Home › How-To › Connecting MCP Servers

Connecting MCP Servers

Set up Model Context Protocol connections via HTTP, stdio, and SSE for external tool discovery

Overview

The Model Context Protocol (MCP) enables OpenRails to discover and use tools provided by external servers. MCP uses a standard open protocol for communication and supports three transport modes: HTTP, stdio, and Server-Sent Events (SSE). Connected MCP servers expose tools that agents can invoke during execution.

Transport Modes

Mode Description Best For
HTTP Standard HTTP POST requests to a remote MCP server endpoint Remote servers, cloud-hosted tools, microservices
stdio Communication via standard input/output with a local process Local tools, CLI-based integrations, development
SSE Server-Sent Events for streaming responses from MCP servers Long-running tools, streaming results, real-time data

Connect an MCP Server

Navigate to MCP Servers

From the sidebar, go to Tools > MCP Servers to view existing connections.

Click "Add MCP Server"

Click Add MCP Server to open the connection configuration form.

Select Transport Mode

Choose the transport mode based on how your MCP server is deployed:

  • HTTP — Enter the server URL (e.g., https://mcp.example.com/rpc)
  • stdio — Enter the command to start the local process (e.g., node /path/to/server.js)
  • SSE — Enter the SSE endpoint URL

Configure Authentication

If the MCP server requires authentication, provide the necessary credentials (API key, bearer token, or client certificate).

Discover Tools

Click Discover Tools to query the server for available tools. OpenRails will display all available tools with their schemas.

Run Health Check

Click Health Check to verify the connection is stable and the server is responding correctly.

Save Connection

Click Save to store the MCP server connection. Discovered tools are now available in the agent tool catalog.

Approval and Clarification Workflows

MCP supports approval and clarification workflows for sensitive tool invocations:

Tip: Use the health check feature regularly to monitor MCP server availability. Set up dashboard notifications for connection failures so you can respond quickly.
Important: MCP tools from external servers execute code outside your control. Review tool schemas carefully before granting agents access, and use HITL gates for any tools that modify data.

Next Steps