REST API

E-invoicing in Germany: How to implement the obligation with SAP Business One

One REST API (Representational State Transfer) is an interface style where system resources are accessed via HTTPS URLs and using the standard methods GET, POST, PATCH and DELETE read or modified. The exchange usually takes place as JSON, states are not held on the server, and each request contains all the information it needs to be processed.

Context

In the SAP Business One environment, the most important REST API is the Service Layer v2 under /b1s/v2/. It represents the business objects — items, Business Partners, Orders, Invoices, ProductionOrders — are provided as OData-v4 endpoints and responds in JSON. Typical tasks include connecting web shops, synchronisation with third-party systems, Python/Node.js microservices, and building B2B portals. From a developer's perspective, the authentication session-based via the login endpoint with set B1 SESSIONCookie; Requests are paginated to 20 records by default and must be over @odata.nextLink to be forwarded. In addition to the Service Layer, many Versino extensions such as DMS access or the Versino Financial Suite offer their own small REST endpoints for specific use cases.

Demarcation

A REST API differs from the older SOAP-Approach of the DI server with lower overhead, leaner payloads and no use of WSDL contracts. Compared to the UI API is it exclusively data and process-oriented — it does not influence the SAP interface. In the B1 context, REST does not automatically mean „Service Layer": B1if scenarios can also publish REST endpoints, and webshop connectors often offer their own REST routes above the Service Layer.