diff --git a/cardano-cli/cardano-cli.cabal b/cardano-cli/cardano-cli.cabal
index 962dbbaee2..30a434b616 100644
--- a/cardano-cli/cardano-cli.cabal
+++ b/cardano-cli/cardano-cli.cabal
@@ -200,7 +200,7 @@ library
                       , binary
                       , bytestring
                       , canonical-json
-                      , cardano-api ^>= 8.22
+                      , cardano-api ^>= 8.23.1
                       , cardano-binary
                       , cardano-crypto
                       , cardano-crypto-class ^>= 2.1.2
diff --git a/cardano-cli/src/Cardano/CLI/Byron/Tx.hs b/cardano-cli/src/Cardano/CLI/Byron/Tx.hs
index 843f4cf8a9..1f4788ddcb 100644
--- a/cardano-cli/src/Cardano/CLI/Byron/Tx.hs
+++ b/cardano-cli/src/Cardano/CLI/Byron/Tx.hs
@@ -160,7 +160,7 @@ txSpendGenesisUTxOByronPBFT gc nId sk (ByronAddress bAddr) outs = do
             , txFee = TxFeeImplicit ByronEraOnlyByron
             , txValidityRange =
                 ( TxValidityNoLowerBound
-                , TxValidityNoUpperBound ValidityNoUpperBoundInByronEra
+                , defaultTxValidityUpperBound
                 )
             , txMetadata = TxMetadataNone
             , txAuxScripts = TxAuxScriptsNone
@@ -209,7 +209,7 @@ txSpendUTxOByronPBFT nId sk txIns outs = do
           , txFee = TxFeeImplicit ByronEraOnlyByron
           , txValidityRange =
               ( TxValidityNoLowerBound
-              , TxValidityNoUpperBound ValidityNoUpperBoundInByronEra
+              , defaultTxValidityUpperBound
               )
           , txMetadata = TxMetadataNone
           , txAuxScripts = TxAuxScriptsNone
diff --git a/cardano-cli/src/Cardano/CLI/Environment.hs b/cardano-cli/src/Cardano/CLI/Environment.hs
index 932bdf71eb..a93b2d3465 100644
--- a/cardano-cli/src/Cardano/CLI/Environment.hs
+++ b/cardano-cli/src/Cardano/CLI/Environment.hs
@@ -11,9 +11,9 @@ module Cardano.CLI.Environment
   , getEnvSocketPath
   ) where
 
-import           Cardano.Api (AnyCardanoEra (..), AnyShelleyBasedEra (..),
-                   AnyShelleyToBabbageEra (..), CardanoEra (..), NetworkId (..), NetworkMagic (..),
-                   ShelleyBasedEra (..), ShelleyToBabbageEra (..))
+import           Cardano.Api (AnyCardanoEra (..), AnyEraInEon (..), CardanoEra (..), NetworkId (..),
+                   NetworkMagic (..), ShelleyBasedEra (..), ShelleyToBabbageEra (..),
+                   forEraInEonMaybe)
 
 import           Data.Word (Word32)
 import qualified System.Environment as IO
@@ -38,31 +38,15 @@ getEnvCli = do
     , envCliAnyCardanoEra = mCardanoEra
     }
 
-envCliAnyShelleyBasedEra :: EnvCli -> Maybe AnyShelleyBasedEra
+envCliAnyShelleyBasedEra :: EnvCli -> Maybe (AnyEraInEon ShelleyBasedEra)
 envCliAnyShelleyBasedEra envCli = do
   AnyCardanoEra era <- envCliAnyCardanoEra envCli
+  forEraInEonMaybe era AnyEraInEon
 
