> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pcxpay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Initiate a checkout payment

> Unified checkout initiate for VA-backed, escrow-backed, and regular payment links. Two stages: call without `payment_method` to get the payer's available payment options for their chosen currency and amount; call again with `payment_method` to dispatch the payment through the orchestrator. The existing `POST /payment-links/va/{link_ref}/initiate` flow is unchanged.




## OpenAPI

````yaml /api-reference/external/openapi.yaml post /payment-links/{identifier}/initiate
openapi: 3.0.3
info:
  title: PCX API
  description: >
    The PCX integration API. Every request requires two headers: `X-Api-Key`
    (your API key — the only supported credential) and `Authorization` (always
    the literal string `NONE`).
  version: '1.0'
servers:
  - url: https://prod-api.pcxpay.com/v1
    description: Production
  - url: https://devs.pcxpay.com/v1
    description: Development
security: []
tags:
  - name: Payment Initiation
    description: Initiate payments and poll for status
  - name: API Keys
    description: Create and manage API keys for programmatic access
  - name: Webhooks
    description: Register endpoints and receive transaction notifications
  - name: Beneficiaries
    description: Manage payment recipients
  - name: Payments
    description: Initiate and track payments
  - name: Bank Validation
    description: Validate bank accounts before initiating a payment
  - name: Transactions
    description: Query the financial transaction ledger
  - name: Virtual Accounts
    description: Multi-currency virtual account provisioning and fund operations
  - name: Payment Links
    description: Generate shareable payment links for customer checkout
  - name: Escrow
    description: Milestone-based escrow projects, parties, contracts, and funding
paths:
  /payment-links/{identifier}/initiate:
    parameters:
      - $ref: '#/components/parameters/AuthorizationHeader'
      - $ref: '#/components/parameters/XApiKeyHeader'
    post:
      tags:
        - Payment Links
      summary: Initiate a checkout payment
      description: >
        Unified checkout initiate for VA-backed, escrow-backed, and regular
        payment links. Two stages: call without `payment_method` to get the
        payer's available payment options for their chosen currency and amount;
        call again with `payment_method` to dispatch the payment through the
        orchestrator. The existing `POST /payment-links/va/{link_ref}/initiate`
        flow is unchanged.
      operationId: initiateCheckoutPayment
      parameters:
        - name: identifier
          in: path
          required: true
          description: >
            The payment link's `link_id`, or a VA link's `link_ref` (values
            beginning `PLV-` are treated as a `link_ref`).
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - payer_currency
                - payer_amount
              properties:
                payer_currency:
                  type: string
                payer_amount:
                  type: number
                  format: float
                payment_method:
                  type: string
                  nullable: true
                  description: >
                    Payment method chosen from the stage 1 `payment_methods`
                    list (e.g. `bank_transfer`, `card`). Omit to get options.
                target_amount:
                  type: number
                  format: float
                  nullable: true
                org_rate_id:
                  type: string
                  nullable: true
                country:
                  type: string
                  nullable: true
                  description: Payer's ISO 3166-1 alpha-2 country code.
      responses:
        '200':
          description: Payment options (stage 1) or initiation result (stage 2)
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                    example: success
                  data:
                    type: object
                    description: >
                      Stage 1: payer_currency, payer_amount, link_currency,
                      payment_methods, payment_reference. Stage 2: the
                      orchestrator's initiation result.
                    additionalProperties: true
        '400':
          $ref: '#/components/responses/BadRequest'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  parameters:
    AuthorizationHeader:
      name: Authorization
      in: header
      required: true
      description: >-
        Reserved for PCX-managed applications. External API integrations must
        always send the literal string `NONE` — this is the only accepted value.
      schema:
        type: string
        enum:
          - NONE
        default: NONE
        example: NONE
    XApiKeyHeader:
      name: X-Api-Key
      in: header
      required: true
      description: Your API key. This is the only supported credential.
      schema:
        type: string
        default: NONE
        example: pcx_abc123_xxxx
  responses:
    BadRequest:
      description: Invalid request parameters
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    NotFound:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  schemas:
    ErrorResponse:
      type: object
      properties:
        message:
          type: string
        status:
          type: string
          enum:
            - error

````

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