Refit.HttpClientFactory v7.0.0 — nugetz

glennawatson/Refit.HttpClientFactoryv7.0.0

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Refit HTTP Client Factory Extensions

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License

MIT

Deps

Install Size

—

Vulns

✓ 0

Published

Feb 6, 2026

Get Started

$ dotnet add package Refit.HttpClientFactory

Readme

Refit

Refit: The automatic type-safe REST library for .NET Core, Xamarin and .NET

	Refit	Refit.HttpClientFactory	Refit.Newtonsoft.Json
NuGet

Refit is a library heavily inspired by Square's library, and it turns your REST API into a live interface:

public interface IGitHubApi
{
    [Get("/users/{user}")]
    Task<User> GetUser(string user);
}

var gitHubApi = RestService.For<IGitHubApi>("https://api.github.com");
var octocat = await gitHubApi.GetUser("octocat");

services
    .AddRefitClient<IGitHubApi>()
    .ConfigureHttpClient(c => c.BaseAddress = new Uri("https://api.github.com"));

[Get("/users/list")]

[Get("/users/list?sort=desc")]

[Get("/group/{id}/users")]
Task<List<User>> GroupList([AliasAs("id")] int groupId);

[Get("/group/{request.groupId}/users/{request.userId}")]
Task<List<User>> GroupList(UserGroupRequest request);

class UserGroupRequest{
    int groupId { get;set; }
    int userId { get;set; }
}

[Get("/group/{id}/users")]
Task<List<User>> GroupList([AliasAs("id")] int groupId, [AliasAs("sort")] string sortOrder);

GroupList(4, "desc");
>>> "/group/4/users?sort=desc"

[Get("/search/{**page}")]
Task<List<Page>> Search(string page);

Search("admin/products");
>>> "/search/admin/products"

public class MyQueryParams
{
    [AliasAs("order")]
    public string SortOrder { get; set; }

    public int Limit { get; set; }

    public KindOptions Kind { get; set; }
}

public enum KindOptions
{
    Foo,

    [EnumMember(Value = "bar")]
    Bar
}


[Get("/group/{id}/users")]
Task<List<User>> GroupList([AliasAs("id")] int groupId, MyQueryParams params);

[Get("/group/{id}/users")]
Task<List<User>> GroupListWithAttribute([AliasAs("id")] int groupId, [Query(".","search")] MyQueryParams params);


params.SortOrder = "desc";
params.Limit = 10;
params.Kind = KindOptions.Bar;

GroupList(4, params)
>>> "/group/4/users?order=desc&Limit=10&Kind=bar"

GroupListWithAttribute(4, params)
>>> "/group/4/users?search.order=desc&search.Limit=10&search.Kind=bar"

[Post("/statuses/update.json")]
Task<Tweet> PostTweet([Query]TweetParams params);

[Get("/users/list")]
Task Search([Query(CollectionFormat.Multi)]int[] ages);

Search(new [] {10, 20, 30})
>>> "/users/list?ages=10&ages=20&ages=30"

[Get("/users/list")]
Task Search([Query(CollectionFormat.Csv)]int[] ages);

Search(new [] {10, 20, 30})
>>> "/users/list?ages=10%2C20%2C30"

var gitHubApi = RestService.For<IGitHubApi>("https://api.github.com",
    new RefitSettings {
        CollectionFormat = CollectionFormat.Multi
    });

[Get("/query")]
[QueryUriFormat(UriFormat.Unescaped)]
Task Query(string q);

Query("Select+Id,Name+From+Account")
>>> "/query?q=Select+Id,Name+From+Account"

[Post("/users/new")]
Task CreateUser([Body] User user);

Task CreateUser([Body(buffered: true)] User user);

var settings = new RefitSettings(new NewtonsoftJsonContentSerializer());

JsonConvert.DefaultSettings =
    () => new JsonSerializerSettings() {
        ContractResolver = new CamelCasePropertyNamesContractResolver(),
        Converters = {new StringEnumConverter()}
    };

