aspnetcore-httpclientextensions

Small System.Text.Json helpers for HttpClient and HttpContent: send JSON with POST, PUT, or PATCH, deserialize JSON from responses or arbitrary content, with optional JsonSerializerOptions and CancellationToken support.

Target framework: .NET Standard 2.0 (broad compatibility across .NET Framework 4.6.1+, .NET Core 2.0+, Mono, Xamarin, Unity, and modern .NET).

When to use this library

This package is aimed mainly at runtimes and workloads from before the “one .NET” era especially .NET Core 3.1 and earlier, .NET Framework, Mono, Xamarin, Unity, and other non-unified .NET environments where you want a lightweight HttpClient + JSON story without pulling in a large stack.

Starting with .NET 5, the shared runtime ships System.Net.Http.Json (GetFromJsonAsync, PostAsJsonAsync, PutAsJsonAsync, ReadFromJsonAsync, and related types). If you target .NET 5 or later, prefer that built-in API (or the standalone System.Net.Http.Json package where applicable) unless you have a concrete reason to standardize on this library.

This project remains useful when you need .NET Standard 2.0-friendly extensions built on System.Text.Json with a small surface area and stream-based deserialization for large bodies (ReadAsJsonAsync on HttpContent).

Installation

From the NuGet package AspNetCore.Http.Extensions:

dotnet add package AspNetCore.Http.Extensions

Package Manager Console:

Install-Package AspNetCore.Http.Extensions

Paket:

paket add AspNetCore.Http.Extensions

Add the namespace:

using AspNetCore.Http.Extensions;

Usage

Create an HttpClient (often via IHttpClientFactory in ASP.NET Core):

public sealed class Foo
{
    public string Name { get; set; } = "";
}

using System.Net.Http;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using AspNetCore.Http.Extensions;

var client = new HttpClient();
var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
var cts = new CancellationTokenSource();

var payload = new Foo { Name = "Bar" };

// POST / PUT / PATCH JSON (returns HttpResponseMessage)
var postResponse = await client.PostAsJsonAsync("https://api.example.com/items", payload, options, cts.Token);
var putResponse = await client.PutAsJsonAsync("https://api.example.com/items/1", payload, options, cts.Token);
var patchResponse = await client.PatchAsJsonAsync("https://api.example.com/items/1", payload, options, cts.Token);

// GET and deserialize JSON (throws if the status is not success)
var item = await client.GetFromJsonAsync<Foo>("https://api.example.com/items/1", options, cts.Token);

// Deserialize from HttpContent (uses a stream; suitable for large payloads)
var fromContent = await postResponse.Content.ReadAsJsonAsync<Foo>(options, cts.Token);

JsonSerializerOptions and CancellationToken are optional on every extension method; omit them when you do not need custom serialization or cancellation.

API overview

Method	Description
PostAsJsonAsync	Serialize body as JSON, POST
PutAsJsonAsync	Serialize body as JSON, PUT
PatchAsJsonAsync	Serialize body as JSON, PATCH (via SendAsync; HttpClient.PatchAsync is not available on .NET Standard 2.0)
GetFromJsonAsync	GET, ensure success, deserialize JSON
ReadAsJsonAsync	Deserialize JSON from HttpContent using a stream

XML documentation is included in the NuGet package for IntelliSense.

License

See LICENSE in the repository.