Open-source C# projects categorized as API

Top 23 C# API Projects

  • GitHub repo Bitwarden

    The core infrastructure backend (API, database, Docker, etc). (by bitwarden)

    Project mention: news.ycombinator.com | 2021-02-22

    What do you think about this reply on that thread? https://github.com/bitwarden/server/issues/589#issuecomment-...

  • GitHub repo Jackett

    API Support for your favorite torrent trackers

    Project mention: Help! How to link radarr to TL ? | reddit.com/r/radarr | 2021-02-23


  • Scout

    Get performance insights in less than 4 minutes. Scout APM uses tracing logic that ties bottlenecks to source code so you know the exact line of code causing performance issues and can get back to building a great product faster.

  • GitHub repo ServiceStack

    Thoughtfully architected, obscenely fast, thoroughly enjoyable web services for all

  • GitHub repo GraphQL for .NET

    GraphQL for .NET

    Project mention: Learn GraphQL + React in 30 mins with Apollo's new learning platform Odyssey! | reddit.com/r/reactjs | 2021-01-29

    If you're loving your current stack, you should stick with it :) But, if you're experiencing some of the problems described in the article, you might want to try Apollo. It's incrementally adoptable, so you don't have to rewrite your whole app to start using it. There's also a community maintained .NET implementation of GraphQL, so you could use that for your graph and use Apollo Client to connect it to the frontend.

  • GitHub repo DocFX

    Tools for building and publishing API documentation for .NET projects

    Project mention: Infrastructure | reddit.com/r/technicalwriting | 2021-01-10

    DocFX is the open source part of this: https://github.com/dotnet/docfx

  • GitHub repo ASP.NET MVC Boilerplate

    .NET project templates with batteries included, providing the minimum amount of code required to get you going faster.

  • GitHub repo WexFlow

    An easy and fast way to build automation and workflows on Windows, Linux, macOS, and the cloud.

    Project mention: WexFlow - What happened to it? | reddit.com/r/csharp | 2021-02-12
  • Uno Platform

    Pixel-Perfect Multi-Platform Applications with C# and XAML. Build single-codebase applications for Windows, Web, Linux, macOS, iOS and Android with open-source Uno Platform. Fluent and Material design included in-the-box. Try now via 3 min tutorial.

  • GitHub repo Hot Chocolate

    Welcome to the home of the Hot Chocolate GraphQL server for .NET, the Strawberry Shake GraphQL client for .NET and Banana Cake Pop the awesome Monaco based GraphQL IDE.

    Project mention: On .NET Episode: Real-time Data fetching with GraphQL and Blazor | dev.to | 2020-11-04

    HotChocolate in GitHub

  • GitHub repo Telegram.Bot

    .NET Client for Telegram Bot API

  • GitHub repo tModLoader

    A mod to make and play Terraria mods. Supports Terraria 1.4 installations - TML itself is 1.3 Terraria currently

    Project mention: Need help with Tmodloader 64 bits | reddit.com/r/Terraria | 2021-02-22

    Releases · tModLoader/tModLoader · GitHub

  • GitHub repo Xamarin.Essentials

    Essential cross platform APIs for your mobile apps. (by xamarin)

  • GitHub repo FFImageLoading - Fast & Furious Image Loading

    Image loading, caching & transforming library for Xamarin and Windows

  • GitHub repo simulator

    A ROS/ROS2 Multi-robot Simulator for Autonomous Vehicles

    Project mention: *Bonk Bonk* | reddit.com/r/ProgrammerHumor | 2021-02-14
  • GitHub repo TLSharp

    Telegram client library implemented in C#

    Project mention: Is it possible to read a Telegram message by a t.me link? | reddit.com/r/dotnet | 2021-02-06

    Hi, you could try to use a lib like this: https://github.com/sochix/TLSharp

  • GitHub repo WebAPI Contrib

    Community Contributions for ASP.NET Web API

  • GitHub repo Twilio-csharp

    Twilio C#/.NET Helper Library for .NET Framework 3.5+ and supported .NET Core versions

  • GitHub repo JsonApiDotNetCore

    JSON:API Framework for ASP.NET Core

    Project mention: Composing and nesting with JsonApiDotNetCore | dev.to | 2020-12-21

    It's so powerful that it even allows you to establish relationships between operations within a single request, using something called local IDs. Work is progressing quickly on the atomic-operations branch. Check it out on Github if you want to follow along.

  • GitHub repo SapphireDb

    SapphireDb Server, a self-hosted, easy to use realtime database for Asp.Net Core and EF Core

  • GitHub repo Lib.AspNetCore.ServerSentEvents

    Lib.AspNetCore.ServerSentEvents is a library which provides Server-Sent Events (SSE) support for ASP.NET Core

  • GitHub repo Nelibur

    Message based webservice framework on the pure WCF

  • GitHub repo Breeze

    Breeze for C#, F#, and VB.NET client applications

  • GitHub repo NGeoNames

    Inspired by https://github.com/AReallyGoodName/OfflineReverseGeocode

  • GitHub repo CommandQuery

    Command Query Separation for 🌐ASP.NET Web API 2 🌐ASP.NET Core ⚡AWS Lambda ⚡Azure Functions

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). The latest post mention was on 2021-02-23.


What are some of the best open-source API projects in C#? This list will help you:

Project Stars
1 Bitwarden 7,097
2 Jackett 5,398
3 ServiceStack 4,875
4 GraphQL for .NET 4,640
5 DocFX 2,562
6 ASP.NET MVC Boilerplate 2,513
7 WexFlow 2,432
8 Hot Chocolate 2,024
9 Telegram.Bot 1,612
10 tModLoader 1,491
11 Xamarin.Essentials 1,332
12 FFImageLoading - Fast & Furious Image Loading 1,285
13 simulator 1,237
14 TLSharp 887
15 WebAPI Contrib 757
16 Twilio-csharp 538
17 JsonApiDotNetCore 457
18 SapphireDb 317
19 Lib.AspNetCore.ServerSentEvents 139
20 Nelibur 124
21 Breeze 76
22 NGeoNames 69
23 CommandQuery 48