acceptance rate, and all the connected signals. Plus having a large userbase where they can A / B test any finetune they create.
but it never occurred to me that, if true, of course the harness becomes increasingly more important. which feels absolutely correct of course.
not sure if the hypothesis is even true though.
People home about Teams sucking, but its market share is several times that of Slack because of distribution.
I guarantee that Microsoft has even more data.
Which I find very unfortunate. There are so many cases, especially in proprietary codebases with non standard infrastructure, where good autocomplete is much better than "agentic" edits that produce nothing but slop which takes longer to clean up.
Our only modification part is that, if the Software (or any derivative works thereof) is used for any of your commercial products or services that have more than 100 million monthly active users, or more than 20 million US dollars (or equivalent in other currencies) in monthly revenue, you shall prominently display "Kimi K2.5" on the user interface of such product or service.
> Our only modification part is that, if the Software (or any derivative works thereof) is used for any of your commercial products or services that have more than 100 million monthly active users, or more than 20 million US dollars (or equivalent in other currencies) in monthly revenue, you shall prominently display "Kimi K2.5" on the user interface of such product or service.
[1] - https://huggingface.co/moonshotai/Kimi-K2.5/blob/main/LICENS...
It goes against the ML community ethos to obscure it, but is common branding practice.
[0] https://chainthink.cn/zh-CN/news/113784276696010804
[1] https://pbs.twimg.com/media/HD2Ky9jW4AAAe0Y?format=jpg&name=...
We know Composer 2 is Kimi K2.5 from that tweet. Where is the evidence for Composer 1 being based on Qwen?
> So funny to see Twitter go wild saying "a 50 person team just beat Anthropic" blah blah.
In this case, it will be the other way round: Anthropic will see Cursor as a competitor AI lab using open weight models for Composor 2 (actually Kimi K2.5) which was allegedly distilled from Opus 4.6, and would be enough for Anthropic to cut off Cursor from using any of models.
That's where it is going.
This feels really rude to me. I have no problem with them fine-tuning open weight models to create their own - they are getting great results, and Cursor's research term should be respected for that. But deliberately hiding the base model they use is disrespectful of the researchers who created that model.
You can't just add random terms to an existing license and use its name. "Modified MIT: Like MIT but pay us 50 million dollars."
Perhaps CC-BY would've been more appropriate.
That said I have a feeling both VSCode and Claude code will catch up to their integration. But neither comes close yet (I say that as someone who mainly uses Claude Code).
The question is, where's the outrage? Why are there no headlines "USA steals Chinese tech?" "All USA can do is make a cheap copy of Chinese SOTA models".
> So funny to see Twitter go wild saying "a 50 person team just beat Anthropic" blah blah.
Well, if it's an American company, then it's a noble underdog story. When Chinese do it, they are thieves leeching on the US tech investment.
It's all so predictable, even the comments here.
The Anthropic ban on OpenCode isn't an Anthropic ban on OpenCode, it's a ban on using a Calude Code subscription with OpenCode. That's justified (or not) under various ToS arguments, but one can still use OpenCode with the more expensive API access.
Anthropic's complaint about distillation attacks is a distinct prong, one not levied against OpenCode. Additionally, the distillation activities described in your link don't describe Cursor's routine use of Anthropic's models. There, the model outputs are a primary product (e.g. the autocompleted code), and any learning signals provided are incidental.
“ CC-BY 4.0 Creative Commons Attribution 4.0 International
This license requires that reusers give credit to the creator. It allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, even for commercial purposes.
BY Credit must be given to you, the creator. ”
it's annoying the open source term is being cargo-culted around and I hate to say it but that ship looks like it has sailed.
funny that free software people were infuriated by the open source term and now the open source term is being completely misused in another context
I haven't dove into using a LLM in my editor, so I am less familiar with workflows there.
I'm also deeply curious about this legal question.
As I see it, model weights are the result of a mechanistic and lossy translation between training data and the final output weights. There is some human creativity involved, but that creativity is found exclusively in the model's code and training data, which are independently covered by copyright. Training is like a very expensive compilation process, and we have long-established that compiled artifacts are not distinct acts of creation.
In the case of a proprietary model like Kimi, copyright might survive based on 'special sauce' training like reinforcement learning – although that competes against the argument that pretraining on copyrighted data is 'fair use' transformation. However, I can't see a good argument that a model trained on a fully public domain dataset (with a genuinely open-source architecture) could support a copyright claim.
That plus Cursor's integration into VSCode feels very deep and part of the IDE, including how it indexes file efficiently and links to changed files, opens plans. Using Claude Code's VScode extension loads into a panel like a file which feels like a hack, not a dedicated sidebar. The output doesn't always properly link to files you can click on. Lots of small stuff like that which significantly improves the DX without swapping tabs or loading a terminal.
I also use Code from terminal sometimes but it feels very isolated unless you're vibecoding something new. I also tried others: Zed is only like 50% of the way there (or less). I also tried to use (Neo)Vim again and it's also nowhere close, probably 25% of the UX of Cursor even with experimental plugins/terminal setups.
I used Cursor for the second half of last year. If you’re hand-editing code, its autocomplete is super nice, basically like reading your mind.
But it turns out the people who say we’re moving to a world where programming is automated are pretty much right.
I switched to Claude Code about three weeks ago and haven’t looked back. Being CLI-first is just so much more powerful than IDE-first, because tons of work that isn’t just coding happens there. I use the VSCode extension in maybe 10% of my sessions when I want targeted edits.
So having a good autocomplete story like Cursor is either not useful, or anti-useful because it keeps you from getting your hands off the code.
You can copy/paste or drag code snippets the chat window and they automatically become context like. (@myFile.cpp:300-310)
You can click any of the generated diffs in the assistant chat window to instantly jump to the code.
Generated code just appears as diffs till you manually approve each snippet or file. (which is fairly easy to do with "jump to next snippet/file" buttons)
These are all features I use constantly as someone who doesn't vibe but wants to just say "pack/unpack this struct into json", "add this new property to the struct, add it to the serialization, and the UI", and other true busywork tasks.
Cursor also has an interesting Debug mode that actively adds specific debug logging logic to your code, runs through several hypotheses in a loop to narrow down the cause, then cleans up the logging. It can be super useful.
Finally, when making peecise changes I can select a function, hit cmd-L and add certain ljnes of code to the context. Hard to do that in Claude. Cursor tends to be much faster for quicker, more precise work in general, and rarely goes "searching through the codebase" for things.
Most importantly, I'm cheap. a If I leave Cursor on Auto I can use it full time, 8 hours a day, and never go past the $20 monthly charge. Yes, it is probably just using free models but they are quite decent now, quick and great for inline work.
I think they probably acquire it in accordance with Chinese law.
> but I don't think the US "started it" to be fair.
Who are you quoting with those marks? Started what? To be fair to whom?
Cursor's auto mode is flaky because you don't know which model they're routing you to, and it could be a smaller, worse model.
It's hard to see why paying a middleman for access to models would be cheaper than going directly to the model providers. I was a heavy Cursor user, and I've completely switched to Codex CLI or Claude Code. I don't have to deal with an older, potentially buggier version of VS Code, and I also have the option of not using VS Code at all.
One nice thing about Cursor is its code and documentation embedding. I don't know how much code embedding really helps, but documentation embedding is useful.
[1] https://marketplace.visualstudio.com/items?itemName=ezforo.c...
You can easily look up[1] how China struggles with effective enforcement of IP laws.
And specifically for LLMs, Anthropic recently claimed that Chinese models trained on it without permission.[2]
> Who are you quoting with those marks?
Double quote marks have other uses besides direct quotes, such as signaling unusual usage.[3] In this case, talking about countries like they're squabbling kids.
> Started what?
Fishy use of others' IP, packaging others' work without attribution.
> To be fair to whom?
To US companies using Chinese LLMs without attribution.
---
[1]: https://en.wikipedia.org/wiki/Allegations_of_intellectual_pr...
[2]: https://www.reuters.com/world/china/chinese-companies-used-c...
[3]: https://en.wikipedia.org/wiki/Quotation_marks_in_English#Sig...
As to what Anthropic said, it's quite specious as this analysis shows [1], ie the amount of "exchanges" is only tantamount to a single day or two of promoting, not nearly enough to actually get good RL training data from. Regardless, it's not as if other American LLM companies obtained training data legitimately, whatever that means in today's world.
[0] https://theworld.org/stories/2014/02/18/us-complains-other-n...
I didn't see anything in there about Chinese companies violating Chinese law.
Can you so easily look up how American companies struggle with effective enforcement of Chinese IP laws? I think it should be pretty easy to see how American companies struggle with effective enforcement of European IP laws, and I can tell you it is similar.
From here, it is not so clear that the US can even enforce its own laws at the moment.
> signaling unusual usage
Thank you!
> In this case, talking about countries like they're squabbling kids.
> > Started what?
> Fishy use of others' IP, packaging others' work without attribution.
I see. I guess if China is 3000 years old then maybe obviously, because the US is such a young country by comparison.
So you think it is "fair"[1] to violate Chinese Law because there were people in China who violated US law first?
If so, I think that is pretty childish.
[1]: I am trying it out!
[1] https://huggingface.co/moonshotai/Kimi-K2.5/blob/main/LICENS...