CoCounsel

CoCounsel, developed by Casetext and now a flagship offering within the Thomson Reuters ecosystem, represents the apex of legal-specific generative AI as of 2026. Built on a proprietary architecture that integrates fine-tuned Large Language Models with the massive primary law databases of Westlaw and Practical Law, CoCounsel is designed to perform complex legal tasks with a zero-retention data policy. Unlike general-purpose LLMs, CoCounsel employs a 'search-then-generate' RAG (Retrieval-Augmented Generation) pipeline specifically optimized for the Bluebook citation standard and jurisdictional nuances. Its 2026 market position is defined by its transition from a simple chatbot to a comprehensive workflow orchestrator, capable of managing multi-stage litigation tasks such as deposition preparation and comprehensive document review at scale. The platform's technical core is engineered to eliminate hallucinations by grounding every response in verified legal authorities, providing practitioners with a hyper-reliable digital associate that handles the heavy lifting of discovery, research, and drafting while maintaining the highest tiers of SOC2 and GDPR compliance.