# FaulltLine

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Francis Bisignano](https://cerebralvalley.ai/u/FrankieBiz)
- **GitHub:** https://github.com/FrankieBiz/Faultline
- **Demo video:** https://www.youtube.com/watch?v=F1X-wlXSpT8
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3580

FaultLine helps developers and coding agents prove a fix actually works before shipping it. Instead of relying on basic unit tests, a real headless browser explores a preview build, catches runtime failures, and outputs reproduction steps alongside a deployment-blocking exit code. From there, Meta’s model proposes a source patch that we run in an isolated sandbox against independent browser and business-logic checks. Our demo walks through a broken checkout flow that gets patched and verified against 44 assertions, showing why a fix that returns a 200 OK can still violate business rules. Developers can inspect the exact diff, screenshots, logs, and verification results before merging. Right now, the prototype handles single-file repairs for this checkout scenario.

## More from Meta Global AI Developer Hackathon

- [Motion Transfer](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3577)
- [OmniSpatial](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3578)
- [Persona Lab](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3579)
- [Alex Sumaila](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3581)
- [newcase.ai](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3582)
- [SIAGA.ID](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3583)

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