Three Handlers for Event Driven GraphQL Subscriptions

Cosmo Streams enhances the Event-Driven Framework for Subscriptions (EDFS) by integrating subscription authorization, per-subscriber event filtering, and mutation validation directly into the router, eliminating the need for custom subscription services. It introduces three lifecycle handlers that manage authorization and data flow at subscription start, during event transmission, and when mutations publish events, offering teams precise control over data access and event filtering without altering schemas or infrastructure. This results in a policy-aware GraphQL subscription system capable of scaling efficiently. Additionally, WunderGraph Hub is introduced as a collaborative platform for API design and deployment. Cosmo Streams improves flexibility and performance by allowing custom logic to run within the router, using Go-written custom modules, and offers initial state delivery and differentiated event distribution for subscribers, thereby transforming GraphQL subscriptions into a more controlled and efficient event system.