Rari – Rust-powered React framework(rari.build) |
Rari – Rust-powered React framework(rari.build) |
"rust-powered" meaning it uses rolldown to bundle the javascript, that's fine, but it's a weird thing to highlight, it's confusing for people that aren't super familiar with vite and might think this is a rust framework
from the docs "one of rari's superpowers is seamless NPM package integration" this makes me think the docs are LLM-written... npm package integration, like every other javascript library.
now, the good: there's very few simple frameworks for react (react router and tanstack) and I think the simplicity here on going from an empty project to RSCs is absolutely great, and should be the tagline
I was also happily surprised at how mature the codebase is in comparison to the docs, the vite plugin actually supports a lot of the options I would have expected to see, they're just not documented yet
edit: I realised after digging a bit deeper this actually does have a rust runtime that runs the js, that was not very clear... is this separate from the framework or does the framework only run in the rust runtime? eg can it run on node?
On the npm integration point: what I should have said is that rari's Rust runtime handles traditional node_modules resolution (require/import from node_modules), which is actually pretty rare for Rust-based JS runtimes. Deno, for example, uses npm specifiers instead of node_modules.
Great feedback on the tagline too. "Zero to RSC in minutes" is way clearer than what we have now. The codebase is definitely ahead of the docs, I've been focused on getting the runtime solid first, but clearly need to catch the documentation up.
Thanks for taking the time to dig in and give constructive feedback. This is exactly the kind of input that helps make it better.
1/ an alternative framework for RSCs similar to nextjs, tanstack or react router
2/ a rust runtime for javascript, similar to node, deno or bun (except maybe not as general purpose)
react-vello [1] exposes Vello (a Rust GPU renderer) as a React renderer via WASM + WebGPU, so you can draw shapes and text declaratively while Rust handles the rendering in the browser.
React Vello seems super cool, by the way. Thanks for sharing it!
If anybody is wondering.
Thanks again.
That said, rari takes a different approach. It's not a pure Rust framework. It's a React Server Components framework that happens to be powered by a Rust runtime. The goal is to abstract away Rust's complexity entirely so JavaScript/TypeScript developers can build high-performance React apps without needing to learn Rust.
I was working on something similar, but for JVM backends [1]. And it seems there are a lot to learn from your project. For example, I'm using GraalVM that executes JS on the server. But I have to compile JS to WebAssembly because otherwise it produces a lot integration issues on the backend. Do you do the same?
The key is that deno_core provides clean Rust bindings to V8's C++ API, which lets us run JS/TypeScript with minimal overhead. We handle module resolution, imports, and the React rendering pipeline all in Rust, then execute the actual component code in V8. No WASM compilation step needed.
Your JVM project looks cool! The GraalVM → WASM approach makes sense for JVM integration. We avoid those integration issues by keeping everything in the Rust/V8 ecosystem. The tradeoff is we're tied to V8, but we get native performance and direct access to V8's features.
I don't really understand how it works, what part is Rust powered, is it reimplementing the JS engine in Rust?
The Rust part is the server runtime. Instead of Node.js running your React Server Components, rari uses a Rust server with an embedded V8 engine. Same React code, different server underneath.
You write React → Rust server executes it → better performance than Node-based alternatives.
it would be interesting to see a performance comparison to node and bun
Native speed with Rust compilation for blazing-fast builds and runtime"
It seems only Rust itself compiles slow while helping others brag about it :).
The inspiration was pretty straightforward: I wanted to build something for myself that was as performant as I could make it. I'd been using Rust a lot more in my day-to-day work and wanted to see if I could bring those performance benefits to React development without forcing JS devs to write Rust. The goal was to abstract away the complexity of Rust but still deliver the same benefits.
Congrats on shipping your project! What did you build?
I built autonomo on github, it's this mcp you plugin to your whatever ai editor and it drives the app/web/desktop whatever thing and validates it actually runs and works... keep building homie!
ref. https://threatprotect.qualys.com/2025/12/04/react-server-com...
