diff --git a/hydra-cardano-api/hydra-cardano-api.cabal b/hydra-cardano-api/hydra-cardano-api.cabal
index 1d567e4abe5..e32ae4d3e2e 100644
--- a/hydra-cardano-api/hydra-cardano-api.cabal
+++ b/hydra-cardano-api/hydra-cardano-api.cabal
@@ -71,7 +71,6 @@ library
     Hydra.Cardano.Api.UTxO
     Hydra.Cardano.Api.ValidityInterval
     Hydra.Cardano.Api.Value
-    Hydra.Cardano.Api.VerificationKey
     Hydra.Cardano.Api.Witness
 
   -- NOTE: We only use an upper bound on cardano-api and have the other
@@ -79,7 +78,6 @@ library
   build-depends:
     , aeson                   >=2
     , base                    >=4.16
-    , base16-bytestring
     , bytestring
     , cardano-api             ^>=10.1
     , cardano-binary
@@ -97,5 +95,4 @@ library
     , lens
     , plutus-ledger-api
     , QuickCheck
-    , serialise
     , text                    >=2
diff --git a/hydra-cardano-api/src/Cardano/Api/UTxO.hs b/hydra-cardano-api/src/Cardano/Api/UTxO.hs
index 08cc50d10f2..67a585a09fd 100644
--- a/hydra-cardano-api/src/Cardano/Api/UTxO.hs
+++ b/hydra-cardano-api/src/Cardano/Api/UTxO.hs
@@ -43,9 +43,6 @@ newtype UTxO' out = UTxO
     , FromJSON
     )
 
-instance Traversable UTxO' where
-  traverse fn (UTxO m) = UTxO <$> traverse fn m
-
 -- | Create a 'UTxO' from a list of 'TxIn' and 'out' pairs.
 fromPairs :: [(TxIn, out)] -> UTxO' out
 fromPairs = UTxO . Map.fromList
diff --git a/hydra-cardano-api/src/Hydra/Cardano/Api.hs b/hydra-cardano-api/src/Hydra/Cardano/Api.hs
index f2f3d32e8de..0fa56d4d624 100644
--- a/hydra-cardano-api/src/Hydra/Cardano/Api.hs
+++ b/hydra-cardano-api/src/Hydra/Cardano/Api.hs
@@ -148,7 +148,6 @@ import Hydra.Cardano.Api.TxOutValue as Extras
 import Hydra.Cardano.Api.UTxO as Extras
 import Hydra.Cardano.Api.ValidityInterval as Extras
 import Hydra.Cardano.Api.Value as Extras
-import Hydra.Cardano.Api.VerificationKey ()
 import Hydra.Cardano.Api.Witness as Extras
 
 import Cardano.Api qualified
diff --git a/hydra-cardano-api/src/Hydra/Cardano/Api/PlutusScript.hs b/hydra-cardano-api/src/Hydra/Cardano/Api/PlutusScript.hs
index d5313ddddb0..63308db7ccf 100644
--- a/hydra-cardano-api/src/Hydra/Cardano/Api/PlutusScript.hs
+++ b/hydra-cardano-api/src/Hydra/Cardano/Api/PlutusScript.hs
@@ -17,16 +17,6 @@ fromPlutusScript =
 
 -- * Orphans
 
-instance IsPlutusScriptLanguage lang => ToJSON (PlutusScript lang) where
-  toJSON = toJSON . serialiseToTextEnvelope Nothing
-
-instance IsPlutusScriptLanguage lang => FromJSON (PlutusScript lang) where
-  parseJSON v = do
-    env <- parseJSON v
-    case deserialiseFromTextEnvelope (proxyToAsType Proxy) env of
-      Left e -> fail $ show e
-      Right a -> pure a
-
 instance Arbitrary (PlutusScript lang) where
   arbitrary =
     PlutusScriptSerialised . SBS.pack <$> listOf arbitrary
diff --git a/hydra-cardano-api/src/Hydra/Cardano/Api/ScriptData.hs b/hydra-cardano-api/src/Hydra/Cardano/Api/ScriptData.hs
index 50478c263a2..5d4406e732d 100644
--- a/hydra-cardano-api/src/Hydra/Cardano/Api/ScriptData.hs
+++ b/hydra-cardano-api/src/Hydra/Cardano/Api/ScriptData.hs
@@ -6,11 +6,7 @@ import Hydra.Cardano.Api.Prelude hiding (left)
 
 import Cardano.Ledger.Era qualified as Ledger
 import Cardano.Ledger.Plutus.Data qualified as Ledger
-import Codec.Serialise (deserialiseOrFail, serialise)
-import Control.Arrow (left)
-import Data.Aeson (Value (String), withText)
 import Data.ByteString qualified as BS
-import Data.ByteString.Base16 qualified as Base16
 import PlutusLedgerApi.V3 qualified as Plutus
 import Test.QuickCheck (arbitrarySizedNatural, choose, oneof, scale, sized, vector)
 
@@ -58,22 +54,6 @@ toLedgerData =
 
 -- * Orphans
 
-instance ToJSON ScriptData where
-  toJSON =
-    String
-      . decodeUtf8
-      . Base16.encode
-      . toStrict
-      . serialise
-      . toPlutusData
-
-instance FromJSON ScriptData where
-  parseJSON v = do
-    text :: Text <- parseJSON v
-    either fail (pure . fromPlutusData) $ do
-      bytes <- Base16.decode (encodeUtf8 text)
-      left show $ deserialiseOrFail $ fromStrict bytes
-
 instance Arbitrary ScriptData where
   arbitrary =
     scale (`div` 2) $
@@ -88,15 +68,6 @@ instance Arbitrary ScriptData where
     arbitraryBS = sized $ \n ->
       BS.pack <$> (choose (0, min n 64) >>= vector)
 
-instance ToJSON HashableScriptData where
-  toJSON = String . decodeUtf8 . Base16.encode . serialiseToCBOR
-
-instance FromJSON HashableScriptData where
-  parseJSON =
-    withText "HashableScriptData" $ \text -> do
-      bytes <- either (fail . show) pure $ Base16.decode $ encodeUtf8 text
-      either (fail . show) pure $ deserialiseFromCBOR (proxyToAsType Proxy) bytes
-
 instance Arbitrary HashableScriptData where
   arbitrary =
     -- NOTE: Safe to use here as the data was not available in serialized form.
diff --git a/hydra-cardano-api/src/Hydra/Cardano/Api/VerificationKey.hs b/hydra-cardano-api/src/Hydra/Cardano/Api/VerificationKey.hs
deleted file mode 100644
index 1e6b7493d89..00000000000
--- a/hydra-cardano-api/src/Hydra/Cardano/Api/VerificationKey.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module Hydra.Cardano.Api.VerificationKey where
-
-import Hydra.Cardano.Api.Prelude
-
--- * Orphans
-
--- XXX: This is quite specific to payment keys
-
-instance ToJSON (VerificationKey PaymentKey) where
-  toJSON = toJSON . serialiseToTextEnvelope Nothing
-
-instance FromJSON (VerificationKey PaymentKey) where
-  parseJSON v = do
-    env <- parseJSON v
-    case deserialiseFromTextEnvelope (AsVerificationKey AsPaymentKey) env of
-      Left e -> fail $ show e
-      Right a -> pure a
diff --git a/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs b/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs
index ecf87a10391..4d034a70122 100644
--- a/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs
+++ b/hydra-chain-observer/src/Hydra/ChainObserver/NodeClient.hs
@@ -36,9 +36,6 @@ data ChainObservation
       }
   deriving stock (Eq, Show, Generic)
 
