Use XOR with Cursor

Add it

Open ~/.cursor/mcp.json (for every project) or .cursor/mcp.json in a project, and add XOR:

{
  "mcpServers": {
    "xor": { "url": "https://systemofreason.com/mcp" }
  }
}

Then open Customize, then MCPs. XOR is in the list. Follow Cursor’s sign-in prompt and enter your email and the code we send you.

With an access key instead

If Cursor can’t open a sign-in page, use an access key. Keep it in XOR_KEY in your environment:

{
  "mcpServers": {
    "xor": {
      "url": "https://systemofreason.com/mcp",
      "headers": { "Authorization": "Bearer ${env:XOR_KEY}" }
    }
  }
}

On a company plan

Admins can limit which MCP servers people may use. If XOR doesn’t connect, ask yours to allow https://systemofreason.com/mcp.

Cloud agents

Cursor’s cloud agents use servers added on the web at cursor.com/agents, with their own sign-in. Add XOR there to use it in runs you start from your phone.