This article was originally published on our engineering blog, WithNext.NET. It's reposted here with the canonical link pointing back to the original.
A while back I wrote about JsxCore — a view engine that lets you write ASP.NET Core views in JSX/TSX and render them with React or Preact, with no Node.js required. At the time it was "about to ship." Well, it just did: JsxCore is now 1.0.0. And its author, David Whitney, is already pushing the same idea further — into Astro, with a proof of concept called AstroSharp. This is the follow-up.
JsxCore 1.0.0 is out
On August 4, 2026, David Whitney announced "JsxCore 1.0.0 is out." In short, everything from the earlier write-up is now a stable release. You write a .tsx view, return it from a controller, and pick server rendering, hydration, or both — per response. View-model types are generated from your C#, and installing is still just dotnet add package JsxCore. The project had a few dozen stars when I first covered it; it's now around 200, so interest is clearly building.
It targets ASP.NET Core MVC, Web API, and Minimal API, runs on the .NET SDK alone, and keeps the "vite-like DX" goal: automatic TypeScript transpilation, bundler-free module resolution in the browser, and hot reload that surfaces TS errors as an overlay.
The next move — AstroSharp
Here's the part I find genuinely interesting. JsxCore brings C# to the React/TSX world. AstroSharp aims to do the same thing for Astro: write your Astro content in .razor (C#), while the tooling underneath is powered by .NET.
The key design choice is that the entry point stays npm, but the inside is .NET. From a front-end developer's perspective, you install a normal npm package. During development, the Astro plugin spawns a .NET sidecar process and uses Roslyn for a static, hot-reloading dev experience. A .NET runtime is needed at build time, but the front-end workflow — the one that starts with npm install — is left intact.
A minimal Astro component in AstroSharp reads like Razor: C# in the frontmatter, markup below.
@{
var name = "World";
}
<h1>Hello @name</h1>
Rendering goes through the sidecar for SSR (HTML produced by C#), and there's an experimental, opt-in WASM path for server-less rendering as well. Both are early — this is a work-in-progress PoC at the time of writing — but the direction is clear.
What developers are saying
The reaction has been warm, especially from people who were shopping around for exactly this kind of tool. One developer put it this way after seeing AstroSharp:
"Nice, I needed something like that. I was evaluating Blazor SSR and HTMX, but I think this is actually what I wanted."
That captures the niche well. It's not "C# for everything" — it's C# where you already wanted server-side power, without giving up the front-end ecosystem you like.
What's actually happening here
Step back and there's a consistent theme across David Whitney's work. Rather than asking front-end developers to abandon their stack for a C#-only model, he's meeting each front-end culture where it is and delivering the feel of C# into it — JSX/TSX with JsxCore, and now Astro with AstroSharp. Whether AstroSharp graduates from PoC to production is an open question, but the pattern — npm on the outside, .NET on the inside — is a pragmatic way to bring .NET's strengths to teams that live in the JavaScript world.
FAQ
Is JsxCore production-ready now that it's 1.0?
It's a stable 1.0.0 release and supports MVC, Web API, and Minimal API with just dotnet add package JsxCore. That said, it's still young, so a sensible path is to adopt it on a small surface first and grow as you gain confidence.
Do I need Node.js for either JsxCore or AstroSharp?
JsxCore needs only the .NET SDK — no Node.js. AstroSharp is different: its entry point is a normal npm package, and it uses a .NET sidecar during development plus a .NET runtime at build time.
Is AstroSharp ready to use?
Not yet. It's an early proof of concept at the time of writing, and the SSR WASM path in particular is experimental.
Sources: JsxCore on GitHub · original announcement threads by @david_whitney.
Originally published at WithNext.NET, where we write about .NET / C# modernization, performance, and AI.
Top comments (0)