# NexusLegis

- **Event:** [Built with Opus 4.7: a Claude Code hackathon](https://cerebralvalley.ai/e/built-with-4-7-hackathon)
- **When:** Apr 21 at 12:00 PM – Apr 27 at 2:00 AM (EDT)
- **Where:** Online
- **Team:** [Marco](https://cerebralvalley.ai/u/marcoantonyo)
- **GitHub:** https://github.com/mbarrueto/lexgraph
- **Demo video:** https://drive.google.com/file/d/12npbxrPU5ssL-jSgI8O_GUBAvgk8gotO/view?usp=sharing
- **Gallery:** https://cerebralvalley.ai/e/built-with-4-7-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/built-with-4-7-hackathon/hackathon/gallery/239

I'm a Peruvian cybercrime victim who has spent four years navigating a justice system with a 1.1% cybercrime conviction rate. Courts worldwide are overwhelmed — prosecutors delay, evidence goes unexamined, crimes expire under statutes of limitations. Victims and attorneys increasingly turn to AI for help drafting legal filings, and the AI hallucinates jurisprudence. My complaint citing fabricated rulings was rejected. Over 100 attorneys globally have been sanctioned for the same mistake. Legal research infrastructure is now a billion-dollar market — but none of the platforms serving Latin America's 130,000+ Peruvian attorneys tell you which citations are real and which the AI fabricated.

LexGraph ingests rulings from Peru's Constitutional Court, extracts entities and relations using Claude Haiku 4.5, and answers legal research questions in Spanish or English using Claude Opus 4.7. When Opus cites a ruling the retrieval layer didn't return, the UI flags it as unverified instead of hiding it. LexGraph tells you which citations it can verify and which it cannot.

Built in 7 days by a non-engineer using Claude Code. The pipeline is jurisdiction-agnostic — Peru is where I needed it first.

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Markdown version of https://cerebralvalley.ai/e/built-with-4-7-hackathon/hackathon/gallery/239. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt