{Dynamics CRM 365 Web API} Add Required People(Activity Party) to an Appointment

An activity party represents a person or group associated with an activity. An activity can have multiple activity parties.

There are 11 activity party type in Dynamics CRM customer engagement.

Activity party type	Value	Description
Sender	1	Specifies the sender.
ToRecipient	2	Specifies the recipient in the To field.
CCRecipient	3	Specifies the recipient in the Cc field.
BccRecipient	4	Specifies the recipient in the Bcc field.
RequiredAttendee	5	Specifies a required attendee.
OptionalAttendee	6	Specifies an optional attendee.
Organizer	7	Specifies the activity organizer.
Regarding	8	Specifies the regarding item.
Owner	9	Specifies the activity owner.
Resource	10	Specifies a resource.
Customer	11	Specifies a customer.

To set required people in an appointment we have use participationtypemask value 5.

Code snippet

POST – {{CRMBaseURL}}/api/data/v8.2/appointments

{
	"scheduledstart": "2017-05-18T09:00:00Z",
	"scheduledend": "2017-05-18T09:30:00Z",  
	"subject": "subject title",  

	"appointment_activity_parties": [
		{      
			"participationtypemask": 5,      
			"partyid_contact@odata.bind": "/contacts(xxxxxxx)"    
		},    
		{      
			"participationtypemask": 5,      
			"partyid_systemuser@odata.bind": "/systemusers(xxxxx)"    
		}  
	]
}

Hope this helps!