Skip to main content

Architecture: hbf-broadcast

C4 Component Diagram​

Key Flows​

One-Shot Broadcast​

A broadcast with method=ONE_SHOT is picked up from hbf-core, the channel authenticates using the bot deployment credentials, all subscribers across all groups are collected, and the message is sent in a single call. The broadcast status is set to COMPLETE on success or ERROR on failure.

Batched Broadcast (multi-cycle)​

A broadcast with method=BATCHES is processed incrementally across scan cycles:

  1. First scan: status is PENDING. Subscriber list is fetched, response records initialized as sent=false, first batch is sent. If more remain, status is set to WAITING with currentBatch and totalBatches saved.
  2. Subsequent scans: status is WAITING. Non-receivers are fetched from hbf-core responses, next batch is sent, counters updated. Continues until the subscriber list is exhausted, then status becomes COMPLETE.

Subscriber info (name, email) is resolved from hbf-core and falls back to the channel's own user info API. New subscribers found during delivery are created in hbf-core.

Per-Tenant Deduplication​

During each scan cycle, at most one broadcast per (tenantId, platform) pair is dispatched. Currently-sending broadcasts block new ones for the same pair. Broadcasts are ordered by sendAt ascending before selection.