Thomson Reuters and Anthropic Expand Partnership to Connect Claude with CoCounsel Legal

New MCP integration brings CoCounsel Legal into Claude workflows to help legal work meet fiduciary-grade standards

TORONTO, May 12, 2026 /PRNewswire/ -- Thomson Reuters (TSX/Nasdaq: TRI), a global content and technology company, today announced a new Model Context Protocol (MCP) integration with Anthropic that connects Claude directly to CoCounsel Legal. Legal professionals can now move seamlessly between general-purpose AI and citation-grounded legal work, from either working environment. As MCP integrations proliferate across the legal market, Thomson Reuters is bringing something distinct: fiduciary-grade AI, our standard for accuracy, accountability and trust.

Adoption of legal AI continues to accelerate, alongside a widening gap between the speed and convenience of general-purpose AI and the accuracy and verifiability of professional-grade systems. CoCounsel Legal is designed to meet the standards of legal professionals, where almost right is not good enough. Now Thomson Reuters is bringing that industry standard to professionals working in Claude, making it possible to seamlessly move work between Claude and CoCounsel Legal's comprehensive, fiduciary-grade workflows. 

"Thomson Reuters is building CoCounsel Legal to be the fiduciary-grade system at the center of how legal work gets done, connected to the tools lawyers use and built to the standard their work demands," said David Wong, Chief Product Officer, Thomson Reuters. "Today's integration with Claude is one example of how those connections will continue to grow as we move toward general availability for the next generation of CoCounsel Legal expected this summer."

The Standard Follows the Work
CoCounsel Legal is already trusted by legal professionals across law firms, corporate legal departments, and government agencies for the work that matters most. It reasons across 1.9 billion Westlaw and Practical Law documents, 1.4 billion KeyCite validity signals, and a patent-pending citation ledger that makes every source traceable in one click. That content is not a database to be searched. It is the foundation on which CoCounsel Legal reasons, plans, and delivers. That is the difference between AI that retrieves information and AI that helps complete professional work.

Built with Anthropic for What Comes Next
The next generation of CoCounsel Legal is rebuilt on Anthropic's Claude Agent SDK and marks a fundamental shift to a system that plans, selects tools, retrieves authoritative content, and adapts mid-workflow. Lawyers will be able to describe a matter in plain language and have CoCounsel Legal pursue the right inquiry, draft with citations, and include validated references in the fiduciary-grade work product.

"Our work with Thomson Reuters reflects a deeper strategic partnership to deliver AI that can operate in high-stakes professional environments," said Scott White, Head of Product, Enterprise at Anthropic. "Integrating Claude with CoCounsel Legal brings together leading AI with trusted legal content and workflows, enabling users to move from exploration to execution with confidence."

"Legal professionals deserve AI they can trust with their most important work. In professional environments, trust in AI is a property of the system itself, built into the architecture and verifiable at every step," said Joel Hron, Chief Technology Officer, Thomson Reuters. "We are actively building integrations that connect general-purpose AI to professional environments, ensuring that wherever lawyers are working, the full power of CoCounsel Legal is available to them. Today's integration is the first place lawyers will experience that."

What 175 Years Makes Possible
Thomson Reuters brings to this partnership capabilities that have taken 175 years to build: authoritative professional content across Westlaw, Practical Law, and KeyCite, curated and validated by practicing attorneys and legal specialists. More than 2,600 experts shape how CoCounsel reasons, ensuring outputs reflect the standards of real professional work. Customer data is not used to train third-party models and is not shared beyond a customer's own environment. In professions where confidentiality is both a legal and ethical obligation, that commitment is a baseline requirement. Today, one million professionals across 107 countries and territories use CoCounsel, Thomson Reuters AI technology.

About Thomson Reuters
Thomson Reuters (TSX/Nasdaq: TRI) powers business-critical professions with trusted AI technology built for high-stakes work. The company serves professionals across legal, tax, audit, accounting, compliance, government, and media with products that combine highly specialized software, authoritative content, and deep domain expertise. Reuters, part of Thomson Reuters, is a world-leading provider of trusted journalism and news. For more information, visit thomsonreuters.com/cocounsel.

Media Contact
Ali Hughes, Director, AI and Innovation Communications
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SOURCE Thomson Reuters