diff --git a/html/api_v0.php b/html/api_v0.php
index 16470aefe8..a80370a98d 100644
--- a/html/api_v0.php
+++ b/html/api_v0.php
@@ -29,20 +29,20 @@ $app->setName('api');
 
 $app->group('/api', function() use ($app) {
   $app->group('/v0', function() use ($app) {
+    $app->get('/bgp', 'authToken', 'list_bgp')->name('list_bgp');//api/v0/bgp
     $app->group('/devices', function() use ($app) {
+      $app->delete('/:hostname', 'authToken', 'del_device')->name('del_device');//api/v0/devices/$hostname
       $app->get('/:hostname', 'authToken', 'get_device')->name('get_device');//api/v0/devices/$hostname
       $app->get('/:hostname/vlans', 'authToken', 'get_vlans')->name('get_vlans');//api/v0/devices/$hostname/vlans
       $app->get('/:hostname/:type', 'authToken', 'get_graph_generic_by_hostname')->name('get_graph_generic_by_hostname');//api/v0/devices/$hostname/$type
       $app->get('/:hostname/ports/:ifname', 'authToken', 'get_port_stats_by_port_hostname')->name('get_port_stats_by_port_hostname');//api/v0/devices/$hostname/ports/$ifName
       $app->get('/:hostname/ports/:ifname/:type', 'authToken', 'get_graph_by_port_hostname')->name('get_graph_by_port_hostname');//api/v0/devices/$hostname/ports/$ifName/$type
     });
+    $app->get('/devices', 'authToken', 'list_devices')->name('list_devices');//api/v0/devices
+    $app->post('/devices', 'authToken', 'add_device')->name('add_device');//api/v0/devices (json data needs to be passed)
     $app->group('/portgroups', function() use ($app) {
         $app->get('/:group', 'authToken', 'get_graph_by_portgroup')->name('get_graph_by_portgroup');//api/v0/portgroups/$group
     });
-    $app->get('/devices', 'authToken', 'list_devices')->name('list_devices');//api/v0/devices
-    $app->post('/devices', 'authToken', 'add_device')->name('add_device');//api/v0/devices (json data needs to be passed)
-    $app->delete('/devices/:hostname', 'authToken', 'del_device')->name('del_device');//api/v0/devices (json data needs to be passed)
-    $app->get('/bgp', 'authToken', 'list_bgp')->name('list_bgp');//api/v0/bpg
   });
   $app->get('/v0', 'authToken', 'show_endpoints');//api/v0
 });
diff --git a/html/includes/api_functions.inc.php b/html/includes/api_functions.inc.php
index 607c4cacd0..2b12d4a374 100644
--- a/html/includes/api_functions.inc.php
+++ b/html/includes/api_functions.inc.php
@@ -380,6 +380,13 @@ function list_bgp() {
 function get_graph_by_portgroup() {
   global $config;
   $app = \Slim\Slim::getInstance();
+  if ($app->request->getMediaType() != "image/png") {
+      // we only support PNG graphs at the moment
+      $app->response->setStatus(406);	// Not Acceptable
+      echo("<h3>Not Acceptable</h3>\n");
+      echo("<p>Only media type 'image/png' is provided at present</p>\n");
+      return;
+  }
   $router = $app->router()->getCurrentRoute()->getParams();
   $group = $router['group'];
   $vars = array();
diff --git a/html/pages/api-docs.inc.php b/html/pages/api-docs.inc.php
index 4fe166783a..bddb64729b 100644
--- a/html/pages/api-docs.inc.php
+++ b/html/pages/api-docs.inc.php
@@ -157,9 +157,9 @@ if ($_SESSION['userlevel'] == '10')
         <tr>
           <td colspan="5"><code>curl -H "Content-Type: application/json" -H "X-Auth-Token: 91c60e737e342c205be5bba8e2954d27" \<br/> "https://librenms.example.com/api/v0/devices/localhost/ports/eth0"</code></td>
         </tr>
-        <a name="graphs_group"></a>
+        <a name="graphs_portgroup"></a>
         <tr class="success">
-          <td colspan="5"><strong>Graphs by group</strong></td>
+          <td colspan="5"><strong>Graphs by portgroup</strong></td>
         </tr>
         <tr>
           <td>/api</td>
@@ -176,14 +176,14 @@ if ($_SESSION['userlevel'] == '10')
             </ul>
           </td>
           <td>
-            JSON
+            image/png
           </td>
         </tr>
         <tr>
-          <td colspan="5"><code>curl -H "Content-Type: application/json" -H "X-Auth-Token: 91c60e737e342c205be5bba8e2954d27" \<br/> "https://librenms.example.com/api/v0/portgroups/peering"</code></td>
+          <td colspan="5"><code>curl -H "Content-Type: image/png" -H "X-Auth-Token: 91c60e737e342c205be5bba8e2954d27" \<br/> "https://librenms.example.com/api/v0/portgroups/peering"</code></td>
         </tr>
         <tr>
-          <td colspan="5"><code>curl -H "Content-Type: application/json" -H "X-Auth-Token: 91c60e737e342c205be5bba8e2954d27" \<br/> "https://librenms.example.com/api/v0/portgroups/peering,transit?width=1024&height=768&from=1405457456&to=1405543856&legend=no"</code></td>
+          <td colspan="5"><code>curl -H "Content-Type: image/png" -H "X-Auth-Token: 91c60e737e342c205be5bba8e2954d27" \<br/> "https://librenms.example.com/api/v0/portgroups/peering,transit?width=1024&height=768&from=1405457456&to=1405543856&legend=no"</code></td>
         </tr>
         <a name="list"></a>
         <tr class="success">