What it means
Messages over a connection
Unlike issuing a separate request for each update, both sides can exchange messages while the connection is open. WebSocket defines transport behavior; an application protocol defines the message types and their business meaning.
Reliable status displays
Connections can close or become unavailable. An application must define authentication, reconnect behavior and how to recover missed updates. Payment truth should come from an authoritative persisted record or documented reconciliation flow rather than only the last message displayed in a browser.
Related concepts
Application programming interface, Webhook, Payment reconciliation.
In practice
A concrete example
A checkout receives live status updates over a WebSocket, then refreshes authoritative payment state after reconnecting.
Technical notes & boundaries
A live connection does not by itself provide a durable event log, guaranteed replay or exactly-once business processing. It differs from a server-to-server webhook.
Go to the source.
Original references used for this definition. Product details and standards can change.