REST API

A REST API (Representational State Transfer application programming interface) is a style of web interface that lets software systems exchange data over HTTP. Resources such as customers, orders or articles are addressed by URLs and manipulated with standard HTTP methods like GET, POST, PUT and DELETE, typically returning data as JSON. In an ERP context a REST API is the most common way to connect the central system to web shops, marketplaces, logistics services and other applications. As a more general concept than any single product, the REST API sits alongside the wider category of the API and competes or coexists with alternatives such as GraphQL and traditional EDI.

Core principles

REST is an architectural style rather than a strict standard. Its defining ideas are that everything is modelled as a resource with a stable identifier (the URL), that interactions are stateless so each request carries all the information needed to process it, and that a uniform set of operations is reused across resources. Responses commonly use JSON, occasionally XML, and rely on standard HTTP status codes to signal success or failure. Because it builds directly on the mechanics of the web, a REST API can be consumed by almost any programming language and tested with ordinary browser or command-line tools, which is a large part of its popularity.

Use in ERP integration

Modern ERP systems expose REST APIs to allow controlled access to their data and processes. Typical scenarios include synchronising stock levels with an online shop, pushing orders from a marketplace into the ERP, retrieving invoices for a portal, or feeding figures into a data warehouse. REST is a building block of the API-first ERP and headless ERP approaches, and integration platforms (iPaaS) frequently orchestrate calls between several REST endpoints. Compared with file-based exchange, REST supports near-real-time updates and finer-grained access to individual records.

Security and governance

Because a REST API can expose business-critical data, access must be controlled. Common measures include:

• Authentication and authorisation, often via tokens such as OAuth, aligned with the system's role concept.
• Transport encryption with HTTPS for every request.
• Rate limiting and quotas to protect the backend from overload.
• Versioning of the interface so that changes do not break existing integrations.
• Logging and an audit trail for traceability.

These controls matter especially where personal or financial data is transferred, and they should be considered together with data-protection obligations.

REST in relation to alternatives

REST is not the only way to integrate. GraphQL lets a client request exactly the fields it needs in a single query, which can reduce over-fetching but adds complexity on the server side. SOAP-based web services remain in use in some enterprise landscapes and are more formally specified. EDI and EDIFACT continue to dominate established supply-chain document exchange. In practice many organisations operate a mix: REST for application and web integrations, EDI for trading-partner documents, and message-based middleware for high-volume internal events. Choosing among them depends on data volumes, latency requirements, partner capabilities and the level of standardisation needed.

Related Topics

• API-first ERP
• iPaaS
• Middleware