Casetext
Casetext CoCounsel is a milestone product in the legal AI track. It was founded by Pablo Arredondo and Jake Heller in 2013. In March 2023, it launched the world's first GPT-4-based
Casetext CoCounsel — Legal AI research assistant, core of Westlaw ecosystem
Core parameters and statistics
| Parameters | Details |
|---|---|
| Date of establishment | 2013 (Casetext company); March 2023 (published by CoCounsel) |
| Founders | Pablo Arredondo, Jake Heller |
| Headquarters | San Francisco, USA |
| Acquirer | Thomson Reuters (August 2023, $650 million) |
| Core model | Based on GPT-4 special optimization |
| Core Functions | Legal research, contract drafting, deposition preparation, document review |
| Integrated Platform | Westlaw AI (part of Thomson Reuters) |
| Target users | Lawyers, legal assistants, corporate legal affairs |
| Pricing Model | Accessed via Westlaw Subscription (pricing not independently disclosed) |
| Database connection | Westlaw full legal database (cases, regulations, legal journals) |
The historical significance of CoCounsel is that it is the first commercial product to prove that GPT-4 can provide reliable output in real legal work scenarios, breaking the legal industry's general doubts about AI tools, and laying the foundation for market recognition for the subsequent explosion of the legal AI track (including the emergence of competitors such as Harvey).
User and market recognition
CoCounsel attracted widespread attention in the legal industry when it was released in March 2023. Many well-known law school professors and practicing lawyers confirmed in public reviews that its performance on legal research tasks is significantly better than using ChatGPT directly. Within months of launch, hundreds of law firms purchased CoCounsel subscriptions, making it one of the fastest-to-commercialize new products in legal tech history at the time.
Thomson Reuters' acquisition price of $650 million (a record funding and valuation since Casetext's inception) is the strongest market endorsement of the product's value. After the acquisition, CoCounsel technology was integrated into the Westlaw platform, which means that Westlaw’s hundreds of thousands of lawyer users around the world can directly access AI legal research capabilities through a familiar interface, significantly lowering the threshold for legal professionals to adopt AI tools.
Cost advantage
| Plan | Price | Key Benefits |
|---|---|---|
| Westlaw + CoCounsel | Included with Westlaw subscription, contact TR Sales | Direct access to CoCounsel AI capabilities through the Westlaw interface |
| CoCounsel Standalone | Contact Casetext Sales for a quote | CoCounsel access independent from Westlaw |
| Corporate Legal Edition | Customized Quotation | Batch Seats for Legal Departments of Large Enterprises |
The strategic value of integrating CoCounsel into Westlaw is that Westlaw is already the basic legal research subscription of most law firms, and CoCounsel is stacked as a value-added feature, reducing additional procurement friction for law firms. For paid Westlaw users, CoCounsel's functionality is potentially available at a low incremental cost, making the price/performance much better than purchasing a standalone AI legal research tool.
Main functions
- Legal Research: Based on natural language questions, intelligent search and analysis are performed in Westlaw's full legal database to generate research summaries with precise legal citations, compressing case studies that traditionally take hours to minutes.
- Contract Drafting: Based on specific business needs and legal requirements, generate drafts of specific types of contracts (NDA, service agreements, merger and acquisition agreements, etc.), with accompanying clause descriptions and common variant options for lawyers to choose from.
- Deposition Preparation: Analyze case materials, relevant precedents and the opponent's testimony, automatically generate question outlines and follow-up question suggestions for specific witnesses, and help lawyers prepare for trial cross-examination efficiently.
- Document Review: Review legal documents in batches, label and classify them according to specified key terms, risk standards or information categories, greatly improving the efficiency of document processing in the discovery stage.
- Contract Summary: Automatically extract and summarize key terms in the contract (validity period, payment terms, termination clauses, liability for compensation, etc.), and generate a structured summary for lawyers to quickly grasp the key points of the contract.
- Westlaw Database Integration: Deep connection to Westlaw, the world’s largest legal database, ensures that AI-generated legal research results are accompanied by verifiable and authentic legal sources, addressing the core concern of legal AI hallucinations.
- Multiple practice areas covered: Supports professional AI support in major legal practice areas such as corporate law, contract law, litigation, mergers and acquisitions, labor law, and intellectual property rights.
