Web API with ASP.NET Core is a course in building REST APIs with ASP.NET Core 10, from REST principles and database access through EF Core to validation, OpenAPI documentation, JWT security and testing before release. It suits C# and backend developers who need to expose data to web front ends, mobile apps or other systems in a clean, secure way.
Web APIs sit at the heart of modern systems, serving single-page web apps, mobile apps, back-office services and integrations between organisations. A well-designed API speaks plain REST, validates data before saving it, reports errors in one consistent format, ships with documentation other teams can use straight away, and is secure enough to open to outside systems. ASP.NET Core on .NET 10 now has all of these tools built in.
This course takes learners through building web APIs with ASP.NET Core 10, starting with REST, HTTP methods and status codes, creating a controller-based project and connecting SQL Server through EF Core 10. Learners then build endpoints that retrieve, search, filter, page, add, update and delete data, with validation and ProblemDetails. The course goes on to built-in OpenAPI documentation, Minimal APIs, JWT authentication, versioning, rate limiting, caching and integration testing, and closes with a workshop that builds a complete API and runs it in Docker. (2 days, 6 hours per day, 12 hours in total, Intermediate level.)
Course Details
This course is the 2026 edition of Web API with ASP.NET Core, rewritten from scratch and updated for .NET 10 and ASP.NET Core 10. It runs for 2 days, 6 hours per day (12 hours in total, 09:00-16:00), as lectures with labs built on a single product and order API throughout. Intermediate level. It focuses on building web APIs, unlike the ASP.NET Core MVC course, which centres on web apps with user interfaces. All examples use C#. Every tool is free and every lab runs on the learner's own machine with Docker. Learners take home a lab guide, source code for every lab and docker-compose files for SQL Server 2025.
Section 1: REST Fundamentals
Section 2: Lab: An ASP.NET Core 10 Web API Project and Routing
Section 3: Lab: Connecting a Database with EF Core 10
Section 4: Lab: Retrieving, Searching and Paging Data
Section 5: Lab: Creating, Updating, Deleting and Validation
Section 6: Lab: OpenAPI Documentation and Minimal APIs
Section 7: Lab: Protecting the API with Authentication and Authorisation
Section 8: Versioning, Rate Limiting and Caching
Section 9: Lab: Testing and Consuming the API
Section 10: Workshop: Building and Deploying a Complete API
No public rounds are open right now. Join the waiting list and we will contact you first when the next round opens, or ask us on LINE. Or call 02-570-8449 or 088-807-9770
REST is a way of designing APIs that treats data as resources, each with its own URL, such as /api/products and /api/products/5. HTTP methods state the action: GET reads, POST creates, PUT replaces, PATCH partly updates and DELETE removes. The server replies with meaningful status codes such as 200 OK, 201 Created, 400 Bad Request and 404 Not Found, usually sends JSON and keeps no client state between requests.
Install the .NET 10 SDK and create a project with dotnet new webapi, or choose the ASP.NET Core Web API template in Visual Studio. The generated Program.cs registers services and exposes an OpenAPI document with AddOpenApi and MapOpenApi. Then add a model and a controller marked with ApiController, or write Minimal API endpoints with MapGet and MapPost. Run it with dotnet run and test with an .http file or Postman. When you need real storage, connect a database through EF Core 10.
Add data annotations to the model, such as Required, StringLength, Range and EmailAddress. When the controller has the ApiController attribute, the model is validated automatically and invalid data gets a 400 Bad Request in ProblemDetails format listing the faulty fields. Minimal APIs in .NET 10 can turn on built-in validation too. For more complex rules, such as checking whether a product code already exists, validate in the service layer and return BadRequest or Conflict as appropriate.
It suits C# and backend developers who need to build web APIs for websites, mobile apps or other systems, and developers on older ASP.NET versions moving to ASP.NET Core 10. You should be able to program in C#, understand the basics of HTTP and write basic SQL.
You will be able to design APIs along REST lines and build ASP.NET Core 10 web APIs on SQL Server through EF Core 10 that retrieve, search, page, add, update and delete data, with validation, ProblemDetails, OpenAPI documentation and JWT protection, then test them and run them in Docker. Participants who complete the training receive a Certificate of Completion with its own number, which can be verified online.
Yes. It can be run in-house for your team, with examples adapted to your own work, such as designing APIs around the data or systems your team needs to expose to others. You can request a quotation from this page, or contact us on LINE @itgenius or by phone on 02-570-8449.
Articles are published in Thai.
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