Channels¶
A channel is how your chatbot interacts with participants — such as Telegram, WhatsApp, or Slack. Linking a channel lets participants chat directly on a platform they already use, instead of requiring them to visit a separate web page.
Channel vs. platform
OCS uses "channel" and "platform" interchangeably. You'll mostly see "channel" in these docs, but some parts of the OCS UI use the label "Platform" for the same thing.
Some channels work out of the box; others require you to first configure a messaging provider — the account that handles message delivery for that platform. Once a channel is linked to your chatbot, participants can start communicating with it through that platform.
The currently supported channels are:
- Telegram
- Facebook Messenger
- Slack
- API
- SureAdhere In-App Messaging
File support¶
Channels differ in whether participants can send files to the chatbot and whether the chatbot can send files back. When the chatbot produces a file that a channel cannot deliver — because the channel doesn't support file sending, or the file's type or size isn't allowed — OCS appends a download link to the chatbot's message instead, so the participant can still get the file.
| Channel | Participants can send files | Chatbot can send files | Types and limits |
|---|---|---|---|
| Web / Chat widget | Yes | As download links | Uploads of up to 50 MB per file (50 MB total per message). Text files are always accepted, along with common document, image, audio and video formats. See the widget file attachments reference for the full list. |
| API | Yes | As attachment metadata | Same upload limits as the web channel. Files the chatbot produces are returned on the message as attachments with download links. |
| Telegram | No | Yes | Outgoing: images up to 10 MB; audio, video and documents up to 50 MB. Photos and documents sent by users are not accepted. |
| Yes | Yes | Incoming: images and documents (a caption becomes the message text). Outgoing: images up to 5 MB, audio and video up to 16 MB, documents up to 100 MB. Applies to all providers (Twilio, Turn.io, Meta Cloud API). | |
| Facebook Messenger | No | As download links | No files in either direction; text and voice messages only. |
| Slack | No | Yes | Outgoing: images, audio, video and documents up to 50 MB. |
| Yes | Yes | Attachments up to 20 MB in both directions. Executable file types are blocked. See email file attachments for details. | |
| SureAdhere | No | As download links | No files in either direction; text messages only. |
Voice notes
Voice notes are handled separately from file attachments. On channels with voice support (Telegram, WhatsApp and Facebook Messenger), a voice note from the participant is transcribed and processed as a regular message rather than being treated as a file.