Minimal APIs in ASP.NET Core 8: Simplifying Microservices

3 min readMar 22, 2024

ASP.NET Core 8 brings an exciting feature to the table: Minimal APIs. These are designed to simplify the process of building APIs, making it more straightforward and less cumbersome, especially for microservice architectures. Let’s delve into what Minimal APIs are and how they’re changing the game in ASP.NET Core 8.

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What Are Minimal APIs?

Minimal APIs are a streamlined way to create HTTP APIs in ASP.NET Core 8. They reduce the amount of boilerplate code required to set up simple APIs, focusing on the core functionality without the need for extensive setup or configuration. This makes them perfect for microservices where simplicity and performance are key.

Why Use Minimal APIs?

Simplicity: With Minimal APIs, you can define endpoints in just a few lines of code. This simplicity is ideal for small services or when you’re prototyping.
Performance: They’re built on the same high-performance foundations as the rest of ASP.NET Core, ensuring your APIs are fast and efficient.
Flexibility: While they are “minimal,” they don’t limit you. You can start with a Minimal API and expand it into a full MVC application if needed, without any major overhaul.

Creating a Minimal API in ASP.NET Core 8

Here’s a quick look at how you can create a Minimal API:

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/", () => "Hello, Minimal API!");
app.Run();

In just a few lines, we’ve set up a basic API that responds to HTTP GET requests at the root with a simple greeting. This simplicity is what makes Minimal APIs a game-changer.

We’re creating a web app and mapping a GET request to the root path. It simply returns ‘Hello World!’ This shows the ease of setting up a basic API endpoint with Minimal APIs.

Routing with Parameters

Minimal APIs also support dynamic routing. See example code:

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/users/{userId}/books/{bookId}", 
 (int userId, int bookId) => $"The user id is {userId} and book id is {bookId}");
app.Run();

In this example, we have route parameters for a user ID and a book ID.
The API responds with these IDs. This demonstrates how easily you can handle more complex routing scenarios.

Use Cases for Minimal APIs

Microservices: They’re perfect for microservices due to their lightweight nature, allowing each service to be lean and focused.
Prototyping: When you need to quickly spin up an API for testing or proof-of-concept work, Minimal APIs are ideal.
Educational Purposes: They’re great for teaching or learning about web APIs without the overhead of a full MVC application.

Extending Minimal APIs

While they’re designed to be minimal, these APIs are not limited in capability. You can add middleware, use dependency injection, and even incorporate Entity Framework Core for data access. This flexibility ensures that as your project grows, your Minimal API can grow with it.

Conclusion

Minimal APIs in ASP.NET Core 8 are transforming how we build web APIs, making it faster and easier to get your services up and running. They embody the principle of doing more with less, offering a streamlined approach to API development without sacrificing power or flexibility. Whether you’re building a suite of microservices or just need a quick API for a project, Minimal APIs are worth exploring.

In the world of microservices and cloud-native development, where simplicity and performance are paramount, Minimal APIs in ASP.NET Core 8 are your go-to tool for building efficient and maintainable services. Embrace the minimalism, and watch your productivity soar!