Enable message streaming for AI-powered chat - Amazon Connect
Enable message streaming using the APIEnable message streaming using the consoleUpdate Lex bot permissionsTimeout limits

Enable message streaming for AI-powered chat

Amazon Connect 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:

  • Amazon Connect agents

    • Eliminates Amazon Lex timeout limitations

    • Provides fulfillment messages during processing (such as "One moment while I review your account")

    • Displays partial responses with progressive text (growing text bubble)

  • Third-party bots via Amazon Lex or Lambda

    • Eliminates Amazon Lex timeout limitations

    • Standard bot response behavior

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:

  1. Open the Amazon Connect console and choose your instance.

  2. In the navigation pane, choose Flows > Amazon Lex bots.

  3. Under Lex bots configuration, select Enable message streaming in Amazon Connect.

Note

When you enable message streaming using the console, the required lex:RecognizeMessageAsync permission is automatically added to the bot alias resource-based policy. When using the API, you must add this permission manually.

Enable message streaming option in the Amazon Connect console.

Update Lex bot permissions

After message streaming is enabled, Amazon Connect 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 Amazon Connect instance.

When to update the bot's resource-based policy

  • New instances – Any newly associated Amazon Lex bot alias will have lex:RecognizeMessageAsync in its alias policy by default.

  • Existing instances with existing bots – If the instance previously used Amazon Lex and you enable message streaming now, you must update the resource-based policy on all associated Amazon Lex bot aliases to include the new permission.

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 Amazon Connect instance ARN resource.

Important

This feature currently does not support branching back to the same Flow block in Amazon Connect: Get customer input flow block or reusing a Amazon Lex bot with the same alias in another Get customer input block. Instead, create a new Get customer input block using a different Amazon Lex bot alias.

Timeout limits

The following timeout limits apply to chat experiences:

  • Standard chat experience – 10-second timeout

  • Chat streaming – 60-second timeout