Cython refactor of Python C wrapping layer

Also set up environment-related details needed for a smooth Cython
experience: have the test script avoid rebuilding all dependencies if the
virtualenv directory already exists, have the PyPI distribution script
distribute the Cython generated C code rather than the .pyx files.

29 files changed, 2852 insertions, 11 deletions

diff --git a/src/python/requirements.txt b/src/python/requirements.txt
index 43395df03b..41d633a2dd 100644
--- a/src/python/requirements.txt
+++ b/src/python/requirements.txt
@@ -1,3 +1,4 @@
 enum34==1.0.4
 futures==2.2.0
 protobuf==3.0.0a3
+cython>=0.22
diff --git a/src/python/src/.gitignore b/src/python/src/.gitignore
index bc15a52cf1..144e501237 100644
--- a/src/python/src/.gitignore
+++ b/src/python/src/.gitignore
@@ -1,3 +1,4 @@
 MANIFEST
 grpcio.egg-info/
+build/
 dist/
diff --git a/src/python/src/grpc/_adapter/.gitignore b/src/python/src/grpc/_adapter/.gitignore
new file mode 100644
index 0000000000..a6f96cd6db
--- /dev/null
+++ b/src/python/src/grpc/_adapter/.gitignore
@@ -0,0 +1,5 @@
+*.a
+*.so
+*.dll
+*.pyc
+*.pyd
diff --git a/src/python/src/grpc/_cython/.gitignore b/src/python/src/grpc/_cython/.gitignore
new file mode 100644
index 0000000000..c315029288
--- /dev/null
+++ b/src/python/src/grpc/_cython/.gitignore
@@ -0,0 +1,7 @@
+*.h
+*.c
+*.a
+*.so
+*.dll
+*.pyc
+*.pyd
diff --git a/src/python/src/grpc/_cython/README.rst b/src/python/src/grpc/_cython/README.rst
new file mode 100644
index 0000000000..c0e66734e8
--- /dev/null
+++ b/src/python/src/grpc/_cython/README.rst
@@ -0,0 +1,52 @@
+GRPC Python Cython layer
+========================
+
+Package for the GRPC Python Cython layer.
+
+What is Cython?
+---------------
+
+Cython is both a superset of the Python language with extensions for dealing
+with C types and a tool that transpiles this superset into C code. It provides
+convenient means of statically typing expressions and of converting Python
+strings to pointers (among other niceties), thus dramatically smoothing the
+Python/C interop by allowing fluid use of APIs in both from the same source.
+See the wonderful `Cython website`_.
+
+Why Cython?
+-----------
+
+- **Python 2 and 3 support**
+  Cython generated C code has precompiler macros to target both Python 2 and
+  Python 3 C APIs, even while acting as a superset of just the Python 2
+  language (e.g. using ``basestring``).
+- **Significantly less semantic noise**
+  A lot of CPython code is just glue, especially human-error-prone
+  ``Py_INCREF``-ing and ``Py_DECREF``-ing around error handlers and such.
+  Cython takes care of that automagically.
+- **Possible PyPy support**
+  One of the major developments in Cython over the past few years was the
+  addition of support for PyPy. We might soon be able to provide such support
+  ourselves through our use of Cython.
+- **Less Python glue code**
+  There existed several adapter layers in and around the original CPython code
+  to smooth the surface exposed to Python due to how much trouble it was to
+  make such a smooth surface via the CPython API alone. Cython makes writing
+  such a surface incredibly easy, so these adapter layers may be removed.
+
+Implications for Users
+----------------------
+
+Nothing additional will be required for users. PyPI packages will contain
+Cython generated C code and thus not necessitate a Cython installation.
+
+Implications for GRPC Developers
+--------------------------------
+
+A typical edit-compile-debug cycle now requires Cython. We install Cython in
+the ``virtualenv`` generated for the Python tests in this repository, so
+initial test runs may take an extra 2+ minutes to complete.  Subsequent test
+runs won't reinstall ``Cython`` (unless required versions change and the
+``virtualenv`` doesn't have installed versions that satisfy the change).
+
+.. _`Cython website`: http://cython.org/
diff --git a/src/python/src/grpc/_cython/__init__.py b/src/python/src/grpc/_cython/__init__.py
new file mode 100644
index 0000000000..b89398809f
--- /dev/null
+++ b/src/python/src/grpc/_cython/__init__.py
@@ -0,0 +1,28 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/src/python/src/grpc/_cython/_cygrpc/__init__.py b/src/python/src/grpc/_cython/_cygrpc/__init__.py
new file mode 100644
index 0000000000..b89398809f
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/__init__.py
@@ -0,0 +1,28 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/src/python/src/grpc/_cython/_cygrpc/call.pxd b/src/python/src/grpc/_cython/_cygrpc/call.pxd
new file mode 100644
index 0000000000..fe9b81e3d3
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/call.pxd
@@ -0,0 +1,37 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+
+
+cdef class Call:
+
+  cdef grpc.grpc_call *c_call
+  cdef list references
+
diff --git a/src/python/src/grpc/_cython/_cygrpc/call.pyx b/src/python/src/grpc/_cython/_cygrpc/call.pyx
new file mode 100644
index 0000000000..4349786b3a
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/call.pyx
@@ -0,0 +1,82 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cimport cpython
+
+from grpc._cython._cygrpc cimport records
+
+
+cdef class Call:
+
+  def __cinit__(self):
+    # Create an *empty* call
+    self.c_call = NULL
+    self.references = []
+
+  def start_batch(self, operations, tag):
+    if not self.is_valid:
+      raise ValueError("invalid call object cannot be used from Python")
+    cdef records.Operations cy_operations = records.Operations(operations)
+    cdef records.OperationTag operation_tag = records.OperationTag(tag)
+    operation_tag.operation_call = self
+    operation_tag.batch_operations = cy_operations
+    cpython.Py_INCREF(operation_tag)
+    return grpc.grpc_call_start_batch(
+        self.c_call, cy_operations.c_ops, cy_operations.c_nops,
+        <cpython.PyObject *>operation_tag)
+
+  def cancel(self,
+             grpc.grpc_status_code error_code=grpc.GRPC_STATUS__DO_NOT_USE,
+             details=None):
+    if not self.is_valid:
+      raise ValueError("invalid call object cannot be used from Python")
+    if (details is None) != (error_code == grpc.GRPC_STATUS__DO_NOT_USE):
+      raise ValueError("if error_code is specified, so must details "
+                       "(and vice-versa)")
+    if isinstance(details, bytes):
+      pass
+    elif isinstance(details, basestring):
+      details = details.encode()
+    else:
+      raise TypeError("expected details to be str or bytes")
+    if error_code != grpc.GRPC_STATUS__DO_NOT_USE:
+      self.references.append(details)
+      return grpc.grpc_call_cancel_with_status(self.c_call, error_code, details)
+    else:
+      return grpc.grpc_call_cancel(self.c_call)
+
+  def __dealloc__(self):
+    if self.c_call != NULL:
+      grpc.grpc_call_destroy(self.c_call)
+
+  # The object *should* always be valid from Python. Used for debugging.
+  @property
+  def is_valid(self):
+    return self.c_call != NULL
+
diff --git a/src/python/src/grpc/_cython/_cygrpc/channel.pxd b/src/python/src/grpc/_cython/_cygrpc/channel.pxd
new file mode 100644
index 0000000000..3e341bf222
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/channel.pxd
@@ -0,0 +1,36 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+
+
+cdef class Channel:
+
+  cdef grpc.grpc_channel *c_channel
+  cdef list references
diff --git a/src/python/src/grpc/_cython/_cygrpc/channel.pyx b/src/python/src/grpc/_cython/_cygrpc/channel.pyx
new file mode 100644
index 0000000000..b20313818d
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/channel.pyx
@@ -0,0 +1,84 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport call
+from grpc._cython._cygrpc cimport completion_queue
+from grpc._cython._cygrpc cimport credentials
+from grpc._cython._cygrpc cimport records
+
+
+cdef class Channel:
+
+  def __cinit__(self, target, records.ChannelArgs arguments=None,
+                credentials.ClientCredentials client_credentials=None):
+    cdef grpc.grpc_channel_args *c_arguments = NULL
+    self.c_channel = NULL
+    self.references = []
+    if arguments is not None:
+      c_arguments = &arguments.c_args
+    if isinstance(target, bytes):
+      pass
+    elif isinstance(target, basestring):
+      target = target.encode()
+    else:
+      raise TypeError("expected target to be str or bytes")
+    if client_credentials is None:
+      self.c_channel = grpc.grpc_channel_create(target, c_arguments)
+    else:
+      self.c_channel = grpc.grpc_secure_channel_create(
+          client_credentials.c_credentials, target, c_arguments)
+      self.references.append(client_credentials)
+    self.references.append(target)
+    self.references.append(arguments)
+
+  def create_call(self, completion_queue.CompletionQueue queue not None,
+                  method, host, records.Timespec deadline not None):
+    if queue.is_shutting_down:
+      raise ValueError("queue must not be shutting down or shutdown")
+    if isinstance(method, bytes):
+      pass
+    elif isinstance(method, basestring):
+      method = method.encode()
+    else:
+      raise TypeError("expected method to be str or bytes")
+    if isinstance(host, bytes):
+      pass
+    elif isinstance(host, basestring):
+      host = host.encode()
+    else:
+      raise TypeError("expected host to be str or bytes")
+    cdef call.Call operation_call = call.Call()
+    operation_call.references = [self, method, host, queue]
+    operation_call.c_call = grpc.grpc_channel_create_call(
+        self.c_channel, queue.c_completion_queue, method, host, deadline.c_time)
+    return operation_call
+
+  def __dealloc__(self):
+    if self.c_channel != NULL:
+      grpc.grpc_channel_destroy(self.c_channel)
diff --git a/src/python/src/grpc/_cython/_cygrpc/completion_queue.pxd b/src/python/src/grpc/_cython/_cygrpc/completion_queue.pxd
new file mode 100644
index 0000000000..fd562ad75b
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/completion_queue.pxd
@@ -0,0 +1,39 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+
+
+cdef class CompletionQueue:
+
+  cdef grpc.grpc_completion_queue *c_completion_queue
+  cdef object poll_condition
+  cdef bint is_polling
+  cdef bint is_shutting_down
+  cdef bint is_shutdown
diff --git a/src/python/src/grpc/_cython/_cygrpc/completion_queue.pyx b/src/python/src/grpc/_cython/_cygrpc/completion_queue.pyx
new file mode 100644
index 0000000000..886d85360a
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/completion_queue.pyx
@@ -0,0 +1,117 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cimport cpython
+
+from grpc._cython._cygrpc cimport call
+from grpc._cython._cygrpc cimport records
+
+import threading
+import time
+
+
+cdef class CompletionQueue:
+
+  def __cinit__(self):
+    self.c_completion_queue = grpc.grpc_completion_queue_create()
+    self.is_shutting_down = False
+    self.is_shutdown = False
+    self.poll_condition = threading.Condition()
+    self.is_polling = False
+
+  def poll(self, records.Timespec deadline=None):
+    # We name this 'poll' to avoid problems with CPython's expectations for
+    # 'special' methods (like next and __next__).
+    cdef grpc.gpr_timespec c_deadline = grpc.gpr_inf_future
+    cdef records.OperationTag tag = None
+    cdef object user_tag = None
+    cdef call.Call operation_call = None
+    cdef records.CallDetails request_call_details = None
+    cdef records.Metadata request_metadata = None
+    cdef records.Operations batch_operations = None
+    if deadline is not None:
+      c_deadline = deadline.c_time
+    cdef grpc.grpc_event event
+
+    # Poll within a critical section
+    with self.poll_condition:
+      while self.is_polling:
+        self.poll_condition.wait(float(deadline) - time.time())
+      self.is_polling = True
+    with nogil:
+      event = grpc.grpc_completion_queue_next(
+          self.c_completion_queue, c_deadline)
+    with self.poll_condition:
+      self.is_polling = False
+      self.poll_condition.notify()
+
+    if event.type == grpc.GRPC_QUEUE_TIMEOUT:
+      return records.Event(event.type, False, None, None, None, None, None)
+    elif event.type == grpc.GRPC_QUEUE_SHUTDOWN:
+      self.is_shutdown = True
+      return records.Event(event.type, True, None, None, None, None, None)
+    else:
+      if event.tag != NULL:
+        tag = <records.OperationTag>event.tag
+        # We receive event tags only after they've been inc-ref'd elsewhere in
+        # the code.
