CloudFormation template publishing without creating and publish an AMI

It is not possible to publish a CloudFormation template without an underlying AMI asset coming from you. AWS Marketplace's publishing process would need the AMI to be built as per the best practices outlined in https://docs.aws.amazon.com/marketplace/latest/userguide/best-practices-for-building-your-amis.html.

Hi! Have the same case here.
Well... Can't we use AMI from Amazon Marketplace, or use smth like Amazon Linux, which is definitely built according all your standards? It would be a great overkill if we will have to maintain our own copy of Amazon Linux which is exactly the same.

You can definitely use an Amazon Linux AMI as your base AMI and build your product on top of it. However, we do need an AMI with your product binaries baked in due to how we assign product code. From https://docs.aws.amazon.com/marketplace/latest/userguide/ami-products.html

Each product in AWS Marketplace is assigned a unique product ID. This ID is used to track and identify the product in our catalog and is included in seller reports. A unique product code is assigned to all AMIs submitted to AWS Marketplace. The unique product ID is used to distinguish your product in AWS Marketplace and provide access to users who purchase your product as well as for the customer billing process.

Thanks for the answer!
I can create and test a template with AMI from the store (like default ubuntu 18.04 image) but this template will not be valid for publication on the marketplace. It seems a bit strange to me.