Transcribe Your Zoom Meetings

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Features

• Real-time Transcription: Live transcription during meetings using AssemblyAI’s streaming API
• Asynchronous Transcription: Complete post-meeting transcription with advanced features
• Flexible Audio Modes:
  • Mixed stream (all participants combined)
  • Individual participant streams transcribed
• Multichannel Audio Support: Separate channels for different participants
• Configurable Processing: Enable/disable real-time or async transcription independently

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Setup

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Prerequisites

• Node.js 16+
• FFmpeg installed on your system
• Zoom RTMS Developer Preview access
• AssemblyAI API key
• ngrok (for local development and testing)

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Installation

1. Clone the example repository and install dependencies:

git clone https://github.com/zkleb-aai/assemblyai-zoom-rtms.git
cd assemblyai-zoom-rtms
npm install

2. Configure environment variables:

cp .env.example .env

# Zoom Configuration
ZM_CLIENT_ID=your_zoom_client_id
ZM_CLIENT_SECRET=your_zoom_client_secret
ZOOM_SECRET_TOKEN=your_webhook_secret_token

# AssemblyAI Configuration
ASSEMBLYAI_API_KEY=your_assemblyai_api_key

# Service Configuration
PORT=8080
REALTIME_ENABLED=true
REALTIME_MODE=mixed
ASYNC_ENABLED=true
AUDIO_CHANNELS=mono
AUDIO_SAMPLE_RATE=16000
TARGET_CHUNK_DURATION_MS=100

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Local development with ngrok

1. Install ngrok: Download from ngrok.com or install via package manager:
   # macOS
   brew install ngrok
   
   # Windows (chocolatey)
   choco install ngrok
   
   # Or download directly from ngrok.com
   
2. Start your local server:
   npm start
   
3. In a separate terminal, start ngrok:
   ngrok http 8080
   
4. Copy the ngrok URL: ngrok will display a forwarding URL like:
   Forwarding    https://example-abc123.ngrok-free.app -> http://localhost:8080
   
5. Use the ngrok URL in your Zoom app webhook configuration:
   https://example-abc123.ngrok-free.app/webhook
   

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Configuration options

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Real-time transcription

• REALTIME_ENABLED: Enable/disable live transcription (default: true)
• REALTIME_MODE:
  • mixed: Single stream with all participants combined
  • individual: Separate streams per participant

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Audio settings

• AUDIO_CHANNELS: mono or multichannel
• AUDIO_SAMPLE_RATE: Audio sample rate in Hz (default: 16000)
• TARGET_CHUNK_DURATION_MS: Audio chunk duration for streaming (default: 100)

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Async transcription

• ASYNC_ENABLED: Enable/disable post-meeting transcription (default: true)

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Usage

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Start the service

npm start

🎧 Zoom RTMS to AssemblyAI Transcription Service
📋 Configuration:
   Real-time: ✅ (mixed)
   Audio: mono @ 16000Hz
   Async: ✅
🚀 Server running on port 8080
📡 Webhook endpoint: http://localhost:8080/webhook

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Configure Zoom webhook

1. In your Zoom App configuration, set the webhook endpoint to:
   # For production
   https://your-domain.com/webhook
   
   # For local development with ngrok
   https://example-abc123.ngrok-free.app/webhook
   
2. Subscribe to these events:
   • meeting.rtms_started
   • meeting.rtms_stopped

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Testing with ngrok

1. Keep ngrok running: The ngrok tunnel must remain active during testing
2. Update webhook URL: If you restart ngrok, you’ll get a new URL that needs to be updated in your Zoom app configuration
3. Monitor ngrok logs: ngrok shows incoming webhook requests in its terminal output
4. Free tier limitations: The free ngrok tier has some limitations; consider upgrading for heavy testing

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Real-time output

🚀 AssemblyAI session started: [abc12345]
🎙️ [abc12345] Hello everyone, welcome to the meeting
📝 [abc12345] FINAL: Hello everyone, welcome to the meeting.

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Post-meeting files

• transcript_[meeting_uuid].json - Full AssemblyAI response with metadata
• transcript_[meeting_uuid].txt - Plain text transcript

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Advanced configuration

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AssemblyAI features

const ASYNC_CONFIG = {
  speaker_labels: true, // Speaker identification
  auto_chapters: true, // Automatic chapter detection
  sentiment_analysis: true, // Sentiment analysis
  entity_detection: true, // Named entity recognition
  redact_pii: true, // PII redaction
  summarization: true, // Auto-summarization
  auto_highlights: true, // Key highlights
};

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Audio processing modes

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Mixed mode (default)

• Single audio stream combining all participants
• Most efficient for general transcription
• Best for meetings with clear speakers

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Individual mode

• Separate transcription stream per participant
• Better speaker attribution
• Higher resource usage

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Multichannel audio

• Separate audio channels for different participants
• Enables advanced speaker separation
• Requires AUDIO_CHANNELS=multichannel

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API endpoints

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POST /webhook

• URL validation
• Meeting start/stop events
• Automatic RTMS connection setup

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Error handling

• Automatic reconnection for dropped connections
• Graceful cleanup on meeting end
• Audio buffer flushing to prevent data loss
• Temporary file cleanup

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Monitoring

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Real-time logs

• Connection status updates
• Audio processing statistics
• Transcription progress
• Error notifications

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Example log output

📡 Connecting to Zoom signaling for meeting abc123
✅ Zoom signaling connected for meeting abc123
🎵 Connecting to Zoom media for meeting abc123
✅ Zoom media connected for meeting abc123
🚀 Started audio streaming for meeting abc123
🎵 [abc12345] 100 chunks, 32768 bytes, 10.2s
📝 [abc12345] FINAL: This is the final transcription.

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Development workflow

1. Start your local server: npm start
2. Start ngrok in another terminal: ngrok http 8080
3. Update your Zoom app webhook URL with the ngrok URL
4. Test with Zoom meetings
5. Monitor logs in both your app and ngrok terminals