diff --git a/.gitignore b/.gitignore
index dacd475..470320d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,5 @@
 cabal.project.local
 cabal.project.local~
 .ghc.environment.*
-*.cabal
+
+.stack-work
diff --git a/github-app.cabal b/github-app.cabal
new file mode 100644
index 0000000..31be0f1
--- /dev/null
+++ b/github-app.cabal
@@ -0,0 +1,74 @@
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.38.1.
+--
+-- see: https://github.com/sol/hpack
+
+name:           github-app
+version:        0.0.1
+synopsis:       Authetnicate as a GitHub App
+description:    Please see the README on GitHub at <https://github.com/serokell/github-app#readme>
+category:       Network
+homepage:       https://github.com/serokell/github-app#readme
+bug-reports:    https://github.com/serokell/github-app/issues
+author:         Serokell
+maintainer:     Kirill Elagin <kirelagin@serokell.io>
+copyright:      2018 Serokell
+license:        MPL-2.0
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    ChangeLog.md
+
+source-repository head
+  type: git
+  location: https://github.com/serokell/github-app
+
+library
+  exposed-modules:
+      Crypto.PubKey.RSA.Read
+      GitHub.App.Auth
+      GitHub.App.Request
+      GitHub.Data.Apps
+      GitHub.Data.Installations
+  other-modules:
+      Paths_github_app
+  hs-source-dirs:
+      src
+  default-extensions:
+      ApplicativeDo
+      DeriveDataTypeable
+      DeriveGeneric
+      FlexibleContexts
+      FlexibleInstances
+      GeneralizedNewtypeDeriving
+      LambdaCase
+      MultiParamTypeClasses
+      NamedFieldPuns
+      OverloadedStrings
+      RankNTypes
+      RecordWildCards
+      ScopedTypeVariables
+      StandaloneDeriving
+      TemplateHaskell
+      TupleSections
+      TypeApplications
+  build-depends:
+      aeson
+    , base >=4.7 && <5
+    , bytestring
+    , cryptonite
+    , github
+    , http-client
+    , http-client-tls
+    , http-types
+    , jwt >=0.8.0
+    , mtl
+    , safe-exceptions
+    , tagged
+    , text
+    , time
+    , x509
+    , x509-store
+  default-language: Haskell2010
diff --git a/package.yaml b/package.yaml
index c0a07d4..d72ec93 100644
--- a/package.yaml
+++ b/package.yaml
@@ -48,6 +48,7 @@ library:
     - jwt >= 0.8.0
     - mtl
     - safe-exceptions
+    - tagged
     - text
     - time
     - x509
diff --git a/src/GitHub/App/Auth.hs b/src/GitHub/App/Auth.hs
index e89f424..5d99313 100644
--- a/src/GitHub/App/Auth.hs
+++ b/src/GitHub/App/Auth.hs
@@ -27,6 +27,7 @@ import qualified Data.ByteString.Lazy as LBS
 import Data.Functor (($>))
 import Data.Maybe (fromMaybe)
 import Data.Semigroup ((<>))
+import Data.Tagged
 import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Text.Encoding (encodeUtf8)
@@ -37,8 +38,7 @@ import GitHub.Data.Apps (App)
 import GitHub.Data.Definitions (Error (HTTPError))
 import GitHub.Data.Id (Id, untagId)
 import GitHub.Data.Installations (Installation)
-import GitHub.Data.Request (StatusMap)
-import GitHub.Request (parseResponse)
+import GitHub.Request (StatusMap, parseResponseJSON)
 import Network.HTTP.Client as HTTP
 import qualified Network.HTTP.Client.Internal as HTTP
 import qualified Network.HTTP.Types as HTTP
@@ -113,7 +113,7 @@ createAccessTokenR InstallationAuth{..} = do
             { iat = Just $ toJsonTime currentTime
             , exp = Just $ toJsonTime expiryTime
             }
-        jwt = encodeSigned (RSAPrivateKey iaAppPrivateKey) claims
+        jwt = encodeSigned (RSAPrivateKey iaAppPrivateKey) mempty claims
 