// Serialized as: {"day":"Saturday"}
await PostSomeStuff(new { Day = DayOfWeek.Saturday });

var gitHubApi = RestService.For<IGitHubApi>("https://api.github.com",
    new RefitSettings {
        ContentSerializer = new NewtonsoftJsonContentSerializer(
            new JsonSerializerSettings {
                ContractResolver = new SnakeCasePropertyNamesContractResolver()
        }
    )});

var otherApi = RestService.For<IOtherApi>("https://api.example.com",
    new RefitSettings {
        ContentSerializer = new NewtonsoftJsonContentSerializer(
            new JsonSerializerSettings {
                ContractResolver = new CamelCasePropertyNamesContractResolver()
        }
    )});

public class Foo
{
    // Works like [AliasAs("b")] would in form posts (see below)
    [JsonProperty(PropertyName="b")]
    public string Bar { get; set; }
}

var options = new JsonSerializerOptions();
options.AddContext<MyJsonSerializerContext>();

var gitHubApi = RestService.For<IGitHubApi>("https://api.github.com",
    new RefitSettings {
        ContentSerializer = new SystemTextJsonContentSerializer(options)
    });

var gitHubApi = RestService.For<IXmlApi>("https://www.w3.org/XML",
    new RefitSettings {
        ContentSerializer = new XmlContentSerializer()
    });

    public class Foo
    {
        [XmlElement(Namespace = "https://www.w3.org/XML")]
        public string Bar { get; set; }
    }

var gitHubApi = RestService.For<IXmlApi>("https://www.w3.org/XML",
    new RefitSettings {
        ContentSerializer = new XmlContentSerializer(
            new XmlContentSerializerSettings
            {
                XmlReaderWriterSettings = new XmlReaderWriterSettings()
                {
                    ReaderSettings = new XmlReaderSettings
                    {
                        IgnoreWhitespace = true
                    }
                }
            }
        )
    });

public interface IMeasurementProtocolApi
{
    [Post("/collect")]
    Task Collect([Body(BodySerializationMethod.UrlEncoded)] Dictionary<string, object> data);
}

var data = new Dictionary<string, object> {
    {"v", 1},
    {"tid", "UA-1234-5"},
    {"cid", new Guid("d1e9ea6b-2e8b-4699-93e0-0bcbd26c206c")},
    {"t", "event"},
};

// Serialized as: v=1&tid=UA-1234-5&cid=d1e9ea6b-2e8b-4699-93e0-0bcbd26c206c&t=event
await api.Collect(data);

public interface IMeasurementProtocolApi
{
    [Post("/collect")]
    Task Collect([Body(BodySerializationMethod.UrlEncoded)] Measurement measurement);
}

public class Measurement
{
    // Properties can be read-only and [AliasAs] isn't required
    public int v { get { return 1; } }

    [AliasAs("tid")]
    public string WebPropertyId { get; set; }

    [AliasAs("cid")]
    public Guid ClientId { get; set; }

    [AliasAs("t")]
    public string Type { get; set; }

    public object IgnoreMe { private get; set; }
}

var measurement = new Measurement {
    WebPropertyId = "UA-1234-5",
    ClientId = new Guid("d1e9ea6b-2e8b-4699-93e0-0bcbd26c206c"),
    Type = "event"
};

// Serialized as: v=1&tid=UA-1234-5&cid=d1e9ea6b-2e8b-4699-93e0-0bcbd26c206c&t=event
await api.Collect(measurement);


public class SomeObject
{
    [JsonProperty(PropertyName = "one")]
    public string FirstProperty { get; set; }

    [JsonProperty(PropertyName = "notTwo")]
    [AliasAs("two")]
    public string SecondProperty { get; set; }
}

[Headers("User-Agent: Awesome Octocat App")]
[Get("/users/{user}")]
Task<User> GetUser(string user);

[Headers("User-Agent: Awesome Octocat App")]
public interface IGitHubApi
{
    [Get("/users/{user}")]
    Task<User> GetUser(string user);

