GraphQL Formatter

GraphQL is a query language for APIs from Facebook (2015). Clients request only the fields they need. It uses one endpoint instead of multiple REST endpoints. It’s used in the GitHub API, Shopify, GitLab, Hasura, and more.

Minified GraphQL reduces the size of an HTTP request (important for mobile networks). The difference can be 30-60%. The server processes both formats the same way.

A query reads data, like GET in REST. A mutation changes data, like POST/PUT/DELETE. A subscription listens for real-time changes over WebSocket.

Schema defines data types and available operations. The Query type defines root queries, and Mutation defines root mutations. Schema is the contract between the client and server.

GraphiQL is a built-in playground for most GraphQL servers (/graphql). Insomnia and Postman support GraphQL. Apollo Studio is for production APIs with tracing.