+        cpython.Py_DECREF(tag)
+        if tag.shutting_down_server is not None:
+          tag.shutting_down_server.notify_shutdown_complete()
+        user_tag = tag.user_tag
+        operation_call = tag.operation_call
+        request_call_details = tag.request_call_details
+        request_metadata = tag.request_metadata
+        batch_operations = tag.batch_operations
+        if tag.is_new_request:
+          # Stuff in the tag not explicitly handled by us needs to live through
+          # the life of the call
+          operation_call.references.extend(tag.references)
+      return records.Event(
+          event.type, event.success, user_tag, operation_call,
+          request_call_details, request_metadata, batch_operations)
+
+  def shutdown(self):
+    grpc.grpc_completion_queue_shutdown(self.c_completion_queue)
+    self.is_shutting_down = True
+
+  def clear(self):
+    if not self.is_shutting_down:
+      raise ValueError('queue must be shutting down to be cleared')
+    while self.poll().type != grpc.GRPC_QUEUE_SHUTDOWN:
+      pass
+
+  def __dealloc__(self):
+    if self.c_completion_queue != NULL:
+      # Ensure shutdown, pump the queue
+      if not self.is_shutting_down:
+        self.shutdown()
+      while not self.is_shutdown:
+        self.poll()
+      grpc.grpc_completion_queue_destroy(self.c_completion_queue)
diff --git a/src/python/src/grpc/_cython/_cygrpc/credentials.pxd b/src/python/src/grpc/_cython/_cygrpc/credentials.pxd
new file mode 100644
index 0000000000..6b74a267e0
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/credentials.pxd
@@ -0,0 +1,45 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+
+
+cdef class ClientCredentials:
+
+  cdef grpc.grpc_credentials *c_credentials
+  cdef grpc.grpc_ssl_pem_key_cert_pair c_ssl_pem_key_cert_pair
+  cdef list references
+
+
+cdef class ServerCredentials:
+
+  cdef grpc.grpc_server_credentials *c_credentials
+  cdef grpc.grpc_ssl_pem_key_cert_pair *c_ssl_pem_key_cert_pairs
+  cdef size_t c_ssl_pem_key_cert_pairs_count
+  cdef list references
diff --git a/src/python/src/grpc/_cython/_cygrpc/credentials.pyx b/src/python/src/grpc/_cython/_cygrpc/credentials.pyx
new file mode 100644
index 0000000000..c14d8844dd
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/credentials.pyx
@@ -0,0 +1,217 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport records
+
+
+cdef class ClientCredentials:
+
+  def __cinit__(self):
+    self.c_credentials = NULL
+    self.c_ssl_pem_key_cert_pair.private_key = NULL
+    self.c_ssl_pem_key_cert_pair.certificate_chain = NULL
+    self.references = []
+
+  # The object *can* be invalid in Python if we fail to make the credentials
+  # (and the core thus returns NULL credentials). Used primarily for debugging.
+  @property
+  def is_valid(self):
+    return self.c_credentials != NULL
+
+  def __dealloc__(self):
+    if self.c_credentials != NULL:
+      grpc.grpc_credentials_release(self.c_credentials)
+
+
+cdef class ServerCredentials:
+
+  def __cinit__(self):
+    self.c_credentials = NULL
+
+  def __dealloc__(self):
+    if self.c_credentials != NULL:
+      grpc.grpc_server_credentials_release(self.c_credentials)
+
+
+def client_credentials_google_default():
+  cdef ClientCredentials credentials = ClientCredentials();
+  credentials.c_credentials = grpc.grpc_google_default_credentials_create()
+  return credentials
+
+def client_credentials_ssl(pem_root_certificates,
+                           records.SslPemKeyCertPair ssl_pem_key_cert_pair):
+  if pem_root_certificates is None:
+    pass
+  elif isinstance(pem_root_certificates, bytes):
+    pass
+  elif isinstance(pem_root_certificates, basestring):
+    pem_root_certificates = pem_root_certificates.encode()
+  else:
+    raise TypeError("expected str or bytes for pem_root_certificates")
+  cdef ClientCredentials credentials = ClientCredentials()
+  cdef const char *c_pem_root_certificates = NULL
+  if pem_root_certificates is not None:
+    c_pem_root_certificates = pem_root_certificates
+    credentials.references.append(pem_root_certificates)
+  if ssl_pem_key_cert_pair is not None:
+    credentials.c_credentials = grpc.grpc_ssl_credentials_create(
+        c_pem_root_certificates, &ssl_pem_key_cert_pair.c_pair
+    )
+    credentials.references.append(ssl_pem_key_cert_pair)
+  else:
+    credentials.c_credentials = grpc.grpc_ssl_credentials_create(
+      c_pem_root_certificates, NULL
+    )
+
+def client_credentials_composite_credentials(
+    ClientCredentials credentials_1 not None,
+    ClientCredentials credentials_2 not None):
+  if not credentials_1.is_valid or not credentials_2.is_valid:
+    raise ValueError("passed credentials must both be valid")
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = grpc.grpc_composite_credentials_create(
+      credentials_1.c_credentials, credentials_2.c_credentials)
+  credentials.references.append(credentials_1)
+  credentials.references.append(credentials_2)
+  return credentials
+
+def client_credentials_compute_engine():
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = grpc.grpc_compute_engine_credentials_create()
+  return credentials
+
+def client_credentials_service_account(
+    json_key, scope, records.Timespec token_lifetime not None):
+  if isinstance(json_key, bytes):
+    pass
+  elif isinstance(json_key, basestring):
+    json_key = json_key.encode()
+  else:
+    raise TypeError("expected json_key to be str or bytes")
+  if isinstance(scope, bytes):
+    pass
+  elif isinstance(scope, basestring):
+    scope = scope.encode()
+  else:
+    raise TypeError("expected scope to be str or bytes")
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = grpc.grpc_service_account_credentials_create(
+      json_key, scope, token_lifetime.c_time)
+  credentials.references.extend([json_key, scope])
+  return credentials
+
+def client_credentials_jwt(json_key, records.Timespec token_lifetime not None):
+  if isinstance(json_key, bytes):
+    pass
+  elif isinstance(json_key, basestring):
+    json_key = json_key.encode()
+  else:
+    raise TypeError("expected json_key to be str or bytes")
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = grpc.grpc_jwt_credentials_create(
+      json_key, token_lifetime.c_time)
+  credentials.references.append(json_key)
+  return credentials
+
+def client_credentials_refresh_token(json_refresh_token):
+  if isinstance(json_refresh_token, bytes):
+    pass
+  elif isinstance(json_refresh_token, basestring):
+    json_refresh_token = json_refresh_token.encode()
+  else:
+    raise TypeError("expected json_refresh_token to be str or bytes")
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = grpc.grpc_refresh_token_credentials_create(
+      json_refresh_token)
+  credentials.references.append(json_refresh_token)
+  return credentials
+
+def client_credentials_fake_transport_security():
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = (
+      grpc.grpc_fake_transport_security_credentials_create())
+  return credentials
+
+def client_credentials_iam(authorization_token, authority_selector):
+  if isinstance(authorization_token, bytes):
+    pass
+  elif isinstance(authorization_token, basestring):
+    authorization_token = authorization_token.encode()
+  else:
+    raise TypeError("expected authorization_token to be str or bytes")
+  if isinstance(authority_selector, bytes):
+    pass
+  elif isinstance(authority_selector, basestring):
+    authority_selector = authority_selector.encode()
+  else:
+    raise TypeError("expected authority_selector to be str or bytes")
+  cdef ClientCredentials credentials = ClientCredentials()
+  credentials.c_credentials = grpc.grpc_iam_credentials_create(
+      authorization_token, authority_selector)
+  credentials.references.append(authorization_token)
+  credentials.references.append(authority_selector)
+  return credentials
+
+def server_credentials_ssl(pem_root_certs, pem_key_cert_pairs):
+  if pem_root_certs is None:
+    pass
+  elif isinstance(pem_root_certs, bytes):
+    pass
+  elif isinstance(pem_root_certs, basestring):
+    pem_root_certs = pem_root_certs.encode()
+  else:
+    raise TypeError("expected pem_root_certs to be str or bytes")
+  pem_key_cert_pairs = list(pem_key_cert_pairs)
+  for pair in pem_key_cert_pairs:
+    if not isinstance(pair, records.SslPemKeyCertPair):
+      raise TypeError("expected pem_key_cert_pairs to be sequence of "
+                      "records.SslPemKeyCertPair")
+  cdef ServerCredentials credentials = ServerCredentials()
+  credentials.references.append(pem_key_cert_pairs)
+  credentials.references.append(pem_root_certs)
+  credentials.c_ssl_pem_key_cert_pairs_count = len(pem_key_cert_pairs)
+  credentials.c_ssl_pem_key_cert_pairs = (
+      <grpc.grpc_ssl_pem_key_cert_pair *>grpc.gpr_malloc(
+          sizeof(grpc.grpc_ssl_pem_key_cert_pair) *
+              credentials.c_ssl_pem_key_cert_pairs_count
+      ))
+  for i in range(credentials.c_ssl_pem_key_cert_pairs_count):
+    credentials.c_ssl_pem_key_cert_pairs[i] = (
+        (<records.SslPemKeyCertPair>pem_key_cert_pairs[i]).c_pair)
+  credentials.c_credentials = grpc.grpc_ssl_server_credentials_create(
+      pem_root_certs, credentials.c_ssl_pem_key_cert_pairs,
+      credentials.c_ssl_pem_key_cert_pairs_count
+  )
+  return credentials
+
+def server_credentials_fake_transport_security():
+  cdef ServerCredentials credentials = ServerCredentials()
+  credentials.c_credentials = (
+      grpc.grpc_fake_transport_security_server_credentials_create())
+  return credentials
diff --git a/src/python/src/grpc/_cython/_cygrpc/grpc.pxd b/src/python/src/grpc/_cython/_cygrpc/grpc.pxd
new file mode 100644
index 0000000000..7db8fbe31c
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/grpc.pxd
@@ -0,0 +1,344 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cimport libc.time
+
+
+cdef extern from "grpc/support/alloc.h":
+  void *gpr_malloc(size_t size)
+  void gpr_free(void *ptr)
+  void *gpr_realloc(void *p, size_t size)
+
+cdef extern from "grpc/support/slice.h":
+  ctypedef struct gpr_slice:
+    # don't worry about writing out the members of gpr_slice; we never access
+    # them directly.
+    pass
+
+  gpr_slice gpr_slice_ref(gpr_slice s)
+  void gpr_slice_unref(gpr_slice s)
+  gpr_slice gpr_slice_new(void *p, size_t len, void (*destroy)(void *))
+  gpr_slice gpr_slice_new_with_len(
+      void *p, size_t len, void (*destroy)(void *, size_t))
+  gpr_slice gpr_slice_malloc(size_t length)
+  gpr_slice gpr_slice_from_copied_string(const char *source)
+  gpr_slice gpr_slice_from_copied_buffer(const char *source, size_t len)
+
+  # Declare functions for function-like macros (because Cython)...
+  void *gpr_slice_start_ptr "GPR_SLICE_START_PTR" (gpr_slice s)
+  size_t gpr_slice_length "GPR_SLICE_LENGTH" (gpr_slice s)
+
+
+cdef extern from "grpc/support/port_platform.h":
+  # As long as the header file gets this type right, we don't need to get this
+  # type exactly; just close enough that the operations will be supported in the
+  # underlying C layers.
