Options

Emit Options

All buses accept functional options when emitting events:

bus.Emit(ctx, event, opts...)

EmitOptions Struct

type EmitOptions struct {
    Subject string // defaults to evt.Name()
}

WithSubject

bus.Emit(ctx, myEvent, event.WithSubject("chat.message.room-general"))

Overrides the publish subject. If not set, the subject defaults to evt.Name(). This is useful for buses like JetStream that support hierarchical NATS subjects.

ApplyEmitOptions Helper

cfg := event.ApplyEmitOptions(evt, opts...)
// cfg.Subject is pre-seeded with evt.Name()

---

Subscribe Options

All buses accept functional options when subscribing:

bus.Subscribe(ctx, subject, handler, opts...)

SubscribeOptions Struct

type SubscribeOptions struct {
    HandlerName string
    Stream      string
    Consumer    string
    MaxDeliver  int
    BackOff     []time.Duration
}

Available Options

WithHandlerName

event.WithHandlerName("send-welcome-email")

Identifies the handler for metrics, logging, and idempotency key scoping. If not set, defaults to the subject name.

WithStream

event.WithStream("CHAT_EVENTS")

Sets the JetStream stream name. Required for JetStream subscriptions.

WithConsumer

event.WithConsumer("chat-processor")

Sets the durable consumer name for JetStream. Defaults to the subject name if not set.

WithMaxDeliver

event.WithMaxDeliver(5)

Limits redelivery attempts per message in JetStream. If zero, messages are redelivered indefinitely (a warning is logged).

WithBackOff

event.WithBackOff([]time.Duration{
    1 * time.Second,
    5 * time.Second,
    30 * time.Second,
    1 * time.Minute,
})

Sets delays between JetStream redelivery attempts. If nil, a default progressive backoff is used.

ApplyOptions Helper

cfg := event.ApplyOptions(opts...)

Applies all options and returns the resulting SubscribeOptions struct.