Built by lawyers for their own use
A (free!) Legal Connector that Gets Out of the AI’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 existing Claude account to a database of millions of legal opinions, state and federal statutes, and court filings from around the country.
We’ve designed DingDuff to be simple, useful, and inexpensive to run, which allows us to currently operate it with a tip jar. All our effort has gone into one thing: building a tool we actually use in our own daily work. That meant making it run seamlessly inside Claude. We don’t dress it up in fancy packaging or try to tell the AI how to do its job. Our goal is to empower Claude to do what we ask, then get out of its way — and we’ve found the results to be quite brilliant when we do.
Used daily by practicing lawyers
What lawyers are saying
“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.”
“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.”
Coverage
Legal Sources in DingDuff
Get started
Get DingDuff
Getting set up takes just a few steps: sign up for DingDuff, add it to your Claude account, set your Claude account settings, and add the DingDuff plugin.
Our step-by-step setup guide walks you through all of it, start to finish — about five minutes.
Where it works
Where DingDuff Works
DingDuff works wherever Claude does — and it adapts to where you’re running it.
On Claude Cowork
DingDuff is at its best in Claude Cowork, where Claude can reach a folder on your computer.
Instead of pulling opinions into the chat, it saves your own full copy of each opinion to a desktop folder so that you can revisit them later.
On the Claude Web App or your Phone
DingDuff can run right inside Claude’s web app and mobile app. Because Claude can’t save files to your device here, you’ll have to make sure the virtual machine feature is turned on in your Claude settings.
To do this, go to your Claude account → Settings → Capabilities. Scroll down and turn on two features: “Claude code execution and file creation” and “Allow network egress.”
About DingDuff
More About DingDuff
DingDuff started as a side project by two practicing lawyers — us, Kyle and Stephanie — who wanted something we could use at work in our own day jobs. We were never trying to build a company.
What we didn’t expect was to get an answer to an empirical question that we hadn’t even thought to ask: does a purpose-built legal AI platform (like Westlaw’s AI/Deep Research) actually perform better than a frontier AI model (like Claude Opus) that has been given direct access to the legal sources?
In our hands, DingDuff was outperforming our firms’ Westlaw AI accounts so consistently that we both eventually stopped using them. That’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’t tried to program a bunch of guardrails into it, or teach Claude how to lawyer. But that same hands-off design means Claude + DingDuff will occasionally get something wrong (although we have never seen it hallucinate a fake case or statute).
With DingDuff, the lawyer reading and checking the output acts as the guardrail. That’s why having a lawyer-user is essential, and the reason we’re making DingDuff available only to lawyers.
By signing up for and using DingDuff you accept the Terms of Service, which includes a promise that you’re a lawyer.
Support us
Costs — Tip Jar
DingDuff is free. But we do have some costs in running it. Thankfully our costs are low enough that we can be supported through a tip jar. If you find DingDuff helpful and would like to help keep it free, please consider donating.
Thank you so much! Your support means a lot to the team.
$
Processed securely by Stripe. No account required.
Who we are
Meet the Team
Like most lawyers these days, we (Kyle and Stephanie) felt acutely the twin fears that (a) the robots would eventually replace us, and (b) in the meantime, the other lawyers would get a better robot and use it against us. So before Westlaw AI even existed, and anticipating that other lawyers would soon have some sort of AI death star we'd have to confront, we began developing our own tool for our own use.
For a year, we've made iterative improvements. DingDuff began as a scrappy interface to a database we had compiled locally, running on a Raspberry Pi tucked away in Kyle's closet. But it has since grown into something far more capable—a powerful legal tool that runs through several databases, including CourtListener** and state and federal statutes. And after two years of dreading the inevitable Westlaw death star, we discovered a happy accident: our homegrown tool works comparably well, and often better in our opinion.
Finding ourselves unexpectedly in possession of an incredibly useful legal tool with significant potential, we wanted to share it with our lawyer friends. To help turn DingDuff from a personal project into a shareable product, we brought on two software developers: Jeremy, a longtime friend from our undergraduate philosophy days at UT Austin, and Julia, a recent computer science graduate.
**This entire project would never have been possible without the data heroes at CourtListener.
Kyle is a mass torts lawyer with a passion for history, philosophy, the law, and everything Reddit. He has served as first or second chair in more than two dozen trials and written and argued appellate briefs before the Texas Supreme Court and federal courts of appeals. Kyle grew up in Austin in a family of engineers and lawyers and is a proud double longhorn (both undergrad and law school) and the main architect behind DingDuff.
Stephanie is a commercial litigator with a background in financial regulation and litigation. Since law school, she has practiced in private firms, served in the federal government, clerked for a federal judge, and taught legal research and writing at Georgetown Law. She grew up in the Austin area in a family of engineers, scientists, and one very skilled carpenter. She has her undergrad degree from UT and her law degree from Columbia Law School.
Jeremy is a software engineer with twenty years of experience across tech start-ups and enterprise organizations. He studied philosophy as an undergrad at UT alongside Kyle and Stephanie; while they went on to law school, he pivoted to software engineering, later earning a master’s in the field (also from UT). Jeremy tends to DingDuff’s infrastructure and security.
Julia is a talented software developer who is always finding ways to pair her computer science degree from Texas A&M with her passion for art and design. Julia also grew up in the Austin area.
Brady has always been an engineer and problem-solver by nature. After undergrad and before contributing to building DingDuff, Brady helped run the nuclear operations onboard a naval submarine.
George is Stephanie's dog and the DingDuff fetcher of legal sources.
Get in touch
Contact Us
Have a question, feedback, or just want to say hello? We'd love to hear from you.