Coupa Core API
The Coupa Core API is a UTF-8, RESTful interface (XML and JSON) for creating, updating, and acting on individual records within a Coupa instance — including purchase orders, requisitions, invoices, suppliers, users, expenses, contracts, receipts, and reference data. It supports offset/limit pagination, field selection, and comparison-suffix filtering (for example _greater_than), and is secured with OAuth 2.0 / OIDC.