    [Post("/users/new")]
    Task CreateUser([Body] User user);
}

[Get("/users/{user}")]
Task<User> GetUser(string user, [Header("Authorization")] string authorization);

// Will add the header "Authorization: token OAUTH-TOKEN" to the request
var user = await GetUser("octocat", "token OAUTH-TOKEN");

[Get("/users/{user}")]
Task<User> GetUser(string user, [Authorize("Bearer")] string token);

// Will add the header "Authorization: Bearer OAUTH-TOKEN}" to the request
var user = await GetUser("octocat", "OAUTH-TOKEN");

//note: the scheme defaults to Bearer if none provided


[Get("/users/{user}")]
Task<User> GetUser(string user, [HeaderCollection] IDictionary<string, string> headers);

var headers = new Dictionary<string, string> {{"Authorization","Bearer tokenGoesHere"}, {"X-Tenant-Id","123"}};
var user = await GetUser("octocat", headers);


 //Custom delegating handler for adding Auth headers to outbound requests
 class AuthHeaderHandler : DelegatingHandler
 {
     private readonly ITenantProvider tenantProvider;
     private readonly IAuthTokenStore authTokenStore;

    public AuthHeaderHandler(ITenantProvider tenantProvider, IAuthTokenStore authTokenStore)
    {
         this.tenantProvider = tenantProvider ?? throw new ArgumentNullException(nameof(tenantProvider));
         this.authTokenStore = authTokenStore ?? throw new ArgumentNullException(nameof(authTokenStore));
         InnerHandler = new HttpClientHandler();
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        var token = await authTokenStore.GetToken();

        //potentially refresh token here if it has expired etc.

        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
        request.Headers.Add("X-Tenant-Id", tenantProvider.GetTenantId());

        return await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
    }
}

//Startup.cs
public void ConfigureServices(IServiceCollection services)
{
    services.AddTransient<ITenantProvider, TenantProvider>();
    services.AddTransient<IAuthTokenStore, AuthTokenStore>();
    services.AddTransient<AuthHeaderHandler>();

    //this will add our refit api implementation with an HttpClient
    //that is configured to add auth headers to all requests

    //note: AddRefitClient<T> requires a reference to Refit.HttpClientFactory
    //note: the order of delegating handlers is important and they run in the order they are added!

    services.AddRefitClient<ISomeThirdPartyApi>()
        .ConfigureHttpClient(c => c.BaseAddress = new Uri("https://api.example.com"))
        .AddHttpMessageHandler<AuthHeaderHandler>();
        //you could add Polly here to handle HTTP 429 / HTTP 503 etc
}

//Your application code
public class SomeImportantBusinessLogic
{
    private ISomeThirdPartyApi thirdPartyApi;

    public SomeImportantBusinessLogic(ISomeThirdPartyApi thirdPartyApi)
    {
        this.thirdPartyApi = thirdPartyApi;
    }

    public async Task DoStuffWithUser(string username)
    {
        var user = await thirdPartyApi.GetUser(username);
        //do your thing
    }
}

var api = RestService.For<ISomeThirdPartyApi>(new HttpClient(new AuthHeaderHandler(tenantProvider, authTokenStore))
    {
        BaseAddress = new Uri("https://api.example.com")
    }
);

var user = await thirdPartyApi.GetUser(username);
//do your thing

[Headers("X-Emoji: :rocket:")]
public interface IGitHubApi
{
    [Get("/users/list")]
    Task<List> GetUsers();

    [Get("/users/{user}")]
    [Headers("X-Emoji: :smile_cat:")]
    Task<User> GetUser(string user);

    [Post("/users/new")]
    [Headers("X-Emoji: :metal:")]
    Task CreateUser([Body] User user, [Header("X-Emoji")] string emoji);
}

// X-Emoji: :rocket:
var users = await GetUsers();

// X-Emoji: :smile_cat:
var user = await GetUser("octocat");

// X-Emoji: :trollface:
await CreateUser(user, ":trollface:");