Model and version evolution
Continuous iterative updates, the latest version introduces performance optimization and new features. Historical version information can be viewed through the official release page. There is currently no complete public version evolution timeline.
Technical advantages
Legal-specific optimization of GPT-4: CoCounsel is not a simple encapsulation of the general GPT-4, but has been carefully engineered and fine-tuned for the specific formats, reasoning modes and citation requirements of legal tasks, making the model perform significantly better than general calls on special tasks such as legal research and contract analysis, reducing the risk of legal illusion (generating non-existent case references).
Verifiability Guarantee of Westlaw Database: The greatest technical value of integrating into Westlaw is that the legal research results generated by AI can be directly linked to the actual legal cases and original texts of regulations in the Westlaw database. Lawyers can verify the accuracy of AI citations with one click, fundamentally solving the core concern of "citation credibility" of legal AI tools - which is one of the biggest psychological barriers for legal professionals to adopt AI tools.
In-depth understanding of legal workflow: Founder Pablo Arredondo's lawyer practice background enables CoCounsel to deeply understand the actual workflow of lawyers from the product design level. The three major functions of testimony preparation, document review and contract drafting are designed for the most time-consuming specific tasks in lawyers' daily work, rather than providing generalized "question and answer" capabilities.
How to use
- Web client: You can use it by visiting the official website and registering an account. Most functions do not require installation.
- API access: Provides RESTful API, developers can obtain the API Key and integrate it into their own applications.
Product Pricing
After CoCounsel was acquired by Thomson Reuters, access is mainly provided through the Westlaw subscription system, and pricing is integrated into Thomson Reuters' legal information product matrix:
- Westlaw Precision (with CoCounsel): Get a quote for total Westlaw + AI capabilities through Thomson Reuters Sales, customized by law firm size and seats used.
- Stand-alone CoCounsel Access: For non-Westlaw users, CoCounsel access may be purchased separately via casetext.com, contact sales for pricing.
- Corporate Legal Plan: Larger corporate in-house legal teams can get specialized quotes, which often include more seats and additional document processing.
- Since it has been integrated into the Thomson Reuters product system, CoCounsel's independent pricing strategy continues to be adjusted, based on the latest information and sales quotations on the official website.
Application scenarios
1. Accelerated case study and precedent retrieval Litigators use CoCounsel during case preparation to quickly retrieve and analyze large volumes of relevant precedents, compressing case law research that traditionally takes hours into 20-30 minutes, while ensuring the authenticity of all references through a Westlaw database connection.
2. Contract review and risk identification When corporate legal personnel review supplier contracts or merger and acquisition documents, they use CoCounsel's contract summary and risk identification functions to quickly grasp the key terms and potential issues of the contract, and focus their limited legal staff time on high-value judgment work.
3. Trial testimony preparation Litigation lawyers use CoCounsel's testimony preparation function to automatically generate a framework of questioning questions for specific witnesses based on analysis of case materials and similar case testimony, helping lawyers fully cover possible testimonial directions before trial.
4. Discovery file batch processing During the discovery phase of U.S. litigation, the legal team faced thousands of documents that needed to be reviewed and used CoCounsel to batch annotate and classify them by key criteria to identify privileged documents, relevant documents and important evidence, significantly reducing the processing cost of large discovery projects.
5. Quick introduction to new legal fields When lawyers need to deal with legal issues in non-specialized practice areas, they use CoCounsel to quickly establish an understanding of the basic legal framework in the field, generate overview research reports, and help lawyers establish the necessary field knowledge base before communicating with clients.
Applicable people
- Existing Westlaw subscribers (law firms and corporate legal affairs): Access CoCounsel's core beneficiary groups through the Westlaw platform, and can obtain AI-assisted capabilities in a familiar work environment with zero migration cost.
- Litigation Attorneys and Research Specialists: Legal research and document review are CoCounsel's most mature functional scenarios and are highly consistent with litigation workflows.
- In-house Counsel: Contract management and compliance research are the core work of corporate counsel. These two functions of CoCounsel provide a leverage effect for small legal teams.
- Law students and legal assistants: Can be used for legal research training and homework assistance to quickly understand the case law framework in a certain field (but academic use must comply with the school's AI usage policy).
