diff --git a/src/cli.js b/src/cli.js
index c17ce95..44c551d 100755
--- a/src/cli.js
+++ b/src/cli.js
@@ -4,6 +4,13 @@ import createSwarmHTTP from "./index.js";
 const swarmHTTP = createSwarmHTTP();
 
 function cli(command, ...args) {
+  process.stdout.write("> ")
+  process.stdin.on("data", data=> {
+    const input = data.toString();
+    swarmHTTP.join(input);
+    process.stdout.write(">")
+  })
+  
   const actions = {
     [undefined]: () => swarmHTTP.client(),
     server: () => swarmHTTP.server(args[0] || "."),
diff --git a/src/client.js b/src/client.js
index a78196e..466f092 100644
--- a/src/client.js
+++ b/src/client.js
@@ -6,10 +6,20 @@ const peerLink = ({ host, port }) => `http://${host}:${port}`;
 
 export default (swarm) => () => {
   const peers = new DictEmitter()
-    .on("add", (peer) => log("connection", peerLink(peer), peerLink(peer.interactive)))
-    .on("delete", (peer) => log("disconnection", peerLink(peer)));
+    .on("add", (peer) =>
+      log("connection", peer&& peerLink(peer), peer && peerLink(peer.interactive))
+    )
+    .on("delete", (peer) => log("disconnection", peer && peerLink(peer)));
 
-  swarm.on("connection", (_, { peer }) => {
+  swarm.on("connection", (_, details) => {
+    swarm.on("data", (data) => {
+      console.log(data.toString());
+      if (data.toString() === "close") {
+        socket.destroy();
+        details.destroy();
+      }
+    });
+    const { peer } = details;
     if (peer) {
       createInteractiveWebdav({
         inject: `<script>window.webdav="${peerLink(peer)}"</script>`,
diff --git a/src/index.js b/src/index.js
index 717b808..26792f5 100644
--- a/src/index.js
+++ b/src/index.js
@@ -3,12 +3,15 @@ import crypto from "crypto";
 
 import limited from "./utils/create-swarm.js";
 
-export default () => {
+const hash = (data) => crypto.createHash("sha256").update(data).digest();
+
+export default (defaultTopic = crypto.randomBytes(20).toString("hex")) => {
   const swarm = limited(hyperswarm());
-  const topic = crypto.createHash("sha256").update("the-commoners").digest();
-  swarm.join(topic, { lookup: true, announce: true });
+  swarm.join(hash(defaultTopic), { lookup: true, announce: true });
 
   return {
+    join: (topic) => swarm.join(hash(topic), { lookup: true, announce: true }),
+    leave: (topic) => swarm.leave(hash(topic)),
     client: (...args) =>
       import("./client.js").then(({ default: f }) => f(swarm)(...args)),
     server: (...args) =>
diff --git a/src/utils/create-swarm.js b/src/utils/create-swarm.js
index 4c37f50..ba90bac 100644
--- a/src/utils/create-swarm.js
+++ b/src/utils/create-swarm.js
@@ -1,18 +1,41 @@
+const getId = (socket) => `${socket.localAddress}:${socket.localPort}`;
+
 export default (swarm) => {
   const callbacks = { connection: [], disconnection: [] };
   const connections = {};
   swarm.on("connection", (socket, details) => {
-    connections[socket.id] = { socket, details };
+    connections[getId(socket)] = { socket, details };
     callbacks.connection.forEach((callback) => callback(socket, details));
   });
   swarm.on("disconnection", (socket, details) => {
-    delete connections[socket.id];
+    delete connections[getId(socket)];
     callbacks.disconnection.forEach((callback) => callback(socket, details));
   });
 
+  swarm.on("disconnection", (socket, details) => {
+    socket.destroy();
+    details.destroy();
+  });
+  let topic = null;
+  const gconnections = () => Object.freeze({ ...connections });
+  const leave = (oldTopic, fn) => {
+    Object.values(gconnections()).forEach(({ socket, details }) => {
+      socket.destroy();
+      details.destroy();
+    });
+    topic = null;
+    swarm.leave(oldTopic, fn);
+  };
+  const join = (newTopic, options) => {
+    if (topic) leave(topic);
+    topic = newTopic;
+    swarm.join(topic, options);
+  };
+
   return {
-    join: (...args) => swarm.join(...args),
-    connections: Object.freeze({ ...connections }),
+    leave,
+    join,
+    connections: () => Object.freeze({ ...connections }),
     on: (event, callback) => {
       callbacks[event] = [...(callbacks[event] || []), callback];
       if (event === "connection") {