WhatsApp Audio Transcriber Bot

Overview

Automatically transcribe WhatsApp audio messages to text using AI-powered speech recognition. This workflow receives audio messages via webhook, processes them through Groq's Whisper API, and replies with the transcribed text in the same conversation.

Use Cases

• Accessibility: Help users with hearing impairments access audio content
• Workplace Communication: Quickly scan audio messages in professional settings
• Language Learning: Get text versions of audio for better comprehension
• Meeting Notes: Convert voice messages to searchable text format
• Multilingual Support: Transcribe audio in Portuguese (configurable for other languages)

How it Works

1. Message Reception: Webhook receives WhatsApp messages in real-time
2. Audio Detection: Filters only audio messages using Switch node
3. Format Conversion: Converts base64 audio to MP3 file format
4. AI Transcription: Processes audio through Groq API with Whisper Large V3 model
5. Response Delivery: Sends transcribed text back to the original conversation

Key Features

• ✅ Real-time Processing: Instant transcription of incoming audio messages
• ✅ High Accuracy: Uses Whisper Large V3 model for reliable transcription
• ✅ Auto-Reply: Automatically responds in the same WhatsApp conversation
• ✅ Message Quoting: References the original audio message in the reply
• ✅ Portuguese Optimized: Configured for Brazilian Portuguese transcription
• ✅ Self-Message Filtering: Ignores messages sent by the bot itself

Prerequisites

Required Services

• Evolution API: WhatsApp integration service
• Groq API: AI transcription service (Whisper model)
• n8n Instance: Workflow automation platform

API Keys & Configuration

• Groq API key (set as environment variable: GROQ_API_KEY)
• Evolution API instance properly configured
• Webhook URL configured in Evolution API

Setup Instructions

1. Import Workflow: Import the JSON workflow into your n8n instance
2. Configure Environment: Set GROQ_API_KEY environment variable
3. Setup Webhook: Configure Evolution API to send messages to the webhook endpoint
4. Test Connection: Send a test audio message to verify the workflow

Workflow Nodes

• Webhook: Receives WhatsApp messages from Evolution API
• Edit Fields: Extracts relevant data (number, name, message, audio)
• Switch: Filters only audio messages (audioMessage type)
• Convert to File: Transforms base64 audio to MP3 format
• HTTP Request: Sends audio to Groq API for transcription
• Evolution API: Sends transcribed text back to WhatsApp

Configuration Options

Groq API Settings

• Model: whisper-large-v3
• Language: pt (Portuguese)
• Temperature: 0 (maximum accuracy)
• Response Format: json

Customization Options

• Change language by modifying the language parameter
• Adjust temperature for different accuracy/creativity balance
• Modify response format for different output styles

Response Format

*Mensagem transcrita automaticamente.*
[Transcribed text content]

Technical Specifications

• Input: Base64 encoded audio from WhatsApp
• Output: Plain text transcription
• Processing Time: Typically 2-5 seconds per audio message
• Supported Audio: MP3 format (converted from WhatsApp audio)
• Language: Portuguese (configurable)

Troubleshooting

• No Response: Check Groq API key and webhook configuration
• Poor Transcription: Ensure audio quality and check language settings
• Error Messages: Monitor n8n execution logs for detailed error information

Version History

• v0.0.1: Initial release with basic transcription functionality