DISCRIMINATOR-OAS

OpenAPI polymorphism keyword applied to EDI schemas.

Definition

discriminator is defined in OpenAPI 3.0+. Declares a propertyName whose value dynamically selects the sub-schema to apply (oneOf mapping). Used to model heterogeneous EDI message families — discriminator.propertyName='transactionSetId', mapping to '850': PurchaseOrder, '855': PurchaseOrderAck, '810': Invoice.

Origin

Introduced in OpenAPI 3.0 (2017), refined in 3.1 (JSON-Schema 2020-12 alignment).

Example in context

components.schemas.X12Message: {oneOf: [{$ref: '#/components/schemas/PO'}, ...], discriminator: {propertyName: 'transactionSetId', mapping: {'850': '#/components/schemas/PO'}}}

Related terms

• OpenAPI 3.1 — specification.
• JSON-Schema 2020-12 — alignment.