STEP 1 · THE RECORD ARRIVES
One exhibit of hundreds.
A deposition enters the record. It's logged and sourced the moment it lands — nothing enters silently.
PURPLEBRAIN LEGAL · FOR LITIGATORS
AI you can sign your name under.
PurpleBrain Legal is a case harness for the AI you already use. It breaks your case into sourced, confidence-scored pieces — every fact tied to the exact page it came from — and keeps counsel's judgment in the loop at every step. No new platform. No vault. No guessing.
Pleadings & motions
Discovery & exhibits
Depositions
Case law & statutes
Opposing filings
THE STAKES
The problem isn't the AI. It's the process around it.
$110,000
the sanction a federal judge issued this year for 23 fabricated citations — the largest AI penalty in U.S. legal history
1,300+
court cases where judges have flagged AI-hallucinated authority, and counting
U.S. v. Heppner
documents drafted with consumer AI ruled not privileged: no counsel direction, no work product
Every attorney knows AI can make things up. The question is whether your process catches it before you sign.
THE HARNESS
Watch a case get built.
Scroll to follow one exhibit from the record to a draft you can sign.
STEP 2 · CLAIMS, WITH PAGE AND LINE
The testimony becomes claims.
Each one carries the exact page and line it came from. Not summaries — receipts.
STEP 3 · THE ADVERSARIAL READERS
A contradiction surfaces.
The interrogatory answers say June 1. The deposition says May 1. Most tools would pick one silently. This one stops.
STEP 4 · COUNSEL DECIDES
Your judgment, on the record.
Counsel keeps the sworn testimony and retires the conflict visibly — preserved as impeachment material, not buried in a footnote.
STEP 5 · A DRAFT YOU CAN SIGN
Every sentence carries its cite.
The motion assembles from approved claims only — each with its exhibit, page, and line. Then it waits for the only thing that matters: your signature.
NO NEW PLATFORM
Your AI. Your subscription. Our harness.
PurpleBrain Legal is not another platform, and it doesn't bundle the AI into an opaque fee. The AI is the subscription you already pay for — you know that cost to the dollar. Your PurpleBrain seat buys the harness around it: the discipline, the checkpoints, the receipts. Two line items you can read. And your files stay where your data agreement already lives — no new vendor holding your client documents.
The harness drives Claude and Gemini today — both with million-token context windows, so an entire case record can fit in a single pass. ChatGPT and Copilot are next: the core routes by provider, so each new assistant is an addition, not a rewrite.
The market is moving this direction: Anthropic's Claude for Legal now ships more than twenty legal connectors — the assistant you already use is becoming the platform. PurpleBrain Legal is the case discipline that runs on top.
A platform asks you to move in. A harness moves in with you.
The platform model
- A new vendor, holding your client files in its vault
- Seat minimums and year-long contracts
- Verification you can't inspect
- Priced for firms with procurement departments
PurpleBrain Legal
- Your AI, your files, where they already live
- Counsel's process enforced at every step
- Every claim traceable to its page
- Two line items you can read — your AI, your seat
BUILT, NOT PITCHED
3,922
tests behind the harness
9
adversarial readers on every matter
5 phases
of drafting, with counsel checkpoints built in
Built inside live motion practice — pleadings, motions, discovery responses — not a demo lab.
What we don't do.
No invented citations — authorities get audited, and AI-drafted summaries are flagged for verification
No filing without counsel — the pipeline stops for your sign-off
No new vault — your files stay under the data agreement your firm already approved
No guessing — gaps get named, not papered over
GET STARTED
Show us your messiest documents.
Bring your hardest document set to a working session. We'll show you what a knowledge layer that cites its sources can find in it.
Your message goes to a person who can act on it — not a queue, not a list. We don't publish or share your contact details.
Book a working session
Tell us what kind of knowledge is scattered, where it lives, and what your team needs to answer.
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