Channel types

Sendbird's SDKs and API provide two basic types of channels. Each type is designed and implemented to support a wide variety of use cases that your business requires. This page presents the differences and characteristics of the two types.

An open channel is a public chat that can handle millions of online users. In open channels, anyone can easily participate without permission.

• Ephemeral: Messages in an ephemeral open channel are not saved in Sendbird's database. This means that old messages pushed out by new ones can't be retrieved as they are one-time data. On the other hand, messages in a persistent open channel are permanently stored in the database, which is the default.

A group channel is a private chat. A user may join the chat only through an invitation by another user who is already a member of the chatroom.

• Distinct: The distinct option determines whether to resume an old channel or to create an entirely new one when someone attempts to open a new channel with a pre-existing member combination. If there is a group channel with those members, the attempt will re-start the existing channel that has their chat history. This is similar to Twitter-style 1-on-1 direct messaging and more. The default value is false.
• 1-on-1 messaging: 1-on-1 messaging is a private channel between two users. By changing the value of the channel's distinct property, you can reuse the channel with the same members like Twitter-style 1-on-1 direct messaging.
• Group messaging: Group messaging is a private channel among multiple users. You can invite up to hundreds of members into a group channel like WhatsApp-style closed group chat.