Quentin Feuillade--Montixi

Seldon Lab Batch #2. In SF building the future of programming

[Quentin Feuillade--Montixi @LLMPsychologist]

3 months ago I joined Seldon Lab as a solo founder.

1 month in, I pivoted. Started building Weft: a programming language designed for AI systems, where LLMs, humans, and infrastructure are first-class primitives.

2 months of heads-down building. Yesterday morning, I shipped.

Since then:
- 2,000 users in 48 hours
- 700 GitHub stars
- 10 paying customers
- Demo day today, went great

Still beta. Production-ready in ~2 months if I keep focus on the product.

Huge thanks to Seldon Lab, @EsbenKC and @MetzFinn81065 for betting on a solo founder.

And Sorhan for the visibility push!

If you want to build real AI systems on Weft, please reach out, I'll start onboarding business in a month or so

[Quentin Feuillade--Montixi @LLMPsychologist]

@theSamPadilla I get the argument, but claude is already 20x better at coding in my language than python. Imagine when it gets trained on it in the next training batch. If you want longer argument you can check the blogpost

[Quentin Feuillade--Montixi @LLMPsychologist]

I'm open sourcing Weft today. A programming language where LLMs, humans, databases, and APIs are base ingredients, not libraries you import. You wire them together. The compiler checks the architecture. You get a visual graph of your program, automatically.

Why I built it ↓

[Quentin Feuillade--Montixi @LLMPsychologist]

Two months of solo work. Very early.
The catalog is small, the shape is still settling, and I'm building in public. If any of this resonates, I'd love your eyes on it.
📖 Blog post: https://t.co/najGHUWOtd
💻 GitHub (stars help more than you think): https://t.co/yzyggYT3YL
🚀 Try it: https://t.co/xYjZdImuuR

[Quentin Feuillade--Montixi @LLMPsychologist]

The bet: don't steer the model harder, change the language under it.

[Quentin Feuillade--Montixi @LLMPsychologist]

Github: https://t.co/jXzUZFfuiE
Chrome: https://t.co/qpQBUYoNzM
Firefox: https://t.co/Ceh9rauzSx

[Quentin Feuillade--Montixi @LLMPsychologist]

You won't be able to see this post — after this

[Quentin Feuillade--Montixi @LLMPsychologist]

@DmytroKrasun You can read more about it https://t.co/onAqpeMSfb, I am going to release in a few days with way more details

[Quentin Feuillade--Montixi @LLMPsychologist]

@instagram The post https://t.co/1GiSLQnwvC

[Quentin Feuillade--Montixi @LLMPsychologist]

Well... things got out of hand. I made a pre-launch video on instagram and it went viral. What I expected even less when I woke up the next day was @Instagram banning me. If you discovered me there please contact me here in the meantime while I try to figure out an appeal. I'll give more details about the programming language I am building here next week 🚀

[Quentin Feuillade--Montixi @LLMPsychologist]

@Meta @instagram
My fresh account got banned (1 day). I just launched with an influencer on insta and I think this is because I got a spike of activity (>80k view), I tried every possible way to contact you but each account I made to do so were banned. My account is quentin_101010 is there any way to appeal on your end, or at least unblock my IP so I can create a new account. This is quite urgent I had important conversation going on. I can send more informations in PM

[Quentin Feuillade--Montixi @LLMPsychologist]

@Meta @instagram
My fresh account got banned (1 day). I just launched with an influencer on insta and I think this is because I got a spike of activity (>80k view), I tried every possible way to contact you but each account I made to do so were banned. My account is quentin_101010 is there any way to appeal on your end, or at least unblock my IP so I can create a new account. This is quite urgent I had important conversation going on. I can send more informations in PM

[Quentin Feuillade--Montixi @LLMPsychologist]

@Meta @instagram
My fresh account got banned (1 day). I just launched with an influencer on insta and I think this is because I got a spike of activity (>80k view), I tried every possible way to contact you but each account I made to do so were banned. My account is quentin_101010 is there any way to appeal on your end, or at least unblock my IP so I can create a new account. This is quite urgent I had important conversation going on. I can send more informations in PM

[Quentin Feuillade--Montixi @LLMPsychologist]

The permission to create PRs and the permission to create workflows are the same permission. You can't give an agent one without the other, unless you set up push rulesets.

Most people treat PR review as the security boundary. But on: push runs before review.

[Quentin Feuillade--Montixi @LLMPsychologist]

I just thought of a big vulnerability for AI coding agent.

The agent needs contents:write to create branches and PRs. But that same permission lets it create files in .github/workflows/. If it pushes a branch with a new workflow triggered on on: push, GitHub runs it from the pushed commit, not from main.

Even if you reject the PR, the workflow already ran with all your Github secrets and elevated autorization.

[Quentin Feuillade--Montixi @LLMPsychologist]

I am only aware of one mitigation that actually prevents this while still letting the agent push code normally: a Push rulesets. It restrict who can push to .github/**/* while allowing pushes everywhere else. The agent can still create branches and PRs, it just can't touch workflow files. That's it. Everything else I am aware of is partial. And this is paid or OS, on the free plan, there's no way to let an agent push code while preventing it from pushing workflow files.