Start Debugging

Tag: httpclient

10 posts

2026-09-25 refit httpclient dotnet

Refit 16.1 Writes Your Paging Loop: PagedEnumerable, [Paged] and [PageToken]

Refit 16.1.0 lets an interface method return PagedEnumerable<TPage, TItem>, and the source generator emits the request-per-page loop for cursors, offsets, response headers and next links. Here is how to declare it, how enumeration behaves, and the RF013 build error you get for a misspelled member.

2026-09-24 errors dotnet dotnet-10

Fix: HttpIOException: The response ended prematurely from HttpClient in .NET

HttpClient reuses a keep-alive connection the server just closed, or the server drops the connection mid-response. Lower PooledConnectionIdleTimeout below the server's idle timeout and retry only idempotent requests.

2026-09-23 dotnet-10 httpclient resilience

Fix: custom DelegatingHandler does not run again on each retry with AddStandardResilienceHandler

A DelegatingHandler registered before AddStandardResilienceHandler runs once per logical request, not once per retry. Move it after the resilience handler, and make it idempotent, because the retry re-sends the same HttpRequestMessage. Measured on Microsoft.Extensions.Http.Resilience 10.10.0 and 8.10.0.

2026-09-07 dotnet dotnet-11 csharp

How to consume an RFC 9457 ProblemDetails response from a typed HttpClient without referencing ASP.NET Core

The BCL has no ProblemDetails type, and adding a FrameworkReference to Microsoft.AspNetCore.App makes your client refuse to start on a runtime-only container. Here is the 20-line model that does the job, the DelegatingHandler that turns problem+json into a typed exception, and the content-type myth that most answers still repeat.

2026-08-10 aspire dotnet dotnet-11

How to override the default resilience handler that Aspire registers

Aspire's AddServiceDefaults applies a standard resilience handler to every HttpClient. Calling AddStandardResilienceHandler again stacks a second one instead of replacing it. Here are the three real override paths, the -standard options name nobody documents, and the infinite timeout you inherit if you just remove it.

2026-06-13 errors dotnet httpclient

Fix: The SSL connection could not be established with HttpClient

The inner AuthenticationException tells you the real cause: an untrusted chain, a name mismatch, or a TLS version gap. Trust the cert, fix the host name, or align protocols. Do not blanket-disable validation.

2026-05-24 comparison polly resilience

Polly vs resilience handlers in .NET 11: which should you use?

Use the Microsoft.Extensions.Http.Resilience handler for HttpClient calls, since it is Polly with HTTP-aware defaults and telemetry in one line. Reach for Polly's ResiliencePipeline directly only when you protect something that is not an HttpClient.

2026-05-23 comparison httpclient httpclientfactory

HttpClient vs HttpClientFactory vs Refit: which should you use in .NET 11?

Never new up HttpClient per request. Use IHttpClientFactory to manage lifetime, and add Refit on top when you want a typed interface instead of hand-written request code. Raw singleton HttpClient is fine only for the simplest cases.

2026-05-09 errors csharp dotnet

Fix: TaskCanceledException: A task was canceled in HttpClient

HttpClient throws TaskCanceledException for three different reasons: timeout, caller cancellation, or a connection-level abort. Tell them apart with InnerException and CancellationToken.IsCancellationRequested, then fix the right one.

2026-04-26 csharp dotnet dotnet-11

How to unit-test code that uses HttpClient

A complete guide to testing HttpClient in .NET 11: why you should not mock HttpClient directly, how to write a stub HttpMessageHandler, swapping the primary handler with IHttpClientFactory, verifying Polly retries, and the WireMock.Net option.