     req <- HTTP.parseRequest . T.unpack $ url
     pure req
@@ -148,7 +148,7 @@ obtainAccessToken mgr ia@InstallationAuth{..} = readMVar iaToken >>= \case
     renew :: IO (Either Error Auth)
     renew = bracketOnError (takeMVar iaToken) (putMVar iaToken) $ \_ -> do
         req <- createAccessTokenR ia
-        result <- runExceptT $ httpLbs' req >>= parseResponse
+        result <- runExceptT $ httpLbs' req >>= parseResponseJSON
         case result of
             Right newToken -> putMVar iaToken (Just newToken) $> Right (itToken newToken)
             Left  err      -> putMVar iaToken Nothing $> Left err
diff --git a/src/GitHub/App/Request.hs b/src/GitHub/App/Request.hs
index 8832307..d4d8e06 100644
--- a/src/GitHub/App/Request.hs
+++ b/src/GitHub/App/Request.hs
@@ -10,6 +10,7 @@ module GitHub.App.Request
        , executeAppRequestWithMgr
        ) where
 
+import Data.Aeson (FromJSON)
 import GitHub.Data (Error (..))
 import GitHub.Data.Request (Request)
 import GitHub.Request (executeRequestWithMgr)
@@ -19,7 +20,7 @@ import Network.HTTP.Client.TLS (newTlsManager)
 import GitHub.App.Auth (InstallationAuth, obtainAccessToken)
 
 
-executeAppRequest :: InstallationAuth -> Request k a -> IO (Either Error a)
+executeAppRequest :: FromJSON a => InstallationAuth -> Request k a -> IO (Either Error a)
 executeAppRequest instAuth req = do
     manager <- newTlsManager
     x <- executeAppRequestWithMgr manager instAuth req
@@ -29,7 +30,8 @@ executeAppRequest instAuth req = do
     pure x
 
 executeAppRequestWithMgr
-    :: Manager
+    :: FromJSON a
+    => Manager
     -> InstallationAuth
     -> Request k a
     -> IO (Either Error a)
diff --git a/stack.yaml b/stack.yaml
index 570edc4..fcf7ead 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,9 +1,11 @@
-resolver: lts-11.5
+resolver: lts-14.19
 
 packages:
 - .
 # Dependency packages to be pulled from upstream that are not in the resolver
 # using the same syntax as the packages field.
 # (e.g., acme-missiles-0.3)
-extra-deps: 
-  - jwt-0.8.0
\ No newline at end of file
+extra-deps:
+  - github-0.24
+  - binary-instances-1
+  # - jwt-0.8.0
diff --git a/stack.yaml.lock b/stack.yaml.lock
new file mode 100644
index 0000000..167e34f
--- /dev/null
+++ b/stack.yaml.lock
@@ -0,0 +1,26 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/topics/lock_files
+
+packages:
+- completed:
+    hackage: github-0.24@sha256:4bf5a06289d36f78bf347b6a4f9906f659be7335cde78386a6c95568714a730b,6955
+    pantry-tree:
+      sha256: e0f84d7a3cdd76c6bd5395c8c72d24a1dda9616f857291820b08947c8290f042
+      size: 7105
+  original:
+    hackage: github-0.24
+- completed:
+    hackage: binary-instances-1@sha256:b17565598b8df3241f9b46fa8e3a3368ecc8e3f2eb175d7c28f319042a6f5c79,2613
+    pantry-tree:
+      sha256: 938ffc6990cac12681c657f7afa93737eecf335e6f0212d8c0b7c1ea3e0f40f4
+      size: 1035
+  original:
+    hackage: binary-instances-1
+snapshots:
+- completed:
+    sha256: 9f79f6494473c9b46911364b94c4b5ef19ca8d35ebf62e46697cf651f198ee19
+    size: 524155
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/14/19.yaml
+  original: lts-14.19