-instance Arbitrary ChainObservation where
-  arbitrary = genericArbitrary
-
 defaultObserverHandler :: Applicative m => ObserverHandler m
 defaultObserverHandler = const $ pure ()
 
diff --git a/hydra-cluster/bench/Bench/EndToEnd.hs b/hydra-cluster/bench/Bench/EndToEnd.hs
index a4e3318d997..d0b03de04ee 100644
--- a/hydra-cluster/bench/Bench/EndToEnd.hs
+++ b/hydra-cluster/bench/Bench/EndToEnd.hs
@@ -333,7 +333,6 @@ data Event = Event
   , confirmedAt :: Maybe UTCTime
   }
   deriving stock (Generic, Eq, Show)
-  deriving anyclass (ToJSON)
 
 processTransactions :: [HydraClient] -> [ClientDataset] -> IO (Map.Map TxId Event)
 processTransactions clients clientDatasets = do
diff --git a/hydra-cluster/bench/Bench/Summary.hs b/hydra-cluster/bench/Bench/Summary.hs
index 8ee2ff8af2d..cc980c4f59a 100644
--- a/hydra-cluster/bench/Bench/Summary.hs
+++ b/hydra-cluster/bench/Bench/Summary.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 
 module Bench.Summary where
@@ -29,7 +28,6 @@ data Summary = Summary
   , quantiles :: Vector Double
   }
   deriving stock (Generic, Eq, Show)
-  deriving anyclass (ToJSON)
 
 errorSummary :: Dataset -> HUnitFailure -> Summary
 errorSummary Dataset{title, clientDatasets} (HUnitFailure sourceLocation reason) =
diff --git a/hydra-cluster/hydra-cluster.cabal b/hydra-cluster/hydra-cluster.cabal
index 66d6c9c4f18..06d1ec3d491 100644
--- a/hydra-cluster/hydra-cluster.cabal
+++ b/hydra-cluster/hydra-cluster.cabal
@@ -101,7 +101,6 @@ library
     , hydra-tx
     , hydra-tx:testlib
     , io-classes
-    , iohk-monitoring
     , lens
     , lens-aeson
     , optparse-applicative
diff --git a/hydra-cluster/src/CardanoNode.hs b/hydra-cluster/src/CardanoNode.hs
index b975d63378a..8ff976d7b2d 100644
--- a/hydra-cluster/src/CardanoNode.hs
+++ b/hydra-cluster/src/CardanoNode.hs
@@ -50,12 +50,12 @@ data NodeLog
   | MsgSynchronizing {percentDone :: Centi}
   | MsgQueryGenesisParametersFailed {err :: Text}
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 type Port = Int
 
 newtype NodeId = NodeId Int
-  deriving newtype (Eq, Show, Num, ToJSON, FromJSON)
+  deriving newtype (Eq, Show, Num)
 
 -- | Configuration parameters for a single node devnet
 data DevnetConfig = DevnetConfig
@@ -67,7 +67,6 @@ data DevnetConfig = DevnetConfig
   -- ^ A list of port
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 -- | Arguments given to the 'cardano-node' command-line to run a node.
 data CardanoNodeArgs = CardanoNodeArgs
@@ -115,7 +114,6 @@ data PortsConfig = PortsConfig
   -- ^ Other peers TCP ports.
   }
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 getCardanoNodeVersion :: IO String
 getCardanoNodeVersion =
@@ -461,8 +459,6 @@ mkTopology peers =
 data ProcessHasExited = ProcessHasExited Text ExitCode
   deriving stock (Show)
 
-instance Exception ProcessHasExited
-
 -- | Cardano-cli wrapper to query protocol parameters. While we have also client
 -- functions in Hydra.Chain.CardanoClient and Hydra.Cluster.CardanoClient,
 -- sometimes we deliberately want to use the cardano-cli to ensure
diff --git a/hydra-cluster/src/Hydra/Cluster/Faucet.hs b/hydra-cluster/src/Hydra/Cluster/Faucet.hs
index 07f5676a545..6ddb3ff56a2 100644
--- a/hydra-cluster/src/Hydra/Cluster/Faucet.hs
+++ b/hydra-cluster/src/Hydra/Cluster/Faucet.hs
@@ -40,7 +40,7 @@ data FaucetLog
   = TraceResourceExhaustedHandled Text
   | ReturnedFunds {returnAmount :: Coin}
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 -- | Create a specially marked "seed" UTXO containing requested 'Lovelace' by
 -- redeeming funds available to the well-known faucet.
diff --git a/hydra-cluster/src/Hydra/Cluster/Fixture.hs b/hydra-cluster/src/Hydra/Cluster/Fixture.hs
index c8763cd715a..38bd6665a4c 100644
--- a/hydra-cluster/src/Hydra/Cluster/Fixture.hs
+++ b/hydra-cluster/src/Hydra/Cluster/Fixture.hs
@@ -73,7 +73,7 @@ data KnownNetwork
   | Mainnet
   | Sanchonet
   deriving stock (Generic, Show, Eq, Enum, Bounded)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 toNetworkId :: KnownNetwork -> NetworkId
 toNetworkId = \case
diff --git a/hydra-cluster/src/Hydra/Cluster/Mithril.hs b/hydra-cluster/src/Hydra/Cluster/Mithril.hs
index 886fffc4495..b0340ba7d2d 100644
--- a/hydra-cluster/src/Hydra/Cluster/Mithril.hs
+++ b/hydra-cluster/src/Hydra/Cluster/Mithril.hs
@@ -17,7 +17,7 @@ data MithrilLog
   | -- | Output captured directly from mithril-client stderr.
     StdErr {output :: Value}
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 -- | Downloads and unpacks latest snapshot for given network in db/ of given
 -- directory.
diff --git a/hydra-cluster/src/Hydra/Cluster/Options.hs b/hydra-cluster/src/Hydra/Cluster/Options.hs
index 0c907392019..5e2763f9c6d 100644
--- a/hydra-cluster/src/Hydra/Cluster/Options.hs
+++ b/hydra-cluster/src/Hydra/Cluster/Options.hs
@@ -18,19 +18,19 @@ data Options = Options
   , scenario :: Scenario
   }
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 data PublishOrReuse = Publish | Reuse [TxId]
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 data UseMithril = NotUseMithril | UseMithril
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 data Scenario = Idle | RespendUTxO
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 parseOptions :: Parser Options
 parseOptions =
diff --git a/hydra-cluster/src/Hydra/Cluster/Scenarios.hs b/hydra-cluster/src/Hydra/Cluster/Scenarios.hs
index 210d5d6c238..583e2c588e9 100644
--- a/hydra-cluster/src/Hydra/Cluster/Scenarios.hs
+++ b/hydra-cluster/src/Hydra/Cluster/Scenarios.hs
@@ -129,7 +129,7 @@ data EndToEndLog
   | UsingHydraScriptsAt {hydraScriptsTxId :: [TxId]}
   | CreatedKey {keyPath :: FilePath}
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 restartedNodeCanObserveCommitTx :: Tracer IO EndToEndLog -> FilePath -> RunningNode -> [TxId] -> IO ()
 restartedNodeCanObserveCommitTx tracer workDir cardanoNode hydraScriptsTxId = do
diff --git a/hydra-cluster/src/HydraNode.hs b/hydra-cluster/src/HydraNode.hs
index c5bd60b1375..c3d8537b698 100644
--- a/hydra-cluster/src/HydraNode.hs
+++ b/hydra-cluster/src/HydraNode.hs
@@ -5,7 +5,6 @@ module HydraNode where
 import Hydra.Cardano.Api
 import Hydra.Prelude hiding (delete)
 
-import Cardano.BM.Tracing (ToObject)
 import CardanoNode (cliQueryProtocolParameters)
 import Control.Concurrent.Async (forConcurrently_)
 import Control.Concurrent.Class.MonadSTM (modifyTVar', newTVarIO, readTVarIO)
@@ -470,4 +469,4 @@ data HydraNodeLog
   | ReceivedMessage {nodeId :: Int, message :: Aeson.Value}
   | EndWaiting {nodeId :: Int}
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON, ToObject)
+  deriving anyclass (ToJSON)
diff --git a/hydra-node/hydra-node.cabal b/hydra-node/hydra-node.cabal
index 8baf427fdff..64c785888aa 100644
--- a/hydra-node/hydra-node.cabal
+++ b/hydra-node/hydra-node.cabal
@@ -101,7 +101,6 @@ library
   build-depends:
     , aeson
     , base
-    , base16-bytestring
     , bytestring
     , cardano-api:internal
     , cardano-binary
diff --git a/hydra-node/src/Hydra/API/APIServerLog.hs b/hydra-node/src/Hydra/API/APIServerLog.hs
index 0d966cac774..be60d689b67 100644
--- a/hydra-node/src/Hydra/API/APIServerLog.hs
+++ b/hydra-node/src/Hydra/API/APIServerLog.hs
@@ -20,7 +20,7 @@ data APIServerLog
       , path :: PathInfo
       }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary APIServerLog where
   arbitrary =
@@ -50,10 +50,6 @@ instance ToJSON PathInfo where
   toJSON (PathInfo bytes) =
     Aeson.String $ decodeUtf8 bytes
 
