Channels’ supported features and restrictions

Before you start developing a bot, you need to find out what features channels support and what restrictions they have. This will allow you to understand which channel is most suitable for achieving your goal.

This article summarizes the supported features and restrictions of the channels into which you can deploy your bots.

Before proceeding to the information about the desired channel, we recommend that you first read the designations in tables.

Categories and designations

In the article, the channels are categorized in the following way:

Chat widget.
Messengers: WhatsApp from edna (2.0), WhatsApp from i-Digital, Slack, Telegram, Viber, WeChat, WhatsApp.
Social networks: Odnoklassniki, VK.
Platforms and services: Bitrix24, Chat2Desk, LiveTex, Webim (External Bot API 2.0), Microsoft Teams, Zendesk Chat.
Voice assistants: Alice, Google Assistant, Marusia, Sber Salut.

You can find the following designations in the tables:

Designation	Description
Both ways	The file transfer is available in both directions: from the bot to clients and from clients to the bot.
To clients	The file transfer is only available from the bot to clients.
To bot	The file transfer is only available from clients to the bot.
Yes	The feature is supported.
No	The feature is not supported.
?	There is no information about the feature.
N/A	The functionality restriction is not applicable to this channel.

Chat widget

File transfer

Feature	Chat widget
Audio	Both ways
Video	Both ways
Audio message	No
Images	Both ways
GIF images	Both ways
PDF files	Both ways
Arbitrary file format	Both ways
Max video size	50 MB
Max image size	50 MB
Max file size	50 MB

Bot features

Feature	Chat widget
HTML markup	Yes
Pushgate	Yes
SMS	Yes
Text campaigns	Yes
Buttons	Yes
Inline buttons	Yes
Carousel	Yes
Location	No
Contact transfer	No
Transfer to agent	Yes
Integration with CRM systems	Yes

Messengers

File transfer

Feature	edna: WhatsApp 2.0	i-Digital: WhatsApp	Slack	Telegram	Viber	WeChat	WhatsApp
Audio	Both ways	Both ways	To bot	Both ways	No	No	Both ways
Video	Both ways	Both ways	Both ways	Both ways	Both ways	To clients	Both ways
Audio message	To bot	Both ways	To bot	Both ways	No	No	Both ways
Images	Both ways	Both ways	To bot	Both ways	Both ways	Both ways	Both ways
GIF images	No	No	To bot	Yes	No	No	No
PDF files	Both ways	No	To bot	To bot	No	To bot	Both ways
Arbitrary file format	Both ways	No	To bot	Both ways	To bot	No	To clients
Max video size	16 MB	16 MB	1 GB	50 MB	50 MB	100 MB	16 MB
Max image size	16 MB	16 MB	1 GB	10 MB	1 MB	10 MB	5 MB
Max file size	100 MB	100 MB	1 GB	50 MB	50 MB	100 MB	100 MB

Bot features

Feature	edna: WhatsApp 2.0	i-Digital: WhatsApp	Slack	Telegram	Viber	WeChat	WhatsApp
HTML markup	No	No	No	Yes	No	No	No
Pushgate	No	Yes	Yes	Yes	Yes	No	Yes
SMS	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Text campaigns	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Buttons	No	Yes	Yes	Yes	Yes	No	Yes
Inline buttons	No	Yes	No	Yes	Yes	No	Yes
Carousel	No	No	No	No	No	No	No
Location	Yes	No	No	Yes	Yes	No	Yes
Contact transfer	No	Yes	No	Yes	Yes	No	Yes
Transfer to agent	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Integration with CRM systems	Yes	Yes	Yes	Yes	Yes	Yes	Yes

