diff --git a/core/LICENSE b/core/LICENSE
new file mode 100644
index 0000000..1221dba
--- /dev/null
+++ b/core/LICENSE
@@ -0,0 +1,203 @@
+
+                                 Apache License
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+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
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+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
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+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
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+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
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+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
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+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
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+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
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+
+   Copyright 2016 Awake Networks
+   Copyright 2015 Alois Cochard https://github.com/aloiscochard/grpc-haskell
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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diff --git a/core/README.md b/core/README.md
new file mode 120000
index 0000000..32d46ee
--- /dev/null
+++ b/core/README.md
@@ -0,0 +1 @@
+../README.md
\ No newline at end of file
diff --git a/core/Setup.hs b/core/Setup.hs
new file mode 120000
index 0000000..115f3bb
--- /dev/null
+++ b/core/Setup.hs
@@ -0,0 +1 @@
+../Setup.hs
\ No newline at end of file
diff --git a/cbits/grpc_haskell.c b/core/cbits/grpc_haskell.c
similarity index 100%
rename from cbits/grpc_haskell.c
rename to core/cbits/grpc_haskell.c
diff --git a/core/default.nix b/core/default.nix
new file mode 100644
index 0000000..5bfb04b
--- /dev/null
+++ b/core/default.nix
@@ -0,0 +1,25 @@
+{ mkDerivation, async, base, bytestring, c2hs, clock, containers
+, grpc, managed, pipes, proto3-suite, proto3-wire, QuickCheck, safe
+, sorted-list, stdenv, stm, tasty, tasty-hunit, tasty-quickcheck
+, text, time, transformers, turtle, unix, vector
+}:
+mkDerivation {
+  pname = "grpc-haskell-core";
+  version = "0.0.0.0";
+  src = ./.;
+  libraryHaskellDepends = [
+    async base bytestring clock containers managed pipes proto3-suite
+    proto3-wire safe sorted-list stm tasty tasty-hunit tasty-quickcheck
+    transformers vector
+  ];
+  librarySystemDepends = [ grpc ];
+  libraryToolDepends = [ c2hs ];
+  testHaskellDepends = [
+    async base bytestring clock containers managed pipes proto3-suite
+    QuickCheck safe tasty tasty-hunit tasty-quickcheck text time
+    transformers turtle unix
+  ];
+  homepage = "https://github.com/awakenetworks/gRPC-haskell";
+  description = "Haskell implementation of gRPC layered on shared C library";
+  license = stdenv.lib.licenses.asl20;
+}
diff --git a/core/grpc-haskell-core.cabal b/core/grpc-haskell-core.cabal
new file mode 100644
index 0000000..71d19f6
--- /dev/null
+++ b/core/grpc-haskell-core.cabal
@@ -0,0 +1,119 @@
+name:                grpc-haskell-core
+version:             0.0.0.0
+synopsis:            Haskell implementation of gRPC layered on shared C library.
+homepage:            https://github.com/awakenetworks/gRPC-haskell
+license:             Apache-2.0
+license-file:        LICENSE
+author:              Awake Networks
+maintainer:          opensource@awakenetworks.com
+copyright:           Copyright 2016 Awake Networks
+category:            Network
+build-type:          Simple
+cabal-version:       >=1.10
+
+Flag Debug
+  Description: Adds debug logging.
+  Manual:      True
+  Default:     False
+
+library
+  build-depends:
+      base >=4.8 && <5.0
+    , clock >=0.6.0 && <0.8.0
+    , bytestring ==0.10.*
+    , stm == 2.4.*
+    , containers ==0.5.*
+    , managed >= 1.0.0 && < 1.1
+    , pipes >=4.1 && <=4.4
+    , transformers
+    , proto3-suite
+    , proto3-wire
+
+    , async ==2.1.*
+    , tasty >= 0.11 && <0.12
+    , tasty-hunit >= 0.9 && <0.10
+    , tasty-quickcheck >= 0.8.4 && < 0.9
+    , safe ==0.3.*
+    , vector
+    , sorted-list >=0.1.6.1 && <=0.3
+
+  c-sources:
+    cbits/grpc_haskell.c
+  exposed-modules:
+  -- NOTE: the order of these matters to c2hs.
