What is GraphQL?

GraphQL is a query language and runtime for APIs that lets clients request exactly the data they need in a single round trip. Instead of multiple REST endpoints with fixed response shapes, a GraphQL server exposes a typed schema, and clients send queries that traverse the schema to retrieve only the relevant fields.

Definition

A GraphQL schema describes types, relationships, and operations: queries to read data, mutations to change it, and subscriptions for real-time updates. Clients send queries against a single endpoint, and the server resolves each field by calling underlying data sources. The strongly typed contract enables tooling, code generation, and clear deprecation paths.

Why it matters

For commerce frontends, GraphQL reduces over-fetching and under-fetching that plague REST integrations across heterogeneous services. A product detail page can request product, pricing, inventory, reviews, and related items in one query, shaped exactly for the component tree. Combined with persisted queries, this also improves cacheability and reduces network overhead.

Considerations

GraphQL adds complexity on the server side, including resolver design, performance tuning, and protection against expensive queries. It is most valuable in environments where multiple frontends share the same backend and where field-level flexibility matters. In composable architectures, GraphQL often lives in the BFF or storefront API layer, fronting REST services from individual microservices.

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