diff --git a/README.md b/README.md
index b916ff05..ec5b610c 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ mvn clean
 Have a fantastic feature idea?  Spot a bug?  We would absolutely love for you to contribute to this project!  Please feel free to:
 
 * Fork this project
-* Create a feature branch from the <strong>dev</strong> branch
+* Create a feature branch from the <strong>master</strong> branch
 * Write awesome code that does awesome things
 * Write awesome test to test your awesome code
 * Verify that everything is working as it should by running <strong>mvn test</strong>.  If everything passes, you may want to make sure that your tests are covering everything you think they are!  Run <strong>mvn org.pitest:pitest-maven:mutationCoverage</strong> to find out!
diff --git a/src/main/java/org/piwik/java/tracking/PiwikTracker.java b/src/main/java/org/piwik/java/tracking/PiwikTracker.java
index 57857562..a0ec1201 100644
--- a/src/main/java/org/piwik/java/tracking/PiwikTracker.java
+++ b/src/main/java/org/piwik/java/tracking/PiwikTracker.java
@@ -18,6 +18,7 @@
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.client.utils.URIBuilder;
+import org.apache.http.concurrent.FutureCallback;
 import org.apache.http.entity.ContentType;
 import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
@@ -112,6 +113,17 @@ public HttpResponse sendRequest(final PiwikRequest request) throws IOException {
    * @throws IOException thrown if there was a problem with this connection
    */
   public Future<HttpResponse> sendRequestAsync(final PiwikRequest request) throws IOException {
+    return sendRequestAsync(request, null);
+  }
+  /**
+   * Send a request.
+   *
+   * @param request request to send
+   * @param callback callback that gets executed when response arrives
+   * @return future with response from this request
+   * @throws IOException thrown if there was a problem with this connection
+   */
+  public Future<HttpResponse> sendRequestAsync(final PiwikRequest request, FutureCallback<HttpResponse> callback) throws IOException {
     final CloseableHttpAsyncClient client = getHttpAsyncClient();
     client.start();
     uriBuilder.setCustomQuery(request.getQueryString());
@@ -119,7 +131,7 @@ public Future<HttpResponse> sendRequestAsync(final PiwikRequest request) throws
 
     try {
       get = new HttpGet(uriBuilder.build());
-      return client.execute(get, null);
+      return client.execute(get, callback);
     } catch (final URISyntaxException e) {
       throw new IOException(e);
     }
@@ -148,7 +160,20 @@ public HttpResponse sendBulkRequest(final Iterable<PiwikRequest> requests) throw
    * @throws IOException thrown if there was a problem with this connection
    */
   public Future<HttpResponse> sendBulkRequestAsync(final Iterable<PiwikRequest> requests) throws IOException {
-    return sendBulkRequestAsync(requests, null);
+    return sendBulkRequestAsync(requests, null, null);
+  }
+
+  /**
+   * Send multiple requests in a single HTTP call.  More efficient than sending
+   * several individual requests.
+   *
+   * @param requests the requests to send
+   * @param callback callback that gets executed when response arrives
+   * @return future with response from these requests
+   * @throws IOException thrown if there was a problem with this connection
+   */
+  public Future<HttpResponse> sendBulkRequestAsync(final Iterable<PiwikRequest> requests, FutureCallback<HttpResponse> callback) throws IOException {
+    return sendBulkRequestAsync(requests, null, callback);
   }
 
