How to determine if PublishAsync (not Jetstream's) succeeded?

[robertmircea]

Is there a way to check if NatsConnection's PublishAsync method has succeeded?

public ValueTask PublishAsync(string subject, NatsHeaders? headers = default, string? replyTo = default, NatsPubOpts? opts = default, CancellationToken cancellationToken = default)

For Jetstream's PublishAsync, I can check PubAckResponse.

[mtmk]

There are no delivery guaranties for core NATS publish. It's essentially fire-and-forget: https://docs.nats.io/nats-concepts/what-is-nats#nats-quality-of-service-qos.

However there are a couple of things you can do with PublishAsync to make sure at least the message is written to TCP stream as close as possible by setting the option WaitUntilSent to true. If WaitUntilSent is set to false messages will be queued up for faster send rate so another thing is to make sure to handle errors (usually serialization errors) by subscribing to the publish options ErrorHandler.