0-2-4-understand-pubsub-topic

name	0.2.4-understand-pubsub_topic
description	[0.2.4] A named channel or subject through which messages are routed from publishers to interested subscribers; the pu

understand-pubsub_topic

CALL NUMBER: deep_event_driven_archite.pubsub_topic DEFINITION: A named channel or subject through which messages are routed from publishers to interested subscribers; the publisher has no knowledge of subscriber identities or count.

Invoke this skill to understand pubsub_topic down to its primitives. The RELATIVE ROOT below is the least-fixed-point closure of everything it bundles from — the full import cone, grouped by the lib each prim comes from. Projected from a prover-typed KB (MAP/SWI-Prolog consistency gate): every reference below resolves.

THE RELATIVE ROOT (the import cone, by lib)

from deep_event_driven_archite

• pubsub_broker (d1): The intermediary component that receives messages from publishers and forwards them to subscribers based on topic subscriptions; may also perform filtering.
• pubsub_message (d1): The payload broadcast by a publisher on a topic; in pub/sub it is typically ephemeral and not persisted beyond active subscriber consumption.
• pubsub_topic_namespace (d1): A hierarchical or scoped naming scheme for topics (e.g., orders.new, orders.cancelled) that enables subscribers to express interest at varying levels of granularity.
• pubsub_dead_letter (d2): A destination for messages that cannot be successfully delivered to any subscriber, capturing failures for later inspection or replay.
• pubsub_subscription (d2): An active registration linking a subscriber to a topic; may be durable (surviving subscriber disconnection) or transient (active only while subscriber is connected).
• pubsub_content_filter (d2): A predicate or attribute-based rule applied at the broker or subscriber side to select a subset of messages on a topic for delivery.
• pubsub_message_schema (d2): A structured format (JSON, Avro, Protobuf) defining the shape of messages on a topic, enabling subscribers to deserialize and interpret published events.
• pubsub_subscriber (d3): An entity that expresses interest in one or more topics and receives messages published to those topics; receives only messages matching its subscriptions.

CONSUMERS (what needs this)

event_streaming, pubsub_publisher

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Projected from the software architecture patterns and styles KB (211 concepts / 192 relations) — consistency-typed by MAP; the facet list after the colon IS the cross-lib dependency web.

(leaf — this is an actual skill.)