How the Telegram Bot API Works: Updates, Methods and Tokens

The short answer

The Telegram Bot API is an HTTP interface between your program and Telegram. The model is simple:

• You → Telegram: send an HTTP request to a method (sendMessage, sendPhoto and so on) and get a JSON response.
• Telegram → you: everything that happens to the bot (messages, button taps, payments) arrives as Update objects.

Every request carries the bot token — it is part of the URL itself. Libraries such as aiogram, python-telegram-bot or grammY do exactly the same, just more conveniently.

The request URL and the token

All methods follow one pattern:

https://api.telegram.org/bot<TOKEN>/<METHOD_NAME>

@BotFather issues the token when you create the bot. It looks like a number, a colon and a long string of characters. Keep in mind:

• the token is full access to the bot: whoever has it can read incoming messages and post as the bot;
• never store it in a public repository or in frontend code — only in environment variables or server secrets;
• if it leaks, regenerate it in @BotFather and the old one stops working immediately.

The simplest check is the getMe method:

curl "https://api.telegram.org/bot<TOKEN>/getMe"

The response format

Every response is JSON with an ok field:

{"ok": true, "result": {"id": 123456789, "is_bot": true, "first_name": "Demo", "username": "demo_bot"}}

On failure ok is false, with error_code and description next to it. The most common ones:

The Update object

Each incoming event is an Update with a unique update_id and exactly one of these fields: message, edited_message, callback_query, channel_post, inline_query, pre_checkout_query, my_chat_member and others.

{
  "update_id": 100000001,
  "message": {
    "message_id": 5,
    "from": {"id": 123456789, "is_bot": false, "first_name": "Ali"},
    "chat": {"id": 123456789, "type": "private"},
    "date": 1700000000,
    "text": "/start"
  }
}

The key value in an update is chat.id: that is where the bot sends its reply.

There are two ways to receive updates:

• getUpdates — your code asks Telegram for new events and passes an offset (last update_id + 1) so it does not get the same ones again;
• webhook — Telegram POSTs each update to your HTTPS address.

Telegram keeps undelivered updates only for a limited time, so a bot that was down for long may miss old events.

Core methods

• sendMessage — text with formatting and buttons.
• sendPhoto, sendDocument, sendVideo — media and files.
• editMessageText, deleteMessage — change or remove the bot's own message.
• answerCallbackQuery — acknowledge an inline button tap, otherwise the user sees a loading spinner.
• setMyCommands — the bot's command menu.
• setWebhook, getWebhookInfo, deleteWebhook — manage update delivery.

Sending a message with a button:

curl -X POST "https://api.telegram.org/bot<TOKEN>/sendMessage" \
  -H "Content-Type: application/json" \
  -d '{"chat_id": 123456789, "text": "Hi! Choose an action:", "reply_markup": {"inline_keyboard": [[{"text": "Catalog", "callback_data": "catalog"}]]}}'

Parameters can go in the query string, as form data or as JSON. Files are uploaded with multipart/form-data.

Beginner mistakes

• Not passing offset to getUpdates and receiving the same messages over and over.
• Not answering callback_query, so the button appears stuck.
• Ignoring 429 and keeping up requests without a pause.
• Not handling 403: the user blocked the bot and should be removed from broadcasts.

The full list of methods and types is in the official Bot API documentation.