Context

Scaffolds a typed HTTP client for calling external APIs, including the client interface, implementation, DelegatingHandler for cross-cutting concerns, and DI registration.

Inputs

$ARGUMENTS - Client name and base URL (e.g., "PaymentGateway https://api.payment.com")

Steps

1. Parse Arguments

Extract:

•Client name (e.g., PaymentGateway)
•Base URL (e.g., https://api.payment.com)

2. Read Standards

Read standards/dotnet.md for HTTP client patterns and DelegatingHandler usage.

3. Create Client Interface

csharp

public interface I{Name}Client
{
    Task<Result<{Response}>> {Method}Async({Request} request, CancellationToken cancellationToken);
}

4. Create Client Implementation

csharp

public class {Name}Client : I{Name}Client
{
    private readonly HttpClient _httpClient;

    public {Name}Client(HttpClient httpClient)
    {
        _httpClient = httpClient;
    }
}

5. Create DelegatingHandler

csharp

public class {Name}DelegatingHandler : DelegatingHandler
{
    protected override async Task<HttpResponseMessage> SendAsync(
        HttpRequestMessage request,
        CancellationToken cancellationToken)
    {
        // Add headers, logging, retry logic
        return await base.SendAsync(request, cancellationToken);
    }
}

6. Register DI

csharp

services.AddTransient<{Name}DelegatingHandler>();
services.AddHttpClient<I{Name}Client, {Name}Client>(client =>
{
    client.BaseAddress = new Uri(configuration["{Name}:BaseUrl"]);
})
.AddHttpMessageHandler<{Name}DelegatingHandler>();

7. Add Configuration

Add to appsettings.json:

json

"{Name}": {
  "BaseUrl": "{baseUrl}"
}

8. Generate Tests

Test client methods with mocked HttpMessageHandler.

9. Verify

Run dotnet build and dotnet test.

Verification

•Builds without errors
•Tests pass
•DI registration uses AddHttpClient
•DelegatingHandler registered
•Configuration section added