GraphQL.

About GraphQL

GraphQL is an open-source query language for APIs and a server-side runtime for executing requests against a strongly typed schema. It lets clients describe the data they need and receive a response shaped around that selection, making API interactions more explicit and reducing the need for separate endpoints or oversized response formats. A GraphQL service defines types, fields, arguments, and relationships that describe the data it can provide. Resolvers connect those schema fields to application logic, databases, services, or other data sources. Before execution, incoming operations can be validated against the schema, helping clients and servers share a clear contract about available data and expected inputs. GraphQL APIs commonly expose Query operations for reading data, Mutation operations for changing data, and Subscription operations for receiving updates. Clients can use variables, fragments, aliases, directives, and nested selections to build requests that match the needs of a screen, feature, or workflow. Introspection makes it possible for tools to discover schema capabilities and provide documentation, validation, and editor assistance. GraphQL is not tied to a specific programming language, database, transport implementation, or storage engine. A wide ecosystem of server libraries, client libraries, code generators, IDE tools, testing utilities, and hosted platforms lets teams implement GraphQL across many technology stacks. It can be introduced over existing data sources rather than requiring a complete database or infrastructure redesign. For frontend teams, GraphQL can make data fetching more predictable by allowing a client to request related fields in one operation and by generating types from the schema. For backend teams, the schema provides a central API contract that can support independent development across services and clients. Teams still need to design authorization, pagination, caching, error handling, query complexity limits, and resolver performance carefully. GraphQL is a strong fit for applications with connected data, multiple clients, evolving UI requirements, or a need for a typed API contract. It may add operational and schema-design complexity compared with a small collection of straightforward REST endpoints, so teams should evaluate the shape of their data and access patterns before adopting it. The GraphQL specification and official documentation provide the foundation, while individual libraries determine the implementation details for each language and framework.