diff --git a/README.md b/README.md
index a9ddd6c..ab89793 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,86 @@ js-libp2p-tcp
 ![](https://raw.githubusercontent.com/diasdavid/abstract-connection/master/img/badge.png)
 ![](https://raw.githubusercontent.com/diasdavid/abstract-transport/master/img/badge.png)
 
-> Node.js implementation of the TCP module that libp2p uses, which implements the [interface-connection](https://github.com/diasdavid/interface-connection) interface for dial/listen.
+> Node.js implementation of the TCP module that libp2p uses, which implements
+> the [interface-connection](https://github.com/diasdavid/interface-connection)
+> interface for dial/listen.
 
-note: libp2p-tcp in Node.js is a very thin shim that adds the support to dial to a `multiaddr`. This small shim will enable libp2p to use other different transports.
+## Description
+
+`libp2p-tcp` in Node.js is a very thin shim that adds the support to dial to a
+`multiaddr`. This small shim will enable libp2p to use other different
+transports.
+
+## Example
+
+```js
+const Tcp = require('libp2p-tcp')
+const multiaddr = require('multiaddr')
+
+const mh1 = multiaddr('/ip4/127.0.0.1/tcp/9090')
+const mh2 = multiaddr('/ip6/::/tcp/9092')
+
+const tcp = new Tcp()
+
+tcp.createListener([mh1, mh2], function handler (socket) {
+  console.log('connection')
+  socket.end('bye')
+}, function ready () {
+  console.log('ready')
+
+  const client = tcp.dial(mh1)
+  client.pipe(process.stdout)
+  client.on('end', () => {
+    tcp.close(function(){})
+  })
+})
+
+```
+
+outputs
+
+```
+ready
+connection
+bye
+```
+
+## Installation
+
+### npm
+
+```sh
+> npm i libp2p-tcp
+```
+
+## API
+
+```js
+const Tcp = require('libp2p-tcp')
+```
+
+### var tcp = new Tcp()
+
+Creates a new TCP object. This does nothing on its own but provide access to
+`dial` and `createListener`.
+
+### tcp.createListener(multiaddrs, handler, callback)
+
+Creates TCP servers that listen on the addresses described in the array
+`multiaddrs`. Each connection will call `handler` with a connection stream.
+`callback` is called once all servers are listening.
+
+### tcp.dial(multiaddr, options={})
+
+Connects to the multiaddress `multiaddr` using TCP, returning the socket stream.
+If `options.ready` is set to a function, it is called when a connection is
+established.
+
+### tcp.close(callback)
+
+Closes all the listening TCP servers, calling `callback` once all of them have
+been shut down.
+
+## License
+
+MIT
diff --git a/circle.yml b/circle.yml
new file mode 100644
index 0000000..2dea02b
--- /dev/null
+++ b/circle.yml
@@ -0,0 +1,8 @@
+dependencies:
+  pre:
+    # setup ipv6
+    - sudo sysctl -w net.ipv6.conf.lo.disable_ipv6=0 net.ipv6.conf.default.disable_ipv6=0 net.ipv6.conf.all.disable_ipv6=0
+
+machine:
+  node:
+    version: stable
diff --git a/src/index.js b/src/index.js
index 3b80273..bb0f709 100644
--- a/src/index.js
+++ b/src/index.js
@@ -26,13 +26,7 @@ function TCP () {
     return conn
   }
 
-  this.createListener = (multiaddrs, options, handler, callback) => {
-    if (typeof options === 'function') {
-      callback = handler
-      handler = options
-      options = {}
-    }
-
+  this.createListener = (multiaddrs, handler, callback) => {
     if (!Array.isArray(multiaddrs)) {
       multiaddrs = [multiaddrs]
     }
@@ -74,7 +68,7 @@ function TCP () {
     var count = 0
     listeners.forEach((listener) => {
       listener.close(() => {
-        if (++count === listeners.length) {
+        if (++count === listeners.length && callback) {
           callback()
         }
       })
diff --git a/tests/libp2p-tcp-test.js b/tests/libp2p-tcp-test.js
index cc30764..5a2c533 100644
--- a/tests/libp2p-tcp-test.js
+++ b/tests/libp2p-tcp-test.js
@@ -15,6 +15,19 @@ describe('libp2p-tcp', function () {
     done()
   })
 
+  it('create without new', (done) => {
+    tcp = TCPlibp2p()
+    expect(tcp).to.exist
+    done()
+  })
+
+  it('close /wo listeners', (done) => {
+    tcp = new TCPlibp2p()
+    expect(tcp).to.exist
+    expect(function () { tcp.close() }).to.throw(Error)
+    done()
+  })
+
   it('listen', (done) => {
     const mh = multiaddr('/ip4/127.0.0.1/tcp/9090')
     tcp.createListener(mh, (socket) => {
@@ -46,13 +59,32 @@ describe('libp2p-tcp', function () {
   it('listen on several', (done) => {
     const mh1 = multiaddr('/ip4/127.0.0.1/tcp/9090')
     const mh2 = multiaddr('/ip4/127.0.0.1/tcp/9091')
+    const mh3 = multiaddr('/ip6/::/tcp/9092')
     const tcp = new TCPlibp2p()
 
-    tcp.createListener([mh1, mh2], (socket) => {}, () => {
+    tcp.createListener([mh1, mh2, mh3], (socket) => {}, () => {
       tcp.close(done)
     })
   })
 
+  it('dial ipv6', (done) => {
+    const mh = multiaddr('/ip6/::/tcp/9091')
+    var dialerObsAddrs
+
+    tcp.createListener(mh, (conn) => {
+      expect(conn).to.exist
+      dialerObsAddrs = conn.getObservedAddrs()
+      conn.end()
+    }, () => {
+      const conn = tcp.dial(mh)
+      conn.on('end', () => {
+        expect(dialerObsAddrs.length).to.equal(1)
+        tcp.close()
+        done()
+      })
+    })
+  })
+
   it('get observed addrs', (done) => {
     const mh = multiaddr('/ip4/127.0.0.1/tcp/9090')
     var dialerObsAddrs
@@ -88,5 +120,12 @@ describe('libp2p-tcp', function () {
     done()
   })
 
-  it.skip('listen on IPv6', (done) => {})
+  it('filter a valid addr for this transport', (done) => {
+    const mh1 = multiaddr('/ip4/127.0.0.1/tcp/9090')
+
+    const valid = tcp.filter(mh1)
+    expect(valid.length).to.equal(1)
+    expect(valid[0]).to.deep.equal(mh1)
+    done()
+  })
 })