Thomson Reuters and AI company Anthropic have announced an expanded partnership, integrating the general-purpose AI assistant Claude directly into their professional legal AI system CoCounsel Legal through a new Model Context Protocol (MCP) integration. This means legal professionals can now seamlessly call upon CoCounsel Legal’s authoritative legal content and workflows from within Claude—without switching platforms or re-entering context—helping them work more efficiently while maintaining professional rigor.
CoCounsel Legal is Thomson Reuters’ fiduciary-grade AI system built specifically for the legal industry, with standards covering accuracy, accountability, and trustworthiness. The platform can reason across more than 1.9 billion Westlaw and Practical Law documents, 1.4 billion KeyCite validity signals, and relies on a patented citation ledger that allows users to trace legal citation sources with one click. David Wong, Chief Product Officer at Thomson Reuters, said: “We are building CoCounsel Legal as the core system for legal work and making it connectable to the tools lawyers use every day.” Chief Technology Officer Joel Hron added: “In a professional environment, trust in AI must be a property of the system itself—built into the architecture and verifiable at every step.”
