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Introduction-to-the-API.md

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+> ⚠️ This is the v20.x version of the wiki. For the v13.x version, please [head to the v13.x wiki](https://github.com/python-telegram-bot/v13.x-wiki/wiki).
+
+## Pure Telegram Bot API
+
+The Bot API is exposed via the [`telegram.Bot`](https://python-telegram-bot.readthedocs.io/telegram.bot.html) class.
+The methods are the `snake_case` equivalents of the methods described in the official [Telegram Bot API](https://core.telegram.org/bots/api).
+The exact `camelCase` method names as in the Telegram docs are also available for your convenience.
+For example, `telegram.Bot.send_message` is the same as `telegram.Bot.sendMessage`.
+All the classes of the Bot API can also be found in the `telegram` module, e.g. the `Message` class is available as [`telegram.Message`](https://python-telegram-bot.readthedocs.io/telegram.message.html).
+
+To generate an Access Token, you have to talk to [BotFather](https://t.me/botfather) and follow a few simple steps (described [here](https://core.telegram.org/bots/features#botfather)).
+
+For full details see the official Telegram documentation at [Bots: An introduction for developers](https://core.telegram.org/bots). You might also find [the official tutorial](https://core.telegram.org/bots/tutorial) useful for getting to know the principles of working with Telegram API (although Java is used in examples there, you will find a link to equivalent Python code).
+
+#### Hello, Telegram!
+
+To get a feeling for the API and how to use it with `python-telegram-bot`, please create a new Python file.
+
+We first want to create an instance of the `telegram.Bot` and check that the credentials are correct.
+Please paste the following code into your file.
+`'TOKEN'` should be replaced by the API token you received from `@BotFather`
+
+```python
+import asyncio
+import telegram
+
+
+async def main():
+    bot = telegram.Bot("TOKEN")
+    async with bot:
+        print(await bot.get_me())
+
+
+if __name__ == '__main__':
+    asyncio.run(main())
+```
+
+Here we simply call the API method [getMe](https://core.telegram.org/bots/api#getme).
+The `async with bot:` ensures that PTB can properly acquire and release resources.
+If you run the file you should get an output along the lines
+
+```pycon
+>>> python main.py
+User(first_name='Toledo's Palace Bot', is_bot=True, username='ToledosPalaceBot', ...)
+```
+
+So far so good.
+Now we can try and actually do something - let's send a message.
+
+However, bots can't initiate conversations with users.
+A user must either add them to a group or send them a message first.
+People can use ``telegram.me/<bot_username>`` links or username search to find your bot.
+
+Because of above note, we'll have to first send a message to the bot.
+If we've done that, we can fetch the update by refactoring the `main` function in our file with
+
+```python
+async def main():
+    bot = telegram.Bot("TOKEN")
+    async with bot:
+        print((await bot.get_updates())[0])
+```
+
+The output should now look something like this (we abbreviated the output a bit):
+
+```pycon
+>>> python main.py
+Update(message=Message(chat=Chat(first_name='John', id=1234567890, last_name='Doe', ...), from_user=User(first_name='John', id=1234567890, last_name='Doe', ...), text='Hi!', ...), update_id=219017225)
+```
+
+We copy the chat id, here `1234567890`.
+Note that you can access it also as `updates[0].message.from_user.id`, because `updates[0]` is an instance of the [`Update`](https://docs.python-telegram-bot.org/telegram.update.html) class.
+Now that we have the chat ID, we can send a message by again adjusting the `main()`:
+
+```python
+async def main():
+    bot = telegram.Bot("TOKEN")
+    async with bot:
+        await bot.send_message(text='Hi John!', chat_id=1234567890)
+```
+
+## Beyond the pure API
+
+That's all very nice, but usually you want your bot to actually react to more complex user input. That is, you want to build a chat-bot. `python-telegram-bot` offers a powerful extension module called `telegram.ext` that takes a lot of work off your shoulders. You can find an introduction at the [[Tutorial: Your first bot|Extensions---Your-first-Bot]].