-  case era of
-    ByronEra -> Nothing
-    ShelleyEra -> Just $ AnyShelleyBasedEra ShelleyBasedEraShelley
-    AllegraEra -> Just $ AnyShelleyBasedEra ShelleyBasedEraAllegra
-    MaryEra -> Just $ AnyShelleyBasedEra ShelleyBasedEraMary
-    AlonzoEra -> Just $ AnyShelleyBasedEra ShelleyBasedEraAlonzo
-    BabbageEra -> Just $ AnyShelleyBasedEra ShelleyBasedEraBabbage
-    ConwayEra -> Just $ AnyShelleyBasedEra ShelleyBasedEraConway
-
-envCliAnyShelleyToBabbageEra :: EnvCli -> Maybe AnyShelleyToBabbageEra
+envCliAnyShelleyToBabbageEra :: EnvCli -> Maybe (AnyEraInEon ShelleyToBabbageEra)
 envCliAnyShelleyToBabbageEra envCli = do
   AnyCardanoEra era <- envCliAnyCardanoEra envCli
-
-  case era of
-    ByronEra -> Nothing
-    ShelleyEra -> Just $ AnyShelleyToBabbageEra ShelleyToBabbageEraShelley
-    AllegraEra -> Just $ AnyShelleyToBabbageEra ShelleyToBabbageEraAllegra
-    MaryEra -> Just $ AnyShelleyToBabbageEra ShelleyToBabbageEraMary
-    AlonzoEra -> Just $ AnyShelleyToBabbageEra ShelleyToBabbageEraAlonzo
-    BabbageEra -> Just $ AnyShelleyToBabbageEra ShelleyToBabbageEraBabbage
-    ConwayEra -> Nothing
+  forEraInEonMaybe era AnyEraInEon
 
 -- | If the environment variable @CARDANO_NODE_NETWORK_ID@ is set, then return the network id therein.
 -- Otherwise, return 'Nothing'.
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Common.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Common.hs
index 9e0c3fa266..59ee2e42f8 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Common.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Common.hs
@@ -58,11 +58,11 @@ import qualified Text.Parsec.String as Parsec
 import qualified Text.Parsec.Token as Parsec
 import           Text.Read (readEither, readMaybe)
 
-defaultShelleyBasedEra :: AnyShelleyBasedEra
-defaultShelleyBasedEra = AnyShelleyBasedEra ShelleyBasedEraBabbage
+defaultShelleyBasedEra :: AnyEraInEon ShelleyBasedEra
+defaultShelleyBasedEra = AnyEraInEon ShelleyBasedEraBabbage
 
-defaultShelleyToBabbageEra :: AnyShelleyToBabbageEra
-defaultShelleyToBabbageEra = AnyShelleyToBabbageEra ShelleyToBabbageEraBabbage
+defaultShelleyToBabbageEra :: AnyEraInEon ShelleyToBabbageEra
+defaultShelleyToBabbageEra = AnyEraInEon ShelleyToBabbageEraBabbage
 
 command' :: String -> String -> Parser a -> Mod CommandFields a
 command' c descr p =
@@ -301,113 +301,113 @@ subInfoParser name i mps = case catMaybes mps of
   [] -> Nothing
   parsers -> Just $ subParser name $ Opt.info (asum parsers) i
 
-pAnyShelleyBasedEra :: EnvCli -> Parser AnyShelleyBasedEra
+pAnyShelleyBasedEra :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pAnyShelleyBasedEra envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraShelley)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraShelley)
         $ mconcat [Opt.long "shelley-era", Opt.help "Specify the Shelley era"]
-      , Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraAllegra)
+      , Opt.flag' (AnyEraInEon ShelleyBasedEraAllegra)
         $ mconcat [Opt.long "allegra-era", Opt.help "Specify the Allegra era"]
-      , Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraMary)
+      , Opt.flag' (AnyEraInEon ShelleyBasedEraMary)
         $ mconcat [Opt.long "mary-era", Opt.help "Specify the Mary era"]
-      , Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraAlonzo)
+      , Opt.flag' (AnyEraInEon ShelleyBasedEraAlonzo)
         $ mconcat [Opt.long "alonzo-era", Opt.help "Specify the Alonzo era"]
-      , Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraBabbage)
+      , Opt.flag' (AnyEraInEon ShelleyBasedEraBabbage)
         $ mconcat [Opt.long "babbage-era", Opt.help "Specify the Babbage era (default)"]
-      , Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraConway)
+      , Opt.flag' (AnyEraInEon ShelleyBasedEraConway)
         $ mconcat [Opt.long "conway-era", Opt.help "Specify the Conway era"]
       ]
     , maybeToList $ pure <$> envCliAnyShelleyBasedEra envCli
     , pure $ pure defaultShelleyBasedEra
   ]
 
