Create a C# app to subscribe live BTCUSDT data with WebSocket
In this page, I will describe how to create an application using C# from Visual Code that connects to the Binance Test network, subscribes to BTCUSDT data, and tracks the price changes of the symbol.
If you need Binance Client Library to subscribe, follow Binance Client Library tutorial.
1. Prerequisites
Install:
• .NET SDK (7 or later recommended)
• Visual Studio Code
• VS Code extension: C# (by Microsoft)
Then verify your .Net version:
dotnet --version
2. Create Solution + Console Project
Open a terminal:
mkdir BinanceTracker
cd BinanceTracker
dotnet new sln -n BinanceTracker
dotnet new console -n BinanceTracker.App
dotnet sln add BinanceTracker.App
Open folder in VS Code:
code .
3. Add Required NuGet Packages
We’ll use:
• WebSocket client
• JSON parsing
Run:
cd BinanceTracker.App
dotnet add package System.Net.WebSockets.Client
dotnet add package Newtonsoft.Json
4. Understand Binance Testnet WebSocket
Binance Spot Testnet WebSocket base:
wss://testnet.binance.vision/ws
BTCUSDT trade stream:
btcusdt@trade
Full URL:
wss://testnet.binance.vision/ws/btcusdt@trade
5. Create Data Model Class
Create a file: Models/TradeMessage.cs
using Newtonsoft.Json;
public class TradeMessage
{
[JsonProperty("e")]
public string EventType { get; set; }
[JsonProperty("E")]
public long EventTime { get; set; }
[JsonProperty("s")]
public string Symbol { get; set; }
[JsonProperty("p")]
public string Price { get; set; }
[JsonProperty("q")]
public string Quantity { get; set; }
}
6. Create Binance WebSocket Service
Create: Services/BinanceSocketService.cs
using System;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Newtonsoft.Json;
public class BinanceSocketService
{
private readonly Uri _uri = new Uri("wss://testnet.binance.vision/ws/btcusdt@trade");
public async Task StartAsync()
{
using var socket = new ClientWebSocket();
Console.WriteLine("Connecting to Binance Testnet...");
await socket.ConnectAsync(_uri, CancellationToken.None);
Console.WriteLine("Connected.");
var buffer = new byte[8192];
while (socket.State == WebSocketState.Open)
{
var result = await socket.ReceiveAsync(new ArraySegment(buffer), CancellationToken.None);
var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
try
{
var trade = JsonConvert.DeserializeObject(message);
if (trade != null)
{
Console.WriteLine($"[{DateTime.Now}] {trade.Symbol} Price: {trade.Price} Qty: {trade.Quantity}");
}
}
catch (Exception ex)
{
Console.WriteLine("Parse error: " + ex.Message);
}
}
}
}
7. Update Program.cs
Replace contents:
using System.Threading.Tasks;
class Program
{
static async Task Main(string[] args)
{
var service = new BinanceSocketService();
await service.StartAsync();
}
}
8. Run the Application
And finally run the application:
dotnet run
