Page 3 - REST-API

RFC 7807 defines a single, predictable JSON format for error responses: type, title, status, detail and instance. This article shows how a PHP API implements this format consistently, from the Problem Details class through the global exception handler to business validation errors with their own extension fields.

Every extra click between a product page and a completed order costs conversion. Express checkout options such as Instant Purchase, Apple Pay and Google Pay reduce the classic checkout to a single tap by carrying over address and payment data from existing wallets or saved customer data, without duplicating the regular checkout logic.

OpenAPI specifications for file operations frequently contain errors: misused format values, missing encoding objects and undocumented response headers for downloads. This article shows how to model uploads and downloads precisely in OpenAPI 3.1, so that client generators produce correct code and integrators encounter no surprises.

Choosing the right documentation UI for a REST API is not a minor decision. It affects how quickly external developers get up to speed on the API, whether consumer teams can try out endpoints directly, and how much effort integrating it into the CI pipeline costs. Swagger UI, Redoc, Scalar and Stoplight Elements each bring different strengths and philosophies to the table.

Anyone still writing manual $request->query->get() and json_decode($request->getContent()) in Symfony controllers is giving up type safety and validation for nothing. MapQueryString and MapRequestPayload have mapped query parameters and request bodies directly into typed DTOs since Symfony 6.3, automatically deserialized, validated, and ready to use.

Testing an HTTP client without making real network calls requires realistic test doubles. The Guzzle MockHandler lets you precisely simulate success responses, error statuses, timeouts, and broken JSON payloads, covering every code path of a client with confidence.

A PIM system solves exactly the problem that plagues many Magento shops with maintained yet inconsistent product data. A well designed PIM integration with clear attribute mapping between the PIM and Magento's EAV structure makes the difference between a catalog full of gaps and one that is complete and current across every language and every channel.

For a library, a developer decides at release time whether a change is breaking and bumps the version number accordingly. For a REST API that is not enough: the contract between the server and dozens of unknown clients changes the moment the OpenAPI specification changes, and nobody on the team can manually track which of ten parallel feature branches just removed a required field. This article shows how to detect breaking changes automatically from OpenAPI diffs and enforce the correct version bump through CI, instead of relying on individual developers to remember.

Anyone who maintains Postman collections by hand while also managing an OpenAPI specification doubles the effort on every API change. With the right import workflow, automatic synchronization and Newman CLI, the OpenAPI specification becomes the single source, for documentation, testing and CI integration.

A mock server that is maintained by hand drifts away from the real API within weeks. Mock servers that work directly from the OpenAPI specification are always in sync, enabling frontend development without a backend dependency, QA tests without production infrastructure, and error scenarios at the push of a button.