solid-rs

Write frontend apps in Rust. The solid-rs CLI parses your Rust source and transpiles it to plain JavaScript that runs on the SolidJS 2.0 runtime. No WASM on the mainline — the browser runs generated JS.

Status: work in progress. This is an early, moving target: it compiles against Solid 2.0 release candidates (solid-js@2.0.0-rc.1, pinned), the API surface grows frequently, and nothing here is stable. Expect breakage.

How it works

Your Rust is source, not something rustc compiles for the browser. The framework reads the Rust AST with syn, type-checks it against a conservative model of the Solid API, and emits JSX modules that esbuild bundles against the Solid 2.0 runtime:

use solid_rs::prelude::*;

#[component]
fn Counter() -> Jsx {
    let (count, set_count) = create_signal(0);
    let double = create_memo(move || count() * 2);

    html! {
        <div class="counter">
            <p>Count: {count()}</p>
            <p>Double: {double()}</p>
            <button onclick=move || set_count(count() + 1)>+</button>
            {if count() > 5 { <span>big</span> } else { <span>small</span> }}
        </div>
    }
}

The transpiler is the compiler: the Rust is never type-checked by rustc, so solid-rs build is the source of truth for what your code means.

Quick start

Requirements: Rust (nightly) and Node.js ≥ 18 with npm on PATH.

cargo install solid-rs
solid-rs init my-app     # scaffold a project
cd my-app
solid-rs install         # npm packages declared in solid-rs.toml
solid-rs dev             # build, serve on :3000, rebuild on changes

CLI subcommands:

Command	What it does
solid-rs init <dir>	Scaffold a new project
solid-rs install	Install [dependencies] from solid-rs.toml into node_modules/
solid-rs build	Parse src/*.rs, emit dist/js/*.jsx, bundle with esbuild
solid-rs check	Parse + codegen only; print or write the emitted JSX
solid-rs dev	Build, serve dist/, rebuild on src/ changes
solid-rs preview	Serve dist/ (per-request SSR when the build produced one)
solid-rs bindings	Regenerate bindings/<pkg>.rs from installed dependencies
solid-rs wasm new/build	Scaffold / build optional wasm-bindgen crates under wasm/

A project is a directory with solid-rs.toml (entry, mode, output, npm dependencies) and src/*.rs — one module per file, #[component] functions become components, module-level consts become shared bindings.

Workspace layout

solid-rs/
├── crates/
│   ├── solid-rs-core/      # IR types + syn-based parser + type validation
│   ├── solid-rs-codegen/   # IR → JavaScript/JSX emitter
│   └── solid-rs/           # the `solid-rs` CLI binary
├── examples/               # runnable apps, each with e2e tests
├── SPEC.md                 # the design document (architecture, semantics, constraints)
└── comparison.md           # API-by-API parity table vs SolidJS 2.0

Examples

Each example builds with solid-rs build and has jsdom-based e2e tests under e2e/.

Example	What it shows
comparison	The feature lab: one section per group of Solid 2.0 APIs
ssr	Server-side rendering, #[server_state], async memos, lazy!, server components and a hand-built frame
tasks	"Momentum" — a client-side task manager (store, fetch, Portal, lazy loading)
blog	"Dispatch" — a server-rendered blog with routing and a newsletter form
deps	npm packages from solid-rs.toml via #[js(…)] extern blocks (router, Kobalte, timer)
compute	The WASM escape hatch: Rust that is compiled, not transpiled
flight	Single-flight mutations: a mutation and the data it invalidated, in one round trip

Documentation

• SPEC.md — the design document: vision, architecture, the Rust API surface, transpilation semantics, and known constraints.
• comparison.md — parity table: every Solid 2.0 API, whether solid-rs supports it, and how.

Testing

cargo test --workspace   # parser, codegen, and validation unit tests

Example e2e suites run against the built bundles:

cd examples/tasks && solid-rs build && node e2e/render.mjs && node e2e/reactivity.mjs

License

TBD — see individual crates.