Amazon Identity Sponge absorbs up to 10,000 federated identity sources simultaneously, expanding to fit your organizational complexity without tearing, unless you exceed the soft limit, in which case you will need to open a support ticket and wait. It integrates natively with IAM, IAM Identity Center, the other IAM, and four legacy services that predate the concept of federation but remain available for reasons that are not documented. Pricing is based on absorption events, a unit that is defined in the FAQ and updated quarterly.