WebSocket Server for AWS Transcribe Streaming

This WebSocket server provides real-time speech-to-text transcription using AWS Transcribe Streaming.

Features

• Real-time transcription of audio streams.
• Supports multiple languages and audio encoding formats.
• Provides partial and final transcription results.
• Health check endpoint for monitoring server status.
• Graceful shutdown and error handling.

Prerequisites

• AWS Account: Required for AWS Transcribe Streaming service.
• Node.js: Ensure Node.js is installed on your system.
• Environment Variables: Configure necessary environment variables.

Installation

1. Clone the repository:

   git clone https://github.com/your-repo.git
   cd your-repo

2. Install dependencies:

   npm install

3. Set up environment variables:

   Create a .env file in the project root with the following variables:

   AWS_ACCESS_KEY_ID=your-access-key-id
   AWS_SECRET_ACCESS_KEY=your-secret-access-key
   AWS_REGION=your-aws-region
   PORT=your-server-port
   API_TOKEN=your-api-token # for client authorization
   LOG_LEVEL=info # optional: debug, info, warn, error

   If another AWS credential method is preferred, update the aws-sdk configuration in server.js. Right now it uses fromEnv().

Running the Server

Start the server with:

npm start

The server will listen on the port specified in the PORT environment variable.

Health Check Endpoint

• URL: http://your-server-address:PORT/health

• Method: GET

• Response:

  { "status": "ok" }

Use this endpoint to monitor the server's health status.

Logging

The server uses pino for logging. Logs include:

• Connection events
• Transcription results
• Errors and exceptions
• Memory usage statistics

Log Levels can be set using the LOG_LEVEL environment variable (debug, info, warn, error).

In development mode, logs are written to the console. In production, logs are also written to a file in JSON format.

Environment Variables Summary

• AWS_ACCESS_KEY_ID: AWS access key ID for Transcribe service.
• AWS_SECRET_ACCESS_KEY: AWS secret access key for Transcribe service.
• AWS_REGION: AWS region where Transcribe service is available.
• PORT: Port number the server listens on.
• API_TOKEN: Token used for client authorization.
• LOG_LEVEL (optional): Logging level for the server.

Graceful Shutdown

The server handles SIGTERM and SIGINT signals to allow for graceful shutdown, ensuring all active connections are properly closed.

Troubleshooting

• Connection Refused: Ensure the server is running and the port is open.
• Authorization Failed: Verify the token parameter matches API_TOKEN.
• Invalid Parameters: Check that query parameters are correctly formatted.
• Transcription Timeout: Ensure audio data is being sent consistently.

License

This project is licensed under the EUPL-1.2-or-later license. See the LICENSE file for details.

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Note: Replace your-server-address, your-api-token, and other placeholders with actual values relevant to your deployment.