Following parameters have been removed from the input of the below APIs and will be ignored if passed in the request:

You will now be able to use either the contact's ID or the email in Contacts API operations.

Send a transactional email has been extended and it's now possible to send a transactional email from a specific sender IP using sender id parameter.

Get AB Test Campaign Results has been extended and it's now possible to retrieve statistics and clickedLinks fields in the response.

The Create Contact via DOI endpoint has been improved and now redirectionURL can be referenced accordingly in the email template.

You will now be able to use either the childId or the childAuthKey in Reseller API operations.

You can now create a new contact and trigger DOI flow to add it to your lists by just calling one endpoint. Simply pass your contact attributes, the list_ids where the contact has agreed to be present and a valid DOI templateId .

You will now receive a processId along with total (backward compatible) in response schema when you pass the parameter "all": true in Delete a contact from a list endpoint.
This is because a process will be created which will handle this task asynchronously.
You can check the status of the process using the processId in the get process API.

You will now get the Id of the reseller child as a number along with authKey (backward compatible) in response when creating a reseller child.

Total number of non-delivered campaigns for a particular campaign id or all campaigns can now be fetched if it exists using returnBounce field.