-instance FromJSON PathInfo where
-  parseJSON = Aeson.withText "PathInfo" $ \t ->
-    pure . PathInfo $ encodeUtf8 t
-
 -- | New type wrapper to define JSON instances.
 --
 -- NOTE: We are not using http-types 'StdMethod' as we do not want to be
@@ -67,7 +63,3 @@ instance Arbitrary Method where
 instance ToJSON Method where
   toJSON (Method bytes) =
     Aeson.String $ decodeUtf8 bytes
-
-instance FromJSON Method where
-  parseJSON = Aeson.withText "Method" $ \t ->
-    pure . Method $ encodeUtf8 t
diff --git a/hydra-node/src/Hydra/Chain.hs b/hydra-node/src/Hydra/Chain.hs
index df19aaa9022..3d660de55d3 100644
--- a/hydra-node/src/Hydra/Chain.hs
+++ b/hydra-node/src/Hydra/Chain.hs
@@ -158,7 +158,6 @@ data OnChainTx tx
 deriving stock instance IsTx tx => Eq (OnChainTx tx)
 deriving stock instance IsTx tx => Show (OnChainTx tx)
 deriving anyclass instance IsTx tx => ToJSON (OnChainTx tx)
-deriving anyclass instance IsTx tx => FromJSON (OnChainTx tx)
 
 instance ArbitraryIsTx tx => Arbitrary (OnChainTx tx) where
   arbitrary = genericArbitrary
@@ -243,8 +242,6 @@ rollbackHistory rollbackChainSlot h@UnsafeChainStateHistory{history, defaultChai
 
 deriving stock instance Eq (ChainStateType tx) => Eq (ChainStateHistory tx)
 deriving stock instance Show (ChainStateType tx) => Show (ChainStateHistory tx)
-deriving anyclass instance ToJSON (ChainStateType tx) => ToJSON (ChainStateHistory tx)
-deriving anyclass instance FromJSON (ChainStateType tx) => FromJSON (ChainStateHistory tx)
 
 instance Arbitrary (ChainStateType tx) => Arbitrary (ChainStateHistory tx) where
   arbitrary = genericArbitrary
@@ -312,7 +309,6 @@ data ChainEvent tx
 deriving stock instance (IsTx tx, IsChainState tx) => Eq (ChainEvent tx)
 deriving stock instance (IsTx tx, IsChainState tx) => Show (ChainEvent tx)
 deriving anyclass instance (IsTx tx, IsChainState tx) => ToJSON (ChainEvent tx)
-deriving anyclass instance (IsTx tx, IsChainState tx) => FromJSON (ChainEvent tx)
 
 instance (ArbitraryIsTx tx, IsChainState tx) => Arbitrary (ChainEvent tx) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Chain/CardanoClient.hs b/hydra-node/src/Hydra/Chain/CardanoClient.hs
index b3af797f409..28a638f0b96 100644
--- a/hydra-node/src/Hydra/Chain/CardanoClient.hs
+++ b/hydra-node/src/Hydra/Chain/CardanoClient.hs
@@ -13,7 +13,6 @@ import Data.Aeson (eitherDecode', encode)
 import Data.Set qualified as Set
 import Data.Text qualified as Text
 import Ouroboros.Consensus.Cardano.Block (EraMismatch (..))
-import Test.QuickCheck (oneof)
 import Text.Printf (printf)
 
 -- XXX: This should be re-exported by cardano-api
@@ -198,17 +197,6 @@ awaitTransaction networkId socket tx =
 data QueryPoint = QueryTip | QueryAt ChainPoint
   deriving stock (Eq, Show, Generic)
 
-deriving anyclass instance ToJSON QueryPoint
-
-instance Arbitrary QueryPoint where
-  -- XXX: This is not complete as we lack an 'Arbitrary ChainPoint' and we have
-  -- not bothered about it yet.
-  arbitrary =
-    oneof
-      [ pure QueryTip
-      , pure $ QueryAt ChainPointAtGenesis
-      ]
-
 -- | Query the latest chain point aka "the tip".
 queryTip :: NetworkId -> SocketPath -> IO ChainPoint
 queryTip networkId socket =
diff --git a/hydra-node/src/Hydra/Chain/Direct/Handlers.hs b/hydra-node/src/Hydra/Chain/Direct/Handlers.hs
index 338f3e6118b..ac65fd07512 100644
--- a/hydra-node/src/Hydra/Chain/Direct/Handlers.hs
+++ b/hydra-node/src/Hydra/Chain/Direct/Handlers.hs
@@ -460,7 +460,7 @@ data DirectChainLog
   | RolledBackward {point :: ChainPoint}
   | Wallet TinyWalletLog
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary DirectChainLog where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Chain/Direct/State.hs b/hydra-node/src/Hydra/Chain/Direct/State.hs
index 287a1b78e63..302de9f1195 100644
--- a/hydra-node/src/Hydra/Chain/Direct/State.hs
+++ b/hydra-node/src/Hydra/Chain/Direct/State.hs
@@ -190,11 +190,6 @@ data ChainState
   | Open OpenState
   | Closed ClosedState
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
-
-instance Arbitrary ChainState where
-  arbitrary = genChainState
-  shrink = genericShrink
 
 instance HasKnownUTxO ChainState where
   getKnownUTxO :: ChainState -> UTxO
@@ -221,7 +216,6 @@ data ChainContext = ChainContext
   , scriptRegistry :: ScriptRegistry
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 instance HasKnownUTxO ChainContext where
   getKnownUTxO ChainContext{scriptRegistry} = registryUTxO scriptRegistry
@@ -249,14 +243,6 @@ data InitialState = InitialState
   , seedTxIn :: TxIn
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
-
-instance Arbitrary InitialState where
-  arbitrary = do
-    ctx <- genHydraContext maxGenParties
-    snd <$> genStInitial ctx
-
-  shrink = genericShrink
 
 instance HasKnownUTxO InitialState where
   getKnownUTxO st =
@@ -277,7 +263,6 @@ data OpenState = OpenState
   , openUtxoHash :: UTxOHash
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 instance Arbitrary OpenState where
   arbitrary = do
@@ -300,15 +285,6 @@ data ClosedState = ClosedState
   , seedTxIn :: TxIn
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
-
-instance Arbitrary ClosedState where
-  arbitrary = do
-    -- XXX: Untangle the whole generator mess here
-    (_, st, _, _) <- genFanoutTx maxGenParties
-    pure st
-
-  shrink = genericShrink
 
 instance HasKnownUTxO ClosedState where
   getKnownUTxO st =
@@ -927,16 +903,6 @@ observeClose st tx = do
 maxGenParties :: Int
 maxGenParties = 3
 
--- | Generate a 'ChainState' within known limits above.
-genChainState :: Gen ChainState
-genChainState =
-  oneof
-    [ pure Idle
-    , Initial <$> arbitrary
-    , Open <$> arbitrary
-    , Closed <$> arbitrary
-    ]
-
 -- | Generate a 'ChainContext' and 'ChainState' within the known limits above, along with a
 -- transaction that results in a transition away from it.
 genChainStateWithTx :: Gen (ChainContext, ChainState, UTxO, Tx, ChainTransition)
diff --git a/hydra-node/src/Hydra/Chain/Direct/Tx.hs b/hydra-node/src/Hydra/Chain/Direct/Tx.hs
index bcfe8f765fb..e7692028a8d 100644
--- a/hydra-node/src/Hydra/Chain/Direct/Tx.hs
+++ b/hydra-node/src/Hydra/Chain/Direct/Tx.hs
@@ -17,7 +17,6 @@ import Hydra.Prelude hiding (toList)
 import Cardano.Api.UTxO qualified as UTxO
 import Data.Aeson qualified as Aeson
 import Data.ByteString qualified as BS
-import Data.ByteString.Base16 qualified as Base16
 import GHC.IsList (IsList (..))
 import Hydra.Contract.Commit qualified as Commit
 import Hydra.Contract.Deposit qualified as Deposit
@@ -59,16 +58,6 @@ type UTxOWithScript = (TxIn, TxOut CtxUTxO, HashableScriptData)
 newtype UTxOHash = UTxOHash ByteString
   deriving stock (Eq, Show, Generic)
 
-instance ToJSON UTxOHash where
-  toJSON (UTxOHash bytes) =
-    Aeson.String . decodeUtf8 $ Base16.encode bytes
-
-instance FromJSON UTxOHash where
-  parseJSON = Aeson.withText "UTxOHash" $ \cborText ->
-    case Base16.decode $ encodeUtf8 cborText of
-      Left e -> fail e
-      Right bs -> pure $ UTxOHash bs
-
 instance Arbitrary UTxOHash where
   arbitrary = UTxOHash . BS.pack <$> vectorOf 32 arbitrary
 
@@ -79,11 +68,6 @@ data InitialThreadOutput = InitialThreadOutput
   , initialParties :: [OnChain.Party]
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
-
-instance Arbitrary InitialThreadOutput where
-  arbitrary = genericArbitrary
-  shrink = genericShrink
 
 -- * Observe Hydra Head transactions
 
@@ -103,9 +87,6 @@ data HeadObservation
   | Fanout FanoutObservation
   deriving stock (Eq, Show, Generic)
 
-instance Arbitrary HeadObservation where
-  arbitrary = genericArbitrary
-
 -- | Observe any Hydra head transaction.
 observeHeadTx :: NetworkId -> UTxO -> Tx -> HeadObservation
 observeHeadTx networkId utxo tx =
@@ -138,19 +119,12 @@ data InitObservation = InitObservation
   }
   deriving stock (Show, Eq, Generic)
 
