ASP.NET Core Complete Tutorial (ShopNest)
Lesson 37 of 75 49% of course

API Versioning in ASP.NET Core

1 · 5 min · 5/24/2026

Learn API Versioning in ASP.NET Core in our free ASP.NET Core Complete Tutorial (ShopNest) series. Step-by-step explanations, examples, and interview tips on Toolliyo Academy.

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API Versioning in ASP.NET Core — ShopNest
Article 37 of 75 · Module 5: Web API · ShopNest Public API with Breaking Changes
Target keyword: api versioning asp.net core · Read time: ~28 min · .NET: 8 / 9 · Project: ShopNest Public API with Breaking Changes

Introduction

When ShopNest adds inventory fields to products, mobile apps on v1 must not break. API versioning lets you ship v2 while deprecating v1 gracefully.

After this article you will

  • Version via URL, header, and query string
  • Use Asp.Versioning.Http package
  • Map v1 vs v2 product responses
  • Document multiple versions in Swagger
  • Deprecate old versions with headers

Prerequisites

Concept deep-dive

builder.Services.AddApiVersioning(options =>
{
    options.DefaultApiVersion = new ApiVersion(1, 0);
    options.AssumeDefaultVersionWhenUnspecified = true;
    options.ReportApiVersions = true;
    options.ApiVersionReader = ApiVersionReader.Combine(
        new UrlSegmentApiVersionReader(),
        new HeaderApiVersionReader("X-Api-Version"));
})
.AddApiExplorer(options => options.GroupNameFormat = "'v'VVV");

[ApiVersion("1.0")]
[Route("api/v{version:apiVersion}/[controller]")]
public class ProductsV1Controller : ControllerBase { ... }

[ApiVersion("2.0")]
public class ProductsV2Controller : ControllerBase
{
  // v2 includes StockQuantity in DTO
}

Deprecation: [MapToApiVersion("1.0")] + response header Deprecation: true and Sunset header per RFC.

Hands-on — ShopNest Public API with Breaking Changes

  1. Install Asp.Versioning.Mvc + ApiExplorer.
  2. ProductsV1 returns basic DTO; ProductsV2 adds inventory + warehouse.
  3. Test: GET /api/v1/products vs GET /api/v2/products.
  4. Swagger shows v1 and v2 document groups.

Common errors & best practices

  • Breaking changes without version bump — breaks mobile clients in production.
  • Multiple versioning strategies conflicting — pick URL or header as primary.

Interview questions

Q: URL vs header versioning?
A: URL is explicit and cache-friendly; header keeps URLs clean — many public APIs use URL (/v1/).

Q: When new major version?
A: Breaking contract changes — removed fields, changed types, URL structure.

Summary

  • Never break existing clients — add version instead
  • URL versioning is clearest for ShopNest public API
  • v1/v2 product DTO difference is classic interview scenario
  • Swagger multi-version docs aid partner developers

Previous: Building REST APIs
Next: Swagger / OpenAPI Documentation

FAQ

How many versions to maintain?

Typically current + one previous; sunset old with notice period.

Version in route template?

Use api/v{version:apiVersion}/[controller] with ApiVersion attribute.

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ASP.NET Core Complete Tutorial (ShopNest)

