{
  "headers": {
    "A2A-Version": "1.0",
    "A2A-Extensions": "https://dossy.dev/a2a/dcp-gateway/1",
    "Authorization": "Bearer <existing-dcp-agent-token>"
  },
  "body": {
    "message": {
      "messageId": "correlation-only-example",
      "role": "ROLE_USER",
      "parts": [{ "kind": "data", "mediaType": "application/json", "data": { "operation": "list_boards", "input": {} } }]
    }
  }
}