+    Network.GRPC.Unsafe.Constants
+    Network.GRPC.Unsafe.Time
+    Network.GRPC.Unsafe.Slice
+    Network.GRPC.Unsafe.ChannelArgs
+    Network.GRPC.Unsafe.ByteBuffer
+    Network.GRPC.Unsafe.Metadata
+    Network.GRPC.Unsafe.Op
+    Network.GRPC.Unsafe
+    Network.GRPC.Unsafe.Security
+    Network.GRPC.LowLevel
+    Network.GRPC.LowLevel.Server.Unregistered
+    Network.GRPC.LowLevel.Client.Unregistered
+    Network.GRPC.LowLevel.CompletionQueue
+    Network.GRPC.LowLevel.CompletionQueue.Internal
+    Network.GRPC.LowLevel.CompletionQueue.Unregistered
+    Network.GRPC.LowLevel.GRPC
+    Network.GRPC.LowLevel.Op
+    Network.GRPC.LowLevel.Server
+    Network.GRPC.LowLevel.Call
+    Network.GRPC.LowLevel.Call.Unregistered
+    Network.GRPC.LowLevel.Client
+  extra-libraries:
+    grpc
+  includes:
+      include/grpc_haskell.h
+    , grpc/grpc.h
+    , grpc/status.h
+    , grpc/support/time.h
+    , grpc/impl/codegen/compression_types.h
+    , grpc/slice_buffer.h
+    , grpc/slice.h
+  build-tools:          c2hs
+  default-language:     Haskell2010
+  ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind
+  include-dirs:         include
+  hs-source-dirs:       src
+  default-extensions:   CPP
+  CC-Options: -std=c99
+  if flag(debug)
+    CPP-Options: -DDEBUG
+    CC-Options:  -DGRPC_HASKELL_DEBUG -std=c99
+
+test-suite tests
+  build-depends:
+      base >=4.8 && <5.0
+    , grpc-haskell-core
+    , bytestring ==0.10.*
+    , unix
+    , time
+    , async
+    , tasty >= 0.11 && <0.12
+    , tasty-hunit >= 0.9 && <0.10
+    , tasty-quickcheck >= 0.8.4 && < 0.9
+    , containers ==0.5.*
+    , managed >= 1.0.0 && < 1.1
+    , pipes >=4.1 && <=4.4
+    , proto3-suite
+    , transformers
+    , safe
+    , clock >=0.6.0 && <0.8.0
+    , turtle >= 1.2.0
+    , text
+    , QuickCheck >=2.8 && <3.0
+  other-modules:
+    LowLevelTests,
+    LowLevelTests.Op,
+    UnsafeTests
+  default-language:     Haskell2010
+  ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind -g -threaded -rtsopts
+  hs-source-dirs:       tests
+  main-is:              Properties.hs
+  type:                 exitcode-stdio-1.0
+  default-extensions:   CPP
+  if flag(debug)
+    CPP-Options: -DDEBUG
+    CC-Options:  -DGRPC_HASKELL_DEBUG
diff --git a/include/grpc_haskell.h b/core/include/grpc_haskell.h
similarity index 100%
rename from include/grpc_haskell.h
rename to core/include/grpc_haskell.h
diff --git a/src/Network/GRPC/LowLevel.hs b/core/src/Network/GRPC/LowLevel.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel.hs
rename to core/src/Network/GRPC/LowLevel.hs
diff --git a/src/Network/GRPC/LowLevel/Call.hs b/core/src/Network/GRPC/LowLevel/Call.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Call.hs
rename to core/src/Network/GRPC/LowLevel/Call.hs
diff --git a/src/Network/GRPC/LowLevel/Call/Unregistered.hs b/core/src/Network/GRPC/LowLevel/Call/Unregistered.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Call/Unregistered.hs
rename to core/src/Network/GRPC/LowLevel/Call/Unregistered.hs
diff --git a/src/Network/GRPC/LowLevel/Client.hs b/core/src/Network/GRPC/LowLevel/Client.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Client.hs
rename to core/src/Network/GRPC/LowLevel/Client.hs
diff --git a/src/Network/GRPC/LowLevel/Client/Unregistered.hs b/core/src/Network/GRPC/LowLevel/Client/Unregistered.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Client/Unregistered.hs
rename to core/src/Network/GRPC/LowLevel/Client/Unregistered.hs
