What you'll learn

Every API eventually needs to change, and without a versioning strategy, every change risks breaking existing consumers. Informal approaches like duplicating controllers or appending "/v2" to routes quickly become unmaintainable. In this course, Versioning ASP.NET Core 10 Web APIs, you'll gain the ability to implement a complete API versioning strategy that lets your API evolve while existing clients continue to work. First, you'll explore why API versioning matters and how to choose among URL-based, query-string, header-based, and media-type strategies, then configure the Asp.Versioning libraries in an ASP.NET Core 10 project. Next, you'll discover how to apply version attributes to controllers, manage major and minor versions, share stable endpoints across versions without duplication, and generate version-aware OpenAPI contracts using .NET 10's built-in OpenAPI support and document transformers. Finally, you'll learn how to communicate API lifecycle information through version response headers, signal deprecation and sunset dates, and validate versioned behavior through integration testing. When you're finished with this course, you'll have the skills and knowledge of ASP.NET Core API versioning needed to evolve your Web APIs confidently, with clean contracts, clear deprecation signals, and tests that prove each version works independently.