Message types - Amazon Chime SDK

Message types

You send messages through channels. You can send STANDARD, CONTROL, or SYSTEM messages.

  • STANDARD messages can be up to 4KB in size and contain metadata. Metadata is arbitrary, and you can use it in a variety of ways, such as containing a link to an attachment.

  • CONTROL messages are limited to 30 bytes and do not contain metadata.

  • STANDARD and CONTROL messages can be persistent or non-persistent. Persistent messages are preserved in the history of a channel and viewed by using a ListChannelMessages API call. Non persistent messages are sent to every AppInstanceUser connected via WebSocket.

  • Amazon Chime SDK sends automated SYSTEM messages for events such as members joining or leaving a channel.