Buttons

Users can interact with your bot via buttons or even inline buttons, straight from inline messages in any chat.
This article describes the full button flow, using the MTProto API.

For a simplified description using the HTTP bot API, see here ».

Buttons

keyboardButton#a2fa4880 text:string = KeyboardButton;
keyboardButtonUrl#258aff05 text:string url:string = KeyboardButton;
keyboardButtonCallback#35bbdb6b flags:# requires_password:flags.0?true text:string data:bytes = KeyboardButton;
keyboardButtonRequestPhone#b16a6c29 text:string = KeyboardButton;
keyboardButtonRequestGeoLocation#fc796b3f text:string = KeyboardButton;
keyboardButtonSwitchInline#568a748 flags:# same_peer:flags.0?true text:string query:string = KeyboardButton;
keyboardButtonGame#50f41ccf text:string = KeyboardButton;
keyboardButtonBuy#afd93fbb text:string = KeyboardButton;
keyboardButtonUrlAuth#10b78d29 flags:# text:string fwd_text:flags.0?string url:string button_id:int = KeyboardButton;
inputKeyboardButtonUrlAuth#d02e7fd4 flags:# request_write_access:flags.0?true text:string fwd_text:flags.1?string url:string bot:InputUser = KeyboardButton;
keyboardButtonRequestPoll#bbc7515d flags:# quiz:flags.0?Bool text:string = KeyboardButton;

keyboardButtonRow#77608b83 buttons:Vector<KeyboardButton> = KeyboardButtonRow;

replyKeyboardHide#a03e5b85 flags:# selective:flags.2?true = ReplyMarkup;
replyKeyboardForceReply#86b40b08 flags:# single_use:flags.1?true selective:flags.2?true placeholder:flags.3?string = ReplyMarkup;
replyKeyboardMarkup#85dd99d1 flags:# resize:flags.0?true single_use:flags.1?true selective:flags.2?true rows:Vector<KeyboardButtonRow> placeholder:flags.3?string = ReplyMarkup;
replyInlineMarkup#48a30254 rows:Vector<KeyboardButtonRow> = ReplyMarkup;

message#85d6cbe2 flags:# out:flags.1?true mentioned:flags.4?true media_unread:flags.5?true silent:flags.13?true post:flags.14?true from_scheduled:flags.18?true legacy:flags.19?true edit_hide:flags.21?true pinned:flags.24?true id:int from_id:flags.8?Peer peer_id:Peer fwd_from:flags.2?MessageFwdHeader via_bot_id:flags.11?long reply_to:flags.3?MessageReplyHeader date:int message:string media:flags.9?MessageMedia reply_markup:flags.6?ReplyMarkup entities:flags.7?Vector<MessageEntity> views:flags.10?int forwards:flags.10?int replies:flags.23?MessageReplies edit_date:flags.15?int post_author:flags.16?string grouped_id:flags.17?long restriction_reason:flags.22?Vector<RestrictionReason> ttl_period:flags.25?int = Message;

---functions---

messages.sendMessage#520c3870 flags:# no_webpage:flags.1?true silent:flags.5?true background:flags.6?true clear_draft:flags.7?true peer:InputPeer reply_to_msg_id:flags.0?int message:string random_id:long reply_markup:flags.2?ReplyMarkup entities:flags.3?Vector<MessageEntity> schedule_date:flags.10?int = Updates;

Bots can attach a ReplyMarkup constructor to outgoing messages, to attach an inline keyboard or a custom reply keyboard:

Pressing buttons

keyboardButton#a2fa4880 text:string = KeyboardButton;
keyboardButtonUrl#258aff05 text:string url:string = KeyboardButton;
keyboardButtonCallback#35bbdb6b flags:# requires_password:flags.0?true text:string data:bytes = KeyboardButton;
keyboardButtonRequestPhone#b16a6c29 text:string = KeyboardButton;
keyboardButtonRequestGeoLocation#fc796b3f text:string = KeyboardButton;
keyboardButtonRequestPoll#bbc7515d flags:# quiz:flags.0?Bool text:string = KeyboardButton;
keyboardButtonSwitchInline#568a748 flags:# same_peer:flags.0?true text:string query:string = KeyboardButton;
keyboardButtonGame#50f41ccf text:string = KeyboardButton;
keyboardButtonBuy#afd93fbb text:string = KeyboardButton;
keyboardButtonUrlAuth#10b78d29 flags:# text:string fwd_text:flags.0?string url:string button_id:int = KeyboardButton;

