README_ConfigSettings.md

January 27, 2026 · View on GitHub

Api Gateway Config Settings

You can keep the ApiKey, RouteKey, Backend API Base Urls and Route Paths,

in your appsettings.json file.

The Identifier is used to identify each ApiSetting & RouteSetting.

In your Gateway API project's appsettings.json file, add a Settings section like shown below:

{
  "Settings": [
    {
      "Identifier": "API1",
      "ApiKey": "weatherservice",
      "BackendAPIBaseUrls": [
        "https://localhost:5003/"
      ],
      "Routes": [
        {
          "Identifier": "ROUTE1",
          "RouteKey": "forecast",
          "Verb":  "GET",
          "BackendAPIRoutePath": "weatherforecast/forecast",
          "ResponseCachingDurationInSeconds": 120
        }
      ]
    },
    {
      "Identifier": "API2",
      "ApiKey": "stockservice",
      "BackendAPIBaseUrls": [
        "https://localhost:5005/"
      ],
      "Routes": [
        {
          "Identifier": "ROUTE1",
          "RouteKey": "stocks",
          "Verb":  "GET",
          "BackendAPIRoutePath": "stock",
          "ResponseCachingDurationInSeconds": 180
        }
      ]
    }
  ],
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*"
}

You can read this appsettings, using a Config Service like below:

For Version 6.0 or higher, you can use the built-in ApiGatewayConfigService.

or you can make a copy of the Service, in your project.

Api Gateway Config Service

Wire up the Config Service for dependency injecton.

services.AddSingleton<IApiGatewayConfigService, ApiGatewayConfigService>();

Create a static Settings class like below:

public static class Settings
{
    private static IApiGatewayConfigService _settings = ApiGatewayConfigProvider.MySettings;

    private const string API1 = "API1";
    private const string API1_ROUTE1 = "ROUTE1";

    public static string API1_ApiKey = _settings[API1].ApiKey;
    public static string[] API1_BackendAPIBaseUrls = _settings[API1].BackendAPIBaseUrls;

    public static string API1_ROUTE1_RouteKey = _settings[API1][API1_ROUTE1].RouteKey;
    public static GatewayVerb API1_ROUTE1_Verb = _settings[API1][API1_ROUTE1].Verb;
    public static string API1_ROUTE1_BackendAPIRoutePath = _settings[API1][API1_ROUTE1].BackendAPIRoutePath;
    public static int API1_ROUTE1_ResponseCachingDurationInSeconds = _settings[API1][API1_ROUTE1].ResponseCachingDurationInSeconds;
}

Then, in the Create method, first intitialize the Config Service.

and then you can pass these Settings to the Api Orchestrator

and where ever else you need them.

//Initialize
var configService = serviceProvider.GetRequiredService<IApiGatewayConfigService>();

orchestrator.AddApi(Settings.API1_ApiKey, Settings.API1_BackendAPIBaseUrls)
                //Get
                .AddRoute(Settings.API1_ROUTE1_RouteKey, Settings.API1_ROUTE1_Verb, new RouteInfo { Path = Settings.API1_ROUTE1_BackendAPIRoutePath, ResponseCachingDurationInSeconds = Settings.API1_ROUTE1_ResponseCachingDurationInSeconds })

In the Filters, you can use the Settings & do like shown below:

public class ActionFilterService : IGatewayActionFilter
{    
    public async Task OnActionExecutionAsync(ActionExecutingContext context, string apiKey, string routeKey, string verb)
    {
        if (apiKey == Settings.API1_ApiKey)
        {
            if (routeKey == Settings.API1_ROUTE1_RouteKey)
            {
                //Do your work here for API1 -> ROUTE1
            }
        }

        await Task.CompletedTask;
    }
}

Deployment to Prod

As with any Web API, when there is any code change, the API Gateway too is published and deployed using Blue/Green deployment.