SaaSHub helps you find the best software and product alternatives Learn more →
Top 15 C# OpenAPI Projects
-
Project mention: Why Startups and IndieDevs Should Choose Monolith First, Lessons From My Micro-SaaS Project, For ... | dev.to | 2026-01-09
Type sharing is possible (think NSwag or OpenAPI codegen).
-
ReSharper
ReSharper is now available in VS Code and Cursor. ReSharper brings a professional toolset for C# developers backed by over 20 years of experience, enterprise-grade security, SOC 2 compliance, and the trust of companies worldwide.
-
-
-
OpenAPI.NET
The OpenAPI.NET SDK contains a useful object model for OpenAPI documents in .NET along with common serializers to extract raw OpenAPI JSON and YAML documents from the model.
Most times you are calling a subset of the endpoints available. Take the Microsoft Graph API for example, the OpenAPI document is very large resulting in too much functions available for the model to work with. Luckily for us there is tooling for that. I used Microsoft Hidi to transform the document by specifying only the operations I am interested in:
-
-
azure-functions-openapi-extension
This extension provides an Azure Functions app with Open API capability for better discoverability to consuming parties
-
-
SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
-
GenHTTP
Lightweight embeddable web server written in pure C# with few dependencies to 3rd-party libraries.
-
-
apiclientcodegen
A collection of Visual Studio code generators for Swagger / OpenAPI specification files
-
Unchase.OpenAPI.Connectedservice
:scroll: Visual Studio extension to generate OpenAPI (Swagger) web service reference.
-
-
-
-
Project mention: Show HN: Abuse Signals API – deterministic domain/email abuse indicators | news.ycombinator.com | 2026-01-14
-
SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
NOTE:
The open source projects on this list are ordered by number of github stars.
The number of mentions indicates repo mentiontions in the last 12 Months or
since we started tracking (Dec 2020).
C# OpenAPI discussion
C# OpenAPI related posts
-
Why Startups and IndieDevs Should Choose Monolith First, Lessons From My Micro-SaaS Project, For ...
-
Forget MCP, Use OpenAPI for external operations
-
Learning TDD by doing: Is Umbraco's management API the answer to acceptance testing?
-
Criando Web APIs modernas, autônomas e rastreáveis com .Net Core utilizando arquitetura de microsserviços – Parte 2
-
NET9: Swagger no compatible [Alternativas]
-
NSwag: OpenAPI/Swagger Toolchain for .NET, Asp.net Core and TypeScript
-
Kiota: OpenAPI-Based HTTP Client Code Generator
-
A note from our sponsor - SaaSHub
www.saashub.com | 17 Jun 2026
Index
What are some of the best open-source OpenAPI projects in C#? This list will help you:
| # | Project | Stars |
|---|---|---|
| 1 | NSwag | 7,338 |
| 2 | kiota | 3,772 |
| 3 | WebApiClient | 2,136 |
| 4 | OpenAPI.NET | 1,593 |
| 5 | dev-proxy | 792 |
| 6 | azure-functions-openapi-extension | 388 |
| 7 | AsyncAPI.NET | 358 |
| 8 | GenHTTP | 271 |
| 9 | openapi-starter | 216 |
| 10 | apiclientcodegen | 205 |
| 11 | Unchase.OpenAPI.Connectedservice | 109 |
| 12 | tgstation-server | 86 |
| 13 | SourceApi | 15 |
| 14 | aspnet-openapi-xml | 9 |
| 15 | abusesignalsapi-examples | 1 |
Sponsored
ReSharper is now available in VS Code and Cursor
ReSharper brings a professional toolset for C# developers backed by over 20 years of experience, enterprise-grade security, SOC 2 compliance, and the trust of companies worldwide.
www.jetbrains.com