Send Voice Notes over Telegram in C#/.NET - Complete Guide

Automate Telegram Voice Note Sharing with C#/.NET

Looking to automate voice message delivery, audio recordings, or spoken notifications from your C#/.NET applications? This guide walks you through sending voice note files (OPUS format) to Telegram users using C# and the WhatsMate Telegram Gateway REST API. Perfect for .NET developers, Windows application builders, and automation enthusiasts who want to integrate voice messaging into their C#-based workflows.

Note for Visual Studio 2022 users: If you’re using Visual Studio 2022, please read this updated tutorial instead.

📋 Prerequisites

Before you begin, ensure you have:

1. A WhatsMate Telegram Gateway account - Required for API access
2. Recipient registration - Each recipient must register with the Gateway first
3. Visual Studio 2019 - .NET development environment (or compatible IDE)
4. Basic C# knowledge - Familiarity with C# programming and .NET framework
5. Voice note file ready - Have the OPUS file you want to send available locally
6. System.Web.Extensions reference - Required for JSON serialization

⚠️ Important: Recipients must register with the WhatsMate Telegram Gateway before they can receive messages. Unregistered users will not receive any messages from the Gateway. Registration instructions are available on the official WhatsMate site.

📝 Step-by-Step Implementation

Follow these steps to send your first voice note to a Telegram user from a C# application:

1. Copy the C# Code Template

Start by copying the following source code into your C# file:

2. Configure a few Parameters

Customize these key parameters in the C# code:

• Lines 10-12: Replace YOUR_INSTANCE_ID, YOUR_CLIENT_ID_HERE, and YOUR_CLIENT_SECRET_HERE with your gateway instance ID, Client ID, and Secret
• Line 20: Replace 12025550105 with the target phone number (including the country code)
• Line 22: Replace C:\\TEMP\\martin-luther-king.opus with the path to your OPUS voice note file
• Line 23: Replace anyname.opus with the desired filename for the voice note
• Line 24: Replace I have a dream with an optional caption for your voice note

3. Add Required Reference

Ensure your project references System.Web.Extensions for JSON serialization:

1. Right-click on References in Solution Explorer
2. Select Add Reference
3. Find and check System.Web.Extensions
4. Click OK

4. Send Your Voice Note

Build and run your C# application in Visual Studio to deliver your voice note to Telegram.

🔧 Common Use Cases

This automation approach is ideal for:

• AI/TTS integration - Generate voice messages using text-to-speech (TTS) APIs and deliver them to Telegram for automated announcements, notifications, or interactive voice responses
• System monitoring alerts - Send voice alerts for server status or monitoring events from Windows applications
• Customer service automation - Send voice responses or information to clients via Telegram
• Audio notifications - Deliver spoken alerts or voice notifications from .NET systems
• Voice message automation - Send pre-recorded voice messages or announcements via Telegram from C# applications

🚀 Get Started Today

Ready to automate your voice note sharing over Telegram with C#? You’ll need a trial account to access the API. Sign up for a 2-week trial and start sending voice notes within minutes!

Next Steps: Once you’ve mastered basic voice note sending, explore advanced features like sending audio files, images, or documents through the WhatsMate Telegram Gateway API documentation.