Thomson Reuters Launches CoCounsel Legal Beta With Agentic AI

Thomson Reuters has launched a beta version of CoCounsel Legal Reimagined on April 20, 2026, introducing a fully agentic AI platform built on Anthropic's Claude Agent SDK for legal professionals worldwide.

This launch marks a significant shift in legal AI from task-based tools to end-to-end workflow automation, arriving at a time when AI accuracy and citation reliability have become central concerns across the legal industry.

Platform Capabilities

The new platform allows users to complete legal tasks through a single conversation. Users describe what they need in plain language, and CoCounsel Legal automatically identifies the required skills and workflows, plans the necessary steps, and executes them without manual intervention.

Thomson Reuters describes this as a move from prompt-driven AI to fully agentic infrastructure. The system plans, selects tools, retrieves authoritative content, and adapts mid-workflow.

Ragunath Ramanathan, President of Legal Professionals at Thomson Reuters, stated: "The next generation of CoCounsel Legal is a unified agentic platform that plans, selects tools, retrieves authoritative content, and adapts mid-workflow just as a senior associate would, not a first-year waiting for the next instruction."

Trust and Accuracy

A central focus of the new platform is citation reliability and output verification. Thomson Reuters has introduced two patent-pending tools designed to address hallucination and sourcing concerns that have affected legal AI tools industry-wide.

The first is a citation ledger architecture, which creates a session-verifiable evidence trail ensuring the AI system can only cite content it actually retrieved. The second involves grounding and verification built directly into the product infrastructure, covering authoritative retrieval, explicit source handling, and verifiable citation flows.

Ramanathan described the approach as "fiduciary-grade AI," stating that "outputs grounded in authoritative content and customer context make verification part of the system's architecture rather than an afterthought."

Research Behind the Build

The development of CoCounsel Legal Reimagined was preceded by extensive research. Thomson Reuters spoke with over 500 legal professionals spanning law firms, corporate legal departments, and government roles.

The research identified more than 40 legal processes across 14 practice areas as strong opportunities for AI development. These ranged from drafting and legal research to patent application preparation and written discovery review.

In-depth interviews with 30 participants surfaced workflow pain points, including difficulty keeping up with legal updates and managing disjointed tools. One interviewee described their current process as "toggling between tabs, notes, PDFs," making it hard to see the bigger picture.

Over 100 Practical Law attorney editors participated in the development process, helping define correct outputs for each task type and setting benchmarks before any new capability reaches production.

Evaluation Framework

Thomson Reuters has built a dedicated evaluation framework that measures quality at each step of the AI workflow. Every new capability must demonstrate measurable improvement against attorney-defined benchmarks before release.

The framework evaluates not only final outputs but also the full reasoning chain that produced them. Tyler Alexander, Director of CoCounsel AI Reliability, summarized the approach: "This isn't build first, ask later. It's ask first, build second."

The beta program is currently open via a waitlist. Thomson Reuters plans to make the platform generally available later in 2026 and is documenting the build process publicly through monthly updates.

About Thomson Reuters

Thomson Reuters is a global content and technology company that provides professionals in the legal, tax, accounting, and media sectors with tools, information, and software. Its CoCounsel product serves over one million professionals across 107 countries and territories. The company is headquartered in Toronto, Canada.

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