Coupa (platform)
Coupa is a Business Spend Management platform with a single clean REST surface. Contingent and services spend (SOW, Coupa Contingent Workforce) sits on top of requisitions, contracts and purchase_orders. VMS Agent publishes canonical intent into those resources.
The public API facts VMS Agent's adapter relies on. Tenant-specific details (custom fields, picklists, approval chains) are confirmed during connection and folded into the MappingProfile.
| Authentication | OAuth 2.0 / OIDC client-credentials with scopes. Token POST https://{instance}.coupahost.com/oauth2/token. Legacy X-COUPA-API-KEY header is retired. |
|---|---|
| API style | REST, JSON or XML via Accept header |
| Base URL | https://{instance}.coupahost.com/api/{resource} (events at https://{instance}.cso.coupahost.com/api/events) |
| Objects | requisitions, purchase_orders, invoices, contracts, suppliers, quote_requests, expenses, budget_lines |
| Events / webhooks | Poll-first via updated-at filters. Events API (CSO) + configurable webhooks supplement; not comprehensive native webhooks. |
| Rate limits | 25 requests/second, burst queue ~20; exponential backoff on 429/503. |
“Docs confidence” describes how deterministic our mapping templates can be before we connect to a tenant. Even with public docs, implementations vary — especially around custom fields, approval flows and object extensions.
Deterministic mapping
Common Workforce Model fields map to known API fields. Best for standard objects (requisitions, assignments, timesheets, POs).
Tenant discovery
VMS Agent can scan tenant configuration (custom fields, picklists, required fields) where the platform permits it, then generate a tenant‑specific MappingProfile.
Enrichment loop
If the target platform requires a field the Intent record doesn't yet have, VMS Agent emits an enrichment_request back to the intake layer.
An opinionated baseline. The platform adapter enforces additional requirements via preflight. “Tenant required” fields are discovered during connection and added to the MappingProfile.
| Object | Canonical fields | Platform target | Required status | Notes |
|---|---|---|---|---|
| Requisition (Contingent) Create external worker request |
role_title, start_date, end_date, cost_center, worker_type | POST /api/requisitions | Required | CCW / Services modelled on requisitions |
| Statement of Work Services / SOW engagement |
service_category, sow.summary, deliverables[], budget, dates | /api/contracts + /api/requisitions | Tenant required | Verify CCW module resource name per tenant |
| Purchase Order Read for back-sync |
po_number, supplier, amount, status | GET /api/purchase_orders | Required | Used for reconciliation |
Idempotency & drift — publish + reconcileExpand
Publish operations are idempotent using a deterministic key {intent_id}-{intent_version}-{target_system}. Because humans can change records inside the platform, VMS Agent supports reconciliation: it compares the platform record snapshot to the canonical intent and flags drift.
Real deployments rely on program-specific custom fields (for compliance, approvals, GL coding, rate rules or supplier constraints). VMS Agent is designed to generate tenant‑specific mappings rather than forcing you to redesign your intake.
How scanning works
High-level flow
What gets produced
Portable artefacts
Important — where this platform is tenant-definedExpand
SOW / Contingent Workforce is not a distinct top-level REST resource; confirm the CCW module resource name in your tenant. Each customer has a separate sandbox instance with its own OAuth clients and scopes.
Use this page alongside the API + Schemas docs to implement: destination connection, preflight validation, publish, webhook back-sync and reconciliation.