On this page

Introduction After this article you will Prerequisites Concept deep-dive Hands-on — ShopNest Public API with Breaking Changes Common errors & best practices Interview questions Summary FAQ How many versions to maintain? Version in route template?
Module 1: Foundations
What is ASP.NET Core? Complete Guide Setting Up ASP.NET Core Development Environment ASP.NET Core Project Structure Explained MVC Architecture in ASP.NET Core — Complete Guide Controllers and Actions in ASP.NET Core Routing in ASP.NET Core — Conventional and Attribute Routing Views and Razor Syntax in ASP.NET Core Layouts, Partial Views and View Components Models and ViewModels in ASP.NET Core Forms, Model Binding and Validation in ASP.NET Core Tag Helpers in ASP.NET Core — Complete Guide Static Files, Bundling and Minification in ASP.NET Core
Module 2: Entity Framework Core
Entity Framework Core — Introduction and Setup EF Core Code First — Models, Migrations, Database EF Core CRUD Operations — Create, Read, Update, Delete EF Core LINQ Queries — Beginner to Advanced EF Core Relationships — One-to-One, One-to-Many, Many-to-Many EF Core Fluent API — Advanced Configuration EF Core Repository Pattern and Unit of Work EF Core Performance Optimization Database First Approach with EF Core (Scaffold) EF Core with SQL Server — Advanced Features
Module 3: Dependency Injection & Middleware
Dependency Injection in ASP.NET Core — Complete Guide Middleware in ASP.NET Core — Complete Guide Configuration in ASP.NET Core — appsettings, Environment Variables, Secrets Filters in ASP.NET Core — Action, Authorization, Exception, Resource, Result Logging in ASP.NET Core — ILogger, Serilog, NLog Error Handling and Exception Management in ASP.NET Core
Module 4: Authentication & Security
ASP.NET Core Identity — Complete Setup Guide Authentication in ASP.NET Core — Cookie and JWT Authorization in ASP.NET Core — Roles, Policies, Claims JWT Authentication with Refresh Tokens — Complete Implementation OAuth2 and External Login (Google, Facebook, Microsoft) Data Protection and Encryption in ASP.NET Core HTTPS, SSL Certificates and Security Best Practices
Module 5: Web API
Building REST APIs with ASP.NET Core — Complete Guide API Versioning in ASP.NET Core Swagger / OpenAPI Documentation in ASP.NET Core Input Validation in Web APIs — FluentValidation and Data Annotations Pagination, Filtering and Sorting in ASP.NET Core APIs HTTP Client and Consuming External APIs in ASP.NET Core Minimal APIs in ASP.NET Core .NET 8 SignalR — Real-Time Web Applications
Module 6: Advanced Architecture
Clean Architecture in ASP.NET Core CQRS Pattern with MediatR in ASP.NET Core Repository Pattern — Deep Dive with Generic Repository Background Services and Hosted Services in ASP.NET Core Caching in ASP.NET Core — In-Memory, Distributed, Redis Health Checks in ASP.NET Core AutoMapper in ASP.NET Core Microservices with ASP.NET Core — Introduction Message Queues with RabbitMQ / Azure Service Bus in ASP.NET Core gRPC with ASP.NET Core
Module 7: Testing
Unit Testing ASP.NET Core with xUnit and Moq Integration Testing in ASP.NET Core Testing EF Core — In-Memory vs SQLite Performance Testing and Load Testing ASP.NET Core APIs Test-Driven Development (TDD) in ASP.NET Core
Module 8: Deployment & DevOps
Deploying ASP.NET Core to IIS on Windows Server Docker and Containerization for ASP.NET Core Deploying ASP.NET Core to Azure App Service CI/CD with GitHub Actions for ASP.NET Core Azure SQL Database with ASP.NET Core Environment Configuration and Secrets Management
Module 9: Real-World Projects
Build a Complete Blog Website with ASP.NET Core MVC Build an E-Commerce Product Catalog API (ASP.NET Core Web API) Build a Student Management System (Complete CRUD App) Build a Job Portal (Full Stack ASP.NET Core) Build a REST API with Clean Architecture — Complete Guide Build a Real-Time Chat App with SignalR and ASP.NET Core
Module 10: Advanced Topics
Blazor WebAssembly and Blazor Server — Complete Guide gRPC, GraphQL and Alternative API Styles in ASP.NET Core Rate Limiting and API Throttling in ASP.NET Core .NET 8 Output Caching in ASP.NET Core .NET 8 ASP.NET Core .NET 9 New Features — Complete Guide