Other usage details

Channel	Feature	Description
i-Digital: WhatsApp	Buttons	1. If you want to add a text or inline button to the bot message that will initialize the dialog, you must first register this button as a template in i-Digital. 2. Text buttons and inline buttons cannot be combined in one state. 3. In a single message, the maximum number of text buttons is 3 and the maximum number of inline buttons is 2. 4. The button’s maximum text length is 20 characters. 5. You can use only 1 button with a link to a website and 1 button with a phone number in a single message.
Telegram	Buttons	1. For each set of text buttons or inline buttons, there should be at least one text reply in the bot message. 2. The maximum number of characters in text buttons is 20 and the maximum number of characters in inline buttons is 15. Button text over the limit moves to the next line. 3. If the data size specified in `callback_data` exceeds 64 bytes, the excess data will be cut.
	Transfer to agent	1. When adding several closing chat phrases in `closeChatPhrases` for the `switch` reply type, only the first phrase of the array will be displayed as a button. However, the chat can be closed with any of the listed phrases. 2. Any button must be followed with a text message. Otherwise, the button will not be displayed until the agent sends their first message.
Viber	Buttons	1. If the focus is active on the message input form, the button will not be displayed for the client in the chat. 2. You can place 1, 2, 3, or 6 text buttons on a single row. 3. The maximum number of inline button rows is 7.
	Transfer to agent	When adding several closing chat phrases in `closeChatPhrases` for the `switch` reply type, only the first phrase of the array will be displayed as a button. However, the chat can be closed with any of the listed phrases.
WeChat	Images	1. Image size must not exceed 1,000×1,000 pixels. 2. Supported image formats are `.jpg`, `.jpeg`, and `.png`.
WhatsApp	Buttons	1. The maximum number of buttons on the screen is 3. 2. The maximum number of characters in each button is 20.
	Inline buttons	Can be created as raw reply type using a template.

Social networks

File transfer

Feature	Odnoklassniki	VK
Audio	No	To clients
Video	Both ways	Both ways
Audio message	No	To bot
Images	Both ways	Both ways
GIF images	Both ways	No
PDF files	To bot	To bot
Arbitrary file format	To bot	To bot
Max video size	?	200 MB
Max image size	?	50 MB
Max file size	?	200 MB

Bot features

Feature	Odnoklassniki	VK
HTML markup	No	No
Pushgate	Yes	Yes
SMS	Yes	Yes
Text campaigns	Yes	Yes
Buttons	No	Yes
Inline buttons	No	Yes
Carousel	No	Yes
Location	No	No
Contact transfer	No	No
Transfer to agent	Yes	Yes
Integration with CRM systems	?	Yes

Other usage details

Channel	Feature	Description
VK	Carousel	1. For the correct display of the carousel in the chat, it is necessary to add a text message to the carousel. 2. Carousel must contain at least 1 button. Learn more about VK restrictions on the use of `carousel` reply type in the VK documentation.
	Buttons	The button’s maximum text length is 20 characters. Button text over the limit moves to the next line.

Platforms and services

File transfer

Feature	Bitrix24	Chat2Desk	LiveTex	Microsoft Teams	Webim (External Bot API 2.0)	Zendesk Chat
Audio	To bot	To bot	Both ways	To bot	To clients	No
Video	Both ways	Both ways	Both ways	Both ways	No	No
Audio message	No	No	No	No	No	No
Images	Both ways	To bot	Both ways	Both ways	Both ways	No
GIF images	Both ways	No	Both ways	Both ways	Both ways	No
PDF files	To bot	To bot	To bot	Both ways	Both ways	No
Arbitrary file format	To bot	To bot	To bot	Both ways	Both ways	No
Max video size	50 MB	?	25 MB	50 MB	N/A	N/A
Max image size	50 MB	?	25 MB	50 MB	10 MB	N/A
Max file size	50 MB	?	25 MB	50 MB	10 MB	N/A

Bot features

Feature	Bitrix24	Chat2Desk	LiveTex	Microsoft Teams	Webim (External Bot API 2.0)	Zendesk Chat
HTML markup	No	No	No	Yes	No	No
Pushgate	No	Yes	Yes	Yes	Yes	Yes
SMS	Yes	Yes	Yes	Yes	Yes	Yes
Text campaigns	Yes	Yes	Yes	Yes	Yes	Yes
Buttons	No	Yes	Yes	Yes	Yes	Yes
Inline buttons	No	Yes	Yes	Yes	No	No
Carousel	No	No	No	No	No	No
Location	No	No	No	No	No	No
Contact transfer	No	No	No	No	No	No
Transfer to agent	Yes	Yes	Yes	Yes	Yes	No
Integration with CRM systems	Yes	Yes	Yes	Yes	Yes	Yes