// Used by bots to send a keyboardButtonUrlAuth
inputKeyboardButtonUrlAuth#d02e7fd4 flags:# request_write_access:flags.0?true text:string fwd_text:flags.1?string url:string bot:InputUser = KeyboardButton;

keyboardButtonRow#77608b83 buttons:Vector<KeyboardButton> = KeyboardButtonRow;

Both reply and inline keyboards are composed of a vector of rows, each row containing a vector of buttons, for each column.
Each row can have a different number of columns, and user clients should properly handle clicking buttons of every type.

Buttons available only in reply keyboards:

Buttons available only in inline keyboards:

Callback queries

keyboardButtonCallback buttons can be used to send the specified data payload back to the bot, when they are clicked.
Additionally, a bot can verify a user's identity by requiring they verify their 2FA password with SRP.

Sending a callback query

keyboardButtonGame#50f41ccf text:string = KeyboardButton;
keyboardButtonCallback#35bbdb6b flags:# requires_password:flags.0?true text:string data:bytes = KeyboardButton;

messages.botCallbackAnswer#36585ea4 flags:# alert:flags.1?true has_url:flags.3?true native_ui:flags.4?true message:flags.0?string url:flags.2?string cache_time:int = messages.BotCallbackAnswer;

---functions---

messages.getBotCallbackAnswer#9342ca07 flags:# game:flags.1?true peer:InputPeer msg_id:int data:flags.0?bytes password:flags.2?InputCheckPasswordSRP = messages.BotCallbackAnswer;

When the user clicks on a keyboardButtonCallback in a message sent by a bot, or generated by an inline query, messages.getBotCallbackAnswer should be called, passing the peer and ID of the message.
The same should happen when clicking on keyboardButtonGame buttons, with the difference that the game flag must be set instead of the data parameter.

Make sure to properly handle bot timeouts in the form of BOT_RESPONSE_TIMEOUT RPC errors, as the bot may be offline and unable to reply.

The returned messages.botCallbackAnswer constructor contains:

  • message if specified, a message that should be shown in a non-blocking toast notification
  • alert indicates whether the message should be shown as a dismissable prompt, instead of a simple toast notification
  • has_url Whether an URL is present
  • url if specified, the client should open the URL, without showing a confirmation prompt.
    This is safe and allowed, because here, bots can only return:
    • URLs to themselves with added query parameters (t.me/bot?start=aaa)
    • URLs to a valid game, if the bot has manually configured games, and the clicked button was a keyboardButtonGame.
  • native_ui whether to open game URLs in a WebView or in native UI.
  • cache_time specifies for how long should this answer be cached, client-side
SRP verification

If the requires_password flag is set, the SRP 2FA payload must also be generated and attached to the query, to verify the identity of the user.

Note that the bot will NOT be able to access your password or the SRP payload.

The SRP payload will be processed exclusively on the Telegram's servers, simply returning an RPC error without passing the query to the bot if the verification fails.
This is just a way of verifying the identity of the user, mainly used by the official @botfather bot to allow securely transferring the ownership of a bot to another user.

Answering a callback query

updateBotCallbackQuery#b9cfc48d flags:# query_id:long user_id:long peer:Peer msg_id:int chat_instance:long data:flags.0?bytes game_short_name:flags.1?string = Update;

updateInlineBotCallbackQuery#691e9052 flags:# query_id:long user_id:long msg_id:InputBotInlineMessageID chat_instance:long data:flags.0?bytes game_short_name:flags.1?string = Update;

---functions---

messages.setBotCallbackAnswer#d58f130a flags:# alert:flags.1?true query_id:long message:flags.0?string url:flags.2?string cache_time:int = Bool;

After the user invokes messages.getBotCallbackAnswer, an updateBotCallbackQuery or updateInlineBotCallbackQuery is generated and sent to the bot, depending on whether the query originated from a normal message sent by the bot, or from a message sent from an inline query.

Either way, bots must reply to the query as quickly as possible using messages.setBotCallbackAnswer:

If a game_short_name is present in the update, the bot should return the URL of the game with the specified name.
The messages.setBotCallbackAnswer method must be called anyway, even if no message or url is returned, to avoid timeouts on the client.