+  ctypedef unsigned int gpr_uint32
+
+
+cdef extern from "grpc/support/time.h":
+
+  ctypedef struct gpr_timespec:
+    libc.time.time_t seconds "tv_sec"
+    int nanoseconds "tv_nsec"
+
+  cdef gpr_timespec gpr_time_0
+  cdef gpr_timespec gpr_inf_future
+  cdef gpr_timespec gpr_inf_past
+
+  gpr_timespec gpr_now()
+
+
+cdef extern from "grpc/status.h":
+  ctypedef enum grpc_status_code:
+    GRPC_STATUS_OK
+    GRPC_STATUS_CANCELLED
+    GRPC_STATUS_UNKNOWN
+    GRPC_STATUS_INVALID_ARGUMENT
+    GRPC_STATUS_DEADLINE_EXCEEDED
+    GRPC_STATUS_NOT_FOUND
+    GRPC_STATUS_ALREADY_EXISTS
+    GRPC_STATUS_PERMISSION_DENIED
+    GRPC_STATUS_UNAUTHENTICATED
+    GRPC_STATUS_RESOURCE_EXHAUSTED
+    GRPC_STATUS_FAILED_PRECONDITION
+    GRPC_STATUS_ABORTED
+    GRPC_STATUS_OUT_OF_RANGE
+    GRPC_STATUS_UNIMPLEMENTED
+    GRPC_STATUS_INTERNAL
+    GRPC_STATUS_UNAVAILABLE
+    GRPC_STATUS_DATA_LOSS
+    GRPC_STATUS__DO_NOT_USE
+
+
+cdef extern from "grpc/byte_buffer_reader.h":
+  struct grpc_byte_buffer_reader:
+    # We don't care about the internals
+    pass
+
+
+cdef extern from "grpc/byte_buffer.h":
+  ctypedef struct grpc_byte_buffer:
+    # We don't care about the internals.
+    pass
+
+  grpc_byte_buffer *grpc_raw_byte_buffer_create(gpr_slice *slices,
+                                                size_t nslices)
+  size_t grpc_byte_buffer_length(grpc_byte_buffer *bb)
+  void grpc_byte_buffer_destroy(grpc_byte_buffer *byte_buffer)
+
+  void grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
+                                    grpc_byte_buffer *buffer)
+  int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
+                                   gpr_slice *slice)
+  void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader)
+
+
+cdef extern from "grpc/grpc.h":
+
+  ctypedef struct grpc_completion_queue:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  ctypedef struct grpc_channel:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  ctypedef struct grpc_server:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  ctypedef struct grpc_call:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  ctypedef enum grpc_arg_type:
+    grpc_arg_string "GRPC_ARG_STRING"
+    grpc_arg_integer "GRPC_ARG_INTEGER"
+    grpc_arg_pointer "GRPC_ARG_POINTER"
+
+  ctypedef struct grpc_arg_value_pointer:
+    void *address "p"
+    void *(*copy)(void *)
+    void (*destroy)(void *)
+
+  union grpc_arg_value:
+    char *string
+    int integer
+    grpc_arg_value_pointer pointer
+
+  ctypedef struct grpc_arg:
+    grpc_arg_type type
+    char *key
+    grpc_arg_value value
+
+  ctypedef struct grpc_channel_args:
+    size_t arguments_length "num_args"
+    grpc_arg *arguments "args"
+
+  ctypedef enum grpc_call_error:
+    GRPC_CALL_OK
+    GRPC_CALL_ERROR
+    GRPC_CALL_ERROR_NOT_ON_SERVER
+    GRPC_CALL_ERROR_NOT_ON_CLIENT
+    GRPC_CALL_ERROR_ALREADY_ACCEPTED
+    GRPC_CALL_ERROR_ALREADY_INVOKED
+    GRPC_CALL_ERROR_NOT_INVOKED
+    GRPC_CALL_ERROR_ALREADY_FINISHED
+    GRPC_CALL_ERROR_TOO_MANY_OPERATIONS
+    GRPC_CALL_ERROR_INVALID_FLAGS
+    GRPC_CALL_ERROR_INVALID_METADATA
+
+  ctypedef struct grpc_metadata:
+    const char *key
+    const char *value
+    size_t value_length
+    # ignore the 'internal_data.obfuscated' fields.
+
+  ctypedef enum grpc_completion_type:
+    GRPC_QUEUE_SHUTDOWN
+    GRPC_QUEUE_TIMEOUT
+    GRPC_OP_COMPLETE
+
+  ctypedef struct grpc_event:
+    grpc_completion_type type
+    int success
+    void *tag
+
+  ctypedef struct grpc_metadata_array:
+    size_t count
+    size_t capacity
+    grpc_metadata *metadata
+
+  void grpc_metadata_array_init(grpc_metadata_array *array)
+  void grpc_metadata_array_destroy(grpc_metadata_array *array)
+
+  ctypedef struct grpc_call_details:
+    char *method
+    size_t method_capacity
+    char *host
+    size_t host_capacity
+    gpr_timespec deadline
+
+  void grpc_call_details_init(grpc_call_details *details)
+  void grpc_call_details_destroy(grpc_call_details *details)
+
+  ctypedef enum grpc_op_type:
+    GRPC_OP_SEND_INITIAL_METADATA
+    GRPC_OP_SEND_MESSAGE
+    GRPC_OP_SEND_CLOSE_FROM_CLIENT
+    GRPC_OP_SEND_STATUS_FROM_SERVER
+    GRPC_OP_RECV_INITIAL_METADATA
+    GRPC_OP_RECV_MESSAGE
+    GRPC_OP_RECV_STATUS_ON_CLIENT
+    GRPC_OP_RECV_CLOSE_ON_SERVER
+
+  ctypedef struct grpc_op_data_send_initial_metadata:
+    size_t count
+    grpc_metadata *metadata
+
+  ctypedef struct grpc_op_data_send_status_from_server:
+    size_t trailing_metadata_count
+    grpc_metadata *trailing_metadata
+    grpc_status_code status
+    const char *status_details
+
+  ctypedef struct grpc_op_data_recv_status_on_client:
+    grpc_metadata_array *trailing_metadata
+    grpc_status_code *status
+    char **status_details
+    size_t *status_details_capacity
+
+  ctypedef struct grpc_op_data_recv_close_on_server:
+    int *cancelled
+
+  union grpc_op_data:
+    grpc_op_data_send_initial_metadata send_initial_metadata
+    grpc_byte_buffer *send_message
+    grpc_op_data_send_status_from_server send_status_from_server
+    grpc_metadata_array *receive_initial_metadata "recv_initial_metadata"
+    grpc_byte_buffer **receive_message "recv_message"
+    grpc_op_data_recv_status_on_client receive_status_on_client "recv_status_on_client"
+    grpc_op_data_recv_close_on_server receive_close_on_server "recv_close_on_server"
+
+  ctypedef struct grpc_op:
+    grpc_op_type type "op"
+    gpr_uint32 flags
+    grpc_op_data data
+
+  void grpc_init()
+  void grpc_shutdown()
+
+  grpc_completion_queue *grpc_completion_queue_create()
+  grpc_event grpc_completion_queue_next(grpc_completion_queue *cq,
+                                        gpr_timespec deadline) nogil
+  void grpc_completion_queue_shutdown(grpc_completion_queue *cq)
+  void grpc_completion_queue_destroy(grpc_completion_queue *cq)
+
+  grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
+                                        size_t nops, void *tag)
+  grpc_call_error grpc_call_cancel(grpc_call *call)
+  grpc_call_error grpc_call_cancel_with_status(grpc_call *call,
+                                               grpc_status_code status,
+                                               const char *description)
+  void grpc_call_destroy(grpc_call *call)
+
+
+  grpc_channel *grpc_channel_create(const char *target,
+                                    const grpc_channel_args *args)
+  grpc_call *grpc_channel_create_call(grpc_channel *channel,
+                                      grpc_completion_queue *completion_queue,
+                                      const char *method, const char *host,
+                                      gpr_timespec deadline)
+  void grpc_channel_destroy(grpc_channel *channel)
+
+  grpc_server *grpc_server_create(const grpc_channel_args *args)
+  grpc_call_error grpc_server_request_call(
+      grpc_server *server, grpc_call **call, grpc_call_details *details,
+      grpc_metadata_array *request_metadata, grpc_completion_queue
+      *cq_bound_to_call, grpc_completion_queue *cq_for_notification, void
+      *tag_new)
+  void grpc_server_register_completion_queue(grpc_server *server,
+                                             grpc_completion_queue *cq)
+  int grpc_server_add_http2_port(grpc_server *server, const char *addr)
+  void grpc_server_start(grpc_server *server)
+  void grpc_server_shutdown_and_notify(
+      grpc_server *server, grpc_completion_queue *cq, void *tag)
+  void grpc_server_cancel_all_calls(grpc_server *server)
+  void grpc_server_destroy(grpc_server *server)
+
+
+cdef extern from "grpc/grpc_security.h":
+
+  ctypedef struct grpc_ssl_pem_key_cert_pair:
+    const char *private_key
+    const char *certificate_chain "cert_chain"
+
+  ctypedef struct grpc_credentials:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  grpc_credentials *grpc_google_default_credentials_create()
+  grpc_credentials *grpc_ssl_credentials_create(
+      const char *pem_root_certs, grpc_ssl_pem_key_cert_pair *pem_key_cert_pair)
+
+  grpc_credentials *grpc_composite_credentials_create(grpc_credentials *creds1,
+                                                      grpc_credentials *creds2)
+  grpc_credentials *grpc_compute_engine_credentials_create()
+  grpc_credentials *grpc_service_account_credentials_create(
+      const char *json_key, const char *scope, gpr_timespec token_lifetime)
+  grpc_credentials *grpc_jwt_credentials_create(const char *json_key,
+                                                gpr_timespec token_lifetime)
+  grpc_credentials *grpc_refresh_token_credentials_create(
+      const char *json_refresh_token)
+  grpc_credentials *grpc_fake_transport_security_credentials_create()
+  grpc_credentials *grpc_iam_credentials_create(const char *authorization_token,
+                                                const char *authority_selector)
+  void grpc_credentials_release(grpc_credentials *creds)
+
+  grpc_channel *grpc_secure_channel_create(
+      grpc_credentials *creds, const char *target,
+      const grpc_channel_args *args)
+
+  ctypedef struct grpc_server_credentials:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  grpc_server_credentials *grpc_ssl_server_credentials_create(
+      const char *pem_root_certs,
+      grpc_ssl_pem_key_cert_pair *pem_key_cert_pairs,
+      size_t num_key_cert_pairs);
+  grpc_server_credentials *grpc_fake_transport_security_server_credentials_create()
+  void grpc_server_credentials_release(grpc_server_credentials *creds)
+
+  int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
+                                        grpc_server_credentials *creds)
+
+  grpc_call_error grpc_call_set_credentials(grpc_call *call,
+                                            grpc_credentials *creds)
diff --git a/src/python/src/grpc/_cython/_cygrpc/records.pxd b/src/python/src/grpc/_cython/_cygrpc/records.pxd
new file mode 100644
index 0000000000..9ee487882a
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/records.pxd
@@ -0,0 +1,129 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+from grpc._cython._cygrpc cimport call
+from grpc._cython._cygrpc cimport server
+
+
+cdef class Timespec:
+
+  cdef grpc.gpr_timespec c_time
+
+
+cdef class CallDetails:
+
+  cdef grpc.grpc_call_details c_details
+
+
+cdef class OperationTag:
+
+  cdef object user_tag
+  cdef list references
+  # This allows CompletionQueue to notify the Python Server object that the
+  # underlying GRPC core server has shutdown
+  cdef server.Server shutting_down_server
+  cdef call.Call operation_call
+  cdef CallDetails request_call_details
+  cdef Metadata request_metadata
+  cdef Operations batch_operations
+  cdef bint is_new_request
+
+
+cdef class Event:
+
+  cdef readonly grpc.grpc_completion_type type
+  cdef readonly bint success
+  cdef readonly object tag
+
+  # For operations with calls
+  cdef readonly call.Call operation_call
+
+  # For Server.request_call
+  cdef readonly CallDetails request_call_details
+  cdef readonly Metadata request_metadata
+
+  # For Call.start_batch
+  cdef readonly Operations batch_operations
+
+
+cdef class ByteBuffer:
+
+  cdef grpc.grpc_byte_buffer *c_byte_buffer
+
+
+cdef class SslPemKeyCertPair:
+
+  cdef grpc.grpc_ssl_pem_key_cert_pair c_pair
+  cdef readonly object private_key, certificate_chain
+
+
+cdef class ChannelArg:
+
+  cdef grpc.grpc_arg c_arg
+  cdef readonly object key, value
+
+
+cdef class ChannelArgs:
+
+  cdef grpc.grpc_channel_args c_args
+  cdef list args
+
+
+cdef class Metadatum:
+
+  cdef grpc.grpc_metadata c_metadata
+  cdef object _key, _value
+
+
+cdef class Metadata:
+
+  cdef grpc.grpc_metadata_array c_metadata_array
+  cdef object metadata
+
+
+cdef class Operation:
+
+  cdef grpc.grpc_op c_op
+  cdef ByteBuffer _received_message
+  cdef Metadata _received_metadata
+  cdef grpc.grpc_status_code _received_status_code
+  cdef char *_received_status_details
+  cdef size_t _received_status_details_capacity
+  cdef int _received_cancelled
+  cdef readonly bint is_valid
+  cdef object references
+
+
+cdef class Operations:
+
+  cdef grpc.grpc_op *c_ops
+  cdef size_t c_nops
+  cdef list operations
+
