diff --git a/IPython/html/services/kernels/handlers.py b/IPython/html/services/kernels/handlers.py
index 147e2a7..c5bdec1 100644
--- a/IPython/html/services/kernels/handlers.py
+++ b/IPython/html/services/kernels/handlers.py
@@ -45,7 +45,8 @@ class MainKernelHandler(IPythonHandler):
         km = self.kernel_manager
         kernel_id = km.start_kernel()
         model = km.kernel_model(kernel_id, self.ws_url)
-        self.set_header('Location', '{0}kernels/{1}'.format(self.base_kernel_url, kernel_id))
+        self.set_header('Location', '{0}api/kernels/{1}'.format(self.base_kernel_url, kernel_id))
+        self.set_status(201)
         self.finish(jsonapi.dumps(model))
 
 
@@ -57,6 +58,7 @@ class KernelHandler(IPythonHandler):
     @json_errors
     def get(self, kernel_id):
         km = self.kernel_manager
+        km._check_kernel_id(kernel_id)
         model = km.kernel_model(kernel_id, self.ws_url)
         self.finish(jsonapi.dumps(model))
 
diff --git a/IPython/html/services/kernels/kernelmanager.py b/IPython/html/services/kernels/kernelmanager.py
index 787abd1..3da9399 100644
--- a/IPython/html/services/kernels/kernelmanager.py
+++ b/IPython/html/services/kernels/kernelmanager.py
@@ -66,16 +66,19 @@ class MappingKernelManager(MultiKernelManager):
                 'dead',
             )
         else:
+            self._check_kernel_id(kernel_id)
             self.log.info("Using existing kernel: %s" % kernel_id)
         return kernel_id
 
     def shutdown_kernel(self, kernel_id, now=False):
         """Shutdown a kernel by kernel_id"""
+        self._check_kernel_id(kernel_id)
         super(MappingKernelManager, self).shutdown_kernel(kernel_id, now=now)
 
     def kernel_model(self, kernel_id, ws_url):
         """Return a dictionary of kernel information described in the
         JSON standard model."""
+        self._check_kernel_id(kernel_id)
         model = {"id":kernel_id, "ws_url": ws_url}
         return model
 
diff --git a/IPython/html/services/kernels/tests/test_kernels_api.py b/IPython/html/services/kernels/tests/test_kernels_api.py
index 894717f..0dc6ccb 100644
--- a/IPython/html/services/kernels/tests/test_kernels_api.py
+++ b/IPython/html/services/kernels/tests/test_kernels_api.py
@@ -31,24 +31,70 @@ class KernelAPITest(NotebookTestBase):
         # POST request
         r = requests.post(self.base_url())
         data = r.json()
+        status = r.status_code
+        header = r.headers
+        self.assertIn('location', header)
+        self.assertEquals(header['location'], '/api/kernels/' + data['id'])
+        self.assertEquals(status, 201)
         assert isinstance(data, dict)
 
         # GET request
         r = requests.get(self.base_url())
+        status = r.status_code
+        self.assertEquals(status, 200)
         assert isinstance(r.json(), list)
         self.assertEqual(r.json()[0]['id'], data['id'])
+        
+        # create another kernel and check that they both are added to the 
+        # list of kernels from a GET request
+        data2 = self.mkkernel()
+        assert isinstance(data2, dict)
+        r = requests.get(self.base_url())
+        kernels = r.json()
+        status = r.status_code
+        self.assertEquals(status, 200)
+        assert isinstance(kernels, list)
+        self.assertEquals(len(kernels), 2)
 
     def test_kernel_handler(self):
-        # GET kernel with id
+        # GET kernel with given id
         data = self.mkkernel()
         url = self.base_url() +'/' + data['id']
         r = requests.get(url)
-        assert isinstance(r.json(), dict)
-        self.assertIn('id', r.json())
-        self.assertEqual(r.json()['id'], data['id'])
+        data1 = r.json()
+        status = r.status_code
+        self.assertEquals(status, 200)
+        assert isinstance(data1, dict)
+        self.assertIn('id', data1)
+        self.assertIn('ws_url', data1)
+        self.assertEqual(data1['id'], data['id'])
+        
+        # Request a bad kernel id and check that a JSON
+        # message is returned!
+        bad_id = '111-111-111-111-111'
+        bad_url = self.base_url() + '/' + bad_id
+        r = requests.get(bad_url)
+        status = r.status_code
+        message = r.json()
+        self.assertEquals(status, 404)
+        assert isinstance(message, dict)
+        self.assertIn('message', message)
+        self.assertEquals(message['message'], 'Kernel does not exist: ' + bad_id)
         
         # DELETE kernel with id
         r = requests.delete(url)
         self.assertEqual(r.status_code, 204)
         r = requests.get(self.base_url())
         self.assertEqual(r.json(), [])
+        
+        # Request to delete a non-existent kernel id
+        bad_id = '111-111-111-111-111'
+        bad_url = self.base_url() + '/' + bad_id
+        r = requests.delete(bad_url)
+        status = r.status_code
+        message = r.json()
+        self.assertEquals(status, 404)
+        assert isinstance(message, dict)
+        self.assertIn('message', message)
+        self.assertEquals(message['message'], 'Kernel does not exist: ' + bad_id)
+        
\ No newline at end of file
diff --git a/IPython/html/services/sessions/handlers.py b/IPython/html/services/sessions/handlers.py
index 4db1004..a72ed5e 100644
--- a/IPython/html/services/sessions/handlers.py
+++ b/IPython/html/services/sessions/handlers.py
@@ -47,15 +47,15 @@ class SessionRootHandler(IPythonHandler):
         km = self.kernel_manager
         model = self.get_json_body()
         if model is None:
-            raise HTTPError(400, "No JSON data provided")
+            raise web.HTTPError(400, "No JSON data provided")
         try:
             name = model['notebook']['name']
         except KeyError:
-            raise HTTPError(400, "Missing field in JSON data: name")
+            raise web.HTTPError(400, "Missing field in JSON data: name")
         try:
             path = model['notebook']['path']
         except KeyError:
-            raise HTTPError(400, "Missing field in JSON data: path")
+            raise web.HTTPError(400, "Missing field in JSON data: path")
         # Check to see if session exists
         if sm.session_exists(name=name, path=path):
             model = sm.get_session(name=name, path=path)