MCP Connector
CoCounsel Legal
AI-powered deep legal research from Thomson Reuters
What is the CoCounsel Legal MCP Connector?
The CoCounsel Legal MCP Connector is a Thomson Reuters MCP server that brings Westlaw deep legal research into Claude conversations. Attorneys can launch a jurisdiction-aware research run, monitor agent progress, retrieve fully cited reports with Westlaw source links, and ask follow-up questions against the same conversation. Coverage spans US federal and state law with multi-jurisdictional analysis. Reports include statutes, case law, secondary sources, and Practical Law commentary, each linked back to authoritative Thomson Reuters legal content for verification by the user.
What you can do with it
- Run jurisdiction-aware deep research on a legal question and receive a cited memo.
- Retrieve a completed deep research report later in the same Claude conversation.
- Ask a follow-up question against an existing deep research conversation without restarting research.
- Compare treatment of an issue across up to three US jurisdictions in a single research run.
Set up in Claude Desktop
- Open Claude Desktop and sign in to your Claude account.
- Go to Settings → Connectors.
- Search for CoCounsel Legal and click Connect.
- When the Thomson Reuters sign-in window opens, complete the sign-in and authorize the connector. You only need to do this once.
- CoCounsel Legal will now appear in the connectors menu inside your Claude conversations and is ready to use.
Once connected, just describe the legal research you want done in plain English. Claude will pick the right CoCounsel Legal tool for you.
Available tools
Claude calls these four tools on your behalf. You do not need to invoke them by name — just describe the research you want.
| Tool | What it does | Example use |
|---|---|---|
| Start Deep Legal Researchstart_deep_research | Start a new deep legal research session for the given query with optional US jurisdiction targeting. Returns a conversation reference used to poll status and retrieve the final report. | "Research how California courts have treated non-compete agreements for executive employees since 2020." |
| Check Deep Research Statuscheck_deep_research_status | Check the progress of an ongoing deep legal research session. Returns the current research plan and percent complete. | "Is the research done yet?" |
| Get Deep Research Reportget_deep_research_report | Retrieve the final cited report for a completed deep legal research session. Returns markdown answer text with Westlaw citation links and citation metrics. | "Show me the full report with the citations." |
| Follow Up on Deep Researchfollow_up_deep_research | Start a follow-up legal research question against an existing completed deep research conversation. Use to clarify or extend an earlier research run on the same topic. | "How does Texas law differ on the same question?" |
Example prompts
These three prompts demonstrate the typical flow: start research, retrieve the cited report, then ask a follow-up — all in one Claude conversation.
Research how California courts have treated non-compete agreements for executive employees since 2020. Give me a concise memo.
What Claude does: Starts a concise deep research run scoped to California, tracks progress, and returns a cited memo summarizing recent California treatment of executive non-competes.
I asked you to research California non-competes earlier. Can you now retrieve the full report?
What Claude does: Retrieves the completed report for the saved conversation, rendering the markdown body with Westlaw citation links intact and appending citation metrics.
Follow up on that research: how does Texas law differ on executive non-competes for the same period?
What Claude does: Starts a follow-up research run against the same conversation, polls status, and returns the follow-up report comparing Texas treatment of executive non-competes to the prior California analysis.
What it's good for — and what it isn't
Optimized for
- Initiating a legal research project with jurisdiction targeting (up to three US jurisdictions).
- Gaining a thorough, nuanced understanding of a legal issue with arguments and counterarguments.
- Synthesizing case law, statutes, regulations, and administrative decisions into a cohesive narrative.
- Choosing between concise (several minutes) and expanded (20+ minute) research depths.
- Asking follow-up questions in the same conversation without restarting research.
Not optimized for
- Retrieving a specific document. Use the traditional search box on Westlaw.
- Getting an exhaustive list of results. Use Boolean search or Precision Research on Westlaw.
- Reviewing every case discussing a specific fact pattern. Use Precision Research on Westlaw.
- Identifying potential causes of action. Use Claims Explorer on Westlaw.
- Comparing how each jurisdiction treats an issue. Use AI Jurisdictional Surveys on Westlaw.
- Litigation analytics or judge, court, attorney, and firm profiles. Use Litigation Analytics on Westlaw.
- Drafting documents or executing tasks on your behalf. Use CoCounsel.
- Searching for non-US law. Use the country-specific version of Westlaw (UK, Canada, or Westlaw International).
Privacy and citations
Thomson Reuters legal research data accessed through this connector is proprietary and subject to licensing restrictions. Reports may include markdown citation links back to authoritative Thomson Reuters sources such as westlaw.com and 1.next.westlaw.com so you can verify each citation in Westlaw.
Do not redistribute connector responses outside your current Claude session in ways that would violate your CoCounsel Legal licensing terms. The full privacy policy describes what is collected, how it is used and stored, retention, and how to contact the owner.
Support
Support is provided by the Thomson Reuters CoCounsel support team. If a tool reports an error or a research run fails, the message Claude shows you will indicate whether to retry, sign in again, or contact support.
Email cocounselsupport@tr.com for help with access, entitlements, or connector issues.
Frequently asked questions
What subscription do I need to use this?
You need a CoCounsel Legal subscription with the MCP connector turned on for your account. Reach out to cocounselsupport@tr.com with questions about access or entitlements.
How long does a research run take?
A concise report typically takes several minutes. An expanded report runs deeper analysis across more sources and often takes 20 minutes or more. Claude will tell you when to expect results and can check progress along the way.
Can I ask follow-up questions on the same research?
Yes. Once a research run completes, you can ask follow-ups in the same Claude conversation. Claude will use the follow-up tool against the existing conversation so you do not have to restart the research from scratch.