diff --git a/src/Network/GRPC/LowLevel/CompletionQueue.hs b/core/src/Network/GRPC/LowLevel/CompletionQueue.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/CompletionQueue.hs
rename to core/src/Network/GRPC/LowLevel/CompletionQueue.hs
diff --git a/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs b/core/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
rename to core/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
diff --git a/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs b/core/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs
rename to core/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs
diff --git a/src/Network/GRPC/LowLevel/GRPC.hs b/core/src/Network/GRPC/LowLevel/GRPC.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/GRPC.hs
rename to core/src/Network/GRPC/LowLevel/GRPC.hs
diff --git a/src/Network/GRPC/LowLevel/Op.hs b/core/src/Network/GRPC/LowLevel/Op.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Op.hs
rename to core/src/Network/GRPC/LowLevel/Op.hs
diff --git a/src/Network/GRPC/LowLevel/Server.hs b/core/src/Network/GRPC/LowLevel/Server.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Server.hs
rename to core/src/Network/GRPC/LowLevel/Server.hs
diff --git a/src/Network/GRPC/LowLevel/Server/Unregistered.hs b/core/src/Network/GRPC/LowLevel/Server/Unregistered.hs
similarity index 100%
rename from src/Network/GRPC/LowLevel/Server/Unregistered.hs
rename to core/src/Network/GRPC/LowLevel/Server/Unregistered.hs
diff --git a/src/Network/GRPC/Unsafe.chs b/core/src/Network/GRPC/Unsafe.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe.chs
rename to core/src/Network/GRPC/Unsafe.chs
diff --git a/src/Network/GRPC/Unsafe/ByteBuffer.chs b/core/src/Network/GRPC/Unsafe/ByteBuffer.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/ByteBuffer.chs
rename to core/src/Network/GRPC/Unsafe/ByteBuffer.chs
diff --git a/src/Network/GRPC/Unsafe/ChannelArgs.chs b/core/src/Network/GRPC/Unsafe/ChannelArgs.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/ChannelArgs.chs
rename to core/src/Network/GRPC/Unsafe/ChannelArgs.chs
diff --git a/src/Network/GRPC/Unsafe/Constants.hsc b/core/src/Network/GRPC/Unsafe/Constants.hsc
similarity index 100%
rename from src/Network/GRPC/Unsafe/Constants.hsc
rename to core/src/Network/GRPC/Unsafe/Constants.hsc
diff --git a/src/Network/GRPC/Unsafe/Metadata.chs b/core/src/Network/GRPC/Unsafe/Metadata.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/Metadata.chs
rename to core/src/Network/GRPC/Unsafe/Metadata.chs
diff --git a/src/Network/GRPC/Unsafe/Op.chs b/core/src/Network/GRPC/Unsafe/Op.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/Op.chs
rename to core/src/Network/GRPC/Unsafe/Op.chs
diff --git a/src/Network/GRPC/Unsafe/Security.chs b/core/src/Network/GRPC/Unsafe/Security.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/Security.chs
rename to core/src/Network/GRPC/Unsafe/Security.chs
diff --git a/src/Network/GRPC/Unsafe/Slice.chs b/core/src/Network/GRPC/Unsafe/Slice.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/Slice.chs
rename to core/src/Network/GRPC/Unsafe/Slice.chs
diff --git a/src/Network/GRPC/Unsafe/Time.chs b/core/src/Network/GRPC/Unsafe/Time.chs
similarity index 100%
rename from src/Network/GRPC/Unsafe/Time.chs
rename to core/src/Network/GRPC/Unsafe/Time.chs
diff --git a/tests/LowLevelTests.hs b/core/tests/LowLevelTests.hs
similarity index 100%
rename from tests/LowLevelTests.hs
rename to core/tests/LowLevelTests.hs
