A thread-safe implementation of a DelegatingHandler that automatically refreshes the access token when the access token expires whilst **not** serializing all requests.
Get Started
$ dotnet add package AutoRefreshTokenHttpMessageHandlerReadme
AutoRefreshTokenHttpMessageHandler
This is a thread-safe implementation of a DelegatingHandler, available as Nuget package, that automatically refreshes the access token when the access token expires whilst not serializing all requests. Most implementations use a lock internally which essentially makes all async actions synchronous again. This implementation only blocks during the actual refresh. Inspired by Bryan Helms' Thread-Safe Auth Token Store Using ConcurrentDictionary and AsyncLazy.
Quickstart
var builder = WebApplication.CreateBuilder(args);
builder.Services.Configure<TokenOptions>(configuration.GetRequiredSection("MyClient"))
.AddTransient<TokenDelegatingHandler>()
.AddHttpClient<ITokenAuthenticationService, TokenAuthenticationService>()
.ConfigureHttpClient(c => c.BaseAddress = new Uri("http://auth.myservice.com")).Services
Custom service:
builder.Services.AddHttpClient<MyService>()
.ConfigureHttpClient(c => c.BaseAddress = new Uri("http://myservice.com"))
.AddHttpMessageHandler<TokenDelegatingHandler>();
public class MyService(HttpClient client)
{
public Task<IEnumerable<MyFoo>> GetFoos() => client.GetFromJsonAsync<IEnumerable<Foo>>("/api/v1/foos");
}