Magento's REST API is comprehensive but not mobile-friendly. Response payloads are large (a product API response can be 50+ fields), performance is slow without caching, and documentation requires digging into Magento's source code. Building a thin API gateway between Magento and your mobile app solves all three problems.
API Gateway Architecture
The gateway is a lightweight Node.js (or PHP) service that sits between mobile clients and Magento. It exposes clean, mobile-optimized endpoints, translates them into Magento API calls, and reshapes the responses. The gateway handles authentication (JWT), response caching (Redis), and request validation — leaving Magento to focus on business logic.
OpenAPI Specification First
Write your OpenAPI spec before writing code. Define every endpoint, request parameter, and response schema. Generate server stubs and client SDKs from the spec (openapi-generator). This approach ensures your mobile team has accurate documentation on day one and your API contract is enforced by tooling rather than convention.
Response Caching Strategy
Cache catalog responses aggressively (products, categories, search results) since they change infrequently compared to request volume. Use Redis with TTLs matched to your data update frequency — product updates every hour, category updates daily. Implement cache invalidation webhooks that Magento triggers when products are saved. Cart and checkout data is user-specific — cache by customer token with short TTLs.
