imageId

The ID of the Amazon Machine Image (AMI) associated with the instance. This field shows the current AMI ID of the instance's root volume. It may differ from the original AMI used when the instance was first launched.

This field appears for:

• Instances with root volume replacements through Instance Refresh

• Instances launched with AMI overrides

This field won't appear for:

• Existing instances launched from Launch Templates without overrides

• Existing instances that didn’t have their root volume replaced through Instance Refresh