Show HN: Time travel debugging AI for more reliable vibe coding
16 comments
·March 4, 2025PetrBrzyBrzek
If anyone is wondering why it looks like Bolt, it’s because it’s using Bolt.DIY, an open-source fork of Bolt (https://github.com/stackblitz-labs/bolt.diy). The catch is that it's still using WebContainers from StackBlitz, so it's not really possible to run it commercially. You need to get rid of WebContainers and find something different.
bhackett
Thanks, yeah we're really thankful to StackBlitz for open sourcing the early version of Bolt.new and to the Bolt.diy community for continuing to develop it.
We don't have a commercial offering yet and are planning to migrate off WebContainers for the upcoming full stack features -- WebContainers show their limits pretty quickly in a full stack context (e.g. CORS issues) and we need observability into the server side of the app for full stack debugging.
Regardless, our interests here are only lightly commercial. We're not really developing Nut to drive revenue but to help us develop the debugging API and push forward the SOTA for AI development as effectively as we can. That API is what we want to sell.
nenadg
Looks fun and it does create something - https://nut.new/chat/prince-of-persia-platform-game
I couldn't start the game though, but it seems runnable given some debugging. Great work!
krat0sprakhar
Can you share the prompt you used to generate this game? (given chats aren't sharable)
bhackett
Thanks! Unfortunately the chat links aren't shareable yet. We're planning on adding this within the next couple weeks along with the other full stack features (database integration and easy deployment).
JackYoustra
Hm, the link isn't working for me
unclad5968
What is vibe coding?
ryandrake
The way I understood it: Cobbling a program together by simply prompting AI assistants over and over, blindly using the generated code, and repeating until it barely approaches satisfying the requirements. Not worrying about things like correctness, proper design, code cleanliness, understandability, performance, code size, security, data protection, maintainability, or even bugs unless they catastrophically stop the user from running the program.
I really hope this doesn't actually catch on in "real" engineering, beside as a meme joke.
spiderfarmer
Judging by how many people blindly posted Stackoverflow answers, there will be a significant amount of code ‘written’ this way.
yoavm
It's when an AI writes the code for you.
zaptrem
Just letting you know the about page has black text on a black background
xeonmc
Can’t expect too much reliability from the result of vibe coding.
theturtletalks
Nut looks like a fork of Bolt, how does Nut differ?
bhackett
Yes, Nut is a fork of https://bolt.diy and like bolt.diy you can add your own API key and use it as much as you want (Nut is hosted though so you don't have to set anything else up).
The improvements we're making are under the hood. When you ask Nut to fix a bug it should do a much better job -- we record the app's behavior and analyze it so the AI has context for the changes it needs to make.
We've also added some UI to approve or reject the changes the AI makes. For now we're using this to gather feedback so we can improve Nut, but down the line we'll also refund the user any credits when they reject changes -- you shouldn't have to pay when the AI screws up, a big issue with these tools (and vibe coding in general).
Hi HN, I'm the CEO at https://replay.io. We've been building a time travel debugger for web apps for several years now (previous HN post: https://news.ycombinator.com/item?id=28539247) and are combining our tech with AI to automate the debugging process.
AIs are really good at writing code but really bad at debugging -- it's amazing to use Claude to prompt an app into existence, and pretty frustrating when that app doesn't work right and Claude is all thumbs fixing the problem.
The basic reason for this is a lack of context. People can use devtools to understand what's going on in the app, but AIs struggle here. With a recording of the app its behavior becomes a giant database for querying using RAG. We've been giving Claude tools to explore and understand what happens in a Replay recording, from basic stuff like seeing console messages to more advanced analysis of React, control dependencies, and dataflow. For now this is behind a chat API (https://blog.replay.io/the-nut-api).
We recently launched Nut (https://nut.new) as an open source project which uses this tech for building apps through prompting (vibe coding), similar to e.g. https://bolt.new and https://v0.dev. We want Nut to fix bugs effectively (cracking nuts, so to speak) and are working to make it a reliable tool for building complete production grade apps.
It's been pretty neat to see Nut fixing bugs that totally stump the AI otherwise. Each of the problems below has a short video but you can also load the associated project and try it yourself.
- Exception thrown from a catch block unmounts the entire app: https://nut.new/problem/57a0b3d7-42ed-4db0-bc7d-9dfec8e3b3a5
- A settings button doesn't work because its modal component isn't always created: https://nut.new/problem/bae8c208-31a1-4ec1-960f-3afa18514674
- An icon is really tiny due to sizing constraints imposed by other elements: https://nut.new/problem/9bb4e5f6-ea21-4b4c-b969-9e7ff4f00f5b
- Loading doesn't finish due to a problem initializing responsive UI state: https://nut.new/problem/486bc534-0c0e-4b2a-bb64-bfe985e623f4
- Infinite rendering loop caused by a missing useCallback: https://nut.new/problem/496f6944-419d-4f38-91b4-20d2aa698a5e
Nut is completely free. You get some free uses or can add an API key, and we're also offering unlimited free access for folks who can give us feedback we'll use to improve Nut. Email me at hi@replay.io if you're interested.
For now Nut is best suited for building frontends but we'll be rolling out more full stack features in the next few weeks. I'd love to know what you think!