This is the specification for GraphQL, a query language and execution engine originally created at Facebook in 2012 for describing the capabilities and requirements of data models for client-server applications. The development of this open standard started in 2015. This specification was licensed under OWFa 1.0 in 2017. Copyright and trademark was transferred to the GraphQL Foundation in 2019. GraphQL has evolved and may continue to evolve in future editions of this specification. GraphQL is not a programming language capable of arbitrary computation, but is instead a language used to make requests to application services that have capabilities defined in this specification. GraphQL does not mandate a particular programming language or storage system for application services that implement it. Instead, application services take their capabilities and map them to a uniform language, type system, and philosophy that GraphQL encodes.