The product that started the legal-AI category
CoCounsel didn't begin as a Thomson Reuters product. It launched on March 1, 2023, built by Casetext as the first AI legal assistant on GPT-4, with early exclusive access to the model before its public release, a genuine first-mover claim in a category that barely existed before it. Thomson Reuters bought Casetext for $650M in cash five months later, in August 2023, and has since rebuilt and relaunched CoCounsel as its flagship legal-AI product, with a broader agentic relaunch announced in August 2025.
That origin story matters for how CoCounsel is positioned today: it carries the credibility of being first, plus three-plus years of production use most competing products, HAQQ included, haven't had the runway to accumulate. We'd rather say that plainly than pretend a track record doesn't count for something.
- “the first AI legal assistant built on GPT-4” , verificado el 2026-09-03
- “Thomson Reuters buys Casetext, an AI legal tech startup, for $650M in cash” , verificado el 2026-09-03