diff --git a/src/python/src/grpc/_cython/_cygrpc/records.pyx b/src/python/src/grpc/_cython/_cygrpc/records.pyx
new file mode 100644
index 0000000000..4814769fd2
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/records.pyx
@@ -0,0 +1,575 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+from grpc._cython._cygrpc cimport call
+from grpc._cython._cygrpc cimport server
+
+
+class StatusCode:
+  ok = grpc.GRPC_STATUS_OK
+  cancelled = grpc.GRPC_STATUS_CANCELLED
+  unknown = grpc.GRPC_STATUS_UNKNOWN
+  invalid_argument = grpc.GRPC_STATUS_INVALID_ARGUMENT
+  deadline_exceeded = grpc.GRPC_STATUS_DEADLINE_EXCEEDED
+  not_found = grpc.GRPC_STATUS_NOT_FOUND
+  already_exists = grpc.GRPC_STATUS_ALREADY_EXISTS
+  permission_denied = grpc.GRPC_STATUS_PERMISSION_DENIED
+  unauthenticated = grpc.GRPC_STATUS_UNAUTHENTICATED
+  resource_exhausted = grpc.GRPC_STATUS_RESOURCE_EXHAUSTED
+  failed_precondition = grpc.GRPC_STATUS_FAILED_PRECONDITION
+  aborted = grpc.GRPC_STATUS_ABORTED
+  out_of_range = grpc.GRPC_STATUS_OUT_OF_RANGE
+  unimplemented = grpc.GRPC_STATUS_UNIMPLEMENTED
+  internal = grpc.GRPC_STATUS_INTERNAL
+  unavailable = grpc.GRPC_STATUS_UNAVAILABLE
+  data_loss = grpc.GRPC_STATUS_DATA_LOSS
+
+
+class CallError:
+  ok = grpc.GRPC_CALL_OK
+  error = grpc.GRPC_CALL_ERROR
+  not_on_server = grpc.GRPC_CALL_ERROR_NOT_ON_SERVER
+  not_on_client = grpc.GRPC_CALL_ERROR_NOT_ON_CLIENT
+  already_accepted = grpc.GRPC_CALL_ERROR_ALREADY_ACCEPTED
+  already_invoked = grpc.GRPC_CALL_ERROR_ALREADY_INVOKED
+  not_invoked = grpc.GRPC_CALL_ERROR_NOT_INVOKED
+  already_finished = grpc.GRPC_CALL_ERROR_ALREADY_FINISHED
+  too_many_operations = grpc.GRPC_CALL_ERROR_TOO_MANY_OPERATIONS
+  invalid_flags = grpc.GRPC_CALL_ERROR_INVALID_FLAGS
+  invalid_metadata = grpc.GRPC_CALL_ERROR_INVALID_METADATA
+
+
+class CompletionType:
+  queue_shutdown = grpc.GRPC_QUEUE_SHUTDOWN
+  queue_timeout = grpc.GRPC_QUEUE_TIMEOUT
+  operation_complete = grpc.GRPC_OP_COMPLETE
+
+
+class OperationType:
+  send_initial_metadata = grpc.GRPC_OP_SEND_INITIAL_METADATA
+  send_message = grpc.GRPC_OP_SEND_MESSAGE
+  send_close_from_client = grpc.GRPC_OP_SEND_CLOSE_FROM_CLIENT
+  send_status_from_server = grpc.GRPC_OP_SEND_STATUS_FROM_SERVER
+  receive_initial_metadata = grpc.GRPC_OP_RECV_INITIAL_METADATA
+  receive_message = grpc.GRPC_OP_RECV_MESSAGE
+  receive_status_on_client = grpc.GRPC_OP_RECV_STATUS_ON_CLIENT
+  receive_close_on_server = grpc.GRPC_OP_RECV_CLOSE_ON_SERVER
+
+
+cdef class Timespec:
+
+  def __cinit__(self, time):
+    if time is None:
+      self.c_time = grpc.gpr_now()
+    elif isinstance(time, float):
+      if time == float("+inf"):
+        self.c_time = grpc.gpr_inf_future
+      elif time == float("-inf"):
+        self.c_time = grpc.gpr_inf_past
+      else:
+        self.c_time.seconds = time
+        self.c_time.nanoseconds = (time - float(self.c_time.seconds)) * 1e9
+    else:
+      raise TypeError("expected time to be float")
+
+  @property
+  def seconds(self):
+    return self.c_time.seconds
+
+  @property
+  def nanoseconds(self):
+    return self.c_time.nanoseconds
+
+  def __float__(self):
+    return <double>self.c_time.seconds + <double>self.c_time.nanoseconds / 1e9
+
+  infinite_future = Timespec(float("+inf"))
+  infinite_past = Timespec(float("-inf"))
+
+
+cdef class CallDetails:
+
+  def __cinit__(self):
+    grpc.grpc_call_details_init(&self.c_details)
+
+  def __dealloc__(self):
+    grpc.grpc_call_details_destroy(&self.c_details)
+
+  @property
+  def method(self):
+    if self.c_details.method != NULL:
+      return <bytes>self.c_details.method
+    else:
+      return None
+
+  @property
+  def host(self):
+    if self.c_details.host != NULL:
+      return <bytes>self.c_details.host
+    else:
+      return None
+
+  @property
+  def deadline(self):
+    timespec = Timespec(float("-inf"))
+    timespec.c_time = self.c_details.deadline
+    return timespec
+
+
+cdef class OperationTag:
+
+  def __cinit__(self, user_tag):
+    self.user_tag = user_tag
+    self.references = []
+
+
+cdef class Event:
+
+  def __cinit__(self, grpc.grpc_completion_type type, bint success,
+                object tag, call.Call operation_call,
+                CallDetails request_call_details,
+                Metadata request_metadata,
+                Operations batch_operations):
+    self.type = type
+    self.success = success
+    self.tag = tag
+    self.operation_call = operation_call
+    self.request_call_details = request_call_details
+    self.request_metadata = request_metadata
+    self.batch_operations = batch_operations
+
+
+cdef class ByteBuffer:
+
+  def __cinit__(self, data):
+    if data is None:
+      self.c_byte_buffer = NULL
+      return
+    if isinstance(data, bytes):
+      pass
+    elif isinstance(data, basestring):
+      data = data.encode()
+    else:
+      raise TypeError("expected value to be of type str or bytes")
+
+    cdef char *c_data = data
+    data_slice = grpc.gpr_slice_from_copied_buffer(c_data, len(data))
+    self.c_byte_buffer = grpc.grpc_raw_byte_buffer_create(
+        &data_slice, 1)
+    grpc.gpr_slice_unref(data_slice)
+
+  def bytes(self):
+    cdef grpc.grpc_byte_buffer_reader reader
+    cdef grpc.gpr_slice data_slice
+    cdef size_t data_slice_length
+    cdef void *data_slice_pointer
+    if self.c_byte_buffer != NULL:
+      grpc.grpc_byte_buffer_reader_init(&reader, self.c_byte_buffer)
+      result = b""
+      while grpc.grpc_byte_buffer_reader_next(&reader, &data_slice):
+        data_slice_pointer = grpc.gpr_slice_start_ptr(data_slice)
+        data_slice_length = grpc.gpr_slice_length(data_slice)
+        result += (<char *>data_slice_pointer)[:data_slice_length]
+      grpc.grpc_byte_buffer_reader_destroy(&reader)
+      return result
+    else:
+      return None
+
+  def __len__(self):
+    if self.c_byte_buffer != NULL:
+      return grpc.grpc_byte_buffer_length(self.c_byte_buffer)
+    else:
+      return 0
+
+  def __str__(self):
+    return self.bytes()
+
+  def __dealloc__(self):
+    if self.c_byte_buffer != NULL:
+      grpc.grpc_byte_buffer_destroy(self.c_byte_buffer)
+
+
+cdef class SslPemKeyCertPair:
+
+  def __cinit__(self, private_key, certificate_chain):
+    if isinstance(private_key, bytes):
+      self.private_key = private_key
+    elif isinstance(private_key, basestring):
+      self.private_key = private_key.encode()
+    else:
+      raise TypeError("expected private_key to be of type str or bytes")
+    if isinstance(certificate_chain, bytes):
+      self.certificate_chain = certificate_chain
+    elif isinstance(certificate_chain, basestring):
+      self.certificate_chain = certificate_chain.encode()
+    else:
+      raise TypeError("expected certificate_chain to be of type str or bytes "
+                      "or int")
+    self.c_pair.private_key = self.private_key
+    self.c_pair.certificate_chain = self.certificate_chain
+
+
+cdef class ChannelArg:
+
+  def __cinit__(self, key, value):
+    if isinstance(key, bytes):
+      self.key = key
+    elif isinstance(key, basestring):
+      self.key = key.encode()
+    else:
+      raise TypeError("expected key to be of type str or bytes")
+    if isinstance(value, bytes):
+      self.value = value
+      self.c_arg.type = grpc.GRPC_ARG_STRING
+      self.c_arg.value.string = self.value
+    elif isinstance(value, basestring):
+      self.value = value.encode()
+      self.c_arg.type = grpc.GRPC_ARG_STRING
+      self.c_arg.value.string = self.value
+    elif isinstance(value, int):
+      self.value = int(value)
+      self.c_arg.type = grpc.GRPC_ARG_INTEGER
+      self.c_arg.value.integer = self.value
+    else:
+      raise TypeError("expected value to be of type str or bytes or int")
+    self.c_arg.key = self.key
+
+
+cdef class ChannelArgs:
+
+  def __cinit__(self, args):
+    self.args = list(args)
+    for arg in self.args:
+      if not isinstance(arg, ChannelArg):
+        raise TypeError("expected list of ChannelArg")
+    self.c_args.arguments_length = len(self.args)
+    self.c_args.arguments = <grpc.grpc_arg *>grpc.gpr_malloc(
+        self.c_args.arguments_length*sizeof(grpc.grpc_arg)
+    )
+    for i in range(self.c_args.arguments_length):
+      self.c_args.arguments[i] = (<ChannelArg>self.args[i]).c_arg
+
+  def __dealloc__(self):
+    grpc.gpr_free(self.c_args.arguments)
+
+  def __len__(self):
+    # self.args is never stale; it's only updated from this file
+    return len(self.args)
+
+  def __getitem__(self, size_t i):
+    # self.args is never stale; it's only updated from this file
+    return self.args[i]
+
+
+cdef class Metadatum:
+
+  def __cinit__(self, key, value):
+    if isinstance(key, bytes):
+      self._key = key
+    elif isinstance(key, basestring):
+      self._key = key.encode()
+    else:
+      raise TypeError("expected key to be of type str or bytes")
+    if isinstance(value, bytes):
+      self._value = value
+    elif isinstance(value, basestring):
+      self._value = value.encode()
+    else:
+      raise TypeError("expected value to be of type str or bytes")
+    self.c_metadata.key = self._key
+    self.c_metadata.value = self._value
+    self.c_metadata.value_length = len(self._value)
+
+  @property
+  def key(self):
+    return <bytes>self.c_metadata.key
+
+  @property
+  def value(self):
+    return <bytes>self.c_metadata.value[:self.c_metadata.value_length]
+
+  def __len__(self):
+    return 2
+
+  def __getitem__(self, size_t i):
+    if i == 0:
+      return self.key
+    elif i == 1:
+      return self.value
+    else:
+      raise IndexError("index must be 0 (key) or 1 (value)")
+
+  def __iter__(self):
+    return iter((self.key, self.value))
+
+
+cdef class _MetadataIterator:
+
+  cdef size_t i
+  cdef Metadata metadata
+
+  def __cinit__(self, Metadata metadata not None):
+    self.i = 0
+    self.metadata = metadata
+
+  def __next__(self):
+    if self.i < len(self.metadata):
+      result = self.metadata[self.i]
+      self.i = self.i + 1
+      return result
+    else:
+      raise StopIteration()
+
+
+cdef class Metadata:
+
+  def __cinit__(self, metadata):
+    self.metadata = list(metadata)
+    for metadatum in metadata:
+      if not isinstance(metadatum, Metadatum):
+        raise TypeError("expected list of Metadatum")
+    grpc.grpc_metadata_array_init(&self.c_metadata_array)
+    self.c_metadata_array.count = len(self.metadata)
+    self.c_metadata_array.capacity = len(self.metadata)
+    self.c_metadata_array.metadata = <grpc.grpc_metadata *>grpc.gpr_malloc(
+        self.c_metadata_array.count*sizeof(grpc.grpc_metadata)
+    )
+    for i in range(self.c_metadata_array.count):
+      self.c_metadata_array.metadata[i] = (
+          (<Metadatum>self.metadata[i]).c_metadata)
+
+  def __dealloc__(self):
+    # this frees the allocated memory for the grpc_metadata_array (although
+    # it'd be nice if that were documented somewhere...) TODO(atash): document
+    # this in the C core
+    grpc.grpc_metadata_array_destroy(&self.c_metadata_array)
+
+  def __len__(self):
+    return self.c_metadata_array.count
+
+  def __getitem__(self, size_t i):
+    return Metadatum(
+        key=<bytes>self.c_metadata_array.metadata[i].key,
+        value=<bytes>self.c_metadata_array.metadata[i].value[
+            :self.c_metadata_array.metadata[i].value_length])
+
+  def __iter__(self):
+    return _MetadataIterator(self)
+
+
+cdef class Operation:
+
+  def __cinit__(self):
+    self.references = []
+    self._received_status_details = NULL
+    self._received_status_details_capacity = 0
+    self.is_valid = False
+
+  @property
+  def type(self):
+    return self.c_op.type
+
+  @property
+  def received_message(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_MESSAGE:
+      raise TypeError("self must be an operation receiving a message")
+    return self._received_message
+
+  @property
+  def received_metadata(self):
+    if (self.c_op.type != grpc.GRPC_OP_RECV_INITIAL_METADATA and
+        self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT):
+      raise TypeError("self must be an operation receiving metadata")
+    return self._received_metadata
+
+  @property
+  def received_status_code(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
