Configuring Topics (Event Streams)

A topic is a named, durable message channel. Publishers append messages; every listener receives all of them, reading from its own position at its own pace; and a message stays readable until the topic's retention window ends, whether or not anything read it. A topic decouples the flow that produces an event from the flows that consume it: add a consumer without touching the producer, pause one consumer while the others carry on, and let it catch up from where it stopped.

A topic is an account resource that lives in one environment, outside any integration -- like a lookup cache. Flows use it through two steps, neither of which takes a connection:

• Publisher -- an import with adaptorType: "TopicImport". Every record it receives becomes one message.
• Listener -- an export with adaptorType: "TopicExport" and type: "stream", the page generator of a flow that runs when messages arrive.

Concerns when working with topics:

• The topic -- name, retention, the license that gates it, and registration on the integrations whose flows use it
• Publishing -- a publisher step in a flow, API, or Tool, or a direct publish call
• Listening -- a listener step, and the flow-enable transition that subscribes it
• Messages -- reading what is retained (never moves a listener) and purging it (irreversible)
• Positions -- each listener's offset on the topic: where its next run resumes