# Realtime GraphQL API

A GraphQL operation type that delivers realtime updates to clients, typically carried over WebSocket using the graphql-ws or legacy graphql-transport-ws protocol, or over SSE using the GraphQL-SSE protocol. Subscriptions are supported by Apollo, Hasura, AWS AppSync, and most production GraphQL servers.

**Documentation:** https://spec.graphql.org/October2021/#sec-Subscription

**References:**

- Documentation: https://the-guild.dev/graphql/ws