+      raise TypeError("self must be an operation receiving a status code")
+    return self._received_status_code
+
+  @property
+  def received_status_details(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
+      raise TypeError("self must be an operation receiving status details")
+    if self._received_status_details:
+      return self._received_status_details
+    else:
+      return None
+
+  @property
+  def received_cancelled(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_CLOSE_ON_SERVER:
+      raise TypeError("self must be an operation receiving cancellation "
+                      "information")
+    return False if self._received_cancelled == 0 else True
+
+  def __dealloc__(self):
+    # We *almost* don't need to do anything; most of the objects are handled by
+    # Python. The remaining one(s) are primitive fields filled in by GRPC core.
+    # This means that we need to clean up after receive_status_on_client.
+    if self.c_op.type == grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
+      grpc.gpr_free(self._received_status_details)
+
+def operation_send_initial_metadata(Metadata metadata):
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_SEND_INITIAL_METADATA
+  op.c_op.data.send_initial_metadata.count = metadata.c_metadata_array.count
+  op.c_op.data.send_initial_metadata.metadata = (
+      metadata.c_metadata_array.metadata)
+  op.references.append(metadata)
+  op.is_valid = True
+  return op
+
+def operation_send_message(data):
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_SEND_MESSAGE
+  byte_buffer = ByteBuffer(data)
+  op.c_op.data.send_message = byte_buffer.c_byte_buffer
+  op.references.append(byte_buffer)
+  op.is_valid = True
+  return op
+
+def operation_send_close_from_client():
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_SEND_CLOSE_FROM_CLIENT
+  op.is_valid = True
+  return op
+
+def operation_send_status_from_server(
+    Metadata metadata, grpc.grpc_status_code code, details):
+  if isinstance(details, bytes):
+    pass
+  elif isinstance(details, basestring):
+    details = details.encode()
+  else:
+    raise TypeError("expected a str or bytes object for details")
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_SEND_STATUS_FROM_SERVER
+  op.c_op.data.send_status_from_server.trailing_metadata_count = (
+      metadata.c_metadata_array.count)
+  op.c_op.data.send_status_from_server.trailing_metadata = (
+      metadata.c_metadata_array.metadata)
+  op.c_op.data.send_status_from_server.status = code
+  op.c_op.data.send_status_from_server.status_details = details
+  op.references.append(metadata)
+  op.references.append(details)
+  op.is_valid = True
+  return op
+
+def operation_receive_initial_metadata():
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_RECV_INITIAL_METADATA
+  op._received_metadata = Metadata([])
+  op.c_op.data.receive_initial_metadata = (
+      &op._received_metadata.c_metadata_array)
+  op.is_valid = True
+  return op
+
+def operation_receive_message():
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_RECV_MESSAGE
+  op._received_message = ByteBuffer(None)
+  # n.b. the c_op.data.receive_message field needs to be deleted by us,
+  # anyway, so we just let that be handled by the ByteBuffer() we allocated
+  # the line before.
+  op.c_op.data.receive_message = &op._received_message.c_byte_buffer
+  op.is_valid = True
+  return op
+
+def operation_receive_status_on_client():
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_RECV_STATUS_ON_CLIENT
+  op._received_metadata = Metadata([])
+  op.c_op.data.receive_status_on_client.trailing_metadata = (
+      &op._received_metadata.c_metadata_array)
+  op.c_op.data.receive_status_on_client.status = (
+      &op._received_status_code)
+  op.c_op.data.receive_status_on_client.status_details = (
+      &op._received_status_details)
+  op.c_op.data.receive_status_on_client.status_details_capacity = (
+      &op._received_status_details_capacity)
+  op.is_valid = True
+  return op
+
+def operation_receive_close_on_server():
+  cdef Operation op = Operation()
+  op.c_op.type = grpc.GRPC_OP_RECV_CLOSE_ON_SERVER
+  op.c_op.data.receive_close_on_server.cancelled = &op._received_cancelled
+  op.is_valid = True
+  return op
+
+
+cdef class _OperationsIterator:
+
+  cdef size_t i
+  cdef Operations operations
+
+  def __cinit__(self, Operations operations not None):
+    self.i = 0
+    self.operations = operations
+
+  def __next__(self):
+    if self.i < len(self.operations):
+      result = self.operations[self.i]
+      self.i = self.i + 1
+      return result
+    else:
+      raise StopIteration()
+
+
+cdef class Operations:
+
+  def __cinit__(self, operations):
+    self.operations = list(operations)  # normalize iterable
+    self.c_ops = NULL
+    self.c_nops = 0
+    for operation in self.operations:
+      if not isinstance(operation, Operation):
+        raise TypeError("expected operations to be iterable of Operation")
+    self.c_nops = len(self.operations)
+    self.c_ops = <grpc.grpc_op *>grpc.gpr_malloc(
+        sizeof(grpc.grpc_op)*self.c_nops)
+    for i in range(self.c_nops):
+      self.c_ops[i] = (<Operation>(self.operations[i])).c_op
+
+  def __len__(self):
+    return self.c_nops
+
+  def __getitem__(self, size_t i):
+    # self.operations is never stale; it's only updated from this file
+    return self.operations[i]
+
+  def __dealloc__(self):
+    grpc.gpr_free(self.c_ops)
+
+  def __iter__(self):
+    return _OperationsIterator(self)
+
diff --git a/src/python/src/grpc/_cython/_cygrpc/server.pxd b/src/python/src/grpc/_cython/_cygrpc/server.pxd
new file mode 100644
index 0000000000..0257542a03
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/server.pxd
@@ -0,0 +1,45 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from grpc._cython._cygrpc cimport grpc
+from grpc._cython._cygrpc cimport completion_queue
+
+
+cdef class Server:
+
+  cdef grpc.grpc_server *c_server
+  cdef bint is_started  # start has been called
+  cdef bint is_shutting_down  # shutdown has been called
+  cdef bint is_shutdown  # notification of complete shutdown received
+  # used at dealloc when user forgets to shutdown
+  cdef completion_queue.CompletionQueue backup_shutdown_queue
+  cdef list references
+  cdef list registered_completion_queues
+
+  cdef notify_shutdown_complete(self)
diff --git a/src/python/src/grpc/_cython/_cygrpc/server.pyx b/src/python/src/grpc/_cython/_cygrpc/server.pyx
new file mode 100644
index 0000000000..dcf9d38337
--- /dev/null
+++ b/src/python/src/grpc/_cython/_cygrpc/server.pyx
@@ -0,0 +1,158 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cimport cpython
+
+from grpc._cython._cygrpc cimport call
+from grpc._cython._cygrpc cimport completion_queue
+from grpc._cython._cygrpc cimport credentials
+from grpc._cython._cygrpc cimport records
+
+import time
+
+
+cdef class Server:
+
+  def __cinit__(self, records.ChannelArgs arguments=None):
+    cdef grpc.grpc_channel_args *c_arguments = NULL
+    self.references = []
+    self.registered_completion_queues = []
+    if arguments is not None:
+      c_arguments = &arguments.c_args
+      self.references.append(arguments)
+    self.c_server = grpc.grpc_server_create(c_arguments)
+    self.is_started = False
+    self.is_shutting_down = False
+    self.is_shutdown = False
+
+  def request_call(
+      self, completion_queue.CompletionQueue call_queue not None,
+      completion_queue.CompletionQueue server_queue not None, tag):
+    if not self.is_started or self.is_shutting_down:
+      raise ValueError("server must be started and not shutting down")
+    if server_queue not in self.registered_completion_queues:
+      raise ValueError("server_queue must be a registered completion queue")
+    cdef records.OperationTag operation_tag = records.OperationTag(tag)
+    operation_tag.operation_call = call.Call()
+    operation_tag.request_call_details = records.CallDetails()
+    operation_tag.request_metadata = records.Metadata([])
+    operation_tag.references.extend([self, call_queue, server_queue])
+    operation_tag.is_new_request = True
+    operation_tag.batch_operations = records.Operations([])
+    cpython.Py_INCREF(operation_tag)
+    return grpc.grpc_server_request_call(
+        self.c_server, &operation_tag.operation_call.c_call,
+        &operation_tag.request_call_details.c_details,
+        &operation_tag.request_metadata.c_metadata_array,
+        call_queue.c_completion_queue, server_queue.c_completion_queue,
+        <cpython.PyObject *>operation_tag)
+
+  def register_completion_queue(
+      self, completion_queue.CompletionQueue queue not None):
+    if self.is_started:
+      raise ValueError("cannot register completion queues after start")
+    grpc.grpc_server_register_completion_queue(
+        self.c_server, queue.c_completion_queue)
+    self.registered_completion_queues.append(queue)
+
+  def start(self):
+    if self.is_started:
+      raise ValueError("the server has already started")
+    self.backup_shutdown_queue = completion_queue.CompletionQueue()
+    self.register_completion_queue(self.backup_shutdown_queue)
+    self.is_started = True
+    grpc.grpc_server_start(self.c_server)
+
+  def add_http2_port(self, address,
+                     credentials.ServerCredentials server_credentials=None):
+    if isinstance(address, bytes):
+      pass
+    elif isinstance(address, basestring):
+      address = address.encode()
+    else:
+      raise TypeError("expected address to be a str or bytes")
+    self.references.append(address)
+    if server_credentials is not None:
+      self.references.append(server_credentials)
+      return grpc.grpc_server_add_secure_http2_port(
+          self.c_server, address, server_credentials.c_credentials)
+    else:
+      return grpc.grpc_server_add_http2_port(self.c_server, address)
+
+  def shutdown(self, completion_queue.CompletionQueue queue not None, tag):
+    cdef records.OperationTag operation_tag
+    if queue.is_shutting_down:
+      raise ValueError("queue must be live")
+    elif not self.is_started:
+      raise ValueError("the server hasn't started yet")
+    elif self.is_shutting_down:
+      return
+    elif queue not in self.registered_completion_queues:
+      raise ValueError("expected registered completion queue")
+    else:
+      self.is_shutting_down = True
+      operation_tag = records.OperationTag(tag)
+      operation_tag.shutting_down_server = self
+      operation_tag.references.extend([self, queue])
+      cpython.Py_INCREF(operation_tag)
+      grpc.grpc_server_shutdown_and_notify(
+          self.c_server, queue.c_completion_queue,
+          <cpython.PyObject *>operation_tag)
+
+  cdef notify_shutdown_complete(self):
+    # called only by a completion queue on receiving our shutdown operation tag
+    self.is_shutdown = True
+
+  def cancel_all_calls(self):
+    if not self.is_shutting_down:
+      raise ValueError("the server must be shutting down to cancel all calls")
+    elif self.is_shutdown:
+      return
+    else:
+      grpc.grpc_server_cancel_all_calls(self.c_server)
+
+  def __dealloc__(self):
+    if self.c_server != NULL:
+      if not self.is_started:
+        pass
+      elif self.is_shutdown:
+        pass
+      elif not self.is_shutting_down:
+        # the user didn't call shutdown - use our backup queue
+        self.shutdown(self.backup_shutdown_queue, None)
+        # and now we wait
+        while not self.is_shutdown:
+          self.backup_shutdown_queue.poll()
+      else:
+        # We're in the process of shutting down, but have not shutdown; can't do
+        # much but repeatedly release the GIL and wait
+        while not self.is_shutdown:
+          time.sleep(0)
+      grpc.grpc_server_destroy(self.c_server)
+
diff --git a/src/python/src/grpc/_cython/adapter_low.py b/src/python/src/grpc/_cython/adapter_low.py
new file mode 100644
index 0000000000..7546dd1599
--- /dev/null
+++ b/src/python/src/grpc/_cython/adapter_low.py
@@ -0,0 +1,114 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+# Adapter from grpc._cython.types to the surface expected by
+# grpc._adapter._intermediary_low.
