How to add User Secrets in a .NET Core console app

The User Secrets feature in .NET Core is a safe, simple way to override values in appsettings.json. The overridden values only exist in a file sitting in your own dev environment, so you don’t accidently commit them to your source control repository.

This feature is enabled in ASP.NET by default, and the framework does most of the work for you. But what if you want to add User Secrets to a console app, or any other project type besides ASP.NET?

There are a few more steps involved to get User Secrets working in a non-ASP.NET project. This article explains how to add and use User Secrets in a console app project.

1 – Add Microsoft.Extensions.Configuration.UserSecrets package

Execute the following in Package Manager Console (View > Other Windows > Package Manager Console).

Install-Package Microsoft.Extensions.Configuration.UserSecrets

This will add the package reference with the latest version to your .csproj file.

<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <OutputType>Exe</OutputType> <TargetFramework>netcoreapp3.1</TargetFramework> </PropertyGroup> <ItemGroup> <None Update="appsettings.json"> <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory> </None> </ItemGroup> <ItemGroup> <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="5.0.0" /> </ItemGroup> </Project>

2 – Add secrets.json

  • Right-click on the project > click Manage User Secrets.
  • This creates the secrets.json file and opens it.

At this point, it’s just an empty JSON file:

{ }

3 – Override settings from appsettings.json in secrets.json

Let’s say your appsettings.json looks like this:

{ "ApiKey": "1234", "Enabled": true, "Timeout": 5000, "ConnectionStrings": { "DefaultDB": "Data Source=ProdServer;Initial Catalog=StocksDB;Integrated Security=SSPI" } }

And you want to override ConnectionStrings. In secrets.json, put the following:

{ "ConnectionStrings": { "DefaultDB": "Data Source=localhost;Initial Catalog=StocksDB;Integrated Security=SSPI" } }

You can override any settings from appsettings.json by adding to secrets.json.

4 – Call AddUserSecrets()

Call ConfigurationBuilder.AddUserSecrets(). This makes it load the User Secrets file that you added in the steps above. Any settings that you overrode will be available when you use the Configuration object.

Note: This is assuming you’re already using ConfigurationBuilder and using appsettings.json. If this looks unfamiliar, take a look at this article that explains how to read from appsettings.json in a console app.

using Microsoft.Extensions.Configuration; class Program { static void Main(string[] args) { var config = new ConfigurationBuilder() .SetBasePath(AppDomain.CurrentDomain.BaseDirectory) .AddJsonFile("appsettings.json") .AddUserSecrets<Program>() .Build(); var conString = config.GetConnectionString("DefaultDB"); Console.WriteLine(conString); } }

When you run this, it outputs the connection string from secrets.json:

Data Source=localhost;Initial Catalog=StocksDB;Integrated Security=SSPI

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