DingDuff MCP Server - Legal Research Made<br>Simple

Built by lawyers for their own use

A (free!) Legal Connector that Gets Out of<br>the AI&rsquo;s Way.

A Claude connector

Millions of cases

Federal statutes and rules

State statutes and rules

DingDuff is a Claude MCP connector for legal research. It links your<br>existing Claude account to a database of millions of legal opinions,<br>state and federal statutes, and court filings from around the country.

We&rsquo;ve designed DingDuff to be simple, useful, and inexpensive to<br>run, which allows us to currently operate it with a<br>tip jar . All<br>our effort has gone into one thing: building a tool we actually use in<br>our own daily work. That meant making it run seamlessly inside Claude.<br>We don&rsquo;t dress it up in fancy packaging or try to tell the AI how<br>to do its job. Our goal is to empower Claude to do what we ask, then get<br>out of its way — and we&rsquo;ve found the results to be quite<br>brilliant when we do.

Get DingDuff

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Used daily by practicing lawyers

What lawyers are saying

&ldquo;DingDuff is a must-have for every litigator. Instead of spending hours devising Westlaw search terms, I can now get legal research through plain English prompts, just like working with an associate. I recently filed a thoroughly researched Ninth Circuit opening brief with DingDuff—without once opening Westlaw. It simply wasn’t needed.&rdquo;

Michael Showalter<br>Showalter PLLC<br>Complex Commercial & Appellate Litigator · former Seventh Circuit Clerk, D.D.C. Clerk, and Senior Editor of the Yale Law Journal

&ldquo;DingDuff is a game changer and I honestly can’t imagine practicing without it. It has completely changed legal research for me from a slog to something I can complete in minutes. Even after spending hours doing research I was always worried I was missing something. And Westlaw’s AI, while helpful, is still regularly incomplete or inaccurate. DingDuff is giving me confidence in my ability to do legal research quickly and thoroughly, and I use it daily in my practice. I also regularly get partner feedback that they are blown away by the research memos I put together using DingDuff and Claude. I can’t imagine going back to a world without it.&rdquo;

Laura Bach

Litigation Associate · former S.D. Texas Clerk, Texas Supreme Court Clerk, and President of Harvard Law School Mock Trial Association

We benchmarked Claude + DingDuff against Westlaw CoCounsel and Lexis<br>Prot&eacute;g&eacute; on the same assignment — and graded every<br>citation by hand.

See how DingDuff compares to the legal-specific AI products<br>&rarr;

Coverage

Legal Sources in DingDuff

Federal sources

Federal court opinions

Federal statutes and regulations<br>USC / CFR

Federal Rules of Civil Procedure

Federal Rules of Appellate Procedure

Federal Rules of Evidence

State sources

For<br>all 50 States + D.C.:

State court opinions

State statutes

Rules of Civil Procedure

Rules of Appellate Procedure

Rules of Criminal Procedure

Rules of Evidence

Our databases / sources

Court opinions<br>CourtListener

Statutes and rules<br>In-house search-optimized database

Citations<br>The Indigo Book, Second Edition (2023)

About DingDuff

More About DingDuff

DingDuff started as a side project by two practicing lawyers — us,<br>Kyle and Stephanie — who wanted something we could use at work in<br>our own day jobs. We were never trying to build a company.

What we didn&rsquo;t expect was to get an answer to an empirical question<br>that we hadn&rsquo;t even thought to ask: does a purpose-built legal AI<br>platform (like Westlaw&rsquo;s AI/Deep Research) actually perform better<br>than a frontier AI model (like Claude Opus) that has been given direct<br>access to the legal sources?

In our hands, DingDuff was outperforming our firms&rsquo; Westlaw AI<br>accounts so consistently that we both eventually stopped using them.<br>That&rsquo;s when we decided to make DingDuff available to other lawyers.

For lawyers

Who Is DingDuff For?

DingDuff is for lawyers. The reason DingDuff works so well is because we haven&rsquo;t tried to<br>program a bunch of guardrails into it, or teach Claude how to lawyer. But<br>that same hands-off design means Claude + DingDuff will occasionally get<br>something wrong (although we have never seen it hallucinate a fake case<br>or statute).

With DingDuff, the lawyer reading and checking the output acts as the<br>guardrail. That&rsquo;s why having a lawyer-user is essential, and the<br>reason we&rsquo;re making DingDuff available only to lawyers.

By signing up for and using DingDuff you accept the<br>Terms of Service, which includes a<br>promise that you&rsquo;re a lawyer.

Get started

Get DingDuff

You need two things to get started: (1) your own Claude plan and (2) a<br>username/password for the DingDuff &ldquo;connector.&rdquo;

Sign Up for DingDuff

Sign Up

Install DingDuff

Open Claude, paste this link into it, and ask Claude to walk you<br>through the installation:<br>github.com/DingDuff/dingduff-public/wiki

Or, if you&rsquo;d prefer to install...