Does the order in which you add handlers matter when registering an HTTP client? - C# .NET

Question

When you are registering an HTTP client in .NET as such

return services
            .Configure<Options>(configuration.GetSection(nameof(Options)))
            .AddHttpClient<IService, Service>()
                .AddPolicyHandlerFromRegistry("Field")
                .AddOAuthHttpMessageHandler(() => configuration.GetBinded<Options>().RealmScope)
                .AddHttpMessageHandler<TrackingHandler>()
                .Services;

Does the order in which you add handlers matter? Would it cause an issue to have AddPolicyHandlerFromRegistry before AddOAuthHttpMessageHandler?

Answer 1

*Does the order which you add handlers matter?

• YES

See this for Policy handler

https://stackoverflow.com/a/63700841/850980

or this for DI services

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/configuration/?view=aspnetcore-6.0#jcp

Would it cause an issue to have "AddPolicyHandlerFromRegistry" before "AddOAuthHttpMessageHandler"?

I think it depends on further implementation details.