What is OCI? A practical guide to Open Catalog Interface.

OCI in plain language

OCI, commonly expanded as Open Catalog Interface, is an interface for calling an external catalog and transferring selected catalog data back into a procurement or ERP application. In a PunchOut scenario, the buyer opens the supplier catalog, selects products and returns the selection to the buying application.

The exact field mapping, version, authentication and return behavior are controlled by the buyer environment. Treat OCI as a protocol family and implementation contract, not as one universal configuration.

The OCI catalog flow

1. 01

   Buyer starts the catalog

   The buyer launches the external supplier catalog from its purchasing context.

2. 02

   Supplier session opens

   The supplier store receives the connection context needed for the shopping session.

3. 03

   Buyer selects items

   The buyer shops in the supplier catalog and builds a cart.

4. 04

   Fields return to procurement

   The selected products and required values are transferred back to the buyer application.

5. 05

   Buyer continues approval

   The returned cart becomes part of the buyer-side requisition or approval process.

OCI inputs to clarify before setup

• The buyer system and OCI version or profile.
• The launch URL, return target and required form fields.
• The buyer and supplier identifiers that must be passed through the session.
• The catalog access, collections and store the buyer should see.
• The expected approved PO path after the cart is returned.

Keep OCI separate from the Shopify catalog itself

OCI carries the buyer-side catalog interaction; it does not replace the supplier's commerce operation. PunchOut Central uses the existing Shopify or Shopify Plus store, then manages the buyer connection, catalog access and transaction visibility around it.

The buyer may use OCI while another buyer uses cXML. That is why a supplier should document each connection separately even when all buyers use the same store.