@cross-native/core

The runtime and JavaScript API for CrossNative. It loads a compiled module (Rust, Go, Zig, C, or C++) and lets you call its functions from JavaScript — the work runs off the JS thread, so the UI stays responsive.

This is the platform-agnostic core. In a React Native app you normally install react-native-cross-native, which wires this up to the native runtime and re-exports everything here. Use @cross-native/core directly for tests, Node tooling, or a non-RN host.

npm install @cross-native/core

Loading a module

createNativeModule returns a handle whose call runs a function by name, and whose fns exposes the module's exported functions directly (snake_case and camelCase both work):

import {createNativeModule, outBuffer} from '@cross-native/core';
import WASM from './compute.rs'; // base64 module (Metro compiles this in RN)

const compute = await createNativeModule({
  name: 'compute',
  source: 'compute.rs',
  language: 'rust',
  bytes: WASM,
});

const sum = await compute.call('add', [1.5, 2.5]); // 4
const matrix = await compute.fns.matrixMultiply(a, b, outBuffer(n * n), n);

compute.dispose();

In React (React Native) there's a hook:

import {useNativeModule} from '@cross-native/core';

const {fns, ready} = useNativeModule({name: 'compute', source: 'compute.rs', language: 'rust', bytes: WASM});

Passing arrays

Numbers and booleans cross by value. Arrays are copied into the module's memory with the buffer helpers:

import {inBuffer, outBuffer, inoutBuffer} from '@cross-native/core';

await compute.call('sum', [inBuffer([1, 2, 3]), 3]);        // module reads
await compute.call('scale', [outBuffer(9), 9]);             // module writes
await compute.call('normalize', [inoutBuffer(data), data.length]); // both

What's exported

• Loading: createNativeModule, useNativeModule, withPlugins
• Arrays: inBuffer, outBuffer, inoutBuffer, isBufferArg, normalizeArg
• Bridge internals: NativeBridge, JSIBackend, registerJSIInstaller, isJSIAvailable, buildCallables
• Environment: isNativeAvailable, getRuntimeInfo
• Plugins: createPlugin, composePlugins, ConsolePlugin, PerformancePlugin
• Errors: NativeError, NativeTimeoutError
• Types: NativeModule, NativeModuleConfig, NativeFunction, NativeArg, FunctionSignature, CallOptions, Plugin, and more

Full types ship with the package, so editors give you completion and checking on all of the above.

License

Apache-2.0