HTTP Status 504 - Gateway Timeout

GET /api/reports/complex HTTP/1.1
Host: api.example.com

HTTP/1.1 504 Gateway Timeout
Content-Type: application/json

{
  "error": "gateway_timeout",
  "message": "Backend did not respond within 60 seconds",
  "suggestion": "Try a more specific date range or use async report generation",
  "async_endpoint": "POST /api/reports/async"
}

POST /api/payment HTTP/1.1
Host: api.example.com
Content-Type: application/json

{"amount": 99.99}

HTTP/1.1 504 Gateway Timeout
Content-Type: application/json

{
  "error": "payment_gateway_timeout",
  "message": "Payment provider did not respond in time",
  "transaction_id": "txn-abc-123",
  "action": "Check transaction status at /api/transactions/txn-abc-123"
}

GET /api/aggregated-data HTTP/1.1
Host: api.example.com

HTTP/1.1 504 Gateway Timeout
Content-Type: application/json
X-Timeout-Service: inventory-service

{
  "error": "upstream_timeout",
  "message": "Dependency service timeout",
  "timeout_service": "inventory-service",
  "timeout_duration": "30s"
}