   /**
@@ -205,6 +230,22 @@ public HttpResponse sendBulkRequest(final Iterable<PiwikRequest> requests, final
    * @throws IOException thrown if there was a problem with this connection
    */
   public Future<HttpResponse> sendBulkRequestAsync(final Iterable<PiwikRequest> requests, final String authToken) throws IOException {
+    return sendBulkRequestAsync(requests, authToken, null);
+  }
+
+  /**
+   * Send multiple requests in a single HTTP call.  More efficient than sending
+   * several individual requests.  Specify the AuthToken if parameters that require
+   * an auth token is used.
+   *
+   * @param requests the requests to send
+   * @param authToken specify if any of the parameters use require AuthToken
+   * @param callback callback that gets executed when response arrives
+   * @return the response from these requests
+   * @throws IOException thrown if there was a problem with this connection
+   */
+  public Future<HttpResponse> sendBulkRequestAsync(final Iterable<PiwikRequest> requests, final String authToken,
+                                                   FutureCallback<HttpResponse> callback) throws IOException {
     if (authToken != null && authToken.length() != PiwikRequest.AUTH_TOKEN_LENGTH) {
       throw new IllegalArgumentException(authToken + " is not " + PiwikRequest.AUTH_TOKEN_LENGTH + " characters long.");
     }
@@ -230,7 +271,7 @@ public Future<HttpResponse> sendBulkRequestAsync(final Iterable<PiwikRequest> re
       post = new HttpPost(uriBuilder.build());
       post.setEntity(new StringEntity(ob.build().toString(),
           ContentType.APPLICATION_JSON));
-      return client.execute(post, null);
+      return client.execute(post, callback);
     } catch (final URISyntaxException e) {
       throw new IOException(e);
     }
diff --git a/src/test/java/org/piwik/java/tracking/PiwikTrackerTest.java b/src/test/java/org/piwik/java/tracking/PiwikTrackerTest.java
index e812fe20..0cdaa39b 100644
--- a/src/test/java/org/piwik/java/tracking/PiwikTrackerTest.java
+++ b/src/test/java/org/piwik/java/tracking/PiwikTrackerTest.java
@@ -13,6 +13,7 @@
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
+import org.apache.http.concurrent.FutureCallback;
 import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
 import org.apache.http.util.EntityUtils;
 import org.junit.After;
@@ -30,11 +31,10 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import java.util.concurrent.Future;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicInteger;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.fail;
+import static org.junit.Assert.*;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Matchers.argThat;
 import static org.mockito.Mockito.doReturn;
@@ -173,6 +173,57 @@ public void testWithLocalServerAsync() throws Exception {
     assertEquals("OK", msgBulk);
   }
 
+  /**
+   * Test async API with local server
+   */
+  @Test
+  public void testWithLocalServerAsyncCallback() throws Exception {
+    CountDownLatch latch = new CountDownLatch(2);
+    BlockingQueue<HttpResponse> responses = new LinkedBlockingQueue<>();
+    BlockingQueue<Exception> exceptions = new LinkedBlockingQueue<>();
+    AtomicInteger cancelled = new AtomicInteger();
+
+    FutureCallback<HttpResponse> cb = new FutureCallback<HttpResponse>() {
+
+      @Override
+      public void completed(HttpResponse httpResponse) {
+        responses.add(httpResponse);
+        latch.countDown();
+      }
+
+      @Override
+      public void failed(Exception e) {
+        exceptions.add(e);
+        latch.countDown();
+      }
+
+      @Override
+      public void cancelled() {
+        cancelled.incrementAndGet();
+        latch.countDown();
+
+      }
+    };
+
+    // one
+    PiwikRequest request = new PiwikRequest(3, new URL("http://test.com"));
+    Future<HttpResponse> respFuture = localTracker.sendRequestAsync(request, cb);
+    // bulk
+    List<PiwikRequest> requests = Collections.singletonList(request);
+    Future<HttpResponse> bulkFuture = localTracker.sendBulkRequestAsync(requests, cb);
+
+    assertTrue("Responses not received", latch.await(100, TimeUnit.MILLISECONDS));
+    assertEquals("Not expecting cancelled responses", 0, cancelled.get());
+    assertEquals("Not expecting exceptions", exceptions.size(), 0);
+    assertTrue("Single response future not done", respFuture.isDone());
+    assertTrue("Bulk response future not done", bulkFuture.isDone());
+    HttpResponse response = responses.poll(1, TimeUnit.MILLISECONDS);
+    assertEquals("OK", EntityUtils.toString(response.getEntity()));
+
+    HttpResponse bulkResponse = responses.poll(1, TimeUnit.MILLISECONDS);
+    assertEquals("OK", EntityUtils.toString(bulkResponse.getEntity()));
+  }
+
   static class CorrectGetRequest implements ArgumentMatcher<HttpGet> {
     String url;
 
@@ -262,7 +313,7 @@ public void testSendBulkRequestAsync_Iterable() throws Exception {
     doReturn(response).when(future).get();
     doReturn(true).when(future).isDone();
 
-    doReturn(future).when(piwikTracker).sendBulkRequestAsync(requests, null);
+    doReturn(future).when(piwikTracker).sendBulkRequestAsync(requests);
 
     assertEquals(response, piwikTracker.sendBulkRequestAsync(requests).get());
   }
@@ -304,7 +355,7 @@ public void testSendBulkRequestAsync_Iterable_StringFF() throws Exception {
     doReturn(future).when(client)
         .execute(argThat(new CorrectPostRequest("{\"requests\":[\"?query\"]}")), any());
 
-    assertEquals(response, piwikTracker.sendBulkRequestAsync(requests, null).get());
+    assertEquals(response, piwikTracker.sendBulkRequestAsync(requests).get());
   }
 
   @Test