2C2P Exchange Rate API

openapi: 3.0.3
info:
  title: 2C2P Payment Gateway API (PGW v4.3) Do Payment Exchange Rate API
  description: 'Server-to-server REST interface for the 2C2P Payment Gateway. Every operation is an HTTPS POST under /payment/4.3/. IMPORTANT: on the wire, each request and response body is a single JSON Web Token (JWS) signed with the merchant''s Secret Key using HMAC SHA-256 - the merchant is identified by the merchantID inside the signed payload, and there is no HTTP Authorization header. For readability this document models the DECODED JSON payloads (request `payload` and response `payload`) rather than the raw JWT string. The field schemas here are MODELED from the documented parameters and are a representative subset, not a byte-for-byte copy of 2C2P''s contract; verify exact fields against developer.2c2p.com. Endpoint paths are confirmed from the 2C2P developer reference index.'
  version: '4.3'
  contact:
    name: 2C2P Developer
    url: https://developer.2c2p.com
  x-transport-notes: All traffic is HTTPS request/response. Asynchronous results are delivered as a backend notification webhook (2C2P POSTs a signed JWT to the merchant's backendReturnUrl). There is no WebSocket or SSE transport.
servers:
- url: https://pgw.2c2p.com/payment/4.3
  description: Production
- url: https://sandbox-pgw.2c2p.com/payment/4.3
  description: Sandbox
tags:
- name: Exchange Rate
  description: Currency exchange rates for DCC / cross-border.
paths:
  /exchangeRate:
    post:
      operationId: exchangeRate
      tags:
      - Exchange Rate
      summary: Exchange rate
      description: Retrieves currency exchange rates for a transaction, supporting dynamic currency conversion (DCC). A JWT+JWS secured variant is also available.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ExchangeRateRequest'
      responses:
        '200':
          description: Decoded exchange rate response payload.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GenericResponse'
components:
  schemas:
    GenericResponse:
      type: object
      properties:
        respCode:
          type: string
        respDesc:
          type: string
      additionalProperties: true
    ExchangeRateRequest:
      type: object
      required:
      - merchantID
      - invoiceNo
      properties:
        merchantID:
          type: string
        invoiceNo:
          type: string
        amount:
          type: number
        currencyCode:
          type: string