[Headers("Header-A: 1")]
public interface ISomeApi
{
    [Headers("Header-B: 2")]
    [Post("/post")]
    Task PostTheThing([Header("Header-C")] int c);
}

// Header-A: 1
// Header-B: 2
// Header-C: 3
var user = await api.PostTheThing(3);

[Headers("X-Emoji: :rocket:")]
public interface IGitHubApi
{
    [Get("/users/list")]
    [Headers("X-Emoji")] // Remove the X-Emoji header
    Task<List> GetUsers();

    [Get("/users/{user}")]
    [Headers("X-Emoji:")] // Redefine the X-Emoji header as empty
    Task<User> GetUser(string user);

    [Post("/users/new")]
    Task CreateUser([Body] User user, [Header("X-Emoji")] string emoji);
}

// No X-Emoji header
var users = await GetUsers();

// X-Emoji:
var user = await GetUser("octocat");

// No X-Emoji header
await CreateUser(user, null);

// X-Emoji:
await CreateUser(user, "");

public interface IGitHubApi
{
    [Post("/users/new")]
    Task CreateUser([Body] User user, [Property("SomeKey")] string someValue);

    [Post("/users/new")]
    Task CreateUser([Body] User user, [Property] string someOtherKey);
}

class RequestPropertyHandler : DelegatingHandler
{
    public RequestPropertyHandler(HttpMessageHandler innerHandler = null) : base(innerHandler ?? new HttpClientHandler()) {}

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        // See if the request has a the property
        if(request.Properties.ContainsKey("SomeKey"))
        {
            var someProperty = request.Properties["SomeKey"];
            //do stuff
        }

        if(request.Properties.ContainsKey("someOtherKey"))
        {
            var someOtherProperty = request.Properties["someOtherKey"];
            //do stuff
        }

        return await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
    }
}

public interface IGetAPI<TEntity>
{
    [Get("/{key}")]
    Task<TEntity> Get(long key);
}

public interface IUsersAPI : IGetAPI<User>
{
}

public interface IOrdersAPI : IGetAPI<Order>
{
}

class RequestPropertyHandler : DelegatingHandler
{
    public RequestPropertyHandler(HttpMessageHandler innerHandler = null) : base(innerHandler ?? new HttpClientHandler()) {}

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        // Get the type of the target interface
        Type interfaceType = (Type)request.Properties[HttpMessageRequestOptions.InterfaceType];

        var builder = new UriBuilder(request.RequestUri);
        // Alter the Path in some way based on the interface or an attribute on it
        builder.Path = $"/{interfaceType.Name}{builder.Path}";
        // Set the new Uri on the outgoing message
        request.RequestUri = builder.Uri;

        return await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
    }
}

class RequestPropertyHandler : DelegatingHandler
{
    public RequestPropertyHandler(HttpMessageHandler innerHandler = null) : base(innerHandler ?? new HttpClientHandler()) {}

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        // Get the method info
        if (request.Options.TryGetValue(HttpRequestMessageOptions.RestMethodInfoKey, out RestMethodInfo restMethodInfo))
        {
            var builder = new UriBuilder(request.RequestUri);
            // Alter the Path in some way based on the method info or an attribute on it
            builder.Path = $"/{restMethodInfo.MethodInfo.Name}{builder.Path}";
            // Set the new Uri on the outgoing message
            request.RequestUri = builder.Uri;
        }

        return await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
    }
}

public interface ISomeApi
{
    [Multipart]
    [Post("/users/{id}/photo")]
    Task UploadPhoto(int id, [AliasAs("myPhoto")] StreamPart stream);
}

someApiInstance.UploadPhoto(id, new StreamPart(myPhotoStream, "photo.jpg", "image/jpeg"));

[Post("/users/new")]
Task CreateUser([Body] User user);

// This will throw if the network call fails
await CreateUser(someUser);

// Returns the content as a string (i.e. the JSON data)
[Get("/users/{user}")]
Task<string> GetUser(string user);

// Returns the raw response, as an IObservable that can be used with the
// Reactive Extensions
[Get("/users/{user}")]
IObservable<HttpResponseMessage> GetUser(string user);

