ServiceContractService
{
    global static SVMXA360.SvmxGlobal.SvmxResponse createServiceContract(ServiceContractData serviceContractData){       
        return new SCON_ServiceContractPlanHandler().createServiceContract(serviceContractData);
}

Parameters	Mandatory (Yes/No)	Description
accountId	Yes	the SFDC record ID of the Account record.
startDate	Yes	the Start Date of the Service Contract.
endDate	No	the End Date of the Service Contract. If not provided, EndDate is calculated as StartDate + Duration in Plan.
pricebookId	No	the Pricebook to be used for Service Contract. If not provided, use it from Contract Plan's pricebook.
servicePlanProductId	Yes	the Product ID or ID of the Service Contract Plan in Service Contract Plan. When this is provided, use the Contract Plan that is linked to this ProductId. There should be only one Contract Plan for a given Product ID.
isCLIPlanProductId	No	The Boolean variable to look on Applicable Contract Line Product Id.   You must provide the Product ID of the Contract Line Item Plan when the isCLIPlanProductId is true. Else, an error is displayed.
serviceContractName	Yes	the name of the Service Contract Name.
description	No	the description of the Service Contract that is to be created.
salesContractId	No	the record ID of the Sales Contract that is to be populated on a custom field on Service Contract.
salesContractIdFieldAPIName	No	the field name related to Sales Contract on Service Contract.

{
    "accountId": "",
    "startDate": "",
    "endDate": "",
    "pricebookId": "",
    "servicePlanProductId": "",
    "isCLIPlanProductId": "",
    "serviceContractName": "",
    "description": "",
    "salesContractId": "",
    "salesContractIdFieldAPIName": ""
}

// Create request object
ServiceContractData serviceContractData = new ServiceContractData();

// Populate data in the request
serviceContractData.accountId='lsdffss'; // SF Account record Id
serviceContractData.servicePlanProductId='wsfczdsda'; // SF Product Record Id
serviceContractData.startDate=System.today();        
serviceContractData.serviceContractName='Test SCON';
serviceContractData.salesContractIdFieldName='Description'; // Custom/Managed Field API Name
serviceContractData.salesContractId='description field'; // Value for the Custom/Managed Field

// Calling Global method to create service contract
SVMXA360.SvmxGlobal.SvmxResponse response = ServiceContractService.createServiceContract(serviceContractData); 
System.debug('Response: ' + response);

{
  "success": true,
  "message": "",
  "data": {
    "accountId": "",
    "startDate": "",
    "endDate": "",
    "pricebookId": "",
    "servicePlanProductId": "",
    "isCLIPlanProductId": "",
    "salesContractId": "",
    "salesContractIdFieldAPIName": "",
    "serviceContractId":""
  },
  "errors": []
}