KIOTA api client generation tips.

Installing it as a dotnet tool

ref: https://learn.microsoft.com/en-us/openapi/kiota/install?source=recommendations&tabs=bash#install-as-net-tool

dotnet tool install --global Microsoft.OpenApi.Kiota

Kiota NuGet package

Add this to the API project!

dotnet add package Microsoft.Kiota.Bundle

Generating some models from an OpenAPI spec

ref: https://learn.microsoft.com/en-gb/openapi/kiota/quickstarts/dotnet

kiota generate -l CSharp -d 3rdparty-openapi.yaml -c The3rdPartyClient -n MyApp.Api.Infrastructure.The3rdPartyClient -o ./Infrastructure/The3rdPartyClient

• -l == destination model Language. We want C Sharp :)
• -d == location of the openapi spec. can be local (to running the command) or a URI.
• -c == class name
• -n == namespace
• -o == output destination folder for all the generated models

How to wire up the generated client

builder.Services.AddHttpClient<The3rdPartyClient>();
builder.Services.AddScoped(sp =>
{
    var httpClient = sp.GetRequiredService<IHttpClientFactory>().CreateClient();
    httpClient.BaseAddress = new Uri("https://example.com/");
    
    // ANON connection
    //var adapter = new HttpClientRequestAdapter(new AnonymousAuthenticationProvider(), httpClient: httpClient);
    
    // AUTH connection
    var apiKeyProvider = new ApiKeyAuthenticationProvider(
        "YOUR_API_KEY",
        "api-header-key",
        ApiKeyAuthenticationProvider.KeyLocation.Header
    );
    var adapter = new HttpClientRequestAdapter(apiKeyProvider, httpClient: httpClient);
    
    return new The3rdPartyClient(adapter);
});

Complex example using strongly typed configuration

namespace MyApp.Api.Infrastructure;

public class The3rdPartyOptions
{
    public const string SectionName = "The3rdParty";
    public string BaseUrl { get; init; } = "https://example.com/";
    public string? ApiKey { get; init; }
}

{
  "The3rdParty": {
    "BaseUrl": "https://example.com/",
    "ApiKey": ""
  }
}

builder.Services.Configure<The3rdPartyOptions>(
    builder.Configuration.GetSection(The3rdPartyOptions.SectionName));

builder.Services.AddScoped(sp =>
{
    var options = sp.GetRequiredService<IOptions<The3rdPartyOptions>>().Value;

    var httpClient = sp.GetRequiredService<IHttpClientFactory>().CreateClient();
    httpClient.BaseAddress = new Uri(options.BaseUrl);

    IAuthenticationProvider authProvider = string.IsNullOrWhiteSpace(options.ApiKey)
        ? new AnonymousAuthenticationProvider()
        : new ApiKeyAuthenticationProvider(
            options.ApiKey,
            "api-header-key",
            ApiKeyAuthenticationProvider.KeyLocation.Header);

    var adapter = new HttpClientRequestAdapter(authProvider, httpClient: httpClient);
    return new The3rdPartyClient(adapter);
});