# Break This PR

- **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:** [Bobai Kaeto](https://cerebralvalley.ai/u/e7raem)
- **GitHub:** https://github.com/e7raem/meta-hackathon-2026
- **Demo video:** https://u.pcloud.link/publink/show?code=XZmDvSJZmntSIYS1wIf0NBdKznFpY0mBK6Hk
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2314

Break This PR helps developers catch checkout pricing bugs before they merge. A change to discounts or vouchers can pass every existing test and still overcharge shoppers or cost the business money. The problem isn’t always a failing test. Sometimes it’s the test nobody thought to write.

Meta’s Muse Spark 1.3 compares the written pricing rule with the proposed checkout code and looks for a basket that exposes a mistake. The developer confirms what the shopper should pay, then Break This PR runs the code to see what it actually charges. If the amounts differ, the developer has a bug they can reproduce, not just a comment to investigate. Muse can propose a targeted correction, and the runner checks that the same regression test fails on the proposed code and passes after the correction.

For example, a £110 basket drops to £99 after a 10% discount, so it no longer qualifies for a voucher. All six existing checks passed, but the changed code applied the voucher anyway and charged £94.50. The developer can keep the new test so that mistake doesn’t slip through again.

## More from Meta Global AI Developer Hackathon

- [lxna_builds](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2311)
- [Robolance by openlance.ai](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2312)
- [Spatial Copilot for Warehouse & Factory Floors](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2313)
- [Wayfog](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2315)
- [Aditi Mehta](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2316)
- [HotPath](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/2317)

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