Our project automation workflow creates tasks via the Workday Project Management REST API, but we’re getting validation errors about missing resource IDs even though we’re passing the worker reference. The task creation request includes project ID, task name, dates, and assigned worker, but the API returns:
Error: Required field missing - Resource_ID
Task creation failed: Resource assignment validation error
The worker exists in Workday and has project resource permissions. When we create tasks manually through the UI with the same worker, it works fine. Is there a separate resource registration step required before assigning workers to tasks via API? This is blocking our entire project automation pipeline where we need to create 50-100 tasks per project based on templates.
Also verify that your API user has the Project_Resources_Create permission domain. Even if the worker has project permissions, your integration user needs specific rights to manage resource assignments. We had a similar issue where task creation worked but resource assignment failed due to missing integration security configuration.
Consider caching resource IDs after initial project setup. We built a resource registry that queries Get_Project_Resources once per project and stores the Worker_ID to Resource_ID mappings. This eliminated redundant API calls and improved our task creation automation performance by 70%. Also handle the case where a worker isn’t yet a project resource - our system automatically calls Add_Project_Resource if the mapping doesn’t exist.
The issue is that workers and project resources are separate entities in Workday. You can’t directly assign a Worker_ID to a task - you need to use the Resource_ID from the project’s resource pool. Check if your worker has been added as a project resource first using the Get_Project_Resources API call.