Using Tooling API, you now can take action on multiple records belonging to the FlexiPage object with a single request. By grouping operations by object type, you reduce the number of round-trips between the client and server. SObject Collections supports XML and JSON formats. Only the FlexiPage object is supported.
Where: This change applies to Lightning Experience and Salesforce Classic in Developer, Enterprise, Performance, and Unlimited editions.
How: Use a POST request to add up to 200 records or a PATCH request to update up to 200 records, returning a list of SaveResult objects.
Use a GET request to retrieve one or more records of the same object type, specified by ID.
Use a DELETE request to delete to up 200 records, specified by ID, returning a list of DeleteResult objects.
For more information, see the Tooling API Reference and Developer Guide.