Thomson Reuters Shows How CoCounsel Legal Reviews 10,000 Contracts

Thomson Reuters unveils contract review and brief drafting capabilities

Thomson Reuters demonstrated the next generation of its CoCounsel Legal platform in a recent webinar, showing how the system can analyze up to 10,000 contracts against 100 questions in a single prompt and draft legal briefs while pausing for attorney review at critical decision points.

Valerie McConnell, Vice President of Solutions Engineering at Thomson Reuters, led the demonstration alongside AI Solutions Architect Jackie Schmiedlin. The session focused on what the company calls Fiduciary-Grade AI—systems built specifically for legal work where precision matters and errors carry consequences beyond lost time.

Why it matters

Law firms face a strategic divide: those with deliberate AI deployment strategies are nearly twice as likely to see revenue growth from AI use, according to Thomson Reuters data. The difference lies not in experimenting more with AI, but in deploying tools that can handle high-stakes work where a missed precedent or misread clause represents genuine risk. Purpose-built legal AI that shows its reasoning and sources may determine which firms can scale complex work profitably.

Bulk document review with transparent sourcing

The Tabular Analysis feature within CoCounsel Legal's Workspaces can process up to 10,000 documents simultaneously. Attorneys can upload their own due diligence or discovery questions, or describe a goal—such as identifying acquisition risks—and let the system generate appropriate questions.

Each answer links directly to the specific contract language that supports it. The system flags ambiguous findings for manual review. McConnell demonstrated filtering results by change-of-control provisions to surface high-risk contracts, then converting the analysis into client memos and disclosure schedules through additional prompts. Part of this review now runs on Thomson, the company's proprietary large language model trained on Westlaw, Practical Law, Checkpoint, and Reuters content.

Brief drafting with four attorney checkpoints

Brief Builder launches with five motion types: motion to dismiss, motion to compel, motion for protective order, motion to exclude evidence, and motion to transfer venue. After uploading a complaint and client summary, attorneys review and approve at four stages: confirming facts and parties, evaluating proposed arguments, examining legal reasoning with Westlaw citations, and receiving a formatted brief.

The system completes research and document review before drafting begins, ensuring briefs reflect current law. Attorneys can accept, edit, or remove any argument before the final document is generated.

Built on Claude, grounded in legal authority

CoCounsel Legal was rebuilt on Claude, Anthropic's reasoning technology, then customized for legal work and grounded in Thomson Reuters' legal content spanning more than 150 years. The system requires no prompt engineering—attorneys describe needs in plain language, and CoCounsel Legal builds its own plan and executes each step while reasoning from Westlaw, Practical Law, and firm precedent.

McConnell emphasized transparency throughout the demonstration. The system flags its own assumptions, notes missing information, and links every citation to its source. "We are doing everything we can to make AI not a black box, but a system that you can use and really stake your reputation on," she said.

During the Q&A session, Schmiedlin confirmed that firm documents remain isolated within each firm's CoCounsel instance, aren't accessible to other users or Thomson Reuters, and aren't used for model training. Integrations with iManage, SharePoint, and NetDocuments are currently available, with additional connections planned through year-end. Shareable workspaces are targeted for early next quarter.

These details were first reported by Thomson Reuters in a webinar demonstration of CoCounsel Legal's capabilities.