-instance Arbitrary InitObservation where
-  arbitrary = genericArbitrary
-
 data NotAnInitReason
   = NoHeadOutput
   | NotAHeadDatum
   | NoSTFound
   | NotAHeadPolicy
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
-
-instance Arbitrary NotAnInitReason where
-  arbitrary = genericArbitrary
 
 -- | Identify a init tx by checking the output value for holding tokens that are
 -- valid head tokens (checked by seed + policy).
@@ -230,9 +204,6 @@ data CommitObservation = CommitObservation
   }
   deriving stock (Eq, Show, Generic)
 
-instance Arbitrary CommitObservation where
-  arbitrary = genericArbitrary
-
 -- | Identify a commit tx by:
 --
 -- - Check that its spending from the init validator,
@@ -304,9 +275,6 @@ data CollectComObservation = CollectComObservation
   }
   deriving stock (Show, Eq, Generic)
 
-instance Arbitrary CollectComObservation where
-  arbitrary = genericArbitrary
-
 -- | Identify a collectCom tx by lookup up the input spending the Head output
 -- and decoding its redeemer.
 observeCollectComTx ::
@@ -352,9 +320,6 @@ data IncrementObservation = IncrementObservation
   }
   deriving stock (Show, Eq, Generic)
 
-instance Arbitrary IncrementObservation where
-  arbitrary = genericArbitrary
-
 observeIncrementTx ::
   UTxO ->
   Tx ->
@@ -395,9 +360,6 @@ data DecrementObservation = DecrementObservation
   }
   deriving stock (Show, Eq, Generic)
 
-instance Arbitrary DecrementObservation where
-  arbitrary = genericArbitrary
-
 observeDecrementTx ::
   UTxO ->
   Tx ->
@@ -436,9 +398,6 @@ data CloseObservation = CloseObservation
   }
   deriving stock (Show, Eq, Generic)
 
-instance Arbitrary CloseObservation where
-  arbitrary = genericArbitrary
-
 -- | Identify a close tx by lookup up the input spending the Head output and
 -- decoding its redeemer.
 observeCloseTx ::
@@ -486,9 +445,6 @@ data ContestObservation = ContestObservation
   }
   deriving stock (Show, Eq, Generic)
 
-instance Arbitrary ContestObservation where
-  arbitrary = genericArbitrary
-
 -- | Identify a close tx by lookup up the input spending the Head output and
 -- decoding its redeemer.
 observeContestTx ::
@@ -528,9 +484,6 @@ observeContestTx utxo tx = do
 
 newtype FanoutObservation = FanoutObservation {headId :: HeadId} deriving stock (Eq, Show, Generic)
 
-instance Arbitrary FanoutObservation where
-  arbitrary = genericArbitrary
-
 -- | Identify a fanout tx by lookup up the input spending the Head output and
 -- decoding its redeemer.
 observeFanoutTx ::
@@ -551,9 +504,6 @@ observeFanoutTx utxo tx = do
 
 newtype AbortObservation = AbortObservation {headId :: HeadId} deriving stock (Eq, Show, Generic)
 
-instance Arbitrary AbortObservation where
-  arbitrary = genericArbitrary
-
 -- | Identify an abort tx by looking up the input spending the Head output and
 -- decoding its redeemer.
 observeAbortTx ::
diff --git a/hydra-node/src/Hydra/Chain/Direct/Wallet.hs b/hydra-node/src/Hydra/Chain/Direct/Wallet.hs
index 541e94f7bca..83319786608 100644
--- a/hydra-node/src/Hydra/Chain/Direct/Wallet.hs
+++ b/hydra-node/src/Hydra/Chain/Direct/Wallet.hs
@@ -456,7 +456,6 @@ data TinyWalletLog
   deriving stock (Eq, Generic, Show)
 
 deriving anyclass instance ToJSON TinyWalletLog
-deriving anyclass instance FromJSON TinyWalletLog
 
 instance Arbitrary TinyWalletLog where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Events.hs b/hydra-node/src/Hydra/Events.hs
index 9276a9ccac6..cb14bf52e26 100644
--- a/hydra-node/src/Hydra/Events.hs
+++ b/hydra-node/src/Hydra/Events.hs
@@ -18,16 +18,12 @@ import Hydra.Prelude
 import Hydra.Chain.ChainState (IsChainState)
 import Hydra.HeadLogic.Outcome (StateChanged)
 import Hydra.Tx.IsTx (ArbitraryIsTx)
-import Test.QuickCheck.Arbitrary.ADT (ToADTArbitrary)
 
 type EventId = Word64
 
 class HasEventId a where
   getEventId :: a -> EventId
 
-instance HasEventId (EventId, a) where
-  getEventId = fst
-
 newtype EventSource e m = EventSource
   { getEvents :: HasEventId e => m [e]
   -- ^ Retrieve all events from the event source.
@@ -67,7 +63,5 @@ instance (ArbitraryIsTx tx, IsChainState tx) => Arbitrary (StateEvent tx) where
   arbitrary = arbitrary >>= genStateEvent
   shrink = genericShrink
 
-instance (ArbitraryIsTx tx, IsChainState tx) => ToADTArbitrary (StateEvent tx)
-
 genStateEvent :: StateChanged tx -> Gen (StateEvent tx)
 genStateEvent sc = StateEvent <$> arbitrary <*> pure sc
diff --git a/hydra-node/src/Hydra/HeadLogic/Error.hs b/hydra-node/src/Hydra/HeadLogic/Error.hs
index 07d4096362d..bbd5f0d025f 100644
--- a/hydra-node/src/Hydra/HeadLogic/Error.hs
+++ b/hydra-node/src/Hydra/HeadLogic/Error.hs
@@ -24,8 +24,6 @@ data LogicError tx
   | NotOurHead {ourHeadId :: HeadId, otherHeadId :: HeadId}
   deriving stock (Generic)
 
-instance (Typeable tx, Show (Input tx), Show (HeadState tx), Show (RequirementFailure tx)) => Exception (LogicError tx)
-
 instance (Arbitrary (Input tx), Arbitrary (HeadState tx), Arbitrary (RequirementFailure tx)) => Arbitrary (LogicError tx) where
   arbitrary = genericArbitrary
   shrink = genericShrink
@@ -33,7 +31,6 @@ instance (Arbitrary (Input tx), Arbitrary (HeadState tx), Arbitrary (Requirement
 deriving stock instance (Eq (HeadState tx), Eq (Input tx), Eq (RequirementFailure tx)) => Eq (LogicError tx)
 deriving stock instance (Show (HeadState tx), Show (Input tx), Show (RequirementFailure tx)) => Show (LogicError tx)
 deriving anyclass instance (ToJSON (HeadState tx), ToJSON (Input tx), ToJSON (RequirementFailure tx)) => ToJSON (LogicError tx)
-deriving anyclass instance (FromJSON (HeadState tx), FromJSON (Input tx), FromJSON (RequirementFailure tx)) => FromJSON (LogicError tx)
 
 data RequirementFailure tx
   = ReqSnNumberInvalid {requestedSn :: SnapshotNumber, lastSeenSn :: SnapshotNumber}
@@ -51,7 +48,6 @@ data RequirementFailure tx
 deriving stock instance Eq (TxIdType tx) => Eq (RequirementFailure tx)
 deriving stock instance Show (TxIdType tx) => Show (RequirementFailure tx)
 deriving anyclass instance ToJSON (TxIdType tx) => ToJSON (RequirementFailure tx)
-deriving anyclass instance FromJSON (TxIdType tx) => FromJSON (RequirementFailure tx)
 
 instance Arbitrary (TxIdType tx) => Arbitrary (RequirementFailure tx) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/HeadLogic/Input.hs b/hydra-node/src/Hydra/HeadLogic/Input.hs
index 14291998e57..157283ca52e 100644
--- a/hydra-node/src/Hydra/HeadLogic/Input.hs
+++ b/hydra-node/src/Hydra/HeadLogic/Input.hs
@@ -30,7 +30,6 @@ data Input tx
 deriving stock instance IsChainState tx => Eq (Input tx)
 deriving stock instance IsChainState tx => Show (Input tx)
 deriving anyclass instance IsChainState tx => ToJSON (Input tx)
-deriving anyclass instance IsChainState tx => FromJSON (Input tx)
 
