Launch HN: Marblism (YC W24) – Generate full-stack web apps from a prompt

[umussetu]

Hi HN,

We are Cyril & Ulric and are building Marblism (https://marblism.com), an LLM-based dev platform to generate and iterate on full-stack web apps.

Here’s a demo video that goes from a comment on Twitter to a working app in 10 minutes: https://www.youtube.com/watch?v=TapOPO-Gv20.

Marblism started when we realized that much of the code we write for web apps is just slightly modified boilerplate: similar login flows, dashboards, API integrations, CRUD operations, etc. While AI tools are helpful, they fall short in delivering a well-architected codebase. The idea of Marblism is to combine the best of both worlds: a solid boilerplate, customized and enhanced with AI.

Here's how it works:

Generate your app - Describe your product, and the AI will build your data model. We create a NextJS app with auth, custom CRUDs, permissions, payment, emails. The AI then generates your front-end pages.

Test and improve your app - Now that your app is set up, use our online workspace to test your app and add more complex features via an AI Chat or directly yourself in the VSCode editor.

Go live - Once you’re happy with your app, deploy it in production in one click.

Here are some examples of apps generated on Marblism in couple of hours of prompting:

Find and validate startup ideas: https://www.muckbrass.com/

A design system directory: https://awesomedesignsystem.app.io

AI-Personalized candle: https://www.scent-a-scene.com/

Marblism currently generates web apps like SaaS, marketplaces, and social networks. It doesn't support Chrome extensions or mobile apps, and it’s not really for small games like Snake/Tetris.

The vision is to add more tech stacks later this year and enable people to create their own templates/tech stack that the AI can customize.

We’re really excited to share this with you and we'd love to hear your thoughts on the potential directions we can take this product.

[marcus_holmes]

Freelancers are shuddering in horror (or gasping in delight) at all the work they'll be getting from this in the next few years.

Endless numbers of ridiculous Ideas Guys will be showing up at tech meetups with "I got this thing like 90% of the way there, now I just need this little bit done, it'll take a good coder a few hours, right?".

Delving into the code base will be a Dantean expedition into the first few rings of Web Dev Hell, replete with LLM hallucinations of API endpoints that would be great if they existed.

[nxicvyvy]

The no code space in YouTube is on fire right now with people showing off how to build apps with ai.

The tools aren't too bad, I've been building a few things with cursor and ChatGPT to see how far you can. It's basically like you're pair programming with a junior who knows how to do all the basics but needs a lot of help in review.

Your read that this is going to be a huge mess in the freelance space soon is very accurate, the better the tooling gets the worse it will be.

[tonyoconnell]

I understand what you mean but Test First Development by LLM's will solve lots of problems with hallucinations and soon LLM's will be much better at coding than humans. I am always surprised that so many highly intelligent people don't understand this.

[blackhaz]

Everything looks great. I have tried to generate an app that generates stupid faces. At first it produced an app that generates what looks like random images - coffee tables, nature, people, pens... I have tried fixing it by chatting. It suggested to add an AI routine to make sure I'll be getting stupid faces. It broke itself and started to produce error messages instead of images. I have asked it to fix itself. It has added error handling, better error messages, and stupid face generation success rate bar to the UI, but I have never been able to generate a stupid face. Great idea though, and hopefully some day it will work.

[umussetu]

thanks for trying it out! I guess everything is fine in your code and just needed to direct the prompt a bit in the actual code (there is a tab 'code editor'). it's a bit what we're trying to improve. The AI gets 98% of stuff correctly, but for example here it missed to adjust the prompt to output stupid face generation - which literally takes 10 seconds to do in the code.

[bambax]

> Find and validate startup ideas: https://www.muckbrass.com/

The first "startup idea" on that page[0] is... an "AI-Powered Startup Idea Generator". I don't know if Singularity is near, but we certainly have attained Circularity.

[0] https://imgur.com/a/H3oNUeB

[notpushkin]

I think it’s what somebody else just submitted. My idea was on the top of that page for a while after I submitted it.

[onion2k]

I'm a huge fan of LLM-based tools, and I use them pretty much daily, but stuff like this concerns me a bit. In any dev process there needs to be a review step somewhere. Someone who understands code well needs to be looking at what the app is doing and making sure it's protecting my data. Someone needs to make sure there isn't a bug that loses the work I put in to creating records with a CRUD operation. They need to be making sure my privacy is respected in a legally compliant way. They need to make sure things are reasonably secure. None of that is guaranteed when you have a dev team, but it is a possibility at least.

Telling Joe Random "describe you app in a prompt and press deploy!" guarantees that isn't happening. This sort of service is great for non-dev people who want to launch something but it's a pretty big threat to my data.

I'm under no illusion that these services are going to be huge, and no doubt someone will sell an app built with one to a service that puts data about me into it. I suspect that means one day an attacker is going to learn something I'd rather they didn't. That sucks.

[space_fountain]

I wonder how much of this is that LLMs are worse than human developers (they are much more error prone right now) and how much of this is that we want someone to blame. When the elevator operator closes a door on someone fingers that's an honest mistake and/or we can fire them, but when the automated elevator bruises some 12 year olds finger that's a big problem that needs fixed

[squigglydonut]

I also feel this way but I am confused why people would want this. Generating from a prompt is still introducing a human step. Why would anyone want something so basic and bland. Then again, I think about the food industry. Fast food sucks but the predictability is really attractive to a lot of people. People like familiar too. It is interesting to watch it unfold.

