Get Started with Horizon3-Hosted MCP Server¶

Before you can authenticate and use the NodeZero MCP Server, you must configure it for use in your IDE or AI client.

Prerequisites¶

• An IDE or AI client that supports streamable HTTP and OAuth 2.1 (e.g., Visual Studio Code, Cursor, Windsurf).
• Node.js v18+ installed to run the local MCP proxy mcp-remote.
• A modern browser for completing the OAuth login.

Set Up Visual Studio Code with GitHub CoPilot¶

To set up the Horizon3-hosted MCP Server in Visual Studio Code, configure it for MCP Server:

1. Open the command palette in VS Code.
2. Click Show and Run Commands.
3. Run the command MCP: Add Server.
4. Select HTTP (HTTP or Server-Sent Events) as the type.
5. Enter the server URL:
   • US: https://mcp.horizon3ai.com/mcp
   • EU: https://mcp.horizon3ai.eu/mcp
   • AU: https://mcp.horizon3ai.au/mcp
   • FedRAMP High: https://mcp.gov-horizon3ai.com/mcp

6. Provide a name for the server.

   Visual Studio Code creates an mcp.json file – or adds to it, if it already exists – with the information you just entered. This example uses horizon3-mcp-server and the US server URL:

       # Visual Studio Code creates an `mcp.json` file (or adds to it if it already exists) with the information you just entered
           {
           "servers": {
               "horizon3-mcp-server": {
                   "url": "https://mcp.horizon3ai.com/mcp",
                   "type": "http"
               }
           },
           "inputs": []
           }
   

7. After you save your configuration, VS Code will prompt you to authenticate to proxy.horizon3ai.com.

8. After clicking Allow, log in to your Horizon3 Portal Account following the redirect. Once you successfully log in, close the browser and you're ready to get started!

Client Compatibility¶

The Horizon3 MCP Server works with MCP-compliant clients that support both OAuth 2.1 authentication and HTTP streamable transport. This includes:

• VS Code with MCP extensions - Fully compatible
• Claude Code - Fully compatible
• Claude Desktop - Currently has some known compatibility issues
• Gemini CLI - Full compatible
• Windsurf - Fully compatible

Set Up Other IDEs or Clients¶

To set up the Horizon3-hosted MCP Server for other IDEs or clients, create an mcp.json file in your workspace or home directory with an entry for the MCP Server:

1. In your client of choice, enter the server URL:
   • US: https://mcp.horizon3ai.com/mcp
   • EU: https://mcp.horizon3ai.eu/mcp
   • AU: https://mcp.horizon3ai.au/mcp
   • FedRAMP High: https://mcp.gov-horizon3ai.com/mcp

2. Use streamable HTTP as the transport mode.

3. Begin the OAuth login process when prompted. After you're redirected, complete login using your NodeZero credentials.

Manual Setup¶

To set up the Horizon3-hosted MCP Server for other IDEs or clients manually, create an mcp.json file in your workspace or home directory, with an entry for the MCP Server. This example uses the US server URL:

{
   "servers": {
       "horizon3-mcp-server": {
           "url": "https://mcp.horizon3ai.com/mcp",
           "type": "http"
       }
   },
   "inputs": []
}

Troubleshoot Common Issues¶