Enable message streaming for AI-powered chat

Connect Customer supports message streaming for AI-powered chat interactions. Responses from AI agents appear progressively as they're generated, improving the customer experience during conversations.

The following are integration options, along with features of each option:

Instances created starting December 2025 are automatically opted into this feature. For existing instances, you must enable message streaming manually using the API or through the console.

Enable message streaming using the API

Use the UpdateInstanceAttribute API to enable message streaming. Set the MESSAGE_STREAMING attribute to true.

aws connect update-instance-attribute \
  --instance-id your-instance-id \
  --attribute-type MESSAGE_STREAMING \
  --value true

To opt out, set the attribute to false.

Enable message streaming using the console

For newly created instances, message streaming is enabled by default.

For existing instances:

Update Lex bot permissions

After message streaming is enabled, Connect Customer needs permission to call the Amazon Lex API:

lex:RecognizeMessageAsync

You must update the resource-based policy for each Amazon Lex bot alias used by the Connect Customer instance.

When to update the bot's resource-based policy

Example snippet for Lex bot alias resource-based policy

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "connect-us-west-2-MYINSTANCEID",
      "Effect": "Allow",
      "Principal": {
        "Service": "connect.amazonaws.com"
      },
      "Action": [
        "lex:RecognizeMessageAsync",
        "lex:RecognizeText",
        "lex:StartConversation
      ],
      "Resource": "arn:aws:lex:us-west-2:123456789012:bot-alias/MYBOT/MYBOTALIAS",
      "Condition": {
        "StringEquals": {
          "AWS:SourceAccount": "123456789012"
        },
        "ArnEquals": {
          "AWS:SourceArn": "arn:aws:connect:us-west-2:123456789012:instance/MYINSTANCEID"
        }
      }
    }
  ]
}

You can add this permission by calling the Amazon Lex UpdateResourcePolicy API to update the Amazon Lex bot alias resource-based policy to include the lex:RecognizeMessageAsync action for the Connect Customer instance ARN resource.

Incremental message responses

To enable incremental responses, start a chat with ParticipantConfiguration and set Response Mode to INCREMENTAL. The default Response Mode is COMPLETE.

Timeout limits

The following timeout limits apply to chat experiences: