Start MongoDB MCP Server as a Standalone Service

You can start the MCP Server as a standalone service, which allows the MCP Server to run independently from an AI client. To start the MCP Server as a standalone service, use the npx command.

Standalone Service Using Environment Variables

You can use npx to start the MCP Server and use environment variables. You must define the MCP Server environment variables in the operating system before running npx.

The following examples define MCP Server Unix environment variables to connect to an Atlas cluster:

export MDB_MCP_API_CLIENT_ID="<atlas-service-account-client-id>"
export MDB_MCP_API_CLIENT_SECRET="<atlas-service-account-client-secret>"
export MDB_MCP_CONNECTION_STRING="mongodb+srv://<user-name>:<password>@<cluster-name>.mongodb.net/<database-name>"

To use the example, consider these points:

Replace the option values with your connection information and other details.
To define environment variables for other operating systems, see Defining MCP Server Environment Variables in the Operating System.
To examine the list of MCP Server options, see MongoDB MCP Server Configuration Options.
To create an Atlas service account, see MongoDB MCP Server Prerequisites for Running Atlas Tools.

The following example uses the previous environment variables that have the connection information, and also sets additional command line options:

npx -y mongodb-mcp-server@latest --readOnly --indexCheck --loggers mcp stderr --logPath=<log-path>

Replace <log-path> with the directory path to store the log files.

Standalone Service Running as an HTTP Server

The default MCP Server transport protocol is stdio, which is suitable for integration with most MCP clients.

You can also use the HTTP transport protocol with the MCP Server. HTTP is useful if you want to interact with the MCP Server from a Web client or to configure the MCP Server to respond to requests on a specific port.

Note

HTTP transport is not recommended for production use without implementing authentication and security measures. Only use HTTP transport if you must use HTTP to interact with the MCP Server.

Security guidelines:

Implement authentication. For example, use an API gateway or a reverse proxy.
Use HTTPS/TLS encryption.
Deploy the MCP Server behind a firewall or in a private network.
Implement rate limiting.
Never expose connection credentials.

To view security recommendations, see MongoDB MCP Server Security and MongoDB MCP Server Security Best Practices.

To start the MCP Server with HTTP transport, use --transport http. For example:

npx -y mongodb-mcp-server@latest --transport http --readOnly

By default, the MCP Server responds to requests on http://127.0.0.1:3000 and only accepts local connections.

Client Connection URL

If you connect an MCP client to the HTTP server, the client's connection URL must include the /mcp endpoint path. For example:

http://127.0.0.1:3000/mcp

Remote Connections

To allow remote connections from other computers or containers, bind the server to all network interfaces using --httpHost=0.0.0.0, and the client can then connect from another computer using the server's IP address or hostname.

Warning

With Streamable HTTP, the MCP Server is bound to localhost (127.0.0.1) by default. This ensures the MCP Server only accepts connections that originate on the same computer.

Binding to 0.0.0.0 exposes the MCP Server to the entire local network, which allows other devices on the same network to potentially access the MCP Server. This is a security risk and could allow unauthorized access to your database context. If you must expose the MCP Server outside of localhost, implement strong security authentication.

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