WATCH: A Proposed HTTP Method for Event-Driven Subscriptions

This document proposes the addition of a WATCH method to the Hypertext Transfer Protocol (HTTP). The WATCH method enables a client to subscribe to change notifications on a specified resource, shifting the communication model from client-initiated polling to server-initiated event delivery. The proposal includes two companion mechanisms: ALIVE, a client- initiated heartbeat protocol that maintains subscription validity and restores economic symmetry between client and server; and UNWATCH, a clean subscription termination method. Together, these introduce an event-driven subscription layer into HTTP while preserving the protocol's existing simplicity and extensibility. This document incorporates formal terminology, a setup phase with confirmation handshake, refined jurisdictional compliance guidance, implementation recommendations, and protocol flow diagrams for all defined interaction patterns.