 instance (ArbitraryIsTx tx, IsChainState tx) => Arbitrary (Input tx) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/HeadLogic/Outcome.hs b/hydra-node/src/Hydra/HeadLogic/Outcome.hs
index f4cd89bfce4..3fa5b577b4c 100644
--- a/hydra-node/src/Hydra/HeadLogic/Outcome.hs
+++ b/hydra-node/src/Hydra/HeadLogic/Outcome.hs
@@ -46,7 +46,6 @@ data Effect tx
 deriving stock instance IsChainState tx => Eq (Effect tx)
 deriving stock instance IsChainState tx => Show (Effect tx)
 deriving anyclass instance IsChainState tx => ToJSON (Effect tx)
-deriving anyclass instance IsChainState tx => FromJSON (Effect tx)
 
 instance (ArbitraryIsTx tx, IsChainState tx) => Arbitrary (Effect tx) where
   arbitrary = genericArbitrary
@@ -151,7 +150,6 @@ instance Semigroup (Outcome tx) where
 deriving stock instance IsChainState tx => Eq (Outcome tx)
 deriving stock instance IsChainState tx => Show (Outcome tx)
 deriving anyclass instance IsChainState tx => ToJSON (Outcome tx)
-deriving anyclass instance IsChainState tx => FromJSON (Outcome tx)
 
 instance (ArbitraryIsTx tx, IsChainState tx) => Arbitrary (Outcome tx) where
   arbitrary = genericArbitrary
@@ -187,7 +185,6 @@ data WaitReason tx
 deriving stock instance IsTx tx => Eq (WaitReason tx)
 deriving stock instance IsTx tx => Show (WaitReason tx)
 deriving anyclass instance IsTx tx => ToJSON (WaitReason tx)
-deriving anyclass instance IsTx tx => FromJSON (WaitReason tx)
 
 instance ArbitraryIsTx tx => Arbitrary (WaitReason tx) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Ledger.hs b/hydra-node/src/Hydra/Ledger.hs
index 5461732af28..da32735ea1b 100644
--- a/hydra-node/src/Hydra/Ledger.hs
+++ b/hydra-node/src/Hydra/Ledger.hs
@@ -50,7 +50,6 @@ data ValidationResult
   = Valid
   | Invalid ValidationError
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 newtype ValidationError = ValidationError {reason :: Text}
   deriving stock (Eq, Show, Generic)
diff --git a/hydra-node/src/Hydra/Logging.hs b/hydra-node/src/Hydra/Logging.hs
index 987d94b3f6b..cc011dbfad5 100644
--- a/hydra-node/src/Hydra/Logging.hs
+++ b/hydra-node/src/Hydra/Logging.hs
@@ -66,7 +66,6 @@ data Envelope a = Envelope
   , message :: a
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (FromJSON)
 
 instance ToJSON a => ToJSON (Envelope a) where
   toEncoding Envelope{timestamp, threadId, namespace, message} =
diff --git a/hydra-node/src/Hydra/Logging/Messages.hs b/hydra-node/src/Hydra/Logging/Messages.hs
index 47cf23a0215..b0465e57bcd 100644
--- a/hydra-node/src/Hydra/Logging/Messages.hs
+++ b/hydra-node/src/Hydra/Logging/Messages.hs
@@ -30,7 +30,6 @@ data HydraLog tx net
 deriving stock instance (Eq net, Eq (HydraNodeLog tx)) => Eq (HydraLog tx net)
 deriving stock instance (Show net, Show (HydraNodeLog tx)) => Show (HydraLog tx net)
 deriving anyclass instance (ToJSON net, ToJSON (HydraNodeLog tx)) => ToJSON (HydraLog tx net)
-deriving anyclass instance (FromJSON net, FromJSON (HydraNodeLog tx)) => FromJSON (HydraLog tx net)
 
 instance (Arbitrary net, Arbitrary (HydraNodeLog tx)) => Arbitrary (HydraLog tx net) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Network.hs b/hydra-node/src/Hydra/Network.hs
index 66240440999..a1edb7f49aa 100644
--- a/hydra-node/src/Hydra/Network.hs
+++ b/hydra-node/src/Hydra/Network.hs
@@ -47,9 +47,6 @@ newtype Network m msg = Network
   -- ^ Send a `msg` to the whole configured hydra network including ourselves.
   }
 
-instance Contravariant (Network m) where
-  contramap f (Network bcast) = Network $ \msg -> bcast (f msg)
-
 -- | Interface from network layer to the application.
 -- XXX: Reliably delivering a message in the crash-recovery fault model is
 -- tricky. According to "Introduction to Reliable and Secure Distributed
@@ -78,12 +75,6 @@ instance FromJSON PortNumber where
 instance Arbitrary PortNumber where
   arbitrary = fromIntegral @Word16 <$> arbitrary
 
-instance ToCBOR PortNumber where
-  toCBOR = toCBOR . toInteger
-
-instance FromCBOR PortNumber where
-  fromCBOR = fmap fromInteger fromCBOR
-
 newtype NodeId = NodeId {nodeId :: Text}
   deriving newtype (Eq, Show, IsString, Read, Ord, ToJSON, FromJSON)
 
@@ -122,19 +113,6 @@ instance Arbitrary Host where
     ip <- toIPv4w <$> arbitrary
     Host (toText $ show ip) <$> arbitrary
 
-instance ToCBOR Host where
-  toCBOR Host{hostname, port} =
-    mconcat
-      [ toCBOR hostname
-      , toCBOR port
-      ]
-
-instance FromCBOR Host where
-  fromCBOR =
-    Host
-      <$> fromCBOR
-      <*> (fromInteger <$> fromCBOR)
-
 showHost :: Host -> String
 showHost Host{hostname, port} =
   unpack hostname <> ":" <> show port
diff --git a/hydra-node/src/Hydra/Network/Authenticate.hs b/hydra-node/src/Hydra/Network/Authenticate.hs
index f65c84fbfe9..5839407525a 100644
--- a/hydra-node/src/Hydra/Network/Authenticate.hs
+++ b/hydra-node/src/Hydra/Network/Authenticate.hs
@@ -27,14 +27,13 @@ data Signed msg = Signed
   , party :: Party
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 data Authenticated msg = Authenticated
   { payload :: msg
   , party :: Party
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 instance (Arbitrary msg, SignableRepresentation msg) => Arbitrary (Signed msg) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Network/Message.hs b/hydra-node/src/Hydra/Network/Message.hs
index 6e7e26628ac..dfcfa3aacc7 100644
--- a/hydra-node/src/Hydra/Network/Message.hs
+++ b/hydra-node/src/Hydra/Network/Message.hs
@@ -22,7 +22,7 @@ data NetworkEvent msg
   = ConnectivityEvent Connectivity
   | ReceivedMessage {sender :: Party, msg :: msg}
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary msg => Arbitrary (NetworkEvent msg) where
   arbitrary = genericArbitrary
@@ -30,7 +30,7 @@ instance Arbitrary msg => Arbitrary (NetworkEvent msg) where
 type HydraVersionedProtocolNumber :: Type
 newtype HydraVersionedProtocolNumber = MkHydraVersionedProtocolNumber {hydraVersionedProtocolNumber :: Natural}
   deriving stock (Eq, Show, Generic, Ord)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary HydraVersionedProtocolNumber where
   arbitrary = genericArbitrary
@@ -40,7 +40,7 @@ data KnownHydraVersions
   = KnownHydraVersions {fromKnownHydraVersions :: [HydraVersionedProtocolNumber]}
   | NoKnownHydraVersions
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary KnownHydraVersions where
   arbitrary = genericArbitrary
@@ -52,10 +52,6 @@ data HydraHandshakeRefused = HydraHandshakeRefused
   , theirVersions :: KnownHydraVersions
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
-
-instance Arbitrary HydraHandshakeRefused where
-  arbitrary = genericArbitrary
 
 data Connectivity
   = Connected {nodeId :: NodeId}
@@ -66,7 +62,7 @@ data Connectivity
       , theirVersions :: KnownHydraVersions
       }
   deriving stock (Generic, Eq, Show)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary Connectivity where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Network/Ouroboros.hs b/hydra-node/src/Hydra/Network/Ouroboros.hs
index 52e3738eabc..1a517c6faa6 100644
--- a/hydra-node/src/Hydra/Network/Ouroboros.hs
+++ b/hydra-node/src/Hydra/Network/Ouroboros.hs
@@ -27,7 +27,7 @@ import Control.Concurrent.STM (
   writeTChan,
  )
 import Control.Exception (IOException)
-import Data.Aeson (object, withObject, (.:), (.=))
+import Data.Aeson (object, (.=))
 import Data.Aeson qualified as Aeson
 import Data.Aeson.Types qualified as Aeson
 import Data.Map.Strict as Map
@@ -372,12 +372,6 @@ instance ToJSON trace => ToJSON (WithHost trace) where
       , "data" .= tr
       ]
 
