var ContactRoles = {
  PRIMARY_CONTACT: -10,
  ALTERNATE_CONTACT: -20,
  DECISION_MAKER: -30,
  CONSULTANT: -40
};

var primaryContact = record.create({ type: record.Type.CONTACT });
primaryContact.setValue({ fieldId: 'firstname', value: firstName });
primaryContact.setValue({ fieldId: 'lastname', value: lastName });
primaryContact.setValue({ fieldId: 'title', value: title });
primaryContact.setValue({ fieldId: 'email', value: email });
primaryContact.setValue({ fieldId: 'phone', value: phone });
primaryContact.setValue({ fieldId: 'company', value: company });
var primaryContactId = primaryContact.save();

record.attach({
  record: { type: record.Type.CONTACT, id: primaryContactId },
  to: { type: type, id: entityId },
  attributes: { role: ContactRoles.PRIMARY_CONTACT }
});