macOS System Audio Recorder

A Node.js library to record system audio on macOS using ScreenCaptureKit.

Features

• Record system audio on macOS
• Get audio stream as raw PCM data
• Configure audio format details (channels, sample rate, etc.)
• Built with Swift and Node.js

Installation

npm install macos-system-audio-recorder

Requirements

• macOS operating system
• Node.js v14.16.0 or later
• Screen Recording permission enabled in System Settings > Privacy & Security

Usage

import { SystemAudioRecorder } from "macos-system-audio-recorder";

// Create recorder instance
const recorder = new SystemAudioRecorder();

// Start recording
recorder.start();

// Get audio format details
const audioDetails = await recorder.getAudioDetails();
console.log("Audio format:", audioDetails);

// Get audio stream
const stream = recorder.getStream();
stream.on("data", (data) => {
  // Handle raw PCM audio data
  console.log("Received audio data:", data.length, "bytes");
});

// Stop recording
recorder.stop();

API Reference

SystemAudioRecorder

Main class to handle system audio recording.

Methods

• start(): Start recording system audio
• stop(): Stop recording
• getAudioDetails(): Get audio format details
• getStream(): Get readable stream of raw PCM audio data

Audio Details

The getAudioDetails() method returns an object with:

interface AudioDetails {
  channels: 1 | 2; // Number of audio channels
  bytesPerFrame: 4 | 8; // Bytes per audio frame
  bitsPerChannel: 16 | 32; // Bits per channel
  formatFlags: number; // Audio format flags
  sampleRate: 48000 | 44100 | 32000; // Sample rate in Hz
  formatID: number; // Audio format ID
}

Error Handling

The library throws these custom errors:

• SystemAudioRecorderError: Base error class
• SystemAudioRecorderNotStartedError: When trying to access recorder before starting
• SystemAudioRecorderSubprocessError: When the Swift subprocess encounters an error

Development

1. Clone the repository
2. Install dependencies: npm install
3. Build the Swift binary: cd swift && ./build.sh
4. Build TypeScript: npm run build
5. Run example: npm run dev

License

MIT

Contributing

Contributions welcome! Please read the contributing guidelines before submitting PRs.

Credits

Developed by Victor Fernandez (@victor141516)