diff --git a/genvalidity-appendful.cabal b/genvalidity-appendful.cabal
--- a/genvalidity-appendful.cabal
+++ b/genvalidity-appendful.cabal
@@ -1,11 +1,11 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.34.7.
+-- This file has been generated from package.yaml by hpack version 0.35.0.
 --
 -- see: https://github.com/sol/hpack
 
 name:           genvalidity-appendful
-version:        0.0.0.0
+version:        0.1.0.0
 description:    Generators for ppend-only cooperative agreement
 homepage:       https://github.com/NorfairKing/appendful#readme
 bug-reports:    https://github.com/NorfairKing/appendful/issues
@@ -14,6 +14,11 @@
 copyright:      Copyright: (c) 2020-2022 Tom Sydney Kerckhove
 license:        MIT
 build-type:     Simple
+extra-source-files:
+    test_resources/collection/client.txt
+    test_resources/collection/request.txt
+    test_resources/collection/response.txt
+    test_resources/collection/server.txt
 
 source-repository head
   type: git
@@ -46,19 +51,24 @@
   hs-source-dirs:
       test
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
+  build-tool-depends:
+      sydtest-discover:sydtest-discover
   build-depends:
       QuickCheck
     , appendful
+    , autodocodec
+    , autodocodec-yaml
     , base >=4.7 && <5
     , containers
     , genvalidity-appendful
-    , genvalidity-hspec
-    , genvalidity-hspec-aeson
+    , genvalidity-sydtest
+    , genvalidity-sydtest-aeson
     , genvalidity-uuid
-    , hspec
     , mtl
     , pretty-show
     , random
+    , safe-coloured-text
+    , sydtest
     , time
     , uuid
   default-language: Haskell2010
diff --git a/test/Data/Appendful/CollectionSpec.hs b/test/Data/Appendful/CollectionSpec.hs
--- a/test/Data/Appendful/CollectionSpec.hs
+++ b/test/Data/Appendful/CollectionSpec.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE RankNTypes #-}
@@ -9,31 +10,53 @@
   )
 where
 
+import Autodocodec
+import Autodocodec.Yaml
 import Control.Monad.State
 import Data.Appendful.Collection
+import Data.Data
 import Data.GenValidity.Appendful.Collection ()
 import Data.GenValidity.UUID ()
 import Data.List
 import qualified Data.Map.Strict as M
 import Data.UUID
+import Data.Word
 import GHC.Generics (Generic)
 import System.Random
-import Test.Hspec
-import Test.Validity
-import Test.Validity.Aeson
+import Test.Syd
+import Test.Syd.Validity
+import Test.Syd.Validity.Aeson
+import Test.Syd.Validity.Utils
+import Text.Colour
 
 {-# ANN module ("HLint: ignore Reduce duplication" :: String) #-}
 
 spec :: Spec
 spec = do
-  genValidSpec @(ClientStore ClientId Int Int)
-  jsonSpec @(ClientStore ClientId Int Int)
-  genValidSpec @(SyncRequest ClientId Int Int)
-  jsonSpec @(SyncRequest ClientId Int Int)
-  genValidSpec @(SyncResponse ClientId Int Int)
-  jsonSpec @(SyncResponse ClientId Int Int)
-  genValidSpec @(ServerStore Int Int)
-  jsonSpec @(ServerStore Int Int)
+  let yamlSchemaSpec :: forall a. (Typeable a, GenValid a, HasCodec a) => FilePath -> Spec
+      yamlSchemaSpec filePath = do
+        it ("outputs the same schema as before for " <> nameOf @a) $
+          pureGoldenTextFile
+            ("test_resources/collection/" <> filePath <> ".txt")
+            (renderChunksText With24BitColours $ schemaChunksViaCodec @a)
+
+  describe "ClientStore" $ do
+    genValidSpec @(ClientStore ClientId Word8 Word8)
+    jsonSpec @(ClientStore ClientId Word8 Word8)
+    yamlSchemaSpec @(ClientStore ClientId Word8 Word8) "client"
+  describe "SyncRequest" $ do
+    genValidSpec @(SyncRequest ClientId Word8 Word8)
+    jsonSpec @(SyncRequest ClientId Word8 Word8)
+    yamlSchemaSpec @(SyncRequest ClientId Word8 Word8) "request"
+  describe "SyncResponse" $ do
+    genValidSpec @(SyncResponse ClientId Word8 Word8)
+    jsonSpec @(SyncResponse ClientId Word8 Word8)
+    yamlSchemaSpec @(SyncResponse ClientId Word8 Word8) "response"
+  describe "ServerStore" $ do
+    genValidSpec @(ServerStore Word8 Word8)
+    jsonSpec @(ServerStore Word8 Word8)
+    yamlSchemaSpec @(ServerStore Word8 Word8) "server"
+
   describe "emptyStore" $ it "is valid" $ shouldBeValid (emptyClientStore @Int @Int @Int)
   describe "storeSize" $ do
     it "does not crash" $ producesValid (storeSize @Int @Int @Int)
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -1,1 +1,1 @@
-{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
+{-# OPTIONS_GHC -F -pgmF sydtest-discover #-}
diff --git a/test_resources/collection/client.txt b/test_resources/collection/client.txt
new file mode 100644
--- /dev/null
+++ b/test_resources/collection/client.txt
@@ -0,0 +1,11 @@
+# ClientStore
+added: # optional
+  # default: {}
+  # added items
+  <key>: 
+    <number> # between 0 and 255
+synced: # optional
+  # default: {}
+  # synced items
+  <key>: 
+    <number> # between 0 and 255
diff --git a/test_resources/collection/request.txt b/test_resources/collection/request.txt
new file mode 100644
--- /dev/null
+++ b/test_resources/collection/request.txt
@@ -0,0 +1,10 @@
+# SyncRequest
+added: # optional
+  # default: {}
+  # new items
+  <key>: 
+    <number> # between 0 and 255
+max-synced: # optional
+  # largest synced value
+  # or null
+  <number> # between 0 and 255
diff --git a/test_resources/collection/response.txt b/test_resources/collection/response.txt
new file mode 100644
--- /dev/null
+++ b/test_resources/collection/response.txt
@@ -0,0 +1,11 @@
+# SyncResponse
+client-added: # optional
+  # default: {}
+  # items added by the client
+  <key>: 
+    <number> # between 0 and 255
+server-added: # optional
+  # default: {}
+  # items added by the server
+  <key>: 
+    <number> # between 0 and 255
diff --git a/test_resources/collection/server.txt b/test_resources/collection/server.txt
new file mode 100644
--- /dev/null
+++ b/test_resources/collection/server.txt
@@ -0,0 +1,2 @@
+<key>: 
+  <number> # between 0 and 255