See the API's various operations for details on their request parameters and response data:

OperationMethodEndpoint
IoT Messages
Delete all objectsDELETE/datastore
List object keysGET/datastore
Upload an objectPUT/datastore/​upload/​{key}
Delete an objectDELETE/datastore/​{key}
Get an objectGET/datastore/​{key}
Get object metadataHEAD/datastore/​{key}