Fga.Net.AspNetCore 0.5.0-alpha

.NET 6.0
This is a prerelease version of Fga.Net.AspNetCore.
There is a newer prerelease version of this package available.
See the version list below for details.
NuGet\Install-Package Fga.Net.AspNetCore -Version 0.5.0-alpha
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
dotnet add package Fga.Net.AspNetCore --version 0.5.0-alpha
<PackageReference Include="Fga.Net.AspNetCore" Version="0.5.0-alpha" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add Fga.Net.AspNetCore --version 0.5.0-alpha
#r "nuget: Fga.Net.AspNetCore, 0.5.0-alpha"
#r directive can be used in F# Interactive, C# scripting and .NET Interactive. Copy this into the interactive tool or source code of the script to reference the package.
// Install Fga.Net.AspNetCore as a Cake Addin
#addin nuget:?package=Fga.Net.AspNetCore&version=0.5.0-alpha&prerelease

// Install Fga.Net.AspNetCore as a Cake Tool
#tool nuget:?package=Fga.Net.AspNetCore&version=0.5.0-alpha&prerelease

Auth0 FGA for Worker Services & ASP.NET Core

Nuget (with prereleases) Nuget (with prereleases)


  • Fga.Net.DependencyInjection: Provides dependency injection extensions for Auth0.Fga

  • Fga.Net.AspNetCore: Additionally includes Authorization middleware to support FGA checks as part of a request's lifecycle.

Getting Started

Note: This project is in its early stages and will have breaking changes as FGA matures.

Please ensure you have a basic understanding of how FGA works before continuing: https://docs.fga.dev/

ASP.NET Core Setup

Before getting started, ensure you have a Store ID, Client ID, and Client Secret ready from How to get your API keys.

I'm also assuming you have authentication setup within your project, such as JWT bearer authentication via Auth0.

  1. Install Fga.Net.AspNetCore from Nuget.
  2. Add your StoreId, ClientId and ClientSecret to your application configuration, ideally via the dotnet secrets manager.
  3. Add the following code to your ASP.NET Core configuration:
// Registers the Auth0FgaApi client
builder.Services.AddAuth0Fga(x =>
    x.ClientId = builder.Configuration["Auth0Fga:ClientId"];
    x.ClientSecret = builder.Configuration["Auth0Fga:ClientSecret"];
    x.StoreId = builder.Configuration["Auth0Fga:StoreId"];

// Register the authorization policy
builder.Services.AddAuthorization(options =>
        p => p
  1. Create an attribute that inherits from TupleCheckAttribute. From here, you can pull the metadata you require to perform your tuple checks out of the HTTP request. For example, an equivalent to the How To Integrate Within A Framework example would be:
public class EntityAuthorizationAttribute : TupleCheckAttribute
    private readonly string _prefix;
    private readonly string _routeValue;
    public EntityAuthorizationAttribute(string prefix, string routeValue)
        _prefix = prefix;
        _routeValue = routeValue;

    public override ValueTask<string> GetUser(HttpContext context) 
        => ValueTask.FromResult(context.User.Identity!.Name!);

    public override ValueTask<string> GetRelation(HttpContext context) 
        => ValueTask.FromResult(context.Request.Method switch 
            "GET" => "viewer",
            "POST" => "writer",
            _ => "owner"

    public override ValueTask<string> GetObject(HttpContext context) 
        => ValueTask.FromResult($"{_prefix}:{context.GetRouteValue(_routeValue)}");
  1. Apply the Authorize and EntityAuthorization attributes to your controller(s):
    // Traditional Controllers
    public class DocumentController : ControllerBase
        [EntityAuthorization("doc", "documentId")]
        public string GetByConvention(string documentId)
            return documentId;

    // Minimal APIs
    [EntityAuthorization("doc", "documentId")]
    (documentId) => Task.FromResult(documentId));

If you need to manually perform checks, inject the Auth0FgaApi as required.

An additional pre-made attribute that allows all tuple values to be hardcoded strings ships with the package (StringTupleCheckAttribute). This attribute is useful for testing and debug purposes, but should not be used in a real application.

Worker Service / Generic Host Setup

Fga.Net ships with the AddAuth0Fga service collection extension that handles all required wire-up.

To get started:

  1. Install Fga.Net
  2. Add your StoreId, ClientId and ClientSecret to your application configuration, ideally via the dotnet secrets manager.
  3. Register the authorization client:
var host = Host.CreateDefaultBuilder(args)
    .ConfigureServices((context, services) =>
        services.AddAuth0Fga(config =>
            config.ClientId = context.Configuration["Auth0Fga:ClientId"];
            config.ClientSecret = context.Configuration["Auth0Fga:ClientSecret"];
            config.StoreId = context.Configuration["Auth0Fga:StoreId"];


await host.RunAsync();
  1. Request the client in your services:
public class MyBackgroundWorker : BackgroundService
    private readonly Auth0FgaApi _authorizationClient;

    public MyBackgroundWorker(Auth0FgaApi authorizationClient)
        _authorizationClient = authorizationClient;

    protected override Task ExecuteAsync(CancellationToken stoppingToken)
        // Do work with the client

Standalone client setup

See the Auth0.Fga docs


I am not affiliated with nor represent Auth0. All support queries regarding the underlying service should go to the Auth0 Labs Discord.

Product Versions
.NET net6.0 net6.0-android net6.0-ios net6.0-maccatalyst net6.0-macos net6.0-tvos net6.0-windows
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

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Version Downloads Last updated
0.7.0-alpha 25 10/1/2022
0.6.0-alpha 44 9/1/2022
0.5.0-alpha 51 6/18/2022
0.4.0-alpha 70 4/17/2022
0.3.0-alpha 68 2/13/2022
0.2.0-alpha 81 12/20/2021
0.1.1-alpha 82 12/20/2021
0.1.0-alpha 73 12/20/2021