Definition
GraphQL is an open-source query language and runtime for APIs, originally developed by Meta (Facebook) in 2012 and published as open sourceSoftware with openly available source code that can be used, modified, and distributed freely. in 2015. Unlike RESTRepresentational State Transfer - architectural style for APIs based on HTTP and resource-oriented design. - where the server defines what data each endpoint returns - GraphQL lets the client specify exactly which fields and relationships it wants in a single request. This eliminates over-fetching (too much data) and under-fetching (too little data in one request). GraphQL has a strong type system (schema) that serves as a contract between frontend and backend. Subscriptions provide real-time updates via WebSocket. GraphQL is used in data-intensive applications where many clients (web, mobile, partners) have different data requirements. In the energy sector, GraphQL is relevant for analytics platforms and dashboards that need flexible access to metering dataData from electricity meters - the foundation for billing, balance settlement and market processes in the power market. and market data. It is an alternative to REST, not a replacement - REST remains the standard for simple CRUD operations and public APIs.