$LATEST.PUBLISHED version in Lambda Managed Instances

Lambda Managed Instances functions support the same numbered versioning workflow as Lambda (default). If you prefer not to maintain numbered versions, Lambda Managed Instances introduces a new version type: $LATEST.PUBLISHED. This version allows you to create or republish a latest published version as needed with updated code or configuration, without managing numbered versions.

Key difference from $LATEST: When you invoke a Lambda Managed Instances function using an unqualified ARN, Lambda implicitly invokes the $LATEST.PUBLISHED version rather than the unpublished $LATEST version.

The following AWS CLI command creates or republishes the $LATEST.PUBLISHED version.

aws lambda publish-version --function-name my-function --publish-to LATEST_PUBLISHED

You should see the following output:

{
  "FunctionName": "my-function",
  "FunctionArn": "arn:aws:lambda:us-east-2:123456789012:function:my-function:$LATEST.PUBLISHED",
  "Version": "$LATEST.PUBLISHED",
  "Role": "arn:aws:iam::123456789012:role/lambda-role",
  "Handler": "function.handler",
  "Runtime": "nodejs24.x",
  ...
}