Apollo is extending its capability to ensure that changes made to a source variant's subgraphs or to the contract filtering configuration won't cause breaking changes to any downstream contract variant's schema or active clients. This is achieved through contract checks, which run two types of tasks: build tasks and operation tasks. These checks are triggered when changes are made to the source variant's subgraphs or when the contract filter configuration is edited in Studio. If any checks fail, a warning will be displayed, but the user can still choose to update the contract even if there are warnings or if checks haven't finished running. Additionally, users can decide which downstream contract variants should be blocking their source variant checks to fail by marking them as "BLOCKING". This feature is available on Apollo's Enterprise plan and requires an upgrade of the Rover CLI to at least v0.8.2 for full functionality.