# ACI Open Payment Platform — Server-to-Server API

**Canonical:** https://apis.io/apis/aci-worldwide/open-payment-platform-server-to-server/  
**Provider:** ACI Worldwide — https://apis.io/providers/aci-worldwide/  
**Base URL:** https://eu-prod.oppwa.com  
**Documentation:** https://docs.aciworldwide.com/integrations/server-to-server

ACI Open Payment Platform — Server-to-Server API is one of 5 APIs that [ACI Worldwide](https://apis.io/providers/aci-worldwide/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Payments, Server-to-Server, Card Payments, and REST. The published artifact set on APIs.io includes API documentation, an API reference, and a getting-started guide.

The core RESTful payment API of the ACI Open Payment Platform (PAY.ON gateway). Server-to-Server integration lets merchants and PSPs run end-to-end payment workflows — preauthorization, debit, capture, refund, and reversal — across cards and alternative payment methods. Requests are authenticated with an Authorization Bearer access token plus a channel entityId. Production host is https://eu-prod.oppwa.com and test host is https://eu-test.oppwa.com.

## Machine-readable artifacts (4)

- **Documentation** — https://docs.aciworldwide.com/integrations/server-to-server
- **APIReference** — https://docs.aciworldwide.com/reference/parameters
- **GettingStarted** — https://docs.aciworldwide.com/integrations/widget
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/aci-worldwide/refs/heads/main/apis.yml

## Other ACI Worldwide APIs (4)

- [ACI COPYandPAY](https://apis.io/apis/aci-worldwide/copyandpay/)
- [ACI BackOffice API](https://apis.io/apis/aci-worldwide/backoffice/)
- [ACI Pay By Link API](https://apis.io/apis/aci-worldwide/pay-by-link/)
- [ACI Mobile SDK](https://apis.io/apis/aci-worldwide/mobile-sdk/)

## Tags

Payments, Server-to-Server, Card Payments, REST

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/aci-worldwide/open-payment-platform-server-to-server/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/aci-worldwide/.