Casetext is an AI-powered legal research and litigation support platform that was acquired by Thomson Reuters in 2023 for approximately 650 million dollars. The platform's flagship AI product, CoCounsel, is a legal AI assistant built on large language model technology that performs substantive legal work including legal research, document review, contract analysis, deposition preparation, and timeline creation. Founded in 2013 by Jake Heller and Pablo Arredondo in San Francisco, Casetext initially launched as a legal research database and evolved into one of the first companies to apply advanced AI to legal practice. CoCounsel can conduct comprehensive legal research by analyzing a legal question, identifying relevant jurisdictions and legal concepts, searching case law and statutes, and producing a research memo with citations and analysis. The platform's document review capabilities allow attorneys to upload large sets of documents and ask questions about their contents, with the AI identifying relevant information, key provisions, and potential issues across the entire document set. CoCounsel's contract analysis feature reviews agreements to identify risks, missing provisions, and deviations from standard terms. The deposition preparation tool generates potential deposition questions based on case documents, while the timeline feature extracts and organizes chronological events from case materials. Following the Thomson Reuters acquisition, CoCounsel technology has been integrated into Westlaw, Thomson Reuters' flagship legal research platform, as CoCounsel on Westlaw, bringing AI-powered research assistance to Westlaw's extensive user base. The platform maintains robust security practices appropriate for handling confidential legal materials. Casetext offers tiered pricing for its standalone platform, with individual plans starting at approximately 250 dollars per month and firm-wide enterprise plans available with custom pricing. Access to CoCounsel features through Westlaw is included in certain Westlaw subscription tiers.

AI 助手

CoCounsel 作为一款 AI 法律助手，处理耗时的法律任务，包括全面的研究、文件审查、证词准备和合同分析。律师以对话方式与 CoCounsel 互动，将实质性法律工作委托给 AI，并获得结构化交付成果，这些成果传统上需要律师助理花费数小时的工作。

AI 文档分析

CoCounsel 的文件审查功能使律师能够上传大型文件集合，并使用自然语言问题查询其内容。AI 分析合同、案件文件、发现材料和其他法律文件，在几分钟内识别相关信息、关键条款、潜在风险和数百或数千页中的事实细节。

AI 法律工具

Casetext CoCounsel 是现有最全面的 AI 法律研究平台之一，为法律专业人士提供 AI 驱动的判例法研究、文件审查、合同分析、证词准备和时间轴创建。现由 Thomson Reuters 所有并整合到 Westlaw 中，它将先进的语言模型技术与最大的法律数据库之一结合在一起，提供实质性的法律工作成果。

AI 搜索引擎

Casetext 提供超越传统基于关键词的法律研究的 AI 增强型法律搜索功能。其搜索技术理解法律概念，识别跨司法管辖区的相关判例法和法规，并为给定的法律问题呈现最相关的权威资源，与传统搜索方法相比显著提高了法律研究的准确性和效率。

AI 写作工具

Casetext CoCounsel 通过生成带有适当引证的研究备忘录、起草合同条款和制作结构化法律分析来协助法律写作。其输出包括判例法引文、法规参考和推理分析，律师可以将这些作为诉状、备忘录和其他法律工作成果的基础。