There is a new update of the CSOM API for SharePoint and Project Online available:
https://dev.office.com/blogs/new-sharepoint-csom-version-released-for-Office-365-january-2017
There is now support for cost rate tables more or less similar to the PSI functionality:
Microsoft.ProjectServer.Client
Following properties, classes and methods have been added.
- public class Microsoft.ProjectServer.Client.CostRateCreationInformation
- public enum Microsoft.ProjectServer.Client.CostRateTableName
- public property Microsoft.ProjectServer.Client.DraftAssignment.CostRateTable
- public property Microsoft.ProjectServer.Client.EnterpriseResource.CostRateTables
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRate
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRateCollection
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRatePropertyNames
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRateTable
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRateTableCollection
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRateTableObjectPropertyNames
- public class Microsoft.ProjectServer.Client.EnterpriseResourceCostRateTablePropertyNames
- public class Microsoft.ProjectServer.Client.PageSizes
- public class Microsoft.ProjectServer.Client.PageSizesPropertyNames
- public property Microsoft.ProjectServer.Client.ProjectContext.PageSizes
- public property Microsoft.ProjectServer.Client.PublishedAssignment.CostRateTable
