The client libraries provide a means to unsubscribe a previous subscription request.
This process requires an interaction with the server, so for an asynchronous subscription there may be a small window of time where a message comes through as the unsubscribe is processed by the library. Ignoring that slight edge case, the client library will clean up any outstanding messages and tell the server that the subscription is no longer used.
nc, err := nats.Connect("demo.nats.io")if err != nil {log.Fatal(err)}defer nc.Close()​// Sync Subscriptionsub, err := nc.SubscribeSync("updates")if err != nil {log.Fatal(err)}if err := sub.Unsubscribe(); err != nil {log.Fatal(err)}​// Async Subscriptionsub, err = nc.Subscribe("updates", func(_ *nats.Msg) {})if err != nil {log.Fatal(err)}if err := sub.Unsubscribe(); err != nil {log.Fatal(err)}
Connection nc = Nats.connect("nats://demo.nats.io:4222");Dispatcher d = nc.createDispatcher((msg) -> {String str = new String(msg.getData(), StandardCharsets.UTF_8);System.out.println(str);});​// Sync SubscriptionSubscription sub = nc.subscribe("updates");sub.unsubscribe();​// Async Subscriptiond.subscribe("updates");d.unsubscribe("updates");​// Close the connectionnc.close();
let nc = NATS.connect({url: "nats://demo.nats.io:4222"});// set up a subscription to process a requestlet sub = nc.subscribe(NATS.createInbox(), (msg, reply) => {if (msg.reply) {nc.publish(reply, new Date().toLocaleTimeString());}});​// without arguments the subscription will cancel when the server receives it// you can also specify how many messages are expected by the subscriptionnc.unsubscribe(sub);
nc = NATS()​await nc.connect(servers=["nats://demo.nats.io:4222"])​future = asyncio.Future()​async def cb(msg):nonlocal futurefuture.set_result(msg)​sid = await nc.subscribe("updates", cb=cb)await nc.publish("updates", b'All is Well')​# Remove interest in subjectawait nc.unsubscribe(sid)​# Won't be received...await nc.publish("updates", b'...')
require 'nats/client'require 'fiber'​NATS.start(servers:["nats://127.0.0.1:4222"]) do |nc|Fiber.new dof = Fiber.current​sid = nc.subscribe("time") do |msg, reply|f.resume Time.nowend​nc.publish("time", 'What is the time?', NATS.create_inbox)​# Use the responsemsg = Fiber.yieldputs "Reply: #{msg}"​nc.unsubscribe(sid)​# Won't be receivednc.publish("time", 'What is the time?', NATS.create_inbox)​end.resumeend
// set up a subscription to process a requestlet sub = await nc.subscribe(createInbox(), (err, msg) => {if (msg.reply) {nc.publish(msg.reply, new Date().toLocaleTimeString());} else {t.log('got a request for the time, but no reply subject was set.');}});​// without arguments the subscription will cancel when the server receives it// you can also specify how many messages are expected by the subscriptionsub.unsubscribe();
natsConnection *conn = NULL;natsSubscription *sub = NULL;natsStatus s = NATS_OK;​s = natsConnection_ConnectTo(&conn, NATS_DEFAULT_URL);​// Subscribeif (s == NATS_OK)s = natsConnection_SubscribeSync(&sub, conn, "updates");​// Unsubscribeif (s == NATS_OK)s = natsSubscription_Unsubscribe(sub);​(...)​// Destroy objects that were creatednatsSubscription_Destroy(sub);natsConnection_Destroy(conn);