Open citation review
Trace legal claims to their authority.
Quo Warranto helps readers inspect whether cited sources exist, bear the attributed claim, and are represented faithfully.
What This Tool Does
Drop a legal document into the box. The tool extracts every citation, verifies that the cited sources exist, and—if you enable it—analyzes whether those sources actually support the propositions they're cited for.
Who It's For
Lawyers verifying briefs before filing.
Partners reviewing associates, supervisors checking memos, faculty reviewing papers.
Opposing counsel identifying citation issues in submissions.
Students learning how citations connect claims to authority.
Self-represented litigants checking their arguments—or the other side's.
Journalists examining whether filings accurately represent precedent.
Researchers and advocates analyzing legal arguments in courts and policy.
Courts and clerks checking citation accuracy before cases proceed.
How It Works
The third step is optional and goes beyond existence-checking. It evaluates whether the source actually supports the proposition—the kind of analysis that catches mischaracterization, not just fabrication.
Current Limitations
This is a proof of concept, not production software:
- United States case law only: Currently restricted to American case law
- Coverage depends on CourtListener: Some cases may not be in their database
- Citations occasionally missed: Unusual citation formats or errors may not be recognized
- AI analysis is fallible: May miss nuanced arguments or context-dependent interpretations
- Analysis, not counsel: The tool evaluates whether sources support propositions. How best to act on that information depends on circumstances beyond what this system can assess (e.g., procedural rules, personal risk tolerance, skill of the opposing attorney, willingness of the opposing party to settle or plea bargain). If you need legal advice, you should consult a qualified attorney.
Data Handling
Loading this server's current data-handling policy…
The Larger Point
AI-generated legal citations have prompted urgent concern about "hallucinated" sources. But the deeper issue—whether cited sources actually support attributed propositions—predates AI and extends beyond it.
This tool demonstrates that verification is a technical problem with a technical solution. And if verification can be automated, it can be democratized. Everyone involved in legal reasoning—authors, reviewers, courts, the public—can access the same tools for evaluating whether legal arguments are grounded in what they claim.
When legal reasoning becomes transparent and verifiable, law becomes what it claims to be: a framework for reasoned disagreement about the terms of social life, open to examination by anyone.
Credits
Developed by Benjamin Leider, Innovation Fellow, William S. Richardson School of Law, University of Hawaiʻi.
Built on CourtListener and the Free Law Project's comprehensive legal database.