Legal Document

How Research Works

What Prosei's legal research searches, how much it reads, what it checks, and its limits.

Effective: September 26, 2026
Table of Contents

1. What Research Is#

Legal research is a tool inside each Prosei case. When you ask a legal research question, an AI model (Claude, made by Anthropic) searches legal sources for your case's jurisdiction, reads what it finds, and writes a summary with a citation and a link for each source it relies on.

The result is legal information, not legal advice. It describes what statutes, rules and court decisions say. It does not tell you what to do in your case, and it does not predict how a court will rule.

2. What It Searches#

  • Court decisions. In the United States, Prosei searches CourtListener, the Free Law Project's database of published court opinions. In other countries it searches the free public legal databases and court websites available for that country, and in some countries it relies on web search of those sites.
  • Statutes. For US state statutes, Prosei first checks its own library of statute text, loaded from each legislature's official publisher and dated. When a section is not in that library, and for other countries, it searches and reads the official government or legislature website.
  • Court rules. For US state and federal court rules, Prosei first checks its own library of official rule text, dated by when it was retrieved. Otherwise it reads the official publisher's page for the individual rule.
  • Everything else. Web search, with official government and court websites preferred over other sources.

3. How Much It Reads#

A research answer draws on a small number of sources, not on a whole database.

  • For a US case-law search, Prosei reads the full text of the three most relevant opinions. The other results arrive with only a short summary. Any statement about what one of those courts decided is marked unverified unless Prosei goes on to read that opinion.
  • For statutes and court rules, Prosei's instructions require it to quote only text it read at the source during that research, and each entry shows when its source was read.

4. What It Checks#

  • Links. Every statute and court-rule link is checked to confirm that it points to an official source and that the page exists. A link that could not be confirmed is never shown as verified.
  • What a court held. A statement of what a court decided is marked unverified unless it was confirmed against a recognized case-law source during that research.
  • Whether a case still stands. For US cases, Prosei checks that the case exists in the citation database and how a sample of later opinions has treated it. This is a signal, not a full citator: it can miss a later decision that overruled or limited the case. Outside the United States, Prosei searches for later appeals instead.
  • Dates. Statute and rule entries show when their source was read, and an entry whose currency could not be confirmed is flagged.

5. Reuse of Recent Results#

If the same research question for the same jurisdiction was answered in the last 30 days, Prosei may reuse that result instead of searching again. A reused result still shows when its sources were read. After 30 days the question is researched again.

6. Limits#

  • AI can be wrong. It can misread a source, miss a relevant decision, or summarize a decision inaccurately.
  • No database is complete. Free legal databases do not hold every decision. Unpublished and very recent decisions are often missing.
  • The law changes. A statute, rule or decision can change after its source was read.
  • Coverage varies by country. It is widest in the United States. Elsewhere it depends on which public sources that country publishes.
  • It is not a citator. Prosei does not replace services such as Shepard's or KeyCite.

7. Your Part, and Getting Help#

You remain responsible for everything you file. Read each source at its link before relying on it, and check every citation.

For advice about your situation, consult a licensed attorney (in the UK, a solicitor or barrister). Inside Prosei, the Find a Lawyer button in the chat links to referral services for your jurisdiction. Prosei is a tool, not a law firm, and using it does not create an attorney-client relationship.