diff --git a/tests/LowLevelTests/Op.hs b/core/tests/LowLevelTests/Op.hs
similarity index 100%
rename from tests/LowLevelTests/Op.hs
rename to core/tests/LowLevelTests/Op.hs
diff --git a/core/tests/Properties.hs b/core/tests/Properties.hs
new file mode 100644
index 0000000..d184a29
--- /dev/null
+++ b/core/tests/Properties.hs
@@ -0,0 +1,12 @@
+import           LowLevelTests
+import           LowLevelTests.Op
+import           Test.Tasty
+import           UnsafeTests
+
+main :: IO ()
+main = defaultMain $ testGroup "GRPC Unit Tests"
+  [ unsafeTests
+  , unsafeProperties
+  , lowLevelOpTests
+  , lowLevelTests
+  ]
diff --git a/tests/UnsafeTests.hs b/core/tests/UnsafeTests.hs
similarity index 100%
rename from tests/UnsafeTests.hs
rename to core/tests/UnsafeTests.hs
diff --git a/tests/ssl/generate-cert.sh b/core/tests/ssl/generate-cert.sh
similarity index 100%
rename from tests/ssl/generate-cert.sh
rename to core/tests/ssl/generate-cert.sh
diff --git a/tests/ssl/localhost.crt b/core/tests/ssl/localhost.crt
similarity index 100%
rename from tests/ssl/localhost.crt
rename to core/tests/ssl/localhost.crt
diff --git a/tests/ssl/localhost.key b/core/tests/ssl/localhost.key
similarity index 100%
rename from tests/ssl/localhost.key
rename to core/tests/ssl/localhost.key
diff --git a/default.nix b/default.nix
index 9e0b5f7..79c1787 100644
--- a/default.nix
+++ b/default.nix
@@ -1,6 +1,6 @@
 { mkDerivation, async, base, bytestring, c2hs, clock, containers
-, grpc, managed, optparse-generic, pipes, proto3-suite, proto3-wire
-, QuickCheck, safe, sorted-list, stdenv, stm, system-filepath
+, criterion, grpc-haskell-core, managed, pipes, proto3-suite
+, proto3-wire, QuickCheck, random, safe, sorted-list, stdenv, stm
 , tasty, tasty-hunit, tasty-quickcheck, text, time, transformers
 , turtle, unix, vector
 }:
@@ -11,21 +11,19 @@ mkDerivation {
   isLibrary = true;
   isExecutable = true;
   libraryHaskellDepends = [
-    async base bytestring clock containers managed pipes proto3-suite
-    proto3-wire safe sorted-list stm tasty tasty-hunit tasty-quickcheck
-    transformers vector
+    async base bytestring clock containers grpc-haskell-core managed
+    pipes proto3-suite proto3-wire safe sorted-list stm tasty
+    tasty-hunit tasty-quickcheck transformers vector
   ];
-  librarySystemDepends = [ grpc ];
   libraryToolDepends = [ c2hs ];
-  executableHaskellDepends = [
-    async base bytestring containers optparse-generic proto3-suite
-    proto3-wire system-filepath text transformers turtle
-  ];
   testHaskellDepends = [
     async base bytestring clock containers managed pipes proto3-suite
     QuickCheck safe tasty tasty-hunit tasty-quickcheck text time
     transformers turtle unix
   ];
+  benchmarkHaskellDepends = [
+    async base bytestring criterion proto3-suite random
+  ];
   homepage = "https://github.com/awakenetworks/gRPC-haskell";
   description = "Haskell implementation of gRPC layered on shared C library";
   license = stdenv.lib.licenses.asl20;
diff --git a/grpc-haskell.cabal b/grpc-haskell.cabal
index 556083a..7c34cd0 100644
--- a/grpc-haskell.cabal
+++ b/grpc-haskell.cabal
@@ -33,6 +33,7 @@ library
     , transformers
     , proto3-suite
     , proto3-wire
+    , grpc-haskell-core
 
     , async ==2.1.*
     , tasty >= 0.11 && <0.12
@@ -42,46 +43,12 @@ library
     , vector
     , sorted-list >=0.1.6.1 && <=0.3
 
-  c-sources:
-    cbits/grpc_haskell.c
   exposed-modules:
-  -- NOTE: the order of these matters to c2hs.