Other usage details

Channel	Feature	Description
Bitrix24	Transfer to agent	1. When using the transfer to an agent, the bot will not be able to automatically return to the dialog. Only the agent can manually return the bot back to the dialog. 2. When the dialog is transferred back to the bot, the script will be restarted. Bitrix24 does not allow returning to the same place in the dialog with the bot where the client stopped before talking with the agent.
Chat2Desk	Buttons	1. Messages with inline or text buttons should also include text. 2. Chat2Desk supports inline buttons only for the Chat2Desk online chat and Viber. 3. Chat2Desk supports text buttons for the Chat2Desk online chat, Facebook, Telegram, Viber, and VK.
LiveTex (inbound channel)	Buttons	LiveTex does not support sending files and adding buttons in one message. Otherwise, buttons will not be displayed in the message.
Microsoft Teams	HTML markup	HTML markup is only displayed when sending bot messages by passing reply objects with the `text` type into `$response.replies`.
Webim (External Bot API 2.0)	File extensions	Webim (External Bot API 2.0) supports the following file extensions: `.png`, `.jpg`, `.jpeg`, `.doc`, `.rtf`, `.gif`, `.txt`, `.pdf`, `.docx`, `.webp`, `.oga`, `.ogg`. If you want your bot to send files in other extensions, such as `.mp3` or `.wav`, please contact Webim support. They will enable the setting for your account.
Zendesk Chat	Text	Zendesk Chat does not support text markup. For example, you cannot add a hyperlink or a line break.
	Buttons	1. The maximum number of buttons in a single message is 3. 2. If the button’s text contains more than 20 characters, the text will be trimmed. When you hover over the button, the full name will be displayed.

Voice assistants

File transfer

Feature	Alice	Google Assistant	Marusia	Sber Salut
Audio message	Both ways	Both ways	Both ways	Both ways
Images	To clients	To clients	To clients	To clients
GIF images	To clients	To clients	To clients	No
Max image size	1 MB	5 MB	5 MB	10 MB

Bot features

Feature	Alice	Google Assistant	Marusia	Sber Salut
HTML markup	No	No	No	No
Pushgate	No	No	No	No
SMS	Yes	No	Yes	Yes
Text campaigns	No	No	No	No
Buttons	Yes	Yes	Yes	Yes
Inline buttons	Yes	No	Yes	Yes
Carousel	Yes	No	No	No
Transfer to agent	No	Yes	No	No
Integration with CRM systems	Yes	Yes	Yes	No

Other usage details

Channel	Feature	Description
Alice	Audio	When connecting audio in the `tts` parameter for the `text` reply type, you must specify the `.opus` file format for the audio from the Alice sound library.
	Images	1. Alice supports the following image extensions: `.png`, `.jpeg`, `.gif`, `.bmp`, `.tiff`, `.webp`. 2. Upload all images to Yandex.Dialogs in the developer console or via HTTP API. 3. Each file must be at least 1 KB and no more than 1 MB in size. Learn more about all Yandex restrictions on the use of images in the Yandex documentation.
	Carousel	1. The `$response.text` field must not be empty. 2. The `description` field of the `carousel` reply type must not be empty. The maximum number of characters is 1,024. Learn more about all Yandex restrictions on the use of `carousel` reply type in the Yandex documentation.
	Buttons	In the skill response, you can use special buttons called suggests. Learn more about the use of such buttons in the Yandex documentation.
	Text	The maximum number of characters allowed to be displayed or read out to clients is 1,024. If you exceed the number of characters in a single message, the displayed or read-out text will be trimmed.
Google Assistant	Images	1. Google Assistant supports the following image extensions: `.png`, `.jpg`, and `.gif`. 2. The image must follow the text, not precede it. 3. You can use only 1 image per bot reply.
	Buttons	The maximum number of buttons in a single message is 8.
	Text	You can use no more than 2 text answers at a time.
Marusia	Images	Images must be at least 600 pixels high, and their aspect ratio must be no more than 2:1.
Sber Salut	Images	1. Sber Salut supports the following image extensions: `.png`, `.jpg`, and `.bmp`. 2. The recommended aspect ratio is 3:2. 3. The recommended resolution is more than 1,024×682 pixels.