# Reflex

- **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:** [Berkay Hasret](https://cerebralvalley.ai/u/berkay123001)
- **GitHub:** https://github.com/berkay123001/Reflex
- **Demo video:** https://youtu.be/lV04TGYplD0
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1905

Reflex is an open-source browser agent built on Meta's Muse Spark. You give it a website and a goal in plain language, and it drives a real Chromium until it can answer. Muse Spark 1.3 reads each page as a numbered list of elements and decides every step, code verifies that each step changed the page, and Muse Spark Open checks the final answer against every requirement of the task before it is shown.

The problem: browser agents look good in demos, but on live websites they often stall or report results they never saw, and running a large model on every step is expensive. Reflex keeps its guards in code rather than in the prompt: it stays on the task's website, catches loops, asks before payments, deletions and sending messages, and fills personal-data fields only with what the user gave it. When a site blocks it, it says so instead of inventing a result.

On all 300 Online-Mind2Web tasks on live websites, Reflex solved 162 (54%), and 70% of the 233 tasks whose sites let it in, for under one cent per task and a median of one minute. On the 67 sites that blocked our network, it presented no made-up result. Answers were judged by Claude, not humans; every answer and final screenshot is in the repo. Use it from the live Studio UI or from Claude Code over MCP.

## More from Meta Global AI Developer Hackathon

- [Tales](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1902)
- [MetaAgents](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1903)
- [Mushtastic Intelligence](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1904)
- [Sourcenote](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1906)
- [Hog rider](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1907)
- [Murugan](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1908)

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