+#
+# TODO(atash): Once this is plugged into grpc._adapter._intermediary_low, remove
+# both grpc._adapter._intermediary_low and this file. The fore and rear links in
+# grpc._adapter should be able to use grpc._cython.types directly.
+
+from grpc._adapter import _types as type_interfaces
+from grpc._cython import cygrpc
+
+
+class ClientCredentials(object):
+  def __init__(self):
+    raise NotImplementedError()
+
+  @staticmethod
+  def google_default():
+    raise NotImplementedError()
+
+  @staticmethod
+  def ssl():
+    raise NotImplementedError()
+
+  @staticmethod
+  def composite():
+    raise NotImplementedError()
+
+  @staticmethod
+  def compute_engine():
+    raise NotImplementedError()
+
+  @staticmethod
+  def service_account():
+    raise NotImplementedError()
+
+  @staticmethod
+  def jwt():
+    raise NotImplementedError()
+
+  @staticmethod
+  def refresh_token():
+    raise NotImplementedError()
+
+  @staticmethod
+  def fake_transport_security():
+    raise NotImplementedError()
+
+  @staticmethod
+  def iam():
+    raise NotImplementedError()
+
+
+class ServerCredentials(object):
+  def __init__(self):
+    raise NotImplementedError()
+
+  @staticmethod
+  def ssl():
+    raise NotImplementedError()
+
+  @staticmethod
+  def fake_transport_security():
+    raise NotImplementedError()
+
+
+class CompletionQueue(type_interfaces.CompletionQueue):
+  def __init__(self):
+    raise NotImplementedError()
+
+
+class Call(type_interfaces.Call):
+  def __init__(self):
+    raise NotImplementedError()
+
+
+class Channel(type_interfaces.Channel):
+  def __init__(self):
+    raise NotImplementedError()
+
+
+class Server(type_interfaces.Server):
+  def __init__(self):
+    raise NotImplementedError()
+
diff --git a/src/python/src/grpc/_cython/adapter_low_test.py b/src/python/src/grpc/_cython/adapter_low_test.py
new file mode 100644
index 0000000000..9bab930e56
--- /dev/null
+++ b/src/python/src/grpc/_cython/adapter_low_test.py
@@ -0,0 +1,187 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Fork of grpc._adapter._low_test; the grpc._cython.types adapter in
+# grpc._cython.low should transparently support the semantics expected of
+# grpc._adapter._low.
+
+import time
+import unittest
+
+from grpc._adapter import _types
+from grpc._cython import adapter_low as _low
+
+
+class InsecureServerInsecureClient(unittest.TestCase):
+
+  def setUp(self):
+    self.server_completion_queue = _low.CompletionQueue()
+    self.server = _low.Server(self.server_completion_queue, [])
+    self.port = self.server.add_http2_port('[::]:0')
+    self.client_completion_queue = _low.CompletionQueue()
+    self.client_channel = _low.Channel('localhost:%d'%self.port, [])
+
+    self.server.start()
+
+  def tearDown(self):
+    self.server.shutdown()
+    del self.client_channel
+
+    self.client_completion_queue.shutdown()
+    while (self.client_completion_queue.next().type !=
+               _types.EventType.QUEUE_SHUTDOWN):
+      pass
+    self.server_completion_queue.shutdown()
+    while (self.server_completion_queue.next().type !=
+               _types.EventType.QUEUE_SHUTDOWN):
+      pass
+
+    del self.client_completion_queue
+    del self.server_completion_queue
+    del self.server
+
+  @unittest.skip('TODO(atash): implement grpc._cython.adapter_low')
+  def testEcho(self):
+    DEADLINE = time.time()+5
+    DEADLINE_TOLERANCE = 0.25
+    CLIENT_METADATA_ASCII_KEY = 'key'
+    CLIENT_METADATA_ASCII_VALUE = 'val'
+    CLIENT_METADATA_BIN_KEY = 'key-bin'
+    CLIENT_METADATA_BIN_VALUE = b'\0'*1000
+    SERVER_INITIAL_METADATA_KEY = 'init_me_me_me'
+    SERVER_INITIAL_METADATA_VALUE = 'whodawha?'
+    SERVER_TRAILING_METADATA_KEY = 'California_is_in_a_drought'
+    SERVER_TRAILING_METADATA_VALUE = 'zomg it is'
+    SERVER_STATUS_CODE = _types.StatusCode.OK
+    SERVER_STATUS_DETAILS = 'our work is never over'
+    REQUEST = 'in death a member of project mayhem has a name'
+    RESPONSE = 'his name is robert paulson'
+    METHOD = 'twinkies'
+    HOST = 'hostess'
+    server_request_tag = object()
+    request_call_result = self.server.request_call(self.server_completion_queue,
+                                                   server_request_tag)
+
+    self.assertEqual(_types.CallError.OK, request_call_result)
+
+    client_call_tag = object()
+    client_call = self.client_channel.create_call(self.client_completion_queue,
+                                                  METHOD, HOST, DEADLINE)
+    client_initial_metadata = [
+        (CLIENT_METADATA_ASCII_KEY, CLIENT_METADATA_ASCII_VALUE),
+        (CLIENT_METADATA_BIN_KEY, CLIENT_METADATA_BIN_VALUE)]
+    client_start_batch_result = client_call.start_batch([
+        _types.OpArgs.send_initial_metadata(client_initial_metadata),
+        _types.OpArgs.send_message(REQUEST),
+        _types.OpArgs.send_close_from_client(),
+        _types.OpArgs.recv_initial_metadata(),
+        _types.OpArgs.recv_message(),
+        _types.OpArgs.recv_status_on_client()
+    ], client_call_tag)
+    self.assertEqual(_types.CallError.OK, client_start_batch_result)
+
+    request_event = self.server_completion_queue.next(DEADLINE)
+    self.assertEqual(_types.EventType.OP_COMPLETE, request_event.type)
+    self.assertIsInstance(request_event.call, _low.Call)
+    self.assertIs(server_request_tag, request_event.tag)
+    self.assertEqual(1, len(request_event.results))
+    self.assertEqual(dict(client_initial_metadata),
+                      dict(request_event.results[0].initial_metadata))
+    self.assertEqual(METHOD, request_event.call_details.method)
+    self.assertEqual(HOST, request_event.call_details.host)
+    self.assertLess(abs(DEADLINE - request_event.call_details.deadline),
+                    DEADLINE_TOLERANCE)
+
+    server_call_tag = object()
+    server_call = request_event.call
+    server_initial_metadata = [
+        (SERVER_INITIAL_METADATA_KEY, SERVER_INITIAL_METADATA_VALUE)]
+    server_trailing_metadata = [
+        (SERVER_TRAILING_METADATA_KEY, SERVER_TRAILING_METADATA_VALUE)]
+    server_start_batch_result = server_call.start_batch([
+        _types.OpArgs.send_initial_metadata(server_initial_metadata),
+        _types.OpArgs.recv_message(),
+        _types.OpArgs.send_message(RESPONSE),
+        _types.OpArgs.recv_close_on_server(),
+        _types.OpArgs.send_status_from_server(
+            server_trailing_metadata, SERVER_STATUS_CODE, SERVER_STATUS_DETAILS)
+    ], server_call_tag)
+    self.assertEqual(_types.CallError.OK, server_start_batch_result)
+
+    client_event = self.client_completion_queue.next(DEADLINE)
+    server_event = self.server_completion_queue.next(DEADLINE)
+
+    self.assertEqual(6, len(client_event.results))
+    found_client_op_types = set()
+    for client_result in client_event.results:
+      # we expect each op type to be unique
+      self.assertNotIn(client_result.type, found_client_op_types)
+      found_client_op_types.add(client_result.type)
+      if client_result.type == _types.OpType.RECV_INITIAL_METADATA:
+        self.assertEqual(dict(server_initial_metadata),
+                          dict(client_result.initial_metadata))
+      elif client_result.type == _types.OpType.RECV_MESSAGE:
+        self.assertEqual(RESPONSE, client_result.message)
+      elif client_result.type == _types.OpType.RECV_STATUS_ON_CLIENT:
+        self.assertEqual(dict(server_trailing_metadata),
+                          dict(client_result.trailing_metadata))
+        self.assertEqual(SERVER_STATUS_DETAILS, client_result.status.details)
+        self.assertEqual(SERVER_STATUS_CODE, client_result.status.code)
+    self.assertEqual(set([
+          _types.OpType.SEND_INITIAL_METADATA,
+          _types.OpType.SEND_MESSAGE,
+          _types.OpType.SEND_CLOSE_FROM_CLIENT,
+          _types.OpType.RECV_INITIAL_METADATA,
+          _types.OpType.RECV_MESSAGE,
+          _types.OpType.RECV_STATUS_ON_CLIENT
+      ]), found_client_op_types)
+
+    self.assertEqual(5, len(server_event.results))
+    found_server_op_types = set()
+    for server_result in server_event.results:
+      self.assertNotIn(client_result.type, found_server_op_types)
+      found_server_op_types.add(server_result.type)
+      if server_result.type == _types.OpType.RECV_MESSAGE:
+        self.assertEqual(REQUEST, server_result.message)
