---
sidebar_label: 'External Payment Operations Endpoint'
sidebar_position: 3
---

# External Payment Operations Endpoint

:::note
Information in this article is in preview status. Do not use information in this article without being in contact with Future Ordering.
:::

This article provides an OpenAPI specification and quick reference for the External Payment API endpoint that the payment provider must expose.

## OpenAPI specification

A specification for the External Payment API is available as a downloadable JSON file:

- [External Payment API OpenAPI specification](/assets/external-payment-provider/external-payment-provider-openapi-spec.json)

This specification defines request schemas, response formats, and error responses.

## Quick reference

| Property | Value |
| --- | --- |
| **Method** | `POST` |
| **Content-Type** | `application/json` |
| **Security** | OAuth 2.0 bearer token |
| **Transport** | HTTPS (TLS 1.2+) |

The concrete endpoint URL is agreed during onboarding.

## Operation payloads

The request body uses a discriminator field named `type`. Future Ordering sends one of these operation payloads:

- `payment.external.transaction.registration`
- `payment.external.transaction.authorization`
- `payment.external.transaction.capture`
- `payment.external.transaction.annulment`

All requests include a `transactionId`. See the [integration guide](./external-payment-integration-guide) for details on each operation type and their mandatory fields.

### Registration example

```json
{
    "type": "payment.external.transaction.registration",
    "merchantId": "eb621215-9ee9-4715-941c-fd6cd2235d63",
    "currency": "EUR",
    "amount": 1000,
    "revenueCenterId": "example-revenue-center-id",
    "orderId": "example-order-id",
    "customerReference": "example-customer-reference",
    "transactionId": "6c1245b4-cdae-4110-8598-9b13a91258d5",
    "deviceId": "example-device-id"
}
```

## Integration details

For comprehensive integration information including:
- Detailed endpoint specifications
- Request and response handling
- Authentication and token validation
- Idempotency requirements
- Retry logic
- Payment Notifications API

See [External Payment Provider integration guide](./external-payment-integration-guide).

## Related articles

- [External Payment Provider](./external-payment-integration-guide) — Comprehensive integration guide
- [External Payment - Flow Descriptions](./external-payment-sequence-diagrams) — Operation flows and sequence diagrams
- [External Payment - Error Responses](./error-responses) — Error response reference