New Westlaw Brief Builder helps litigators move from legal research and issue analysis to first-draft briefs within a single AI-powered workflow

TORONTO, Aug. 20, 2026 /PRNewswire/ -- Thomson Reuters (Nasdaq/TSX: TRI), a global content and technology company, today announced the general availability of the next generation of CoCounsel Legal, a fully agentic AI experience designed to help legal professionals move from research and issue analysis to trusted work product within a single workflow.

Purpose-built for legal work and grounded in the trusted authority of Westlaw and Practical Law, CoCounsel Legal is engineered to reason, plan, and execute at the level of a senior associate. The enhanced experience brings together legal research, drafting, legal intelligence, verification, and matter-centric workflows in one connected environment, helping law firms and legal departments move seamlessly from question to strategy to execution.

As legal organizations shift from AI experimentation to enterprise-wide adoption, they are increasingly evaluating technology based not on whether it can generate answers, but on whether it can be trusted to support legal work. CoCounsel Legal addresses that need by combining transparent reasoning, citation-backed results, and trusted legal content with agentic capabilities that can orchestrate complex, multi-step tasks.

"The legal industry is moving beyond AI that simply generates answers," said Raghu Ramanathan, President, Legal Professionals, Thomson Reuters. "Whether you're at an Am Law 100 firm, a midsize or small practice, or a corporate legal department, the challenge is the same: turning insight into action. The next generation of CoCounsel Legal helps professionals complete legal work with confidence by combining trusted legal content, agentic intelligence, and workflow execution in a single experience. That's a fundamentally different approach to legal AI and a major step forward for the profession."

Built on Anthropic's Claude Agent SDK, CoCounsel Legal can plan, reason, and execute across complex legal workflows rather than respond to isolated prompts. Every output remains grounded in verified, traceable legal authority and adheres to Thomson Reuters Fiduciary-Grade AI™ principles, providing the transparency, accountability, and confidence professionals demand.

"What sets the new CoCounsel Legal apart is that it doesn't just answer questions; it builds toward real work product," said Jennifer Eng, Shareholder, Commercial Litigation, Polsinelli. "Its grounding in Westlaw gives me confidence that the research is authoritative, while the agentic workflow carries that analysis through reasoning, drafting, and verification. As a litigator, I need speed without sacrificing precision, and this is the first tool that gets me from a complex legal question to a defensible draft, faster and with real confidence, which is not a small shift."

Since introducing early access to customers, Thomson Reuters has worked closely with legal professionals to refine the experience and develop new capabilities that address the most critical moments in the legal workflow.

Through the evolution of CoCounsel Legal, Thomson Reuters committed to building partnerships with customers, inviting them to join the beta and early access programs to gather feedback. As the product developed, Thomson Reuters introduced several new agentic capabilities designed to help legal professionals accelerate high-value work.

New Capabilities for Legal Work

Westlaw Brief Builder

The newest addition to CoCounsel Legal, Westlaw Brief Builder helps litigators move from research and issue analysis to first-draft brief creation while validating authority along the way. Powered by Westlaw Deep Research, KeyCite, and Practical Law, it proposes relevant facts, arguments, and supports authority while keeping lawyers firmly in control of strategy, legal theory, and final decisions.

Workspaces

Workspaces provide a dedicated environment for every matter, combining firm and legal department documents, precedents, and institutional knowledge to inform analysis from the outset. Context is preserved across matters and teams, helping legal professionals build on prior work instead of starting from scratch.

Drafting

The Drafting Agent in CoCounsel for Word enables legal professionals to draft, edit, and review agreements using natural language instructions directly within Microsoft Word, leveraging Practical Law content alongside an organization's own documents and playbooks.

Tabular Analysis

Designed for high-volume document review, Tabular Analysis allows attorneys to review up to 10,000 documents and ask up to 100 questions, with results returned in a dynamic, filterable table. Powered by Thomson, Thomson Reuters proprietary legal-focused large language model, it is optimized for complex legal analysis where domain-specific AI can outperform general-purpose models.

Deep Research Verify

Deep Research Verify checks whether cited Westlaw and Practical Law authority supports specific legal assertions, helping legal professionals strengthen confidence in AI-assisted work product.

"A brief is only as strong as the thinking behind it," said Emily Colbert, SVP, CoCounsel Litigation at Thomson Reuters. "Westlaw Brief Builder was built to support that thinking, not replace it, by transforming how litigators research, test, and refine their arguments at every stage, from spotting the right issues to backing them with authoritative law. The goal is not to simply generate a document faster; it's to help lawyers build a stronger, more defensible case they're confident standing behind in court."

Partnerships

Thomson Reuters is continuing its work with Anthropic, including the launch of an expanded CoCounsel Legal MCP with Claude in August. The integration enables legal professionals to access CoCounsel Legal directly from Claude and receive cited, traceable work product grounded in Westlaw, Practical Law, and their organization's own knowledge.

Thomson Reuters and AWS are also expanding their collaboration, with a forthcoming MCP connection designed to extend CoCounsel Legal's trusted, verifiable legal AI into Amazon Quick, AWS's AI companion built for work, as well as other AWS offerings.

Beginning in October, an integration with Reveal will allow litigation teams to bring reviewed evidence directly from Reveal into CoCounsel Legal for research, analysis, and drafting, eliminating the need to manually export and re-upload documents.

Availability

One million professionals across 107 countries and territories now rely on CoCounsel, reflecting the industry's shift from AI experimentation to AI embedded directly into professional workflows where trust, sourcing, and accountability matter most.

The new CoCounsel Legal experience is available now in the United States. Availability in Canada, the United Kingdom, and Australia is expected later this year.

With the next generation of CoCounsel Legal, Thomson Reuters is helping define the future of legal work, combining trusted authority, agentic intelligence, and professional expertise to enable legal teams to work with greater confidence, efficiency, and impact. As the industry moves beyond AI experimentation, CoCounsel Legal delivers a trusted path from legal question to defensible work product.

For more information, visit thomsonreuters.com/cocounsel.

Thomson Reuters

Thomson Reuters (Nasdaq/TSX: TRI) informs the way forward by bringing together the trusted content and technology that people and organizations need to make the right decisions. The company serves professionals across legal, tax, audit, accounting, compliance, government, and media. Its products combine highly specialized software and insights to empower professionals with the data, intelligence, and solutions needed to make informed decisions, and to help institutions in their pursuit of justice, truth, and transparency. Reuters, part of Thomson Reuters, is a world leading provider of trusted journalism and news. For more information, visit thomsonreuters.com.

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