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JavaScript@langchain/langgraphstreammatchesSubscription
Function●Since v0.3

matchesSubscription

Copy
matchesSubscription(event: MatchableEvent, definition: SubscribeParams): boolean
View source on GitHub

Parameters

NameTypeDescription
event*MatchableEvent

Event being checked for delivery.

definition*SubscribeParams

Subscription filter definition to evaluate against. The optional since field (a seq cursor) is read leniently because it is not a declared field on the base SubscribeParams shape.

Returns whether an event should be delivered for a subscription definition.

When the definition carries a since replay cursor, events at or before that sequence number are excluded — letting the same predicate drive both live fan-out and buffered replay over a StreamChannel.