-pAnyShelleyToBabbageEra :: EnvCli -> Parser AnyShelleyToBabbageEra
+pAnyShelleyToBabbageEra :: EnvCli -> Parser (AnyEraInEon ShelleyToBabbageEra)
 pAnyShelleyToBabbageEra envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyToBabbageEra ShelleyToBabbageEraShelley)
+    [ [ Opt.flag' (AnyEraInEon ShelleyToBabbageEraShelley)
         $ mconcat [Opt.long "shelley-era", Opt.help "Specify the Shelley era"]
-      , Opt.flag' (AnyShelleyToBabbageEra ShelleyToBabbageEraAllegra)
+      , Opt.flag' (AnyEraInEon ShelleyToBabbageEraAllegra)
         $ mconcat [Opt.long "allegra-era", Opt.help "Specify the Allegra era"]
-      , Opt.flag' (AnyShelleyToBabbageEra ShelleyToBabbageEraMary)
+      , Opt.flag' (AnyEraInEon ShelleyToBabbageEraMary)
         $ mconcat [Opt.long "mary-era", Opt.help "Specify the Mary era"]
-      , Opt.flag' (AnyShelleyToBabbageEra ShelleyToBabbageEraAlonzo)
+      , Opt.flag' (AnyEraInEon ShelleyToBabbageEraAlonzo)
         $ mconcat [Opt.long "alonzo-era", Opt.help "Specify the Alonzo era"]
-      , Opt.flag' (AnyShelleyToBabbageEra ShelleyToBabbageEraBabbage)
+      , Opt.flag' (AnyEraInEon ShelleyToBabbageEraBabbage)
         $ mconcat [Opt.long "babbage-era", Opt.help "Specify the Babbage era (default)"]
       ]
     , maybeToList $ pure <$> envCliAnyShelleyToBabbageEra envCli
     , pure $ pure defaultShelleyToBabbageEra
   ]
 
-pShelleyBasedShelley :: EnvCli -> Parser AnyShelleyBasedEra
+pShelleyBasedShelley :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pShelleyBasedShelley envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraShelley)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraShelley)
           $ mconcat [Opt.long "shelley-era", Opt.help "Specify the Shelley era"]
       ]
     , maybeToList
         $ fmap pure
-        $ mfilter (== AnyShelleyBasedEra ShelleyBasedEraShelley)
+        $ mfilter (== AnyEraInEon ShelleyBasedEraShelley)
         $ envCliAnyShelleyBasedEra envCli
     ]
 
-pShelleyBasedAllegra :: EnvCli -> Parser AnyShelleyBasedEra
+pShelleyBasedAllegra :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pShelleyBasedAllegra envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraAllegra)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraAllegra)
           $ mconcat [Opt.long "allegra-era", Opt.help "Specify the Allegra era"]
       ]
     , maybeToList
         $ fmap pure
-        $ mfilter (== AnyShelleyBasedEra ShelleyBasedEraAllegra)
+        $ mfilter (== AnyEraInEon ShelleyBasedEraAllegra)
         $ envCliAnyShelleyBasedEra envCli
     ]
 
-pShelleyBasedMary :: EnvCli -> Parser AnyShelleyBasedEra
+pShelleyBasedMary :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pShelleyBasedMary envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraMary)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraMary)
           $ mconcat [Opt.long "mary-era", Opt.help "Specify the Mary era"]
       ]
     , maybeToList
         $ fmap pure
-        $ mfilter (== AnyShelleyBasedEra ShelleyBasedEraMary)
+        $ mfilter (== AnyEraInEon ShelleyBasedEraMary)
         $ envCliAnyShelleyBasedEra envCli
     ]
 
-pShelleyBasedAlonzo :: EnvCli -> Parser AnyShelleyBasedEra
+pShelleyBasedAlonzo :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pShelleyBasedAlonzo envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraAlonzo)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraAlonzo)
           $ mconcat [Opt.long "alonzo-era", Opt.help "Specify the Alonzo era"]
       ]
     , maybeToList
         $ fmap pure
-        $ mfilter (== AnyShelleyBasedEra ShelleyBasedEraAlonzo)
+        $ mfilter (== AnyEraInEon ShelleyBasedEraAlonzo)
         $ envCliAnyShelleyBasedEra envCli
     ]
 
