Build Your First .NET 10 Web API in 15 Minutes with Swagger

C# .NET 10 Web API: Step-by-Step Guide with Swagger & VS 2026 🚀 Build your *first .NET 10 Web API with Swagger* using C# and Visual Studio 2026 in this comprehensive, step-by-step tutorial! Unlock the power of backend development as we guide you through creating a fully functional Web API, integrating Swagger for seamless API testing and documentation. Whether you're a beginner in C# or looking to master ASP.NET Core, this video provides the essential knowledge to kickstart your journey. *What You'll Achieve:* *Effortless Project Setup:* Create a new ASP.NET Core Web API project in Visual Studio 2026 with .NET 10. *Understand Project Structure:* Gain clarity on the essential components of a .NET 10 Web API project. *Master Swagger Integration:* Manually configure Swagger (OpenAPI) and verify its functionality. *Develop Your First Controller:* Write and implement your initial API controller in C#. *Run & Test Your API:* Execute your Web API using Visual Studio (F5) and test endpoints directly in Swagger UI. *Troubleshoot Common Issues:* Learn to resolve problems like Swagger 404 errors and understand HTTP status codes. *Why Learn Web APIs & Swagger?* A Web API acts as a bridge, allowing different applications (web, mobile, services) to communicate via HTTP, typically exchanging data in JSON format. ASP.NET Core simplifies building robust and scalable APIs in C#, while .NET 10 offers enhanced performance and modern features. Swagger (OpenAPI) is indispensable for: *Automated Documentation:* Generate clear, up-to-date API documentation. *Interactive Testing:* Test your API endpoints directly through a user-friendly UI. *Developer Clarity:* Understand request/response formats easily. *Video Chapters:* 0:00 Introduction: Building a Web API with .NET 10 & Visual Studio 2026 00:26 Project Overview: What We'll Build 00:49 Creating a New Project 02:01 Troubleshooting Swagger 404 Errors 02:28 Installing Swagger Packages (UI) 03:06 Installing Swagger Packages via CLI 04:13 Registering Swagger Services 04:44 Enabling Swagger Middleware 05:35 Running and Verifying Swagger UI 06:14 `UseSwagger()` vs. `UseSwaggerUI()` Explained 07:56 Understanding Comment Lines in .NET 08:38 ASP.NET Core Web API Project Structure Deep Dive 10:33 Creating and Explaining an API Controller 12:00 Example: Handling a 400 Bad Request Status Code 13:41 Testing a New Endpoint in Swagger UI 14:24 Configuring Swagger in `launchSettings.json` 15:17 Tutorial Recap *Quick Q&A:* *Q1: What is a Web API?* A: A backend service enabling client-server communication over HTTP, usually returning JSON data. *Q2: What is Swagger and why use it?* A: Swagger (OpenAPI) provides interactive API documentation and a testing interface. *Q3: `UseSwagger()` vs. `UseSwaggerUI()`?* A: `UseSwagger()` generates the spec; `UseSwaggerUI()` renders the interactive UI. *Q4: How to test my API?* A: Use Swagger UI, Postman, or C# HttpClient. *Q5: Who is this tutorial for?* A: Beginners in C# Web APIs, students, fresh graduates, developers new to ASP.NET Core or .NET 10, and those upgrading their skills. **Prerequisites: ** .NET 10 installed (Check out our previous tutorial: [Install .NET 10 and Visual Studio 2026] (   • Your VS 2026 Setup is Probably Wrong (Here...  ) Visual Studio 2026 installed *Support Us:* If you found this tutorial helpful, please give it a thumbs up 👍, share it with your network, and subscribe for more coding tutorials! 🔔 Subscribe:    / @muthudevhub   #dotnet10 #csharp #webapi #aspnetcore #swagger #visualstudio2026 #backenddevelopment #apidesign #programmingtutorial #softwaredevelopment