ASP.NET Core Complete Tutorial (ShopNest)
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Minimal APIs in ASP.NET Core .NET 8

1 · 5 min · 5/24/2026

Learn Minimal APIs in ASP.NET Core .NET 8 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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Minimal APIs in ASP.NET Core .NET 8 — ShopNest
Article 42 of 75 · Module 5: Web API · ShopNest Lightweight Microservice
Target keyword: minimal apis asp.net core · Read time: ~28 min · .NET: 8 / 9 · Project: ShopNest Lightweight Microservice

Introduction

Minimal APIs map routes to lambdas or methods in Program.cs — ideal for ShopNest microservices (inventory snapshot, health probes) without full controller ceremony.

After this article you will

  • Map GET/POST/PUT/DELETE with MapGroup
  • Bind route, query, and body parameters
  • Inject services into route handlers
  • Add filters and OpenAPI to minimal endpoints
  • Compare minimal vs controller-based APIs

Prerequisites

Concept deep-dive

var inventory = app.MapGroup("/api/inventory").WithTags("Inventory");

inventory.MapGet("/", async (IInventoryService svc) =>
    Results.Ok(await svc.GetAllAsync()));

inventory.MapGet("/{sku}", async (string sku, IInventoryService svc) =>
{
    var item = await svc.GetBySkuAsync(sku);
    return item is null ? Results.NotFound() : Results.Ok(item);
});

inventory.MapPost("/", async (CreateInventoryDto dto, IInventoryService svc) =>
{
    var created = await svc.CreateAsync(dto);
    return Results.Created($"/api/inventory/{created.Sku}", created);
}).RequireAuthorization();
Minimal APIsControllers
Fast to prototype, less boilerplateBetter for large teams, filters, conventions
Great for microservicesGreat for full ShopNest monolith MVC+API

Hands-on — ShopNest Lightweight Microservice

  1. ShopNest.InventoryService — minimal API only project.
  2. MapGroup with route prefix and OpenAPI tag.
  3. Validation filter or Validate on POST.
  4. Dockerfile for lightweight container deploy.

Common errors & best practices

  • Giant Program.cs — use extension methods MapInventoryEndpoints().
  • Skipping authorization on write endpoints.

Interview questions

Q: When Minimal APIs?
A: Small services, BFFs, internal tools — not mandatory for all ShopNest APIs.

Q: DI in minimal handlers?
A: Parameters resolved from DI like controller constructors.

Summary

  • Minimal APIs reduce ceremony for small services
  • MapGroup organizes related endpoints
  • Same auth, validation, OpenAPI as controllers
  • ShopNest inventory microservice is ideal use case

Previous: HTTP Client and External APIs
Next: SignalR — Real-Time Web Applications

FAQ

Minimal API filters?

IEndpointFilter in .NET 7+ — like action filters for endpoints.

Test minimal APIs?

WebApplicationFactory integration tests hit endpoints in-memory.

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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 Lightweight Microservice Common errors & best practices Interview questions Summary FAQ Minimal API filters? Test minimal APIs?
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