Features - REST API Client Code Generator

Visual Studio Integration

REST API Client Code Generator provides seamless integration across all major Visual Studio platforms with consistent functionality and user experience.

Add a new REST API Client directly from the Visual Studio Add menu

Configure your OpenAPI specification URL, namespace, and code generator

Supported Platforms

Visual Studio 2017, 2019, 2022 - Full integration with all modern Visual Studio versions
Visual Studio Code - Context menu integration for JSON and YAML files
Visual Studio for Mac - Complete feature parity across platforms

Right-click context menu options in Solution Explorer for quick access to code generation

Code Generators

Custom Tools

Custom tools let you associate a tool with an item in a project and run that tool whenever the file is saved, enabling automatic code regeneration when your OpenAPI specifications change.

NSwagCodeGenerator

Version: v14.4.0

Generates a single file C# REST API Client using the NSwag.CodeGeneration.CSharp NuGet package. Produces clean, strongly-typed code with full async support and comprehensive error handling.

Key Features:

Strongly-typed client generation
Full async/await support
Comprehensive exception handling
Integration with ASP.NET Core

OpenApiCodeGenerator

Version: v7.14.0

Generates a single file C# REST API Client using OpenAPI Generator. The output file merges all generated files using the command: generate -g csharp --input-spec [swagger file] --output [output file] -DapiTests=false -DmodelTests=false -DpackageName=[namespace] --skip-overwrite

Configuration Options:

Generate Multiple Files support
Extensive customization properties
Template customization
Multiple output formats

KiotaCodeGenerator

Version: v1.28.0

Generates a single file C# REST API Client using Microsoft Kiota. The output merges files generated with: generate -l CSharp -d [swagger file] -o [output file] -n [namespace]

Microsoft Integration:

Microsoft Graph API support
Azure authentication patterns
Modern .NET practices
Strong typing and validation

SwaggerCodeGenerator

Version: v3.0.34

Generates a single file C# REST API Client using Swagger Codegen CLI. Uses the command: generate -l csharp --input-spec [swagger file] --output [output file] -DapiTests=false -DmodelTests=false -DpackageName=[namespace] --skip-overwrite

Proven Reliability:

Extensive language support
Legacy project compatibility
Established workflow integration
Community-driven templates

AutoRestCodeGenerator

Version: v3.0.0-beta.20210504.2 (v3), v2.0.4417 (v2)

Generates a single file C# REST API Client using AutoRest. Equivalent to: --csharp --input-file=[swagger file] --output-file=[output file] --namespace=[namespace] --add-credentials

Enterprise Features:

Azure service optimization
Advanced authentication
Retry policies and timeout configuration
Enterprise-grade reliability

RefitterCodeGenerator

Version: v1.6.1

Generates a single file C# REST API Client interface for Refit using Refitter.Core. Combines a Refit interface generated by Refitter with contracts generated using NSwag.CodeGeneration.CSharp.

Reactive Patterns:

Refit interface generation
Reactive programming support
Clean interface design
Comprehensive testing capabilities

Configuration File Support

Generate code from NSwag Studio .nswag configuration files

Refitter .refitter settings file integration

Microsoft Kiota kiota-lock.json configuration support

Generate code using configuration files:

.nswag configuration files from NSwagStudio by including it in the project and using the Generate NSwag Studio output context menu
.refitter settings files from Refitter by including it in the project and using the Generate Refitter output context menu
kiota-lock.json configuration files from Microsoft Kiota by including it in the project and using the Generate Kiota output context menu

Auto-Generation Features

🔄 Automatic Code Regeneration

Custom tools automatically regenerate client code whenever your OpenAPI specification files change, keeping your code always in sync with your API.

Auto-updating of generated code file when changes are made to the OpenAPI specification JSON or YAML file
Custom namespace definition for the generated file
Multiple file generation support for OpenAPI Generator and Kiota (configurable in settings)
Context menu integration for quick access to generation options

Advanced Configuration

Settings and Customization

The extension provides extensive configuration options for each code generator, accessible through the Visual Studio Tools menu.

General settings for Java, NPM, and tool paths

NSwag-specific configuration options

OpenAPI Generator customization settings

Customizable Settings

Environment Configuration

Java path configuration - Specify custom Java installation paths
NPM and Node.js paths - Configure custom Node.js environments
JAR file locations - Use existing Swagger Codegen CLI and OpenAPI Generator JAR files

Generator-Specific Options

AutoRest Customization - Support for all C# generator settings, custom authentication schemes, retry policies
NSwag Customization - Full access to NSwag package properties, custom serialization settings, advanced type mapping
OpenAPI Generator Options - Access to additional properties, template customization, multiple output formats

AutoRest generator configuration

Refitter customization settings

Microsoft Kiota configuration options

Cross-Platform Support

Visual Studio Code Integration

VS Code command palette integration

Context menu support for C# generation in VS Code

TypeScript code generation support in VS Code

Visual Studio for Mac

Visual Studio for Mac "Add New" menu integration

OpenAPI specification configuration dialog on macOS

Code generation context menu in Visual Studio for Mac

Dependencies and Requirements

Automatic Dependency Management

The Visual Studio Extension automatically adds the required NuGet packages that the generated code depends on:

NSwag Dependencies

Newtonsoft.Json - JSON serialization

OpenAPI Generator Dependencies

RestSharp - HTTP client library
JsonSubTypes - Polymorphic JSON serialization
Polly - Resilience and fault-handling library
Newtonsoft.Json - JSON serialization

Microsoft Kiota Dependencies

Microsoft.Kiota.Abstractions
Microsoft.Kiota.Http.HttpClientLibrary
Microsoft.Kiota.Serialization.* packages
Microsoft.Kiota.Authentication.Azure
Azure.Identity

Refitter Dependencies

Refit - REST library for .NET

Swagger Codegen CLI Dependencies

RestSharp - HTTP client library
JsonSubTypes - Polymorphic JSON serialization

AutoRest Dependencies

Microsoft.Rest.ClientRuntime
Newtonsoft.Json - JSON serialization

Runtime Requirements

Java Runtime Environment - Required for Swagger Codegen CLI and OpenAPI Generator
NPM - Required for AutoRest and NSwag CLI installations
.NET 7.0 - Required for Microsoft Kiota

📦 On-Demand Installation

The Swagger Codegen CLI and OpenAPI Generator are distributed as JAR files and downloaded on demand. AutoRest is installed via NPM as a global tool, and Microsoft Kiota is installed as a .NET Tool - all automatically managed for you.

Analytics and Error Reporting

Analytics and error reporting configuration options

Anonymous usage tracking - Helps improve the tool through Exceptionless and Azure Application Insights
Error reporting - Automatic error collection to improve stability and user experience
Privacy-focused - Uses secure hash of username@host for anonymous identification
Configurable - Can be completely disabled through the settings panel

Custom Tool Examples

NSwag custom tool configuration in file properties

OpenAPI Generator custom tool setup

Swagger Codegen CLI custom tool configuration