Wire QueueBox

This guide shows you how to send events to other systems with QueueBox. Deedbox writes a QueueBox outbox row in the append’s transaction, so a message exists exactly when its event commits. QueueBox delivers it, with retries, at least once.

1. Run QueueBox against the same database, and let it create its outbox table.

2. Add the package:

   dotnet add package Deedbox.QueueBox --prerelease

3. Choose the events to publish:

   services.AddDeedbox(es => es
       .UsePostgres(connStr)
       .Keys(keys => keys.FromEnvironment("DEEDBOX_MASTER_KEY"))
       .Stream<Cart>(s => s.Events<ItemAdded, CheckedOut>())
       .Stream<Manuscript>(s => s.Events<ReviewerInvited, CoAuthorAdded>())
       .UseQueueBox(q => q
           .Publish<CheckedOut>("cart.checked_out")
           // Events with [PersonalData] need a payload you shape, so no personal data leaks by default.
           .Publish<ReviewerInvited>("review.invited", (e, info) => new { e.ManuscriptId, e.ReviewerId })
           // Tell downstream systems to erase too.
           .Publish<SubjectErased>("privacy.subject_erased")));

What each row holds

Column	Value
id	The event ID. A destination deduplicates on X-Message-Id.
topic	The topic you chose.
key	The stream ID, so one stream’s messages keep their order.
payload	The event’s JSON, or the payload you shaped.
headers	X-Correlation-Id, traceparent, and the event’s type, stream and version.
aggregate_type	The stream type.

An event with [PersonalData] needs a payload you shape; start-up fails otherwise (DBX032).

If QueueBox runs with a custom table or column mapping, match it with UseTable and UseColumns.