DefineEventConsumerOptions

Defined in: packages/server/src/events/consumer.ts:223

Type Parameters

TRegistry

TRegistry extends SyncTableRegistry

Properties

batchSize?

optional batchSize?: number

Defined in: packages/server/src/events/consumer.ts:240

Max messages per read. Defaults to DEFAULT_EVENT_CONSUMER_BATCH_SIZE.

---

callback

callback: EventConsumerCallback

Defined in: packages/server/src/events/consumer.ts:232

---

concurrency?

optional concurrency?: number

Defined in: packages/server/src/events/consumer.ts:253

Max CONCURRENT callback invocations per Event stream. Defaults to 1 (strictly sequential). Values above 1 are safe for the idempotent callback the lane already requires: ADR-0053 decision 6 disclaims any ordering across sub-batches precisely so concurrency is available. Reads stay serial — only the callbacks of one delivered read run in parallel.

---

maxAttempts?

optional maxAttempts?: number

Defined in: packages/server/src/events/consumer.ts:258

Deliveries a sub-batch gets before a further callback failure dead-letters it. Defaults to DEFAULT_EVENT_MAX_ATTEMPTS. A malformed body never gets attempts — it dead-letters on sight.

---

onDeadLetter?

optional onDeadLetter?: (report) => void

Defined in: packages/server/src/events/consumer.ts:265

Notified for every dead-lettered sub-batch. The runner ALSO warn-logs each one unconditionally: loudness is the ADR’s requirement and a hook that swallows (or throws) must not be able to make a dead letter silent.

Parameters

report

EventDeadLetterReport

Returns

void

---

onPoll?

optional onPoll?: (report) => void

Defined in: packages/server/src/events/consumer.ts:276

Notified after EVERY read the runner performs — productive or empty, in both pacing modes — which makes it the host’s liveness heartbeat. The DefineEventConsumerOptions.callback fires only on delivered batches, so on an idle queue it goes quiet and a liveness/readiness probe answering from it would report a healthy runner as dead; beat from this instead and treat fault as the queue-health signal.

It fires on the READ, before the batch is delivered, so a slow callback cannot delay the heartbeat. A hook that THROWS can never take a loop down: the throw is caught, warn-logged ONCE per runner (a hook that throws every poll must not drown the log), and the loop carries on.

Parameters

report

EventPollReport

Returns

void

---

poll?

optional poll?: EventConsumerPollOptions

Defined in: packages/server/src/events/consumer.ts:260

Adaptive-poll tuning. See EventConsumerPollOptions.

---

queue

queue: EventQueue

Defined in: packages/server/src/events/consumer.ts:231

The queue to consume from — REQUIRED, and the reason the runner is backend-agnostic by construction. The ordinary wiring is createPgmqEventQueue({ db }) with the app’s own drizzle handle; constructing it here from a db option would bake the shipped backend into the runner for one line of ergonomics.

---

registry

registry: TRegistry

Defined in: packages/server/src/events/consumer.ts:225

The sync registry whose streams this runner consumes.

---

streams?

optional streams?: readonly string[]

Defined in: packages/server/src/events/consumer.ts:238

Narrow to a subset of the registered Event streams — the knob that splits streams across processes. Defaults to ALL registered streams. An unknown name is a definition-time throw (fail-closed): a runner that silently consumed nothing is the failure mode this forbids.

---

visibilityTimeoutSeconds?

optional visibilityTimeoutSeconds?: number

Defined in: packages/server/src/events/consumer.ts:246

The delivered-message invisibility window, renewed at half of it while the runner is still working through a read. Defaults to DEFAULT_EVENT_VISIBILITY_TIMEOUT_SECONDS. Size it above ONE callback’s worst case (renewal covers the rest of the batch), not above the whole batch’s.