The Durable Object namespace serving reply inboxes, plus its binding name.
Present only when the plugin's messaging.rpc arm is configured; its absence
is what makes request and respond refuse.
readonly
namespace: IDurableObjectNamespace
The Durable Object namespace binding.
readonly
binding: string
The binding name, for error messages.
readonly
optional
defaultTimeoutMs: number
Reply budget when RequestOptions.timeoutMs is omitted.