Will .NET 6 Minimal APIs turn heads?

I am pretty excited about the Minimal APIs feature that is coming with .NET 6. Three lines of code will be enough to build a fully functional REST microservice1:

var app = WebApplication.Create(args);
app.MapGet("/", () => "Hello World!");
await app.RunAsync();

If you’re a seasoned ASP.NET MVC/WebApi developer, the snippet caught your attention because, pre-.NET 6, achieving the same result will have you messing with a lot of extra cruft2. I suspect, however, that this feature is not primarily targeted at existing .NET developers. Developers new and old looking at .NET for the first time, or those like me returning after a long break; these are, I think, the designated audience.

A long time ago, I left C# and .NET behind precisely because I had to write REST APIs, and back then, the options available in .NET were, to put it mildly, cumbersome. Admittedly, there were other reasons for switching, like .NET not being cross-platform - I wanted to run my APIs on Linux - and general dissatisfaction with the Microsoft ecosystem. Long story short, I went with Python. Check out this snippet from Flask’s renowned Quickstart:

app = Flask(__name__)

def hello_world():
    return "<p>Hello, World!</p>"

Launched with the compelling motto ‘web development, one drop at a time’ and presented as a ‘micro’ web framework, Flask immediately caught my attention3. Cruft-free and elegant APIs are not a Flask (or Python, for the matter) exclusive. A Node code snippet for a REST API would be similar. Now, with NET 6 Minimal APIs, we’re finally matching the industry standard for code clarity and simplicity. Moreover, .NET has better performance4 and strongly typed languages that offer excellent type inference (F# reigns supreme there, with C# catching up nicely.) I’d dare to say that the C# snippet is a winner. I mean, look at that inline lambda, with no casts!

Minimal APIs typical use-case is everyone’s favourite, microservices. I do not doubt the delivery56. The challenge, I think, is the actual adoption rate. Whether veterans will adopt them or not (over time, they will) is relatively significant, I guess. The critical question is, will Minimal APIs succeed in attracting new developers to .NET?

That will mainly depend on communication. Will evangelism be robust, persistent and persuasive enough? That’s the tricky part. Every time I speak to the Python or JavaScript crowd, I am amazed that the majority don’t even know that .NET is now open-source, cross-platform, and blazingly performant. Most, if not all, are tied to the old idea of a Windows-only, cumbersome, black-boxed, enterprise-oriented offering. That’s not the case anymore. .NET is on par with the other cool stacks or is getting there very rapidly. I am afraid it’s just a little bit too late for the vast majority of the web development crowd to take notice. It will take an enormous, coordinated effort to bring the message across.

With the platform now ready, effective communication, branding, and evangelism will eventually change the tide. Tutorials, getting-started guides, conference talks, YouTube videos, and workshops should all be explicitly conceived for new developers. The process started already. The observant can see the numerous efforts being made in this area. Will it be enough to attract new crowds? It is a hard bet, but I sure hope so because C# and F# are great languages, and NET 6 is modern, robust, feature-rich, and powerful enough to go at war, and with no fear.

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  1. You will still be able to scale up to (or start right away with) a fully-functional WebApi/MVC application, with all its classes and controllers. [return]
  2. Mind you. The dev team isn’t just adding a layer of abstraction on top of the existing code. Quoting fellow MVP Dave Brock “With minimal APIs, the goal is to move out core API-building capabilities—the ones that only exist in MVC today—and allow them to be used outside of MVC. When extracting these components away to a new paradigm, you can rely on middleware-like performance.” [return]
  3. Long story short, besides lazily maintaining my Python open source projects, I am mostly back to C# these days. [return]
  4. Sure, all benchmarks should be taken with a grain of salt, but check this out. ASPCORE ranks at #2; Flask and Node #338 and #173 respectively. And NET 6 is expected to still improve on performance. [return]
  5. For examples of real-life-scenarios, see Damian Edwards’ Minimal APIs playground. [return]
  6. Cool. As I am writing this, NET 6 Preview 6 is released, which adds OpenAPI (Swagger UI) support to Minimal APIs. [return]