Since Casetext was acquired by Thomson Reuters, its AI assistant has been folded into the Westlaw and Practical Law stack. 12 For US litigators with the budget, CoCounsel offers verified research grounded in primary case law. Standalone access has changed 11, though: mid-sized firms report that reaching CoCounsel usually means keeping an active, expensive core Westlaw subscription. 10 The result is meaningful recurring fees with limited room to customise internal templates, precedents, or non-English cases.

LexisNexis offers Lexis+ AI with its assistant, Protégé. Like CoCounsel, its strength is a vast library of proprietary treatises, guidance, and primary law 8, with reliable citations and risk-minimised answers. Commercially, it is an add-on tier to an existing contract 7, predictable for domestic frameworks, but a closed, vendor-controlled public cloud. There is no private-cloud install and no deep integration with a firm's own historical document databases.