-    Network.GRPC.Unsafe.Constants
-    Network.GRPC.Unsafe.Time
-    Network.GRPC.Unsafe.Slice
-    Network.GRPC.Unsafe.ChannelArgs
-    Network.GRPC.Unsafe.ByteBuffer
-    Network.GRPC.Unsafe.Metadata
-    Network.GRPC.Unsafe.Op
-    Network.GRPC.Unsafe
-    Network.GRPC.Unsafe.Security
-    Network.GRPC.LowLevel
-    Network.GRPC.LowLevel.Server.Unregistered
-    Network.GRPC.LowLevel.Client.Unregistered
-    Network.GRPC.LowLevel.CompletionQueue
-    Network.GRPC.LowLevel.CompletionQueue.Internal
-    Network.GRPC.LowLevel.CompletionQueue.Unregistered
-    Network.GRPC.LowLevel.GRPC
-    Network.GRPC.LowLevel.Op
-    Network.GRPC.LowLevel.Server
-    Network.GRPC.LowLevel.Call
-    Network.GRPC.LowLevel.Call.Unregistered
-    Network.GRPC.LowLevel.Client
     Network.GRPC.HighLevel
     Network.GRPC.HighLevel.Generated
     Network.GRPC.HighLevel.Server
     Network.GRPC.HighLevel.Server.Unregistered
     Network.GRPC.HighLevel.Client
-  extra-libraries:
-    grpc
-  includes:
-      include/grpc_haskell.h
-    , grpc/grpc.h
-    , grpc/status.h
-    , grpc/support/time.h
-    , grpc/impl/codegen/compression_types.h
-    , grpc/slice_buffer.h
-    , grpc/slice.h
   build-tools:          c2hs
   default-language:     Haskell2010
   ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind
@@ -101,6 +68,7 @@ executable hellos-server
       , bytestring == 0.10.*
       , containers ==0.5.*
       , grpc-haskell
+      , grpc-haskell-core
       , proto3-suite
       , proto3-wire
       , text
@@ -120,6 +88,7 @@ executable hellos-client
       , bytestring == 0.10.*
       , containers ==0.5.*
       , grpc-haskell
+      , grpc-haskell-core
       , proto3-suite
       , proto3-wire
       , text
@@ -139,6 +108,7 @@ executable echo-server
       , bytestring == 0.10.*
       , containers ==0.5.*
       , grpc-haskell
+      , grpc-haskell-core
       , optparse-generic
       , proto3-suite
       , proto3-wire
@@ -162,6 +132,7 @@ executable arithmetic-server
       , bytestring == 0.10.*
       , containers ==0.5.*
       , grpc-haskell
+      , grpc-haskell-core
       , optparse-generic
       , proto3-suite
       , proto3-wire
@@ -184,6 +155,7 @@ executable arithmetic-client
       , bytestring == 0.10.*
       , containers ==0.5.*
       , grpc-haskell
+      , grpc-haskell-core
       , optparse-generic
       , proto3-suite
       , proto3-wire
@@ -206,6 +178,7 @@ executable echo-client
       , bytestring == 0.10.*
       , containers ==0.5.*
       , grpc-haskell
+      , grpc-haskell-core
       , optparse-generic
       , proto3-suite
       , proto3-wire
@@ -243,9 +216,6 @@ test-suite tests
     , text
     , QuickCheck >=2.8 && <3.0
   other-modules:
-    LowLevelTests,
-    LowLevelTests.Op,
-    UnsafeTests,
     GeneratedTests
   default-language:     Haskell2010
   ghc-options:          -Wall -fwarn-incomplete-patterns -fno-warn-unused-do-bind -g -threaded -rtsopts
diff --git a/release.nix b/release.nix
index bba5f06..0748429 100644
--- a/release.nix
+++ b/release.nix
@@ -173,6 +173,20 @@ let
         ];
       };
 
+      usesGRPC = haskellPackage:
+        pkgs.haskell.lib.overrideCabal haskellPackage (oldAttributes: {
+            preBuild = (oldAttributes.preBuild or "") +
+              pkgs.lib.optionalString pkgs.stdenv.isDarwin ''
+                export DYLD_LIBRARY_PATH=${grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
+              '';
+
+            shellHook = (oldAttributes.shellHook or "") +