-instance FromJSON trace => FromJSON (WithHost trace) where
-  parseJSON = withObject "WithHost" $ \obj ->
-    WithHost
-      <$> (obj .: "host")
-      <*> (obj .: "data")
-
 data TraceOuroborosNetwork msg
   = TraceSubscriptions (WithIPList (SubscriptionTrace SockAddr))
   | TraceErrorPolicy (WithAddr SockAddr ErrorPolicyTrace)
diff --git a/hydra-node/src/Hydra/Network/Reliability.hs b/hydra-node/src/Hydra/Network/Reliability.hs
index 231906b7cf5..36beac9dd4b 100644
--- a/hydra-node/src/Hydra/Network/Reliability.hs
+++ b/hydra-node/src/Hydra/Network/Reliability.hs
@@ -122,7 +122,7 @@ data ReliableMsg msg = ReliableMsg
   , payload :: msg
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance ToCBOR msg => ToCBOR (ReliableMsg msg) where
   toCBOR ReliableMsg{knownMessageIds, payload} = toCBOR knownMessageIds <> toCBOR payload
@@ -156,7 +156,7 @@ data ReliabilityLog
       , numberOfParties :: Int
       }
   deriving stock (Show, Eq, Generic)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary ReliabilityLog where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Node.hs b/hydra-node/src/Hydra/Node.hs
index 4482fe76fba..596d0696ef2 100644
--- a/hydra-node/src/Hydra/Node.hs
+++ b/hydra-node/src/Hydra/Node.hs
@@ -234,9 +234,6 @@ data HydraNode tx m = HydraNode
   , server :: Server tx m
   }
 
-instance HasParty (HydraNode tx m) where
-  getParty HydraNode{env} = getParty env
-
 runHydraNode ::
   ( MonadCatch m
   , MonadAsync m
@@ -391,7 +388,6 @@ data HydraNodeLog tx
 deriving stock instance IsChainState tx => Eq (HydraNodeLog tx)
 deriving stock instance IsChainState tx => Show (HydraNodeLog tx)
 deriving anyclass instance IsChainState tx => ToJSON (HydraNodeLog tx)
-deriving anyclass instance IsChainState tx => FromJSON (HydraNodeLog tx)
 
 instance (ArbitraryIsTx tx, IsChainState tx) => Arbitrary (HydraNodeLog tx) where
   arbitrary = genericArbitrary
diff --git a/hydra-node/src/Hydra/Node/ParameterMismatch.hs b/hydra-node/src/Hydra/Node/ParameterMismatch.hs
index 3efd2c21053..60bf96e75ae 100644
--- a/hydra-node/src/Hydra/Node/ParameterMismatch.hs
+++ b/hydra-node/src/Hydra/Node/ParameterMismatch.hs
@@ -20,7 +20,7 @@ data ParamMismatch
   | PartiesMismatch {loadedParties :: [Party], configuredParties :: [Party]}
   | SavedNetworkPartiesInconsistent {numberOfParties :: Int}
   deriving stock (Generic, Eq, Show)
-  deriving anyclass (ToJSON, FromJSON)
+  deriving anyclass (ToJSON)
 
 instance Arbitrary ParamMismatch where
   arbitrary = genericArbitrary
diff --git a/hydra-node/test/Hydra/BehaviorSpec.hs b/hydra-node/test/Hydra/BehaviorSpec.hs
index 09ff9ed70ea..1541075c7da 100644
--- a/hydra-node/test/Hydra/BehaviorSpec.hs
+++ b/hydra-node/test/Hydra/BehaviorSpec.hs
@@ -23,7 +23,7 @@ import Data.List qualified as List
 import Hydra.API.ClientInput
 import Hydra.API.Server (Server (..))
 import Hydra.API.ServerOutput (DecommitInvalidReason (..), ServerOutput (..))
-import Hydra.Cardano.Api (ChainPoint (..), SigningKey, SlotNo (SlotNo), Tx)
+import Hydra.Cardano.Api (SigningKey)
 import Hydra.Chain (
   Chain (..),
   ChainEvent (..),
@@ -33,7 +33,6 @@ import Hydra.Chain (
  )
 import Hydra.Chain.ChainState (ChainSlot (ChainSlot), ChainStateType, IsChainState, chainStateSlot)
 import Hydra.Chain.Direct.Handlers (getLatest, newLocalChainState, pushNew, rollback)
-import Hydra.Chain.Direct.State (ChainStateAt (..))
 import Hydra.Events.FileBased (eventPairFromPersistenceIncremental)
 import Hydra.HeadLogic (
   Effect (..),
@@ -995,15 +994,6 @@ class IsChainState a => IsChainStateTest a where
 instance IsChainStateTest SimpleTx where
   advanceSlot SimpleChainState{slot} = SimpleChainState{slot = nextChainSlot slot}
 
-instance IsChainStateTest Tx where
-  advanceSlot cs@ChainStateAt{recordedAt} =
-    let newChainPoint = case recordedAt of
-          Just (ChainPoint (SlotNo slotNo) bh) ->
-            ChainPoint (SlotNo slotNo + 1) bh
-          _NothingOrGenesis ->
-            ChainPoint (SlotNo 1) (error "should not use block header hash in tests")
-     in cs{recordedAt = Just newChainPoint}
-
 -- | Creates a simulated chain and network to which 'HydraNode's can be
 -- connected to using 'connectNode'. NOTE: The 'tickThread' needs to be
 -- 'cancel'ed after use. Use 'withSimulatedChainAndNetwork' instead where
diff --git a/hydra-node/test/Hydra/Chain/Direct/TxTraceSpec.hs b/hydra-node/test/Hydra/Chain/Direct/TxTraceSpec.hs
index f4f40d74f63..c36635b6914 100644
--- a/hydra-node/test/Hydra/Chain/Direct/TxTraceSpec.hs
+++ b/hydra-node/test/Hydra/Chain/Direct/TxTraceSpec.hs
@@ -258,11 +258,6 @@ instance Num ModelSnapshot where
       , toDecommit = mempty
       }
 
-instance Arbitrary ModelSnapshot where
-  arbitrary = genericArbitrary
-
-  shrink = genericShrink
-
 data State
   = Open
   | Closed
diff --git a/hydra-node/test/Hydra/Model/Payment.hs b/hydra-node/test/Hydra/Model/Payment.hs
index 275d06aa6d0..aaa2d715275 100644
--- a/hydra-node/test/Hydra/Model/Payment.hs
+++ b/hydra-node/test/Hydra/Model/Payment.hs
@@ -16,8 +16,6 @@ import Hydra.Tx.IsTx (IsTx (..))
 import Test.Hydra.Tx.Fixture (testNetworkId)
 import Test.Hydra.Tx.Gen (genKeyPair)
 import Test.QuickCheck (choose)
-import Test.QuickCheck.StateModel (HasVariables)
-import Test.QuickCheck.StateModel.Variables (HasVariables (..))
 import Prelude qualified
 
 -- NOTE: New type wrapper to add Ord and Eq instances to signing keys
@@ -72,18 +70,12 @@ instance Show Payment where
       <> show value
       <> " }"
 
-instance Arbitrary Payment where
-  arbitrary = error "don't use"
-
 instance ToCBOR Payment where
   toCBOR = error "don't use"
 
 instance FromCBOR Payment where
   fromCBOR = error "don't use"
 
-instance HasVariables Payment where
-  getAllVariables _ = mempty
-
 -- | Making `Payment` an instance of `IsTx` allows us to use it with `HeadLogic'`s messages.
 instance IsTx Payment where
   type TxIdType Payment = Int
diff --git a/hydra-node/test/Hydra/Node/InputQueueSpec.hs b/hydra-node/test/Hydra/Node/InputQueueSpec.hs
index c14c2a9bf3b..74ec0b096dd 100644
--- a/hydra-node/test/Hydra/Node/InputQueueSpec.hs
+++ b/hydra-node/test/Hydra/Node/InputQueueSpec.hs
@@ -14,7 +14,7 @@ spec =
   prop "adds sequential id to all enqueued items" prop_identify_enqueued_items
 
 newtype DummyInput = DummyInput Int
-  deriving newtype (Eq, Show, Arbitrary)
+  deriving newtype (Eq, Show)
 
 prop_identify_enqueued_items :: NonEmptyList Int -> Property
 prop_identify_enqueued_items (NonEmpty inputs) =
diff --git a/hydra-plutus-extras/hydra-plutus-extras.cabal b/hydra-plutus-extras/hydra-plutus-extras.cabal
index 429394ce918..42217fa97d3 100644
--- a/hydra-plutus-extras/hydra-plutus-extras.cabal
+++ b/hydra-plutus-extras/hydra-plutus-extras.cabal
@@ -50,12 +50,10 @@ library
     , aeson
     , base
     , base16-bytestring
-    , bytestring
     , cardano-api
     , hydra-prelude
     , plutus-ledger-api     >=1.1.1.0
     , plutus-tx             >=1.1.1.0
-    , QuickCheck
     , quickcheck-instances
     , time
 
