OptionalclientInjected transport (bypasses lazy SDK load).
OptionalcredentialsService-account credentials (object or key path). SDK ADC is used when omitted.
OptionaldefaultDefault consumer-group subscription-name PREFIX (default
'messaging-consumers'). A subscription with no
SubscribeOptions.queue uses <defaultQueue>.<topic ID>, one
subscription per topic, because Pub/Sub subscription names are
project-global (M101b).
OptionalenableCreate the transport's own subscriptions with message ordering enabled
(default false), required before a native orderingKey is delivered in
order. Fixed at subscription creation and it costs throughput, so it is
opt-in (M106 §3.5). Refused together with client: an injected
transport creates its own subscriptions, so pass the flag to
adaptPubSubModule instead.
OptionalloggerOptional logger.
OptionalprojectGCP project ID. Required unless client is injected.
OptionalpublishPublish bound in ms, default 15000; 0 disables it. A timeout may still deliver.
OptionalreplyShared reply topic for request-reply (must pre-exist).
Options for GCP Pub/Sub broker.