+              pkgs.lib.optionalString pkgs.stdenv.isDarwin ''
+                export DYLD_LIBRARY_PATH=${grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
+              '';
+          }
+        );
+
       haskellPackages = pkgs.haskellPackages.override {
         overrides = haskellPackagesNew: haskellPackagesOld: rec {
           aeson =
@@ -198,83 +212,71 @@ let
             pkgs.haskell.lib.dontCheck
               (haskellPackagesNew.callPackage ./nix/proto3-suite.nix {});
 
+          grpc-haskell-core =
+            usesGRPC (haskellPackagesNew.callPackage ./core { });
+
           grpc-haskell-no-tests =
-            pkgs.haskell.lib.overrideCabal
-              (haskellPackagesNew.callPackage ./default.nix { })
-              (oldDerivation: {
-                doCheck = false;
-
-                preBuild =
-                  pkgs.lib.optionalString pkgs.stdenv.isDarwin ''
-                    export DYLD_LIBRARY_PATH=${grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
-                  '';
-
-                shellHook = (oldDerivation.shellHook or "") + ''
-                  export DYLD_LIBRARY_PATH=${grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
-                '';
-
-              });
+            usesGRPC
+              (pkgs.haskell.lib.dontCheck
+                (haskellPackagesNew.callPackage ./default.nix { })
+              );
 
           grpc-haskell =
-            pkgs.haskell.lib.overrideCabal
-              (haskellPackagesNew.callPackage ./default.nix { })
-              (oldDerivation:
-                let
-                  ghc =
-                    haskellPackagesNew.ghcWithPackages (pkgs: [
-                      pkgs.grpc-haskell-no-tests
-                      # Include some additional packages in this custom ghc for
-                      # running tests in the nix-shell environment.
-                      pkgs.tasty-quickcheck
-                      pkgs.turtle
+            usesGRPC
+              (pkgs.haskell.lib.overrideCabal
+                (haskellPackagesNew.callPackage ./default.nix { })
+                (oldDerivation:
+                  let
+                    ghc =
+                      haskellPackagesNew.ghcWithPackages (pkgs: [
+                        pkgs.grpc-haskell-no-tests
+                        # Include some additional packages in this custom ghc for
+                        # running tests in the nix-shell environment.
+                        pkgs.tasty-quickcheck
+                        pkgs.turtle
+                      ]);
+
+                    python = pkgs.python.withPackages (pkgs: [
+                      # pkgs.protobuf3_0
+                      grpcio-tools
                     ]);
 
-                  python = pkgs.python.withPackages (pkgs: [
-                    # pkgs.protobuf3_0
-                    grpcio-tools
-                  ]);
+                  in rec {
+                    buildDepends = [
+                      pkgs.makeWrapper
+                      # Give our nix-shell its own cabal so we don't pick up one
+                      # from the user's environment by accident.
+                      haskellPackagesNew.cabal-install
+                    ];
 
-                in rec {
-                  buildDepends = [
-                    pkgs.makeWrapper
-                    # Give our nix-shell its own cabal so we don't pick up one
-                    # from the user's environment by accident.