diff --git a/hydra-plutus-extras/src/Hydra/Plutus/Orphans.hs b/hydra-plutus-extras/src/Hydra/Plutus/Orphans.hs
index bf4d2514fa0..c77f508ecb4 100644
--- a/hydra-plutus-extras/src/Hydra/Plutus/Orphans.hs
+++ b/hydra-plutus-extras/src/Hydra/Plutus/Orphans.hs
@@ -8,44 +8,21 @@ import Hydra.Prelude
 
 import Data.Aeson (object, withObject, (.:), (.=))
 import Data.Aeson qualified as Aeson
-import Data.ByteString qualified as BS
 import Data.ByteString.Base16 qualified as Base16
-import PlutusLedgerApi.V3 (CurrencySymbol, POSIXTime (..), PubKeyHash (..), TokenName, TxId (..), TxOutRef (..), UpperBound, Value, upperBound)
-import PlutusTx.AssocMap qualified as AssocMap
-import PlutusTx.Prelude (BuiltinByteString, Eq, fromBuiltin, toBuiltin)
-import Test.QuickCheck (choose, vectorOf)
+import PlutusLedgerApi.V3 (CurrencySymbol, POSIXTime (..), PubKeyHash (..))
+import PlutusTx.Prelude (BuiltinByteString, fromBuiltin, toBuiltin)
 import Test.QuickCheck.Instances.ByteString ()
 
 instance Arbitrary BuiltinByteString where
   arbitrary = toBuiltin <$> (arbitrary :: Gen ByteString)
 
-instance Arbitrary TokenName where
-  arbitrary = genericArbitrary
-  shrink = genericShrink
-
 instance Arbitrary CurrencySymbol where
   arbitrary = genericArbitrary
   shrink = genericShrink
 
-instance Arbitrary Value where
-  arbitrary = genericArbitrary
-  shrink = genericShrink
-
-instance (PlutusTx.Prelude.Eq k, Arbitrary k, Arbitrary v) => Arbitrary (AssocMap.Map k v) where
-  arbitrary = AssocMap.safeFromList <$> arbitrary
-
 instance Arbitrary POSIXTime where
   arbitrary = POSIXTime <$> arbitrary
 
-instance ToJSON POSIXTime where
-  toJSON (POSIXTime ms) = toJSON ms
-
-instance FromJSON POSIXTime where
-  parseJSON = fmap POSIXTime . parseJSON
-
-instance Arbitrary a => Arbitrary (UpperBound a) where
-  arbitrary = upperBound <$> arbitrary
-
 instance ToJSON PubKeyHash where
   toJSON kh =
     object
@@ -66,9 +43,3 @@ instance FromJSON PubKeyHash where
 
 instance Arbitrary PubKeyHash where
   arbitrary = genericArbitrary
-
-instance Arbitrary TxOutRef where
-  arbitrary = do
-    txId <- TxId . toBuiltin . BS.pack <$> vectorOf 32 arbitrary
-    txIx <- choose (0, 99)
-    pure $ TxOutRef txId txIx
diff --git a/hydra-plutus/src/Hydra/Data/ContestationPeriod.hs b/hydra-plutus/src/Hydra/Data/ContestationPeriod.hs
index 222746fb1d6..083507445c6 100644
--- a/hydra-plutus/src/Hydra/Data/ContestationPeriod.hs
+++ b/hydra-plutus/src/Hydra/Data/ContestationPeriod.hs
@@ -21,14 +21,6 @@ PlutusTx.unstableMakeIsData ''ContestationPeriod
 instance Arbitrary ContestationPeriod where
   arbitrary = fromInteger <$> arbitrary
 
-instance FromJSON ContestationPeriod where
-  parseJSON =
-    fmap (UnsafeContestationPeriod . fromInteger) . parseJSON
-
-instance ToJSON ContestationPeriod where
-  toJSON =
-    toJSON . toInteger . milliseconds
-
 contestationPeriodFromDiffTime :: NominalDiffTime -> ContestationPeriod
 contestationPeriodFromDiffTime = UnsafeContestationPeriod . truncate . (* 1000) . nominalDiffTimeToSeconds
 
diff --git a/hydra-plutus/src/Hydra/Data/Party.hs b/hydra-plutus/src/Hydra/Data/Party.hs
index 99245df7130..3bec0282503 100644
--- a/hydra-plutus/src/Hydra/Data/Party.hs
+++ b/hydra-plutus/src/Hydra/Data/Party.hs
@@ -2,9 +2,7 @@ module Hydra.Data.Party where
 
 import Hydra.Prelude hiding (init)
 
-import Data.Aeson (Value (String), object, withObject, (.:), (.=))
 import Data.ByteString qualified as BS
-import Data.ByteString.Base16 qualified as Base16
 import PlutusTx qualified
 import PlutusTx.Builtins (BuiltinByteString, fromBuiltin, toBuiltin)
 import PlutusTx.IsData
@@ -36,18 +34,6 @@ instance PlutusTx.FromData Party where
 instance PlutusTx.UnsafeFromData Party where
   unsafeFromBuiltinData = UnsafeParty . unsafeFromBuiltinData
 
-instance ToJSON Party where
-  toJSON (UnsafeParty bytes) =
-    object ["vkey" .= String (decodeUtf8 $ Base16.encode $ fromBuiltin bytes)]
-
-instance FromJSON Party where
-  parseJSON =
-    withObject "Party" $ \o -> do
-      hexText :: Text <- o .: "vkey"
-      case Base16.decode $ encodeUtf8 hexText of
-        Left e -> fail e
-        Right bs -> pure UnsafeParty{vkey = toBuiltin bs}
-
 -- | Create an on-chain 'Party' from some verification key bytes.
 partyFromVerificationKeyBytes :: ByteString -> Party
 partyFromVerificationKeyBytes =
diff --git a/hydra-tx/src/Hydra/Tx/Close.hs b/hydra-tx/src/Hydra/Tx/Close.hs
index c0938a0f279..76339b6421b 100644
--- a/hydra-tx/src/Hydra/Tx/Close.hs
+++ b/hydra-tx/src/Hydra/Tx/Close.hs
@@ -44,7 +44,6 @@ data OpenThreadOutput = OpenThreadOutput
   , openParties :: [OnChain.Party]
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 -- | Create a transaction closing a head with either the initial snapshot or
 -- with a multi-signed confirmed snapshot.
diff --git a/hydra-tx/src/Hydra/Tx/Contest.hs b/hydra-tx/src/Hydra/Tx/Contest.hs
index d0d1be156ba..202179c5473 100644
--- a/hydra-tx/src/Hydra/Tx/Contest.hs
+++ b/hydra-tx/src/Hydra/Tx/Contest.hs
@@ -37,7 +37,6 @@ data ClosedThreadOutput = ClosedThreadOutput
   , closedContesters :: [Plutus.PubKeyHash]
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 -- XXX: This function is VERY similar to the 'closeTx' function (only notable
 -- difference being the redeemer, which is in itself also the same structure as
diff --git a/hydra-tx/src/Hydra/Tx/Crypto.hs b/hydra-tx/src/Hydra/Tx/Crypto.hs
index 8c15582972b..57e59f7be98 100644
--- a/hydra-tx/src/Hydra/Tx/Crypto.hs
+++ b/hydra-tx/src/Hydra/Tx/Crypto.hs
@@ -31,10 +31,8 @@ import Cardano.Crypto.DSIGN (
   genKeyDSIGN,
   hashVerKeyDSIGN,
   rawDeserialiseSigDSIGN,
-  rawDeserialiseSignKeyDSIGN,
   rawDeserialiseVerKeyDSIGN,
   rawSerialiseSigDSIGN,
-  rawSerialiseSignKeyDSIGN,
   rawSerialiseVerKeyDSIGN,
   seedSizeDSIGN,
   signDSIGN,
@@ -51,7 +49,7 @@ import Data.ByteString qualified as BS
 import Data.ByteString.Base16 qualified as Base16
 import Data.Map qualified as Map
 import Hydra.Cardano.Api (
-  AsType (AsHash, AsSigningKey, AsVerificationKey),
+  AsType (AsHash, AsVerificationKey),
   HasTextEnvelope (..),
   HasTypeProxy (..),
   Hash,
@@ -129,13 +127,6 @@ instance Key HydraKey where
 instance Arbitrary (SigningKey HydraKey) where
   arbitrary = generateSigningKey . BS.pack <$> vectorOf 32 arbitrary
 
