Vienna vs CoCounsel
Last reviewed: October 9, 2026
Vienna
Vienna is a legal operations AI agent that works inside Nougat, a legal workspace. You email Vienna at vienna@nougat.law or message her in Slack or Microsoft Teams, and she does the work across your firm's email, calendar, documents, practice management, and court dockets, then reports back in the same thread.
CoCounsel
CoCounsel is Thomson Reuters' generative AI assistant for legal professionals. Thomson Reuters describes it as working with Westlaw and Practical Law content for research, document review, and drafting.
Side by side
| Area | Vienna | CoCounsel |
|---|---|---|
| How you work with it | An agent you delegate matter work to by email, Slack, or Teams. She works across your connected tools and replies in the same thread. | An AI assistant you open and prompt, connected to Thomson Reuters products. |
| Legal research | Finds and summarizes authorities with links to the source opinions, and checks case-law quotes against the original opinion text before showing them. | Research grounded in Westlaw content, for teams that already subscribe to Westlaw. |
| Citation checking | Checks every cite in a draft, by email or in the public Cite Checker, to confirm each authority exists and its quotes match. | See Thomson Reuters for current citation features. |
| Drafting | Drafts complaints, motions, client correspondence, and engagement letters inside the matter, in your firm's voice. | Drafting and document review tasks inside the CoCounsel interface. |
| Dockets and deadlines | Connects to PACER for federal dockets, pulls deadlines from filings and correspondence, and keeps them on the matter calendar. | Not positioned as a docket-monitoring or matter-operations tool. |
| Where it works | Gmail, Outlook and Microsoft 365, Slack, Teams, Zoom, Google Drive, OneDrive, Dropbox, iManage, Clio, PACER, and firm single sign-on. | Thomson Reuters products, including Westlaw and Practical Law. |
| Built for | Litigators, small and mid-size firms, legal teams, and businesses, with workspaces for civil litigation, criminal defense, startups and VC, and in-house teams. | Legal professionals and firms using Thomson Reuters research products. |
CoCounsel details are summarized from Thomson Reuters's public descriptions. Check Thomson Reuters for current features and pricing.
Choose CoCounsel if
You live in Westlaw and want an AI assistant grounded in Thomson Reuters' research content.
Choose Vienna if
You want an agent that runs matter work from your inbox: reading filings and correspondence, tracking federal dockets and deadlines, drafting in the matter, and checking cites, across the tools your firm already uses.
Questions
Can I use Vienna and CoCounsel together?
Yes. They do different jobs. CoCounsel is a research and drafting assistant tied to Thomson Reuters content; Vienna handles matter operations across your email, calendar, documents, practice management, and dockets.
Is Vienna a law firm?
No. Vienna is legal software made by Vienna Legal Technology Corporation. Nothing Vienna produces is legal advice, and a qualified person should review her work before it is filed, sent, or relied on.
What is the difference between Nougat and Vienna?
Nougat is the legal workspace that holds your matters, documents, dockets, and connections. Vienna is the AI agent who works in it. You give Vienna work by email, Slack, or Teams.