BYO (Custom MCP)

Overview

BYO (Custom MCP) extends the Connector Library by letting your firm add its own MCP servers alongside Harvey’s curated connectors. If your firm relies on a proprietary knowledge management system, a niche practice-area tool, or a third-party tool that isn’t currently available in Harvey’s Connector Library, you can now bring it into Harvey as a custom MCP server.

Key Features

• Self-serve setup: Register a custom MCP server directly from the Connector Library, the same settings flow you already use for curated connectors.
• Granular access control: Grant access to specific users and choose whether tools are allowed, blocked, or require a prompt each time the assistant tries to use them.
• Security attestation: Confirm your server meets your own security standards before the connection goes live.

Add and Manage a Custom MCP Server (Admins)

Add a Custom MCP Server

1. Go to Command Center → Configurations → Connectors.
2. Select Custom MCP at the top-right.
3. Review and accept the terms and conditions in the dialog that appears.
4. Enter the name and the server URL for the tool you want to connect.
5. [Optional] Configure scopes and OAuth credentials if your specific MCP server requires a client ID and client secret to authenticate.
6. Select Add MCP, then grant access on the following authentication page.
7. Set permissions for which specific users and groups can use the custom MCP server, then designate which MCP tools Harvey can access. You can set the following permissions for each tool:

   1. Always allow: The Harvey agent can call and use the tool without asking the user.
   2. Ask user: The Harvey agent prompts the user in the thread when it tries to access the tool.
   3. Block: The Harvey agent is not allowed to use the tool.
8. Select Done to complete setup.

Your new custom server appears at the bottom of the Connectors page with a badge indicating it’s a custom connector.

Manage an Existing Custom MCP Server

1. Go to Command Center → Configurations → Connectors.
2. Find your existing custom MCP server and select Manage.
3. Select the user count to adjust user and role permissions, or go to Configuration to manage Harvey’s access to individual MCP tools.

How to Use BYO (Custom MCP)

Once an admin adds a custom MCP server and grants you permission to use it, you can use the connected tool the same way you use any other knowledge source.

1. Start a new thread in Harvey, then select the Sources button.
2. Find or search for your custom MCP tool in the list, then toggle it on.
3. Run your query. Harvey will use the custom MCP tool to accomplish its task.

You can also go to Personal Settings → Connectors to customize the tool permissions for the custom MCP server for when you use it in Harvey.

Security, Data, and Privacy

• Your firm is responsible for the security of any custom MCP server you connect. Harvey’s security team does not review or manage custom servers the way it does for Harvey-approved connectors. For more information, see the Bring Your Own MCP Server section of our Connecting MCP Servers to Harvey article.

FAQs

Q: Does Harvey need to build anything for my firm to use BYO (Custom MCP)?
No. As long as the tool is MCP-compatible, your firm can connect it entirely on your own. Harvey’s engineering team is not involved in setting up or maintaining custom MCP connections.

Q: Who controls access to a custom MCP connection?
Your firm’s admin controls which tools are connected and which users or groups in the workspace have access, the same governance model used for Harvey’s curated connectors.

Q: What kinds of tools can I connect with BYO (Custom MCP)?
Any MCP-compatible tool, including proprietary knowledge management systems, niche practice-area tools, or a third-party tool that isn’t currently available in Harvey’s Connector Library.