Webhooks

With Webhook, your web application gets notified automatically by Telegram when new updates arrive for your bot.

Your application will receive HTTP POST requests with an Update structure in the body, using specific JSON serialization settings Telegram.Bot.JsonBotAPI.Options.

Below, you will find how to configure an ASP.NET Core Web API project to make it work with Telegram.Bot, either with Controllers or Minimal APIs

⚠️ IMPORTANT: This guide describes configuration for versions 21.* and later of the library (based on System.Text.Json rather than NewtonsoftJson). If you're using older versions, you should upgrade first!

ASP.NET Core with Controllers (MVC)

First you need to configure your Web App startup code:

Locate the line services.AddControllers(); (in Program.cs or Startup.cs)
If you're using .NET 6.0 or more recent, add the line:
```
services.ConfigureTelegramBotMvc();
```

For older .NET versions, add the line:

services.ConfigureTelegramBot<Microsoft.AspNetCore.Mvc.JsonOptions>(opt => opt.JsonSerializerOptions);

Next, in a controller class (like BotController.cs), you need to add an action for the updates. Typically:

[HttpPost]
public async Task HandleUpdate([FromBody] Update update)
{
    // put your code to handle one Update here.
}

Good, now skip to SetWebHook below

ASP.NET Core with Minimal APIs

First you need to configure your Web App startup code:

Locate the line builder.Build(); (in Program.cs)

Above it, insert the line:

builder.Services.ConfigureTelegramBot<Microsoft.AspNetCore.Http.Json.JsonOptions>(opt => opt.SerializerOptions);

Next, you need to map an action for the updates. Typically:

app.MapPost("/bot", (Update update) => HandleUpdate(update));
...

async Task HandleUpdate(Update update)
{
    // put your code to handle one Update here.
}

Good, now skip to SetWebHook below

Old ASP.NET 4.x support

For older .NET Framework usage, you may use the following code:

public async Task<IHttpActionResult> Post()
{
    Update update;
    using (var body = await Request.Content.ReadAsStreamAsync())
        update = System.Text.Json.JsonSerializer.Deserialize<Update>(body, JsonBotAPI.Options);
    await HandleUpdate(update);
    return Ok();
}

SetWebHook

Your update handler code is ready, now you need to instruct Telegram to send updates to your URL, by running:

var bot = new TelegramBotClient("YOUR_BOT_TOKEN");
await bot.SetWebhook("https://your.public.host:port/bot", allowedUpdates: []);

You can now deploy your app to your webapp host machine.

Note: If you decide to switch back to Long Polling, remember to call bot.DeleteWebhook()

Common issues