Oracle HCM REST API overview
Oracle HCM Cloud provides REST APIs covering Workers, Assignments, Positions, Payroll, Absence, and more. These are Fusion REST APIs — they follow the same patterns as Finance and SCM REST endpoints, with HCM-specific subject areas.
The base URL pattern: https://your-instance.fa.em2.oraclecloud.com/hcmRestApi/resources/latest/
Authentication
HCM REST uses OAuth 2.0 or Basic Auth. For OIC integrations:
- Create a dedicated HCM user with the minimum roles needed for your integration
- Use OAuth 2.0 Client Credentials for production (Basic Auth for dev/test)
- In OIC, configure the REST Adapter connection with Oracle Cloud Applications as the type and your HCM base URL
Key HCM endpoints for common integrations
Worker data:
GET /hcmRestApi/resources/latest/workers
GET /hcmRestApi/resources/latest/workers/{PersonNumber}
Assignments:
GET /hcmRestApi/resources/latest/assignments
Payroll elements:
POST /hcmRestApi/resources/latest/payrollElements
The expand parameter — critical for HCM
HCM REST responses by default return minimal data. Use the expand query parameter to include nested resources:
GET /workers?expand=assignments,assignments.payrollAssociation
Without expand, you’d need multiple API calls to get what one call with expand provides. This dramatically affects integration performance for bulk operations.
The q filter parameter
HCM REST supports server-side filtering with the q parameter:
GET /workers?q=EffectiveStartDate>2026-01-01 and ActiveStatus='ACTIVE'
Always filter server-side rather than fetching all and filtering in OIC. HCM can have tens of thousands of worker records.
Pagination
HCM REST uses offset and limit:
GET /workers?limit=500&offset=0
The response includes hasMore and count to drive your pagination loop in OIC.
Common integration patterns
Inbound to HCM (e.g. new hire from external HRIS): use HDBI or REST POST to workers with the minimum required payload.
Outbound from HCM (e.g. payroll data to payroll provider): scheduled OIC integration using changed-since filtering on lastUpdateDate.
Real-time event (e.g. termination notification): use HCM Business Events via OIC’s Oracle HCM Cloud Adapter trigger — more reliable than polling for event-driven scenarios.