On March 14, 2023, Casetext announced that its AI legal assistant CoCounsel was powered by OpenAI’s GPT-4, billing it as the first AI legal assistant of its kind. Casetext had been given early, exclusive access to GPT-4 before the model’s public release and had been building the product on it for months, with select clients from the Am Law 50 and large companies including Ford Motor Company testing it beforehand.
CoCounsel was designed to perform substantive legal tasks rather than just chat: searching a firm’s documents and case law, reviewing documents, drafting research memos, and analyzing contracts. The announcement also highlighted that GPT-4 had passed both the multiple-choice and written portions of the Uniform Bar Exam, a first for a large language model and a milestone Casetext used to argue the technology had reached professional-grade reliability. The company stressed data-privacy controls, saying client data was never used to train the underlying models.
Casetext was acquired by Thomson Reuters for 650 million dollars later in 2023, folding CoCounsel into the legal-research giant’s product line.
Why business readers should care: CoCounsel was the first commercially shipped GPT-4 product in a regulated profession, and it set the pattern - early model access plus domain-specific tooling and privacy guarantees - that defined the legal-AI market that followed.