//Returns the content within a wrapper class containing metadata about the request/response
[Get("/users/{user}")]
Task<ApiResponse<User>> GetUser(string user);

//Calling the API
var response = await gitHubApi.GetUser("octocat");

//Getting the status code (returns a value from the System.Net.HttpStatusCode enumeration)
var httpStatus = response.StatusCode;

//Determining if a success status code was received
if(response.IsSuccessStatusCode)
{
    //YAY! Do the thing...
}

//Retrieving a well-known header value (e.g. "Server" header)
var serverHeaderValue = response.Headers.Server != null ? response.Headers.Server.ToString() : string.Empty;

//Retrieving a custom header value
var customHeaderValue = string.Join(',', response.Headers.GetValues("A-Custom-Header"));

//Looping through all the headers
foreach(var header in response.Headers)
{
    var headerName = header.Key;
    var headerValue = string.Join(',', header.Value);
}

//Finally, retrieving the content in the response body as a strongly-typed object
var user = response.Content;

public interface IReallyExcitingCrudApi<T, in TKey> where T : class
{
    [Post("")]
    Task<T> Create([Body] T payload);

    [Get("")]
    Task<List<T>> ReadAll();

    [Get("/{key}")]
    Task<T> ReadOne(TKey key);

    [Put("/{key}")]
    Task Update(TKey key, [Body]T payload);

    [Delete("/{key}")]
    Task Delete(TKey key);
}

// The "/users" part here is kind of important if you want it to work for more
// than one type (unless you have a different domain for each type)
var api = RestService.For<IReallyExcitingCrudApi<User, string>>("http://api.example.com/users");

public interface IBaseService
{
    [Get("/resources")]
    Task<Resource> GetResource(string id);
}

public interface IDerivedServiceA : IBaseService
{
    [Delete("/resources")]
    Task DeleteResource(string id);
}

public interface IDerivedServiceB : IBaseService
{
    [Post("/resources")]
    Task<string> AddResource([Body] Resource resource);
}

[Headers("User-Agent: AAA")]
public interface IAmInterfaceA
{
    [Get("/get?result=Ping")]
    Task<string> Ping();
}

[Headers("User-Agent: BBB")]
public interface IAmInterfaceB : IAmInterfaceA
{
    [Get("/get?result=Pang")]
    [Headers("User-Agent: PANG")]
    Task<string> Pang();

    [Get("/get?result=Foo")]
    Task<string> Foo();
}

public interface IAmInterfaceC : IAmInterfaceA, IAmInterfaceB
{
    [Get("/get?result=Foo")]
    Task<string> Foo();
}

public interface IApiClient
{
    // implemented by Refit but not exposed publicly
    [Get("/get")]
    internal Task<string> GetInternal();
    // Publicly available with added logic applied to the result from the API call
    public async Task<string> Get()
        => FormatResponse(await GetInternal());
    private static String FormatResponse(string response)
        => $"The response is: {response}";
}

internal interface IApiClientInternal
{
    [Get("/get")]
    Task<string> Get();
}
public interface IApiClient
{
    public Task<string> Get();
}
internal class ApiClient : IApiClient
{
    private readonly IApiClientInternal client;
    public ApiClient(IApiClientInternal client) => this.client = client;
    public async Task<string> Get()
        => FormatResponse(await client.Get());
    private static String FormatResponse(string response)
        => $"The response is: {response}";
}

services.AddRefitClient<IWebApi>()
        .ConfigureHttpClient(c => c.BaseAddress = new Uri("https://api.example.com"));
        // Add additional IHttpClientBuilder chained methods as required here:
        // .AddHttpMessageHandler<MyHandler>()
        // .SetHandlerLifetime(TimeSpan.FromMinutes(2));

var settings = new RefitSettings();
// Configure refit settings here

services.AddRefitClient<IWebApi>(settings)
        .ConfigureHttpClient(c => c.BaseAddress = new Uri("https://api.example.com"));
        // Add additional IHttpClientBuilder chained methods as required here:
        // .AddHttpMessageHandler<MyHandler>()
        // .SetHandlerLifetime(TimeSpan.FromMinutes(2));