- Unsuitable Scenarios: Non-common law (civil law) legal practices (Westlaw database is mainly based on the British and American legal systems, with limited support for Chinese and European legal systems); users who need a real-time independent SaaS platform that does not rely on the Westlaw ecosystem (Harvey may be a more suitable alternative); very small law firms or individual lawyers (the Westlaw subscription fee itself is a fixed cost).
Summary and Outlook
Casetext CoCounsel has established market awareness through the first-mover advantage of "the first GPT-4 legal AI assistant" and achieved deep integration with the industry's largest legal database at the fastest speed through the Thomson Reuters acquisition - a strategic advantage that any independent legal AI startup will be difficult to replicate in the short term.
Current challenges: Integration into Westlaw is a major opportunity, but it also means that control of independent brands and product roadmaps is transferred to large enterprises, and the speed of product innovation may be affected by the pace of the parent company; the high threshold for Westlaw subscriptions limits the accessibility of products to small and medium-sized law firms; the rapid growth of independent AI legal platforms such as Harvey creates direct competition in the high-end law firm market.
Follow-up focus: Actual user experience and adoption data after the integration of Westlaw AI; international expansion into non-Common law legal markets; further integration with other Thomson Reuters legal products (Practical Law, Elite); and the evolution of the Casetext brand's positioning in the Thomson Reuters product matrix as the AI legal tool market matures.
Version evolution of Casetext
| Milestone | Time | Description |
|---|---|---|
| Founded by Casetext | 2013 | Legal annotation and research tools, building the foundation of legal databases |
| CARA (Early AI Research) | 2016-2022 | Early AI legal research tool, using machine learning to assist case retrieval |
| CoCounsel GPT-4 released | 2023-03 | The world’s first GPT-4 legal AI assistant, a legal AI milestone |
| Thomson Reuters Acquisition | 2023-08 | $650 million acquisition, one of the largest acquisitions in legal technology |
| Westlaw AI integration | ~2024-06 | CoCounsel is fully integrated into the Westlaw AI platform |
How to use Casetext
| Entrance | Description |
|---|---|
| Westlaw interface | Directly call the CoCounsel AI assistant function in the Westlaw search interface |
| Casetext standalone portal | Access standalone CoCounsel workbench via casetext.com |
| Task Selection | Select the specific task type (research/drafting/review) in the CoCounsel interface |
| Document upload | Upload contracts or documents that need to be analyzed, and AI will automatically summarize and identify issues |
Typical steps (lawyer legal research tasks):
- Log in through your Westlaw subscription account and access the CoCounsel AI function module on the main interface.
- Describe a legal research question in natural language (e.g. "What are the conditions for enforcing employee non-compete agreements in California?").
- CoCounsel searches the Westlaw database for relevant cases and statutes and generates research summaries with citations.
- Lawyers review the abstract and verify accuracy by linking to the original legal document.
- If you need to draft relevant contract clauses, switch to the "Contract Drafting" mode and generate a draft clause based on the research results.
- Use AI output as a starting point for research and combine it with professional judgment to complete the final legal opinion or document.
Version Info
- CoCounsel integrated into Westlaw AI platform ：CoCounsel's core technology is fully integrated into the Thomson Reuters Westlaw AI platform, becoming an AI legal research assistant that Westlaw users can directly call; a new deep connection with the Westlaw database is added to support AI research based on real-time legal databases; the legal document drafting template library is expanded to cover more practice areas.
- CoCounsel GPT-4 version released ：Casetext launches CoCounsel, the world's first GPT-4-based AI legal assistant, which supports the four core legal workflows of legal research, contract drafting, testimony preparation and document review; with GPT-4 calls optimized for legal scenarios as the core technology, it quickly caused a sensation in the legal industry after its release and became a pioneer product in the commercialization of AI legal tools.
- Thomson Reuters $650 million acquisition ：Thomson Reuters acquired Casetext for US$650 million, setting one of the largest legal technology acquisition records at the time. After the acquisition, CoCounsel began to integrate with the Westlaw platform and maintain independent operations in parallel. The acquisition marked the traditional legal information giant's strategic recognition of AI-native legal tools, accelerating Westlaw's AI transformation.
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