Best of JS • Neon

Rust bindings for writing safe and fast Node.js native addons.

Getting started

Once you have the platform dependencies installed, getting started is as simple as:

$ npm init neon my-project

Then see the Hello World guide for writing your first Hello World in Neon!

Docs

See our Neon fundamentals docs and our API docs.

Neon 1.0.0 Migration Guide

The latest version of Neon, 1.0.0, includes several breaking changes in order to fix unsoundness, improve consistency, and add features.

Read the new migration guide to learn how to port your Neon projects to 1.0.0!

Platform Support

Operating Systems

Linux	macOS	Windows
✓	✓	✓

Node.js

Node 18	Node 20	Node 21
✓	✓	✓

Support for LTS versions of Node and current are expected. If you're using a different version of Node and believe it should be supported, let us know.

Bun (experimental)

Bun is an alternate JavaScript runtime that targets Node compatibility. In many cases Neon modules will work in bun; however, at the time of this writing, some Node-API functions are not implemented.

Rust

Neon supports Rust stable version 1.65 and higher. We test on the latest stable, beta, and nightly versions of Rust.

A Taste...

fn make_an_array(mut cx: FunctionContext) -> JsResult<JsArray> {
    // Create some values:
    let n = cx.number(9000);
    let s = cx.string("hello");
    let b = cx.boolean(true);

    // Create a new array:
    let array = cx.empty_array();

    // Push the values into the array:
    array.set(&mut cx, 0, n)?;
    array.set(&mut cx, 1, s)?;
    array.set(&mut cx, 2, b)?;

    // Return the array:
    Ok(array)
}

#[neon::main]
fn main(mut cx: ModuleContext) -> NeonResult<()> {
    cx.export_function("make_an_array", make_an_array)?;
    Ok(())
}

For more examples, see our examples repo and integration tests.

Get Involved

The Neon community is just getting started and there's tons of fun to be had. Come play! :)

The Neon Community Slack is open to all; use this invite link to receive an invitation.

Testing Neon

The Neon project is both an NPM workspace and a Cargo workspace. The full suite of tests may be executed by installing and testing the NPM workspace.

npm install
npm test

Individual JavaScript packages may be tested with an npm workspace command:

npm --workspace=create-neon test

Individual Rust crates may be tested with a cargo workspace command:

cargo test -p neon-build

License

Licensed under either of

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Linux

macOS

Windows

✓

Node 18

Node 20

Node 21

✓

fn make_an_array(mut cx: FunctionContext) -> JsResult<JsArray> { // Create some values: let n = cx.number(9000); let s = cx.string("hello"); let b = cx.boolean(true); // Create a new array: let array = cx.empty_array(); // Push the values into the array: array.set(&mut cx, 0, n)?; array.set(&mut cx, 1, s)?; array.set(&mut cx, 2, b)?; // Return the array: Ok(array) } #[neon::main] fn main(mut cx: ModuleContext) -> NeonResult<()> { cx.export_function("make_an_array", make_an_array)?; Ok(()) }