// or injected from the container
services.AddRefitClient<IWebApi>(provider => new RefitSettings() { /* configure settings */ })
        .ConfigureHttpClient(c => c.BaseAddress = new Uri("https://api.example.com"));
        // Add additional IHttpClientBuilder chained methods as required here:
        // .AddHttpMessageHandler<MyHandler>()
        // .SetHandlerLifetime(TimeSpan.FromMinutes(2));

public class HomeController : Controller
{
    public HomeController(IWebApi webApi)
    {
        _webApi = webApi;
    }

    private readonly IWebApi _webApi;

    public async Task<IActionResult> Index(CancellationToken cancellationToken)
    {
        var thing = await _webApi.GetSomethingWeNeed(cancellationToken);
        return View(thing);
    }
}

RestService.For<ISomeApi>(new HttpClient()
{
    BaseAddress = new Uri("https://www.someapi.com/api/")
});

interface ISomeApi
{
    // This will automagically be populated by Refit if the property exists
    HttpClient Client { get; }

    [Headers("Authorization: Bearer")]
    [Get("/endpoint")]
    Task<string> SomeApiEndpoint();
}

SomeApi = RestService.For<ISomeApi>("https://www.someapi.com/api/", new RefitSettings()
{
    AuthorizationHeaderValueGetter = (rq, ct) => GetTokenAsync()
});

SomeApi.Client.Timeout = timeout;

var response = await _myRefitClient.GetSomeStuff();
if(response.IsSuccessStatusCode)
{
   //do your thing
}
else
{
   _logger.LogError(response.Error, response.Error.Content);
}

// ...
try
{
   var result = await awesomeApi.GetFooAsync("bar");
}
catch (ApiException exception)
{
   //exception handling
}
// ...

// ...
try
{
   var result = await awesomeApi.GetFooAsync("bar");
}
catch (ValidationApiException validationException)
{
   // handle validation here by using validationException.Content,
   // which is type of ProblemDetails according to RFC 7807

   // If the response contains additional properties on the problem details,
   // they will be added to the validationException.Content.Extensions collection.
}
catch (ApiException exception)
{
   // other exception handling
}
// ...

var nullTask = Task.FromResult<Exception>(null);

var gitHubApi = RestService.For<IGitHubApi>("https://api.github.com",
    new RefitSettings {
        ExceptionFactory = httpResponse => nullTask;
    });

glennawatson/Refit.HttpClientFactoryv7.0.0

Get Started

Readme

Refit: The automatic type-safe REST library for .NET Core, Xamarin and .NET

Table of Contents

Where does this work?

SDK Requirements

Breaking changes in 6.x

Updates in 6.3

API Attributes

Dynamic Querystring Parameters

Collections as Querystring parameters

Unescape Querystring parameters

Body content

Buffering and the Content-Length header

JSON content

JSON source generator

XML Content

Form posts

Setting request headers

Static headers

Dynamic headers

Bearer Authentication

Reducing header boilerplate with DelegatingHandlers (Authorization headers worked example)

Redefining headers

Removing headers

Passing state into DelegatingHandlers

Support for Polly and Polly.Context

Target Interface Type and method info

Multipart uploads

Retrieving the response

Using generic interfaces

Interface inheritance

Headers inheritance

Default Interface Methods

Using HttpClientFactory

Providing a custom HttpClient

Handling exceptions

When returning Task<IApiResponse>, Task<IApiResponse<T>>, or Task<ApiResponse<T>>

When returning Task<T>

Providing a custom ExceptionFactory

ApiException deconstruction with Serilog

Buffering and the `Content-Length` header

When returning `Task<IApiResponse>`, `Task<IApiResponse<T>>`, or `Task<ApiResponse<T>>`

When returning `Task<T>`

Providing a custom `ExceptionFactory`

`ApiException` deconstruction with Serilog