nats.docs/developing-with-nats/intro/connect_timeout.md

Setting a Connect Timeout

Each library has its own, language preferred way, to pass connection options. One of the most common options is a connection timeout. To set the maximum time to connect to a server to 10 seconds:

{% tabs %} {% tab title="Go" %}

nc, err := nats.Connect("demo.nats.io", nats.Name("API Options Example"), nats.Timeout(10*time.Second))
if err != nil {
	log.Fatal(err)
}
defer nc.Close()

// Do something with the connection

{% endtab %}

{% tab title="Java" %}

Options options = new Options.Builder().
                            server("nats://demo.nats.io:4222").
                            connectionTimeout(Duration.ofSeconds(10)). // Set timeout
                            build();
Connection nc = Nats.connect(options);

// Do something with the connection

nc.close();

{% endtab %}

{% tab title="JavaScript" %}

{% endtab %}

{% tab title="Python" %}

nc = NATS()
await nc.connect(connect_timeout=2)

# Do something with the connection

await nc.close()

{% endtab %}

{% tab title="Ruby" %}

# There is currently no connect timeout as part of the Ruby NATS client API, but you can use a timer to mimic it.
require 'nats/client'

timer = EM.add_timer(5) do
  NATS.connect do |nc|
    # Do something with the connection

    # Close the connection
    nc.close
  end
end
EM.cancel_timer(timer)

{% endtab %}

{% tab title="TypeScript" %}

let nc = await connect({
    url: "nats://demo.nats.io:4222",
    timeout: 1000
});

{% endtab %} {% endtabs %}