-pShelleyBasedBabbage :: EnvCli -> Parser AnyShelleyBasedEra
+pShelleyBasedBabbage :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pShelleyBasedBabbage envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraBabbage)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraBabbage)
           $ mconcat [Opt.long "babbage-era", Opt.help "Specify the Babbage era (default)"]
       ]
     , maybeToList
         $ fmap pure
-        $ mfilter (== AnyShelleyBasedEra ShelleyBasedEraBabbage)
+        $ mfilter (== AnyEraInEon ShelleyBasedEraBabbage)
         $ envCliAnyShelleyBasedEra envCli
     ]
 
-pShelleyBasedConway :: EnvCli -> Parser AnyShelleyBasedEra
+pShelleyBasedConway :: EnvCli -> Parser (AnyEraInEon ShelleyBasedEra)
 pShelleyBasedConway envCli =
   asum $ mconcat
-    [ [ Opt.flag' (AnyShelleyBasedEra ShelleyBasedEraConway)
+    [ [ Opt.flag' (AnyEraInEon ShelleyBasedEraConway)
           $ mconcat [Opt.long "conway-era", Opt.help "Specify the Conway era"]
       ]
     , maybeToList
         $ fmap pure
-        $ mfilter (== AnyShelleyBasedEra ShelleyBasedEraConway)
+        $ mfilter (== AnyEraInEon ShelleyBasedEraConway)
         $ envCliAnyShelleyBasedEra envCli
     ]
 
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance.hs
index 2014204e37..09ac10b52a 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance.hs
@@ -44,7 +44,7 @@ pGovernanceCmds era envCli =
 
 pCreateMirCertificatesCmds :: CardanoEra era -> Maybe (Parser (GovernanceCmds era))
 pCreateMirCertificatesCmds era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "create-mir-certificate"
     $ Opt.info (pMIRPayStakeAddresses w <|> mirCertParsers w)
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Actions.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Actions.hs
index 9627cbeef4..3c36629a2a 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Actions.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Actions.hs
@@ -43,7 +43,7 @@ pGovernanceActionNewInfoCmd
   :: CardanoEra era
   -> Maybe (Parser (GovernanceActionCmds era))
 pGovernanceActionNewInfoCmd era = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "create-info"
     $ Opt.info
@@ -63,7 +63,7 @@ pGovernanceActionNewConstitutionCmd
   :: CardanoEra era
   -> Maybe (Parser (GovernanceActionCmds era))
 pGovernanceActionNewConstitutionCmd era = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "create-constitution"
     $ Opt.info
@@ -85,7 +85,7 @@ pGovernanceActionNewCommitteeCmd
   :: CardanoEra era
   -> Maybe (Parser (GovernanceActionCmds era))
 pGovernanceActionNewCommitteeCmd era = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "create-new-committee"
     $ Opt.info
@@ -116,7 +116,7 @@ pGovernanceActionNoConfidenceCmd
   :: CardanoEra era
   -> Maybe (Parser (GovernanceActionCmds era))
 pGovernanceActionNoConfidenceCmd era = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "create-no-confidence"
     $ Opt.info
@@ -145,7 +145,7 @@ pGovernanceActionProtocolParametersUpdateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceActionCmds era))
 pGovernanceActionProtocolParametersUpdateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "create-protocol-parameters-update"
     $ Opt.info
@@ -280,7 +280,7 @@ dpGovActionProtocolParametersUpdate = \case
 