-                    haskellPackagesNew.cabal-install
-                  ];
+                    patches = [ tests/tests.patch ];
 
-                  patches = [ tests/tests.patch ];
-
-                  preBuild =
-                    pkgs.lib.optionalString pkgs.stdenv.isDarwin ''
-                      export DYLD_LIBRARY_PATH=${grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
+                    postPatch = ''
+                      patchShebangs tests
+                      substituteInPlace tests/simple-client.sh \
+                        --replace @makeWrapper@ ${pkgs.makeWrapper} \
+                        --replace @grpc@ ${grpc}
+                      substituteInPlace tests/simple-server.sh \
+                        --replace @makeWrapper@ ${pkgs.makeWrapper} \
+                        --replace @grpc@ ${grpc}
+                      wrapProgram tests/protoc.sh \
+                        --prefix PATH : ${python}/bin
+                      wrapProgram tests/test-client.sh \
+                        --prefix PATH : ${python}/bin
+                      wrapProgram tests/test-server.sh \
+                        --prefix PATH : ${python}/bin
+                      wrapProgram tests/simple-client.sh \
+                        --prefix PATH : ${ghc}/bin
+                      wrapProgram tests/simple-server.sh \
+                        --prefix PATH : ${ghc}/bin
                     '';
 
-                  postPatch = ''
-                    patchShebangs tests
-                    substituteInPlace tests/simple-client.sh \
-                      --replace @makeWrapper@ ${pkgs.makeWrapper} \
-                      --replace @grpc@ ${grpc}
-                    substituteInPlace tests/simple-server.sh \
-                      --replace @makeWrapper@ ${pkgs.makeWrapper} \
-                      --replace @grpc@ ${grpc}
-                    wrapProgram tests/protoc.sh \
-                      --prefix PATH : ${python}/bin
-                    wrapProgram tests/test-client.sh \
-                      --prefix PATH : ${python}/bin
-                    wrapProgram tests/test-server.sh \
-                      --prefix PATH : ${python}/bin
-                    wrapProgram tests/simple-client.sh \
-                      --prefix PATH : ${ghc}/bin
-                    wrapProgram tests/simple-server.sh \
-                      --prefix PATH : ${ghc}/bin
-                  '';
-
-                  shellHook = (oldDerivation.shellHook or "") + ''
-                    export DYLD_LIBRARY_PATH=${grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
-                    # This lets us use our custom ghc and python environments in the shell.
-                    export PATH=${ghc}/bin:${python}/bin''${PATH:+:}$PATH
-                  '';
-                });
+                    shellHook = (oldDerivation.shellHook or "") + ''
+                      # This lets us use our custom ghc and python environments in the shell.
+                      export PATH=${ghc}/bin:${python}/bin''${PATH:+:}$PATH
+                    '';
+                  })
+              );
 
           swagger2 =
             pkgs.haskell.lib.dontCheck (pkgs.haskell.lib.dontHaddock (haskellPackagesNew.callPackage ./nix/swagger2.nix { }));
diff --git a/stack.yaml b/stack.yaml
index ec60fd6..fdcdcb4 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -7,6 +7,7 @@ resolver: lts-8.23
 # Local packages, usually specified by relative directory name
 packages:
 - '.'
+- 'core'
 - location:
     git: git@github.com:awakenetworks/proto3-suite.git
     commit: bb66853dcaa7372ef061cf83f39e4ba5193898de
diff --git a/tests/Properties.hs b/tests/Properties.hs
index ce84244..6f72793 100644
--- a/tests/Properties.hs
+++ b/tests/Properties.hs
@@ -1,14 +1,5 @@
-import           LowLevelTests
-import           LowLevelTests.Op
 import           Test.Tasty
-import           UnsafeTests
 import           GeneratedTests
 
 main :: IO ()
-main = defaultMain $ testGroup "GRPC Unit Tests"
-  [ unsafeTests
-  , unsafeProperties
-  , lowLevelOpTests
-  , lowLevelTests
-  , generatedTests
-  ]
+main = defaultMain $ testGroup "GRPC Unit Tests" [ generatedTests ]