MCP Connector
CoCounsel Legal
Thomson Reuters' AI for legal professionals, in Claude
What is the CoCounsel Legal MCP Connector?
The CoCounsel Legal MCP Connector brings the CoCounsel agent into Claude. CoCounsel is Thomson Reuters' AI assistant for legal professionals, designed to work at the level of a senior associate, with Westlaw and Practical Law content natively embedded in how it reasons.
Through the connector, Claude hands legal work off to CoCounsel and streams back its results — drawing on any of its capabilities (research, drafting, review, summarization, and more) without you having to pick between them.
Examples of what you can do with it today
- Upload contracts, briefs, or case files and ask CoCounsel to review, summarize, compare, or extract key terms.
- Run deep legal research with jurisdiction targeting across up to three US jurisdictions.
- Draft correspondence, memos, or sections of legal documents grounded in Westlaw and Practical Law.
- Build chronologies, compare document versions, or pull structured data from a document set.
- Ask follow-up questions in the same conversation — CoCounsel keeps the context.
Set up in Claude Desktop
For Claude administrators — enable the connector (one-time)
If users do not see CoCounsel Legal in the connectors directory, a Claude administrator needs to add it for the organization first. This only needs to be done once.
- Sign in to Claude with an administrator account.
- Open Settings → Organization → Connectors (or the equivalent admin area for your plan).
- Add CoCounsel Legal from the connector directory and save.
- Confirm the connector is visible to the intended user groups.
Once enabled, users in your organization can follow the steps below to connect their own Thomson Reuters account. For the full org-level workflow, see Claude's guide to authorizing MCP connectors for your organization.
In Claude Desktop — connect your account as an end user
- 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 may be prompted to sign in again periodically to keep your session secure.
- CoCounsel Legal will now appear in the connectors menu inside your Claude conversations and is ready to use.
Once connected, describe the legal work you want done in plain English and explicitly mention CoCounsel in your request. If you are new to connectors in Claude, see Claude's help article on using connectors to extend Claude's capabilities.
CoCounsel Legal is available across your Claude.ai, Claude Desktop, and Cowork sessions, and can be invoked by the agent as part of longer task chains.
Available tools
For legal work, the connector deliberately exposes a single tool — Ask CoCounsel. Rather than splitting research, drafting, review, and the rest into separate endpoints, every legal request flows through this one tool, so the legal intelligence and skill orchestration stay on the CoCounsel side rather than being second-guessed by the host. The remaining tools are supporting plumbing — they start a session, upload and list files, and retrieve generated deliverables. Claude calls them on your behalf, you do not need to invoke them by name.
| Tool | What it does | Example use |
|---|---|---|
| Ask CoCounselTalk to CoCounsel | Routes your request and any attached files to the CoCounsel agent, which selects and runs the appropriate skill(s) and returns the result with citations where applicable. | "Using CoCounsel, prepare a research memo on the grounds under Florida state law to dismiss a complaint for breach of contract." |
| Upload File to CoCounselUpload a file | Opens a file-picker view in Claude chat so you can attach documents to your current CoCounsel session. | "Upload this contract to CoCounsel." |
| List CoCounsel FilesList uploaded files | Returns the files uploaded to the current chat to the host, so Claude knows which documents are available in the session. | "Which files are available in this CoCounsel session?" |
| Get CoCounsel DeliverableGet a deliverable | Returns a specific CoCounsel document artifact generated as part of a CoCounsel run. | "Get the memo CoCounsel generated for that research run." |
| Start CoCounsel ChatStart a session | Starts a new CoCounsel session. Runs automatically when CoCounsel is first called in a Claude chat; skipped if a session already exists. | Runs automatically — no direct user prompt. |
| Get CoCounsel TokenDisplay MCP App View | Used to display the MCP App view to end users. Not exposed to the model as a tool. | N/A |
As CoCounsel adds new skills, they become available through the same tool automatically — no reconnect or reinstall needed. If you don't see the new tools, refresh the connector tool list using the "Refresh tools list" option on the CoCounsel connector listing page.
Example prompts
These prompts show typical interactions across CoCounsel's skill set.
Upload three vendor agreements to CoCounsel.
Claude runs the Upload File tool and opens a picker so you can attach the three agreements to your CoCounsel session.
Now flag any clauses where the indemnity terms differ materially across these agreements.
What Claude does: Passes the documents and instructions to CoCounsel, which runs a review and returns a side-by-side comparison of the indemnity provisions.
With CoCounsel, research how California courts have treated non-compete agreements for executive employees since 2020. Give me a concise memo.
What Claude does: CoCounsel runs a research scoped to California and returns a cited memo. You can ask for an expanded report when you want deeper analysis.
Follow up on that research: how does Texas law differ on executive non-competes for the same period?
What Claude does: CoCounsel picks up the prior research context and returns a comparative analysis without restarting from scratch.
Privacy and citations
Use of the CoCounsel MCP is subject to the Thomson Reuters General Terms and Conditions, which prohibit the use of Thomson Reuters Content with another Professional AI Tool, either directly or via an interface such as an MCP.
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 and Practical Law so you can verify each citation at its source.
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@thomsonreuters.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 package subscription. Reach out to cocounselsupport@thomsonreuters.com with questions about access or entitlements.
Will more CoCounsel Legal capabilities be added to the connector?
Yes. CoCounsel Legal capabilities will be added to the same connector over time, you'll see new features become available without needing to reconnect or reinstall. If you don't see the new tools, refresh the connector tool list using the "Refresh tools list" option on the CoCounsel connector listing page.
How long does a CoCounsel agent run take?
It depends on the work. The waiting times are the same as the ones on the CoCounsel application on the web. Document review and shorter drafting tasks usually complete in a few minutes. A concise research run takes several minutes; an expanded research run can take 10 minutes or more.
How can I upload a file to CoCounsel?
Just ask Claude to upload a file to CoCounsel — for example, "Upload this to CoCounsel." Claude runs the Upload File tool, which opens a file-picker view right in the chat where you can attach your document. Once uploaded, the file is available to CoCounsel for the rest of that chat, so you can follow up with a request like "Using CoCounsel, summarize the key obligations in this contract." Uploading attaches the file to your current CoCounsel session, so a session needs to exist first. If you haven't used CoCounsel yet in this chat, just include CoCounsel in your request (or upload a file) and the session starts automatically. Note: Claude's native upload button (the paperclip in the message box) does not send files to CoCounsel — those attachments stay with Claude. To get a file to CoCounsel, always use the Upload File tool by asking Claude to upload it to CoCounsel.
Can I ask follow-up questions on the same topic?
Yes. CoCounsel keeps context within a Claude conversation, so you can iterate on a memo, refine a draft, or layer in new questions without starting over.