Understanding 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
andCONTROL
messages can be persistent or non-persistent. Persistent messages are preserved in the history of a channel and viewed by using aListChannelMessages
API call. Non persistent messages are sent to everyAppInstanceUser
connected via WebSocket.Amazon Chime SDK sends automated
SYSTEM
messages for events such as members joining or leaving a channel.