Other 5xx codes
All HTTP status codes in ASP.NET Core
5xx Server error
504 Gateway Timeout
A gateway or proxy did not get a response from the server behind it in time.
In ASP.NET Core: Comes from reverse proxies when your app is too slow.
504 in .NET
The StatusCodes constant, HttpStatusCode enum name, reason phrase, class, and how EnsureSuccessStatusCode() and the standard resilience handler treat 504.
| Constant | StatusCodes.Status504GatewayTimeout |
|---|---|
| HttpStatusCode | HttpStatusCode.GatewayTimeout |
| Reason phrase | Kestrel sends Gateway Timeout |
| Class | 5xx, server error |
| IsSuccessStatusCode | false |
| EnsureSuccessStatusCode() | throws HttpRequestException: Response status code does not indicate success: 504 (Gateway Timeout). |
| Standard resilience handler | retries it (treated as transient) |
Returning 504
Minimal APIs
Results.StatusCode(StatusCodes.Status504GatewayTimeout)
Results.Problem(statusCode: StatusCodes.Status504GatewayTimeout, detail: "...")Controllers
StatusCode(StatusCodes.Status504GatewayTimeout)
Problem(statusCode: StatusCodes.Status504GatewayTimeout, detail: "...")The ProblemDetails body
What Results.Problem(statusCode: 504) sends (with AddProblemDetails()), as application/problem+json:
{
"type": "https://tools.ietf.org/html/rfc9110#section-15.6.5",
"title": "Gateway Timeout",
"status": 504,
"traceId": "0HNA1B2C3D4E5:00000001"
}A controller's Problem(statusCode: 504) sends the same body.
A bare StatusCode(504) in an [ApiController] also gets a ProblemDetails body automatically; Results.StatusCode(504) in a minimal API sends an empty body unless you add UseStatusCodePages().
Every response on this page was recorded from ASP.NET Core 10.0.12 on Kestrel in the Production environment; the HttpClient rows come from .NET 10.0.12 and Microsoft.Extensions.Http.Resilience 10.10.0.