Configuration in .NET Core

Here’s some basic examples for reading from a configuration file:

1) Create an appsettings.json file in your project.

2) Add this to your csproj file, so that it gets to your output directory:

    <None Update="appsettings.json">

3) Install the appropriate NuGet packages:

dotnet add package Microsoft.Extensions.Configuration.Json
dotnet add package Microsoft.Extensions.Configuration.Binder

4) Add data to your appsettings file, either as simple key-value pairs, or nest them:

    "ApplicationName": "Some Application",
    "ConnectionStrings": {
        "CS1": "some-connection-string",
        "CS2": "some-other-connection-string"
    "Queries": {
        "Q1": {
            "ConnectionStringKey": "CS1",
            "QueryText": "some query",
            "Timeout": 40
        "Q2": {
            "ConnectionStringKey": "CS2",
            "QueryText": "some other query"
5) Profit:

public class QueryInfo {
    public string ConnectionStringKey { get; set; }
    public string QueryText { get; set; }
var config = new ConfigurationBuilder()
string appName = config["ApplicationName"];
var queries = config.GetSection("Queries").GetChildren()
    .Select(x => new
        QueryInfo = x.Get<QueryInfo>()
foreach (var query in queries)
    // Special GetConnectionString reads from "ConnectionStrings"
    string connString = config.GetConnectionString(query.QueryInfo.ConnectionStringKey); 


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