-instance SerialiseAsRawBytes (SigningKey HydraKey) where
-  serialiseToRawBytes (HydraSigningKey sk) =
-    rawSerialiseSignKeyDSIGN sk
-
-  deserialiseFromRawBytes (AsSigningKey AsHydraKey) bs =
-    maybe (error "TODO: SerialiseAsRawBytesError, but constructor not exported") (Right . HydraSigningKey) (rawDeserialiseSignKeyDSIGN bs)
-
 instance HasTextEnvelope (SigningKey HydraKey) where
   textEnvelopeType _ =
     "HydraSigningKey_"
@@ -278,7 +269,6 @@ data Verified
   | FailedKeys {failedKeys :: [VerificationKey HydraKey]}
   | KeyNumberMismatch
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 -- | Verify a given 'MultiSignature a' and value 'a' provided a list of
 -- 'VerificationKey'.
diff --git a/hydra-tx/src/Hydra/Tx/HeadId.hs b/hydra-tx/src/Hydra/Tx/HeadId.hs
index c12e86ddf50..2ef6ad91c5b 100644
--- a/hydra-tx/src/Hydra/Tx/HeadId.hs
+++ b/hydra-tx/src/Hydra/Tx/HeadId.hs
@@ -21,7 +21,6 @@ import Test.QuickCheck.Instances.Time ()
 newtype HeadId = UnsafeHeadId ByteString
   deriving stock (Show, Eq, Ord, Generic)
   deriving (ToJSON, FromJSON) via (UsingRawBytesHex HeadId)
-  deriving newtype (FromCBOR, ToCBOR)
 
 instance SerialiseAsRawBytes HeadId where
   serialiseToRawBytes (UnsafeHeadId bytes) = bytes
diff --git a/hydra-tx/src/Hydra/Tx/ScriptRegistry.hs b/hydra-tx/src/Hydra/Tx/ScriptRegistry.hs
index 72e4400f1d9..8f9f5247fe4 100644
--- a/hydra-tx/src/Hydra/Tx/ScriptRegistry.hs
+++ b/hydra-tx/src/Hydra/Tx/ScriptRegistry.hs
@@ -26,7 +26,6 @@ data ScriptRegistry = ScriptRegistry
   , headReference :: (TxIn, TxOut CtxUTxO)
   }
   deriving stock (Eq, Show, Generic)
-  deriving anyclass (ToJSON, FromJSON)
 
 data NewScriptRegistryException = MissingScript
   { scriptName :: Text
diff --git a/hydra-tx/src/Hydra/Tx/Snapshot.hs b/hydra-tx/src/Hydra/Tx/Snapshot.hs
index 3b174956f94..67617b18799 100644
--- a/hydra-tx/src/Hydra/Tx/Snapshot.hs
+++ b/hydra-tx/src/Hydra/Tx/Snapshot.hs
@@ -113,27 +113,6 @@ instance IsTx tx => FromJSON (Snapshot tx) where
               (Just utxo) -> pure utxo
           )
 
-instance (Typeable tx, ToCBOR tx, ToCBOR (UTxOType tx)) => ToCBOR (Snapshot tx) where
-  toCBOR Snapshot{headId, number, utxo, confirmed, utxoToCommit, utxoToDecommit, version} =
-    toCBOR headId
-      <> toCBOR version
-      <> toCBOR number
-      <> toCBOR confirmed
-      <> toCBOR utxo
-      <> toCBOR utxoToCommit
-      <> toCBOR utxoToDecommit
-
-instance (Typeable tx, FromCBOR tx, FromCBOR (UTxOType tx)) => FromCBOR (Snapshot tx) where
-  fromCBOR =
-    Snapshot
-      <$> fromCBOR
-      <*> fromCBOR
-      <*> fromCBOR
-      <*> fromCBOR
-      <*> fromCBOR
-      <*> fromCBOR
-      <*> fromCBOR
-
 instance (Arbitrary tx, Arbitrary (UTxOType tx)) => Arbitrary (Snapshot tx) where
   arbitrary = genericArbitrary
 
diff --git a/hydra-tx/testlib/Test/Hydra/Tx/Gen.hs b/hydra-tx/testlib/Test/Hydra/Tx/Gen.hs
index 1dbc42bae3b..9f96f541908 100644
--- a/hydra-tx/testlib/Test/Hydra/Tx/Gen.hs
+++ b/hydra-tx/testlib/Test/Hydra/Tx/Gen.hs
@@ -23,11 +23,8 @@ import Hydra.Contract.Util (hydraHeadV1)
 import Hydra.Plutus (commitValidatorScript, initialValidatorScript)
 import Hydra.Tx (ScriptRegistry (..))
 import Hydra.Tx.Close (OpenThreadOutput)
-import Hydra.Tx.Contest (ClosedThreadOutput)
 import Hydra.Tx.Crypto (Hash (..))
-import Hydra.Tx.Deposit (DepositObservation)
 import Hydra.Tx.Party (Party (..))
-import Hydra.Tx.Recover (RecoverObservation)
 import PlutusTx.Builtins (fromBuiltin)
 import Test.Cardano.Ledger.Conway.Arbitrary ()
 import Test.Hydra.Tx.Fixture qualified as Fixtures
@@ -264,16 +261,6 @@ instance Arbitrary OpenThreadOutput where
   arbitrary = genericArbitrary
   shrink = genericShrink
 
-instance Arbitrary ClosedThreadOutput where
-  arbitrary = genericArbitrary
-  shrink = genericShrink
-
-instance Arbitrary DepositObservation where
-  arbitrary = genericArbitrary
-
-instance Arbitrary RecoverObservation where
-  arbitrary = genericArbitrary
-
 instance Arbitrary Tx where
   -- TODO: shrinker!
   arbitrary = fromLedgerTx <$> arbitrary
diff --git a/hydra-tx/testlib/Test/Hydra/Tx/Mutation.hs b/hydra-tx/testlib/Test/Hydra/Tx/Mutation.hs
index dec711e0a5e..61f92a22041 100644
--- a/hydra-tx/testlib/Test/Hydra/Tx/Mutation.hs
+++ b/hydra-tx/testlib/Test/Hydra/Tx/Mutation.hs
@@ -507,30 +507,6 @@ deriving stock instance Eq Head.DecrementRedeemer
 deriving stock instance Eq Head.CloseRedeemer
 deriving stock instance Eq Head.ContestRedeemer
 
-instance Arbitrary Head.IncrementRedeemer where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.DecrementRedeemer where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.CloseRedeemer where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.ContestRedeemer where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.Input where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.OpenDatum where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.ClosedDatum where
-  arbitrary = genericArbitrary
-
-instance Arbitrary Head.State where
-  arbitrary = genericArbitrary
-
 -- * Helpers
 
 -- | Identify Head script's output.
diff --git a/weeder.toml b/weeder.toml
index 75709b4eb11..379b7f034e5 100644
--- a/weeder.toml
+++ b/weeder.toml
@@ -1,4 +1,5 @@
-roots = [ "^Main.main$"
+roots = [
+   "^Main.main$"
  , "^Spec.main$"
  , "^main$"
  , "validatorHash$"
@@ -11,4 +12,31 @@ roots = [ "^Main.main$"
  , "showFromAction$"
  , "redeemer$"
  ]
-type-class-roots = true
+root-instances = [
+ # Stock instances are treated as roots.
+   { class = '\.Eq$' }
+ , { class = '\.Show$' }
+ , { class = '\.Read$' }
+ , { class = '\.Enum$' }
+ , { class = '\.Bounded$' }
+ , { class = '\.Generic$' }
+ , { class = '\.Ord$' }
+ , { class = '\.Num$' }
+ , { class = '\.Real$' }
+ , { class = '\.Integral$' }
+ # unstableMakeIsData creates all Data instances at once, some are unused and
+ # so are treated as roots.
+ , { module = "Hydra.Contract.Commit", instance = "UnsafeFromData Commit" }
+ , { module = "Hydra.Contract.Commit", instance = "FromData RedeemerType" }
+ , { module = "Hydra.Contract.Commit", instance = "UnsafeFromData RedeemerType" }
+ , { module = "Hydra.Contract.Deposit", instance = "FromData DepositRedeemer" }
+ , { module = "Hydra.Contract.MintAction", instance = "FromData MintAction" }
+ # This one is odd.
+ , { module = "Hydra.Network.Ouroboros.Type", instance = "Protocol" }
+ # TODO: Remove this
+ , { module = "Hydra.Model.Payment", instance = "IsTx" }
+ # These are used for debugging.
+ , { module = "Hydra.Chain.Direct.TxTraceSpec", instance = "HasVariables" }
+ , { module = "Hydra.Chain.Direct.TxTraceSpec", instance = "MonadFail AppM" }
+ , { module = "Hydra.Chain.Direct.TxTraceSpec", instance = "MonadThrow AppM" }
+ ]