Documentation for Nexi POS API

Nexi POS API is a modern REST API for operating payment terminals. It is designed to be used by Electronic Cash Registers (ECRs) to process payment transactions on terminals. The API is optimized for ease of integration and consistency across different payment methods and terminal types.

The API is fully cloud-based, meaning that the ECRs connect directly to an internet endpoint to process transactions. Payment terminals will maintain an independent internet connection to the cloud via Ethernet, Wifi or cellular networks. The ECR can be deployed in a completely separate network from the terminals, or on the same network, or even on the same device in the case of smart Android terminals. Regardless of the setup, REST API is always used the same way to communicate with the terminals.

Calling the REST API is built to be simple and straightforward without requiring the use of complex libraries or SDKs. If an SDK is desired, users can generate one for their programming language using the OpenAPI specification provided in the documentation.

Fully simulated terminals are publicly available for testing and development through the same live endpoint. These simulated terminals can be used to test the API without the need for physical hardware. Terminal simulator supports all payment methods and features of the API, allowing developers to fully build and test their applications before deploying them to production. Simulated terminals also support automated testing, making it easy to integrate the API into continuous integration and deployment pipelines.

The API is designed to be future-proof and extensible, allowing for easy addition of new payment methods and features as they become available. The API follows strict versioning practices, ensuring that changes to the API are backward compatible and do not break existing integrations and that older versions of the API are still supported.