[jfdjkfdhjds]

I take it you never worked at a cheap/local/small software shop, usually associated with an advertising agency.

because I would rather those fill-in-the-blank-forced-prompts that just add form fields and obviously broken business logic to a generic template they curate.

[candiddevmike]

What kind of liability do you take on with the code? Can I sue you if my app gets hacked?

I can't find anything around ToS or even a privacy policy.

[geor9e]

There is a joke about YC startups starting as "illegal taxi", "illegal hotel" … It makes sense, since law firms don't bother with lawsuits until the target has deep pockets. There are a thousand ways a startup can fail, and "got sued" in somewhere in that list of worries to focus on, but maybe not near the top at first.

[a2128]

The autogenerated app in their demo video comes with fake reviews and falsely claims you can make lists private when they're actually all public. Of course there's also zero GDPR/CCPA compliance on the generated app, there is no privacy policy (not that an AI could really read your mind about what you wanna with user data), no privacy contact and no account deletion, just a faceless AI-generated website. Security-wise I would place no confidence, it even failed to add a check to stop two people from having the same username. Legally this should be treated more like a toy for personal entertainment than anything

[umussetu]

good question, it's not a no-code tool - we generate code (similar to a cursor or copilot) and we expect people to review the generated codebase. We'll add a section on the documentation like checklist you need to review to make sure there is no security issues. should probably add ToS also yes

[nicksergeant]

I hope we can soon teach our robot overlords about web accessibility, because this is pretty rough: https://i.nick.sg/03510726333f4a2b85daf5dd156d6289.png

[umussetu]

indeed! our initial focus was to make it work, shouldn't too hard to make it score well on accessibility - good point

[ilrwbwrkhv]

I tried one and it threw this error:

Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

The fact that this whole AI fuzzy controlled thing builds on top of Javascript fuzzy controlled thing is really messy.

[ned_at_codomain]

This is really cool, guys!

One use case that occurs to me is to build personal SaaS apps. It's the sort of thing a lot of people use spreadsheets or Notion for.

I just made a simple little app with Marblism to help me keep track of whether I took my medication on a given day.

I couldn't tell you why, but I prefer this to little mobile apps and it's less upkeep than the spreadsheets I've tried to make in the past.

[umussetu]

thanks! true you could use it like that although I find notion and airtable to do a decent jobs if you really just want a todo list or a crm so unsure if we should dive into that segment

[TripleChecker]

Can I use my own existing postgresql database to connect it and generate the UI on top of it?

Also, typo on homepage - 'Authentification' (per our error report: https://triplechecker.com/s/t2ryxA/marblism.com?v=M0bXQ)

[umussetu]

not at the moment, but it's a good idea yes it's technically possible Fixed! good catch :)

[suriya-ganesh]

I've been using marblism to build a couple of projects over the last 2 weeks. It's an incredible product.

Here are my reviews:

- The tech stack selection is exceptional. It comes with batteries included, backend, auth, permissions etc.

- I love the ability to view the database, auth, in one place.

- The LLM itself gets stuck once the APIs and their interactions become slightly complex and deviates from the happy path. (likely because even the starter code is closer 10K lines of code across different files and frameworks)

- I wonder if instead being very opinionated, just a cloud LLM environment with a slightly less "fat" template would be optimal. because after all, people who would be twiddling with generated code are going to be developers who can (most likely) decide what they want.

[xs83]

I like the interface - I will say that it doesnt work when there is an ad-blocker installed (the workspace wont open).

When I am into the app it seems the database wasnt generated for items like the authentication system (which I would expect as it is included and mandatory).

Still more work needed but overall it looks great and I can see the advanced workings you have put in behind the scenes to make it do what it does.

[henning]

Evaluating startup ideas based on search volume reminds me of the apocryphal Henry Ford quote about "If I had asked people what they wanted, they would have said faster horses". VC-backed startups don't succeed by finding an underserved niche and generating a nice, steadily growing profit over time. They are by their nature supposed to either explosively succeed or rapidly die.

[dangoodmanUT]

Why do i have to choose between light and dark mode? If you can do both, why not support dynamic mode?

[umussetu]

we could indeed!

[atebyagrue]

This is great. Created a character generator & editor for my TTRPG group in about 5 minutes. Haven't dug too deep yet, but it created a working baseline that I was hoping for. Thanks! Will definitely be an eye on this. Keep up the good work!

[morgante]

Did you make Marblism with Marblism?

[meiraleal]

This should be the minimum requirement to launch a system like that

[beardyw]

I've been there and the chicken/egg thing doesn't come for free.

[umussetu]

haha no, the infrastructure we use is a bit intense to be entirely managed by an AI but one day maybe :)

[jatins]

Congrats on the launch!

I evaluated this a while back. While the app is impressive, I couldn't figure our who'd use it. A developer will feel restricted by it, a non-technical person will feel overwhelmed by it since code is at the center of it.

[cryptoz]

How do you make modifications to code once it is generated? This is the most interesting part to me - you say there is a chat assistant that can make changes? Does it rewrite the whole file, or how does that work? Do you use git diffs?

[codegeek]

"We create a NextJS app "

Are you considering adding other languages in the future ? I would like to try but not with NextJS. I have a special hate for JavaScript so I try to avoid it as much as possible except for Frontend.

[smt88]

TypeScript is one of the few languages (Rust being another) that should be a target of LLM-generated code, just because the static analysis is so strict you'd actually catch a lot of bugs before runtime.

[bickett]

I'm most interested how the product can do at iterating and making a better product overall. Building a website can be kinda hard, but building the *right* website for the market is very hard