The part that I don't see are the 'use server' .
The Rust part is the runtime engine that executes your React code on the server. Think of it as a faster alternative to Node.js for running React Server Components. You still write normal React code, but the server-side execution happens in Rust instead of Node.js, which gives it massive performance gains (46.5x higher throughput than Next.js).
It handles routing, server-side rendering, and serves both server components (rendered on the server) and client components (interactive JavaScript sent to the browser). The output is still HTML + JavaScript that runs in the browser—just generated much faster.
But its far from the worst.
It was the first framework to put together JSX, a functional way of defining components and simplifying state. This was a monumental improvement. As a result they earned mass adoption.
As a result its the framework that now has a community moat that is not going to crumble until someone else can break ground in the way they did.
Sure, some of these could be considered "better" but they're all better due to incremental improvements for Frontend Engineering.
None of which are substantial enough to unseat the king
That's rather amusing. "Am I wrong? No it's the rest of the world!"
How are these other frameworks so far ahead? I've used a couple of frameworks and React has been the easiest from the big ones to wrap my head around.
I can only speak for Svelte, in Svelte 3/4 it was so dead simple that I built my first basic webapp with 0 javascript, css or html experience in 3 days.
By week 2 I was trying out different UI libraries and css frameworks, that part was super rough though, back then lots of compat issues.
Also, vue interops better with webcomponents and non-framework code than React in my experience. Most non-React libraries need a React wrapper to work in a React project.
It can be made better if you write it using non standard patterns - but the community is so dogmatic you'll get laughed out of the room.
All of my personal react projects use the MVC/MVVM architecture and are so much easier to work with
export class AppViewModel {
@rx accessor message = new TextField()
}
export function App() {
const vm = useViewModel(AppViewModel)
return <div>
<p>{vm.message.value}</p>
<input
onChange={vm.message.fromEvent}
value={vm.message.value} />
<div>
}
One day my dream is to delete 75% of the code, sprinkle some svelte into the business logic, and be left with a strictly superior, more performant version of the platform.
That means it is mostly React/Next.js and in some cases, Angular.
Anything else will get side looks on why are we not using the official SDKs from partners.
Better update performance by default.
definitely better dev tools
Anyway, I see we have a bit different approaches on how to handle JS part, and I could get some ideas from that.
The runtime piece is definitely less general-purpose than Node/Deno/Bun. It's optimized specifically for React Server Components with things like streaming, Suspense boundary handling, and server action execution baked in. You wouldn't use it to run arbitrary JS apps.
While we use Deno's excellent crates (deno_core for V8 bindings, we're big fans of the project!), you're not locked into the Deno ecosystem. rari uses standard node_modules resolution, so your existing Node/npm workflows just work. Think of it like this: Deno gives you a runtime to build on, while rari gives you the full stack with integrated bundler, router, HMR, and dev server all configured to work together for RSC apps.
- You can test the view model independently of the rendering logic
- Dramatically reduces the code that lives directly in the component (it's only TSX)
- Allows for better abstractions and state management (services)
- Clear path to leveraging threads in front end applications
- Simple "visual" components (like <Input />, <Button />) don't need view models, just orchestrating components.
In practice, when writing traditional React, I focus too much on rendering cycles and the nuances of managing component state while spending much less time on making the application look good and feel performant/nice to use.
Having a component be pretty much exclusively TSX gives me a clear separation of "view" and "what the view needs" - so I just think of the html structure and css. I tend to create much better looking and nicer applications this way.
> It's way more skipping around in the codebase to find the parts you actually care about
Not really. You cnt+click to an implementation. Say you have "await someApi.getItems()" - you just click and go directly there. Traditional React apps need to thunk with redux or have a bunch of custom hooks that quickly become a source of confusion.
There are some examples under: https://github.com/alshdavid/mvvm/blob/main/examples/basic/i...
Yes, every one of those apps is c++ powered.