Embed Bare in a React Native app

Run a Bare worklet from a React Native or Expo app and exchange messages with it over the bare-kit IPC channel.

This guide runs a Bare core inside a React Native app using react-native-bare-kit, and wires a two-way message channel between the UI and the core. This is the practical version of the pattern described in One core, many platforms: your peer-to-peer logic lives in the worklet, your UI stays native.

You'll need an existing React Native or Expo project to add this to.

Install the kit

npm i react-native-bare-kit b4a

For Expo, follow the bare-expo example, which shows the config-plugin setup; the worklet code below is identical.

Write the Bare core

The worklet entry script runs on its own thread. It reaches the host through the BareKit.IPC channel—an instance of Bare.IPC. Here it echoes back whatever it receives:

// app.js—runs inside the worklet
const { IPC } = BareKit

IPC.on('data', (data) => {
  const message = data.toString()
  IPC.write(Buffer.from(`echo: ${message}`))
})

This is ordinary Bare code: it can require any bare-* module and open a Hyperswarm or Corestore just as it would on the desktop.

Start the worklet from React Native

In your React Native component—for example App.tsx, not the worklet's /app.js—create a Worklet, start it with the core's source, and read and write the IPC object it exposes:

import { Worklet } from 'react-native-bare-kit'
import b4a from 'b4a'

const source = `
const { IPC } = BareKit
IPC.on('data', (data) => IPC.write(Buffer.from('echo: ' + data.toString())))
`

const worklet = new Worklet()
worklet.start('/app.js', source)

const { IPC } = worklet
IPC.on('data', (data) => console.log(b4a.toString(data)))
IPC.write(b4a.from('Hello from React Native!'))

The worklet honours the Bare lifecycle, so call worklet.suspend() and worklet.resume() from your app's background/foreground handlers to keep the core in step with the OS.

Run it

Build and run on a simulator or device with your usual React Native toolchain. Worklet console.* output is written to the system log under the bare identifier—view it with the platform's native logging tools (Console.app on iOS, logcat on Android).

echo: Hello from React Native!

Next steps

Inlining source is fine for a snippet, but real apps ship a prebuilt bundle. See Bundle a Bare app to produce a .bundle and load it with worklet.start('/app.bundle', bundle).
Passing raw bytes gets unwieldy fast. See Type a native RPC bridge to put typed, schema-generated methods on top of this IPC channel.
For the full Worklet and IPC API, see the bare-kit reference.