Create a party relationship

To add a party to a module record, you can use the create relationship endpoint and specify the party ID as the relationshipTypeId. For example, to associate contact record 200 to deal record 100 as party ID 1, you can use the following request:

POST /v4/relationship

{
    "parentRecordId": 100,
    "parentCharTypeId": 4,
    "childRecordId": 200,
    "childCharTypeId": 2,
    "relationshipType":{
        "relationshipTypeId": 1
    }
}

Party IDs can be found via the UI under Configuration > Parties.