+      elif server_result.type == _types.OpType.RECV_CLOSE_ON_SERVER:
+        self.assertFalse(server_result.cancelled)
+    self.assertEqual(set([
+          _types.OpType.SEND_INITIAL_METADATA,
+          _types.OpType.RECV_MESSAGE,
+          _types.OpType.SEND_MESSAGE,
+          _types.OpType.RECV_CLOSE_ON_SERVER,
+          _types.OpType.SEND_STATUS_FROM_SERVER
+      ]), found_server_op_types)
+
+    del client_call
+    del server_call
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/src/grpc/_cython/cygrpc.pyx b/src/python/src/grpc/_cython/cygrpc.pyx
new file mode 100644
index 0000000000..dcb06f345c
--- /dev/null
+++ b/src/python/src/grpc/_cython/cygrpc.pyx
@@ -0,0 +1,111 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cimport cpython
+
+from grpc._cython._cygrpc cimport grpc
+from grpc._cython._cygrpc cimport call
+from grpc._cython._cygrpc cimport channel
+from grpc._cython._cygrpc cimport credentials
+from grpc._cython._cygrpc cimport completion_queue
+from grpc._cython._cygrpc cimport records
+from grpc._cython._cygrpc cimport server
+
+from grpc._cython._cygrpc import call
+from grpc._cython._cygrpc import channel
+from grpc._cython._cygrpc import credentials
+from grpc._cython._cygrpc import completion_queue
+from grpc._cython._cygrpc import records
+from grpc._cython._cygrpc import server
+
+StatusCode = records.StatusCode
+CallError = records.CallError
+CompletionType = records.CompletionType
+OperationType = records.OperationType
+Timespec = records.Timespec
+CallDetails = records.CallDetails
+Event = records.Event
+ByteBuffer = records.ByteBuffer
+SslPemKeyCertPair = records.SslPemKeyCertPair
+ChannelArg = records.ChannelArg
+ChannelArgs = records.ChannelArgs
+Metadatum = records.Metadatum
+Metadata = records.Metadata
+Operation = records.Operation
+
+operation_send_initial_metadata = records.operation_send_initial_metadata
+operation_send_message = records.operation_send_message
+operation_send_close_from_client = records.operation_send_close_from_client
+operation_send_status_from_server = records.operation_send_status_from_server
+operation_receive_initial_metadata = records.operation_receive_initial_metadata
+operation_receive_message = records.operation_receive_message
+operation_receive_status_on_client = records.operation_receive_status_on_client
+operation_receive_close_on_server = records.operation_receive_close_on_server
+
+Operations = records.Operations
+
+ClientCredentials = credentials.ClientCredentials
+ServerCredentials = credentials.ServerCredentials
+
+client_credentials_google_default = (
+    credentials.client_credentials_google_default)
+client_credentials_ssl = credentials.client_credentials_ssl
+client_credentials_composite_credentials = (
+    credentials.client_credentials_composite_credentials)
+client_credentials_compute_engine = (
+    credentials.client_credentials_compute_engine)
+client_credentials_jwt = credentials.client_credentials_jwt
+client_credentials_refresh_token = credentials.client_credentials_refresh_token
+client_credentials_fake_transport_security = (
+    credentials.client_credentials_fake_transport_security)
+client_credentials_iam = credentials.client_credentials_iam
+server_credentials_ssl = credentials.server_credentials_ssl
+server_credentials_fake_transport_security = (
+    credentials.server_credentials_fake_transport_security)
+
+CompletionQueue = completion_queue.CompletionQueue
+Channel = channel.Channel
+Server = server.Server
+Call = call.Call
+
+
+#
+# Global state
+#
+
+cdef class _ModuleState:
+
+  def __cinit__(self):
+    grpc.grpc_init()
+
+  def __dealloc__(self):
+    grpc.grpc_shutdown()
+
+_module_state = _ModuleState()
+
diff --git a/src/python/src/grpc/_cython/cygrpc_test.py b/src/python/src/grpc/_cython/cygrpc_test.py
new file mode 100644
index 0000000000..838e1e2254
--- /dev/null
+++ b/src/python/src/grpc/_cython/cygrpc_test.py
@@ -0,0 +1,276 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import time
+import unittest
+
+from grpc._cython import cygrpc
+from grpc._cython import test_utilities
+
+
+class TypeSmokeTest(unittest.TestCase):
+
+  def testStringsInUtilitiesUpDown(self):
+    self.assertEqual(0, cygrpc.StatusCode.ok)
+    metadatum = cygrpc.Metadatum('a', 'b')
+    self.assertEqual('a'.encode(), metadatum.key)
+    self.assertEqual('b'.encode(), metadatum.value)
+    metadata = cygrpc.Metadata([metadatum])
+    self.assertEqual(1, len(metadata))
+    self.assertEqual(metadatum.key, metadata[0].key)
+
+  def testMetadataIteration(self):
+    metadata = cygrpc.Metadata([
+        cygrpc.Metadatum('a', 'b'), cygrpc.Metadatum('c', 'd')])
+    iterator = iter(metadata)
+    metadatum = next(iterator)
+    self.assertIsInstance(metadatum, cygrpc.Metadatum)
+    self.assertEqual(metadatum.key, 'a'.encode())
+    self.assertEqual(metadatum.value, 'b'.encode())
+    metadatum = next(iterator)
+    self.assertIsInstance(metadatum, cygrpc.Metadatum)
+    self.assertEqual(metadatum.key, 'c'.encode())
+    self.assertEqual(metadatum.value, 'd'.encode())
+    with self.assertRaises(StopIteration):
+      next(iterator)
+
+  def testOperationsIteration(self):
+    operations = cygrpc.Operations([
+        cygrpc.operation_send_message('asdf')])
+    iterator = iter(operations)
+    operation = next(iterator)
+    self.assertIsInstance(operation, cygrpc.Operation)
+    # `Operation`s are write-only structures; can't directly debug anything out
+    # of them. Just check that we stop iterating.
+    with self.assertRaises(StopIteration):
+      next(iterator)
+
+  def testTimespec(self):
+    now = time.time()
+    timespec = cygrpc.Timespec(now)
+    self.assertAlmostEqual(now, float(timespec), places=8)
+
+  def testClientCredentialsUpDown(self):
+    credentials = cygrpc.client_credentials_fake_transport_security()
+    del credentials
+
+  def testServerCredentialsUpDown(self):
+    credentials = cygrpc.server_credentials_fake_transport_security()
+    del credentials
+
+  def testCompletionQueueUpDown(self):
+    completion_queue = cygrpc.CompletionQueue()
+    del completion_queue
+
+  def testServerUpDown(self):
+    server = cygrpc.Server(cygrpc.ChannelArgs([]))
+    del server
+
+  def testChannelUpDown(self):
+    channel = cygrpc.Channel('[::]:0', cygrpc.ChannelArgs([]))
+    del channel
+
+  def testSecureChannelUpDown(self):
+    channel = cygrpc.Channel(
+        '[::]:0', cygrpc.ChannelArgs([]),
+        cygrpc.client_credentials_fake_transport_security())
+    del channel
+
+  @unittest.skip('TODO(atash): undo skip after #2229 is merged')
+  def testServerStartNoExplicitShutdown(self):
+    server = cygrpc.Server()
+    completion_queue = cygrpc.CompletionQueue()
+    server.register_completion_queue(completion_queue)
+    port = server.add_http2_port('[::]:0')
+    self.assertIsInstance(port, int)
+    server.start()
+    del server
+
+  @unittest.skip('TODO(atash): undo skip after #2229 is merged')
+  def testServerStartShutdown(self):
+    completion_queue = cygrpc.CompletionQueue()
+    server = cygrpc.Server()
+    server.add_http2_port('[::]:0')
+    server.register_completion_queue(completion_queue)
+    server.start()
+    shutdown_tag = object()
+    server.shutdown(completion_queue, shutdown_tag)
+    event = completion_queue.poll()
+    self.assertEqual(cygrpc.CompletionType.operation_complete, event.type)
+    self.assertIs(shutdown_tag, event.tag)
+    del server
+    del completion_queue
+
+
+class InsecureServerInsecureClient(unittest.TestCase):
+
+  def setUp(self):
+    self.server_completion_queue = cygrpc.CompletionQueue()
+    self.server = cygrpc.Server()
+    self.server.register_completion_queue(self.server_completion_queue)
+    self.port = self.server.add_http2_port('[::]:0')
+    self.server.start()
+    self.client_completion_queue = cygrpc.CompletionQueue()
+    self.client_channel = cygrpc.Channel('localhost:{}'.format(self.port))
+
+  def tearDown(self):
+    del self.server
+    del self.client_completion_queue
+    del self.server_completion_queue
+
+  def testEcho(self):
+    DEADLINE = time.time()+5
+    DEADLINE_TOLERANCE = 0.25
+    CLIENT_METADATA_ASCII_KEY = b'key'
+    CLIENT_METADATA_ASCII_VALUE = b'val'
+    CLIENT_METADATA_BIN_KEY = b'key-bin'
+    CLIENT_METADATA_BIN_VALUE = b'\0'*1000
+    SERVER_INITIAL_METADATA_KEY = b'init_me_me_me'
+    SERVER_INITIAL_METADATA_VALUE = b'whodawha?'
