# Unsubscribing 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. {% tabs %} {% tab title="Go" %} ```go nc, err := nats.Connect("demo.nats.io") if err != nil { log.Fatal(err) } defer nc.Close() // Sync Subscription sub, err := nc.SubscribeSync("updates") if err != nil { log.Fatal(err) } if err := sub.Unsubscribe(); err != nil { log.Fatal(err) } // Async Subscription sub, err = nc.Subscribe("updates", func(_ *nats.Msg) {}) if err != nil { log.Fatal(err) } if err := sub.Unsubscribe(); err != nil { log.Fatal(err) } ``` {% endtab %} {% tab title="Java" %} ```java 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 Subscription Subscription sub = nc.subscribe("updates"); sub.unsubscribe(); // Async Subscription d.subscribe("updates"); d.unsubscribe("updates"); // Close the connection nc.close(); ``` {% endtab %} {% tab title="JavaScript" %} ```javascript let nc = NATS.connect({ url: "nats://demo.nats.io:4222" }); // set up a subscription to process a request let 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 subscription nc.unsubscribe(sub); ``` {% endtab %} {% tab title="Python" %} ```python nc = NATS() await nc.connect(servers=["nats://demo.nats.io:4222"]) future = asyncio.Future() async def cb(msg): nonlocal future future.set_result(msg) sid = await nc.subscribe("updates", cb=cb) await nc.publish("updates", b'All is Well') # Remove interest in subject await nc.unsubscribe(sid) # Won't be received... await nc.publish("updates", b'...') ``` {% endtab %} {% tab title="Ruby" %} ```ruby require 'nats/client' require 'fiber' NATS.start(servers:["nats://127.0.0.1:4222"]) do |nc| Fiber.new do f = Fiber.current sid = nc.subscribe("time") do |msg, reply| f.resume Time.now end nc.publish("time", 'What is the time?', NATS.create_inbox) # Use the response msg = Fiber.yield puts "Reply: #{msg}" nc.unsubscribe(sid) # Won't be received nc.publish("time", 'What is the time?', NATS.create_inbox) end.resume end ``` {% endtab %} {% tab title="TypeScript" %} ```typescript // set up a subscription to process a request let 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 subscription sub.unsubscribe(); ``` {% endtab %} {% tab title="C" %} ```c natsConnection *conn = NULL; natsSubscription *sub = NULL; natsStatus s = NATS_OK; s = natsConnection_ConnectTo(&conn, NATS_DEFAULT_URL); // Subscribe if (s == NATS_OK) s = natsConnection_SubscribeSync(&sub, conn, "updates"); // Unsubscribe if (s == NATS_OK) s = natsSubscription_Unsubscribe(sub); (...) // Destroy objects that were created natsSubscription_Destroy(sub); natsConnection_Destroy(conn); ``` {% endtab %} {% endtabs %}