curl --request POST \
  --url https://unify.bundleup.io/v1/mcp \
  --header 'Authorization: Bearer <token>' \
  --header 'BU-Connection-ID: <bu-connection-id>'

{
  "success": false,
  "errors": [
    {
      "code": 7001,
      "message": "Input Validation Error",
      "path": [
        "body"
      ]
    }
  ]
}