+    SERVER_TRAILING_METADATA_KEY = b'California_is_in_a_drought'
+    SERVER_TRAILING_METADATA_VALUE = b'zomg it is'
+    SERVER_STATUS_CODE = cygrpc.StatusCode.ok
+    SERVER_STATUS_DETAILS = b'our work is never over'
+    REQUEST = b'in death a member of project mayhem has a name'
+    RESPONSE = b'his name is robert paulson'
+    METHOD = b'twinkies'
+    HOST = b'hostess'
+
+    cygrpc_deadline = cygrpc.Timespec(DEADLINE)
+
+    server_request_tag = object()
+    request_call_result = self.server.request_call(
+        self.server_completion_queue, self.server_completion_queue,
+        server_request_tag)
+
+    self.assertEqual(cygrpc.CallError.ok, request_call_result)
+
+    client_call_tag = object()
+    client_call = self.client_channel.create_call(self.client_completion_queue,
+                                                  METHOD, HOST, cygrpc_deadline)
+    client_initial_metadata = cygrpc.Metadata([
+        cygrpc.Metadatum(CLIENT_METADATA_ASCII_KEY,
+                         CLIENT_METADATA_ASCII_VALUE),
+        cygrpc.Metadatum(CLIENT_METADATA_BIN_KEY, CLIENT_METADATA_BIN_VALUE)])
+    client_start_batch_result = client_call.start_batch(cygrpc.Operations([
+        cygrpc.operation_send_initial_metadata(client_initial_metadata),
+        cygrpc.operation_send_message(REQUEST),
+        cygrpc.operation_send_close_from_client(),
+        cygrpc.operation_receive_initial_metadata(),
+        cygrpc.operation_receive_message(),
+        cygrpc.operation_receive_status_on_client()
+    ]), client_call_tag)
+    self.assertEqual(cygrpc.CallError.ok, client_start_batch_result)
+    client_event_future = test_utilities.CompletionQueuePollFuture(
+        self.client_completion_queue, cygrpc_deadline)
+
+    request_event = self.server_completion_queue.poll(cygrpc_deadline)
+    self.assertEqual(cygrpc.CompletionType.operation_complete,
+                      request_event.type)
+    self.assertIsInstance(request_event.operation_call, cygrpc.Call)
+    self.assertIs(server_request_tag, request_event.tag)
+    self.assertEqual(0, len(request_event.batch_operations))
+    self.assertEqual(dict(client_initial_metadata),
+                      dict(request_event.request_metadata))
+    self.assertEqual(METHOD, request_event.request_call_details.method)
+    self.assertEqual(HOST, request_event.request_call_details.host)
+    self.assertLess(
+        abs(DEADLINE - float(request_event.request_call_details.deadline)),
+        DEADLINE_TOLERANCE)
+
+    server_call_tag = object()
+    server_call = request_event.operation_call
+    server_initial_metadata = cygrpc.Metadata([
+        cygrpc.Metadatum(SERVER_INITIAL_METADATA_KEY,
+                         SERVER_INITIAL_METADATA_VALUE)])
+    server_trailing_metadata = cygrpc.Metadata([
+        cygrpc.Metadatum(SERVER_TRAILING_METADATA_KEY,
+                         SERVER_TRAILING_METADATA_VALUE)])
+    server_start_batch_result = server_call.start_batch([
+        cygrpc.operation_send_initial_metadata(server_initial_metadata),
+        cygrpc.operation_receive_message(),
+        cygrpc.operation_send_message(RESPONSE),
+        cygrpc.operation_receive_close_on_server(),
+        cygrpc.operation_send_status_from_server(
+            server_trailing_metadata, SERVER_STATUS_CODE, SERVER_STATUS_DETAILS)
+    ], server_call_tag)
+    self.assertEqual(cygrpc.CallError.ok, server_start_batch_result)
+
+    client_event = client_event_future.result()
+    server_event = self.server_completion_queue.poll(cygrpc_deadline)
+
+    self.assertEqual(6, len(client_event.batch_operations))
+    found_client_op_types = set()
+    for client_result in client_event.batch_operations:
+      # we expect each op type to be unique
+      self.assertNotIn(client_result.type, found_client_op_types)
+      found_client_op_types.add(client_result.type)
+      if client_result.type == cygrpc.OperationType.receive_initial_metadata:
+        self.assertEqual(dict(server_initial_metadata),
+                         dict(client_result.received_metadata))
+      elif client_result.type == cygrpc.OperationType.receive_message:
+        self.assertEqual(RESPONSE, client_result.received_message.bytes())
+      elif client_result.type == cygrpc.OperationType.receive_status_on_client:
+        self.assertEqual(dict(server_trailing_metadata),
+                         dict(client_result.received_metadata))
+        self.assertEqual(SERVER_STATUS_DETAILS,
+                         client_result.received_status_details)
+        self.assertEqual(SERVER_STATUS_CODE, client_result.received_status_code)
+    self.assertEqual(set([
+          cygrpc.OperationType.send_initial_metadata,
+          cygrpc.OperationType.send_message,
+          cygrpc.OperationType.send_close_from_client,
+          cygrpc.OperationType.receive_initial_metadata,
+          cygrpc.OperationType.receive_message,
+          cygrpc.OperationType.receive_status_on_client
+      ]), found_client_op_types)
+
+    self.assertEqual(5, len(server_event.batch_operations))
+    found_server_op_types = set()
+    for server_result in server_event.batch_operations:
+      self.assertNotIn(client_result.type, found_server_op_types)
+      found_server_op_types.add(server_result.type)
+      if server_result.type == cygrpc.OperationType.receive_message:
+        self.assertEqual(REQUEST, server_result.received_message.bytes())
+      elif server_result.type == cygrpc.OperationType.receive_close_on_server:
+        self.assertFalse(server_result.received_cancelled)
+    self.assertEqual(set([
+          cygrpc.OperationType.send_initial_metadata,
+          cygrpc.OperationType.receive_message,
+          cygrpc.OperationType.send_message,
+          cygrpc.OperationType.receive_close_on_server,
+          cygrpc.OperationType.send_status_from_server
+      ]), found_server_op_types)
+
+    del client_call
+    del server_call
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/src/grpc/_cython/test_utilities.py b/src/python/src/grpc/_cython/test_utilities.py
new file mode 100644
index 0000000000..21ea3075b4
--- /dev/null
+++ b/src/python/src/grpc/_cython/test_utilities.py
@@ -0,0 +1,46 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import threading
+
+from grpc._cython._cygrpc import completion_queue
+
+
+class CompletionQueuePollFuture:
+
+  def __init__(self, completion_queue, deadline):
+    def poller_function():
+      self._event_result = completion_queue.poll(deadline)
+    self._event_result = None
+    self._thread = threading.Thread(target=poller_function)
+    self._thread.start()
+
+  def result(self):
+    self._thread.join()
+    return self._event_result
diff --git a/src/python/src/setup.py b/src/python/src/setup.py
index 5398b09936..70314bb26c 100644
--- a/src/python/src/setup.py
+++ b/src/python/src/setup.py
@@ -29,11 +29,20 @@
 
 """A setup module for the GRPC Python package."""
 
+import os
+import sys
+
 from distutils import core as _core
+from distutils import extension as _extension
 import setuptools
-import sys
 
-_EXTENSION_SOURCES = (
+
+# Use environment variables to determine whether or not the Cython extension
+# should *use* Cython or use the generated C files. Note that this requires the
+# C files to have been generated by building first *with* Cython support.
+_BUILD_WITH_CYTHON = os.environ.get('GRPC_PYTHON_BUILD_WITH_CYTHON', False)
+
+_C_EXTENSION_SOURCES = (
     'grpc/_adapter/_c/module.c',
     'grpc/_adapter/_c/types.c',
     'grpc/_adapter/_c/utility.c',
@@ -45,6 +54,19 @@ _EXTENSION_SOURCES = (
     'grpc/_adapter/_c/types/server.c',
 )
 
+_CYTHON_EXTENSION_PACKAGE_NAMES = (
+)
+
+_CYTHON_EXTENSION_MODULE_NAMES = (
+    'grpc._cython.cygrpc',
+    'grpc._cython._cygrpc.call',
+    'grpc._cython._cygrpc.channel',
+    'grpc._cython._cygrpc.completion_queue',
+    'grpc._cython._cygrpc.credentials',
+    'grpc._cython._cygrpc.records',
+    'grpc._cython._cygrpc.server',
+)
+
 _EXTENSION_INCLUDE_DIRECTORIES = (
     '.',
 )
@@ -56,15 +78,45 @@ _EXTENSION_LIBRARIES = (
 if not "darwin" in sys.platform:
     _EXTENSION_LIBRARIES += ('rt',)
 
-_EXTENSION_MODULE = _core.Extension(
-    'grpc._adapter._c', sources=list(_EXTENSION_SOURCES),
+
+_C_EXTENSION_MODULE = _core.Extension(
+    'grpc._adapter._c', sources=list(_C_EXTENSION_SOURCES),
     include_dirs=list(_EXTENSION_INCLUDE_DIRECTORIES),
     libraries=list(_EXTENSION_LIBRARIES),
-    )
+)
+_C_EXTENSION_MODULES = [_C_EXTENSION_MODULE]
+
+
+def cython_extensions(package_names, module_names, include_dirs, libraries,
+                      build_with_cython=False):
+  file_extension = 'pyx' if build_with_cython else 'c'
+  module_files = [name.replace('.', '/') + '.' + file_extension
+                  for name in module_names]
+  extensions = [
+      _extension.Extension(
+          name=module_name, sources=[module_file],
+          include_dirs=include_dirs, libraries=libraries
+      ) for (module_name, module_file) in zip(module_names, module_files)
+  ]
+  if build_with_cython:
+    import Cython.Build
+    return Cython.Build.cythonize(extensions)
+  else:
+    return extensions
+
+_CYTHON_EXTENSION_MODULES = cython_extensions(
+    list(_CYTHON_EXTENSION_PACKAGE_NAMES), list(_CYTHON_EXTENSION_MODULE_NAMES),
+    list(_EXTENSION_INCLUDE_DIRECTORIES), list(_EXTENSION_LIBRARIES),
+    bool(_BUILD_WITH_CYTHON))
+
+_EXTENSION_MODULES = _C_EXTENSION_MODULES + _CYTHON_EXTENSION_MODULES
+
 
 _PACKAGES = (
     'grpc',
     'grpc._adapter',
+    'grpc._cython',
+    'grpc._cython._cygrpc',
     'grpc._junkdrawer',
     'grpc.early_adopter',
     'grpc.framework',
@@ -79,6 +131,7 @@ _PACKAGES = (
 _PACKAGE_DIRECTORIES = {
     'grpc': 'grpc',
     'grpc._adapter': 'grpc/_adapter',
+    'grpc._cython': 'grpc/_cython',
     'grpc._junkdrawer': 'grpc/_junkdrawer',
     'grpc.early_adopter': 'grpc/early_adopter',
     'grpc.framework': 'grpc/framework',
@@ -87,7 +140,7 @@ _PACKAGE_DIRECTORIES = {
 setuptools.setup(
     name='grpcio',
     version='0.9.0a1',
-    ext_modules=[_EXTENSION_MODULE],
+    ext_modules=_EXTENSION_MODULES,
     packages=list(_PACKAGES),
     package_dir=_PACKAGE_DIRECTORIES,
     install_requires=[
diff --git a/tools/distrib/python/submit.py b/tools/distrib/python/submit.py
index dd48f440ba..a3615b3640 100755
--- a/tools/distrib/python/submit.py
+++ b/tools/distrib/python/submit.py
@@ -66,6 +66,12 @@ try:
 except:
   pass
 
+# Build the Cython C files
+build_env = os.environ.copy()
+build_env['GRPC_PYTHON_BUILD_WITH_CYTHON'] = "1"
+cmd = ['python', 'setup.py', 'build_ext', '--inplace']
+subprocess.call(cmd, cwd=pkgdir, env=build_env)
+
 # Make the push.
 cmd = ['python', 'setup.py', 'sdist']
 subprocess.call(cmd, cwd=pkgdir)
diff --git a/tools/run_tests/build_python.sh b/tools/run_tests/build_python.sh
index d9b7644f44..108dd6aeff 100755
--- a/tools/run_tests/build_python.sh
+++ b/tools/run_tests/build_python.sh
@@ -34,9 +34,21 @@ set -ex
 cd $(dirname $0)/../..
 
 root=`pwd`
-rm -rf python2.7_virtual_environment
-virtualenv -p /usr/bin/python2.7 python2.7_virtual_environment
-source python2.7_virtual_environment/bin/activate
-pip install -r src/python/requirements.txt
-CFLAGS="-I$root/include -std=c89 -Werror" LDFLAGS=-L$root/libs/$CONFIG pip install src/python/src
+
+if [ ! -d 'python2.7_virtual_environment' ]
+then
+  # Build the entire virtual environment
+  virtualenv -p /usr/bin/python2.7 python2.7_virtual_environment
+  source python2.7_virtual_environment/bin/activate
+  pip install -r src/python/requirements.txt
+else
+  source python2.7_virtual_environment/bin/activate
+  # Uninstall and re-install the packages we care about. Don't use
+  # --force-reinstall or --ignore-installed to avoid propagating this
+  # unnecessarily to dependencies. Don't use --no-deps to avoid missing
+  # dependency upgrades.
+  (yes | pip uninstall grpcio) || true
+  (yes | pip uninstall interop) || true
+fi
+CFLAGS="-I$root/include -std=c89" LDFLAGS=-L$root/libs/$CONFIG GRPC_PYTHON_BUILD_WITH_CYTHON=1 pip install src/python/src
 pip install src/python/interop
diff --git a/tools/run_tests/python_tests.json b/tools/run_tests/python_tests.json
index 6c969d765f..3bef345029 100755
--- a/tools/run_tests/python_tests.json
+++ b/tools/run_tests/python_tests.json
@@ -1,5 +1,11 @@
 [
   {
+    "module": "grpc._cython.cygrpc_test"
+  },
+  {
+    "module": "grpc._cython.adapter_low_test"
+  },
+  {
     "module": "grpc._adapter._c_test"
   },
   {