DotnetClientGenerator 2.1.0

DotnetClientGenerator

A .NET tool for generating C# API clients from OpenAPI specifications.

Quick Start

Install the tool globally:

dotnet tool install --global DotnetClientGenerator

Generate a client:

dotnet-client-generator --input openapi.json --output ApiClient.cs

Features

• ✅ OpenAPI 3.0 specification support
• ✅ Modern C# with HttpClient and async/await
• ✅ JSON serialization with System.Text.Json
• ✅ Customizable class names and namespaces
• ✅ Watch mode for automatic regeneration
• ✅ Support for URLs and local files
• ✅ Query parameters and path parameters
• ✅ Request body handling
• ✅ Type-safe response handling with pattern matching
• ✅ Optional interface generation for dependency injection

Usage Examples

Basic Generation

dotnet-client-generator -i openapi.json -o MyClient.cs

Custom Class and Namespace

dotnet-client-generator \
  --input https://petstore.swagger.io/v2/swagger.json \
  --output PetStoreClient.cs \
  --class-name PetStoreClient \
  --namespace PetStore.Api

Watch Mode

dotnet-client-generator -i openapi.json -o ApiClient.cs --watch

Generate with Interface

dotnet-client-generator -i openapi.json -o ApiClient.cs --generate-interface

Generated Client Usage

// Dependency injection setup
services.AddHttpClient<IApiClient, ApiClient>();

// Manual setup
var httpClient = new HttpClient { BaseAddress = new Uri("https://api.example.com") };
var client = new ApiClient(httpClient);

// Use the client with pattern matching
var response = await client.GetUser(userId);

switch (response)
{
    case GetUserResponse.Ok ok:
        Console.WriteLine($"Found user: {ok.Value.Name}");
        break;
    case GetUserResponse.NotFound:
        Console.WriteLine("User not found");
        break;
    case GetUserResponse.BadRequest:
        Console.WriteLine("Invalid request");
        break;
    case GetUserResponse.Unexpected unexpected:
        Console.WriteLine($"Unexpected status: {unexpected.StatusCode}");
        break;
}

// Or use switch expressions
var message = response switch
{
    GetUserResponse.Ok { Value: var user } => $"Hello, {user.Name}!",
    GetUserResponse.NotFound => "User not found",
    GetUserResponse.Unauthorized => "Please log in",
    GetUserResponse.Unexpected { StatusCode: var code } => $"Error: {code}",
    _ => "Unknown response"
};

Command Line Options

Requirements

• .NET 10.0 or later
• OpenAPI 3.0 specification

More Information

For detailed documentation, examples, and contribution guidelines, visit the main repository.