• Add a builtin HTTP cache invalidation system able to store all requests in Varnish (or any other proxy supporting cache tags) and purge it instantly when needed
• Add an authorization system configurable directly from the resource class
• Add support for subresources (like /posts/1/comments or /posts/1/comments/2
• Revamp the automatic documentation UI (upgraded to the React-based version of Swagger UI, added a custom stylesheet)
• Add a new filter to select explicitly which properties to serialize
• Add a new filter to choose which serialization group to apply
• Add a new filter to test if a property value exists or not
• Add support for OAuth 2 in the UI
• Add support for embedded fields
• Add support for customizable API resources folder's name
• Filters's ids now defaults to the Symfony's service name
• Add configuration option to define custom metadata loader paths
• Make Swagger UI compatible with a strict CSP environment
• Add nulls comparison to OrderFilter
• Add a flag to disable all request listeners
• Add a default order option in the configuration
• Allow to disable all operations using the XML configuration format and deprecate the previous format
• Allow upper cased property names
• Improve the overall performance by optimizing RequestAttributesExtractor
• Improve the performance of the filters subsystem by using a PSR-11 service locator and deprecate the FilterCollection class
• Add compatibility with Symfony Flex and Symfony 4
• Allow the Symfony Dependency Injection component to autoconfigure data providers and query extensions
• Allow to use service for dynamic validation groups
• Allow using PHP constants in YAML resources files
• Upgrade to the latest version of the Hydra spec
• Add pagination and itemPerPage parameters in the Swagger/Open API documentation
• Add support for API key authentication in Swagger UI
• Allow to specify a whitelist of serialization groups
• Allow to use the new immutable date and time types of Doctrine in filters