 pGovernanceActionTreasuryWithdrawalCmd :: CardanoEra era -> Maybe (Parser (GovernanceActionCmds era))
 pGovernanceActionTreasuryWithdrawalCmd era = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "create-treasury-withdrawal"
     $ Opt.info
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Committee.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Committee.hs
index 8ab2f8212a..71d91c1c76 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Committee.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Committee.hs
@@ -33,7 +33,7 @@ pGovernanceCommitteeKeyGenColdCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceCommitteeCmds era))
 pGovernanceCommitteeKeyGenColdCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "key-gen-cold"
     $ Opt.info (pCmd w)
@@ -54,7 +54,7 @@ pGovernanceCommitteeKeyGenHotCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceCommitteeCmds era))
 pGovernanceCommitteeKeyGenHotCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "key-gen-hot"
     $ Opt.info (pCmd w)
@@ -75,7 +75,7 @@ pGovernanceCommitteeKeyHashCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceCommitteeCmds era))
 pGovernanceCommitteeKeyHashCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "key-hash"
     $ Opt.info
@@ -91,7 +91,7 @@ pGovernanceCommitteeCreateHotKeyAuthorizationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceCommitteeCmds era))
 pGovernanceCommitteeCreateHotKeyAuthorizationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "create-hot-key-authorization-certificate"
     $ Opt.info
@@ -109,7 +109,7 @@ pGovernanceCommitteeCreateColdKeyResignationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceCommitteeCmds era))
 pGovernanceCommitteeCreateColdKeyResignationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "create-cold-key-resignation-certificate"
     $ Opt.info
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/DRep.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/DRep.hs
index f238e5732a..98df4e65ea 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/DRep.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/DRep.hs
@@ -42,7 +42,7 @@ pGovernanceDRepKeyGenCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceDRepCmds era))
 pGovernanceDRepKeyGenCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "key-gen"
     $ Opt.info
@@ -56,7 +56,7 @@ pGovernanceDRepKeyIdCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceDRepCmds era))
 pGovernanceDRepKeyIdCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "id"
     $ Opt.info
@@ -85,7 +85,7 @@ pRegistrationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceDRepCmds era))
 pRegistrationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "registration-certificate"
     $ Opt.info (mkParser w)
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Query.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Query.hs
index 941b3397cb..d47eb8e0c0 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Query.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Query.hs
@@ -33,7 +33,7 @@ pGovernanceQueryGetConstitutionCmd :: ()
   -> EnvCli
   -> Maybe (Parser (GovernanceQueryCmds era))
 pGovernanceQueryGetConstitutionCmd era env = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "constitution"
     $ Opt.info (GovernanceQueryConstitutionCmd cOn <$> pNoArgQueryCmd env)
@@ -44,7 +44,7 @@ pGovernanceQueryGetGovStateCmd :: ()
   -> EnvCli
   -> Maybe (Parser (GovernanceQueryCmds era))
 pGovernanceQueryGetGovStateCmd era env = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "gov-state"
     $ Opt.info (GovernanceQueryGovStateCmd cOn <$> pNoArgQueryCmd env)
@@ -60,7 +60,7 @@ pGovernanceQueryDRepStateCmd :: ()
   -> EnvCli
   -> Maybe (Parser (GovernanceQueryCmds era))
 pGovernanceQueryDRepStateCmd era env = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "drep-state"
     $ Opt.info (GovernanceQueryDRepStateCmd cOn <$> pDRepStateQueryCmd)
@@ -79,7 +79,7 @@ pGovernanceQueryDRepStakeDistributionCmd :: ()
   -> EnvCli
   -> Maybe (Parser (GovernanceQueryCmds era))
 pGovernanceQueryDRepStakeDistributionCmd era env = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "drep-stake-distribution"
     $ Opt.info (GovernanceQueryDRepStakeDistributionCmd cOn <$> pDRepStakeDistributionQueryCmd)
@@ -98,7 +98,7 @@ pGovernanceQueryGetCommitteeStateCmd :: ()
   -> EnvCli
   -> Maybe (Parser (GovernanceQueryCmds era))
 pGovernanceQueryGetCommitteeStateCmd era env = do
-  cOn <- maybeEonInEra era
+  cOn <- forEraMaybeEon era
   pure
     $ subParser "committee-state"
     $ Opt.info (GovernanceQueryCommitteeStateCmd cOn <$> pNoArgQueryCmd env)
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Vote.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Vote.hs
index a3c8b54658..4c286afbb4 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Vote.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/Governance/Vote.hs
@@ -32,7 +32,7 @@ pGovernanceVoteCreateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (GovernanceVoteCmds era))
 pGovernanceVoteCreateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "create"
     $ Opt.info
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/StakeAddress.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/StakeAddress.hs
index 309a243029..be0d1a6ec3 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/StakeAddress.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/StakeAddress.hs
@@ -39,7 +39,7 @@ pStakeAddressKeyGenCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressKeyGenCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "key-gen"
     $ Opt.info
@@ -54,7 +54,7 @@ pStakeAddressKeyHashCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressKeyHashCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "key-hash"
     $ Opt.info
@@ -69,7 +69,7 @@ pStakeAddressBuildCmd :: ()
   -> EnvCli
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressBuildCmd era envCli = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "build"
     $ Opt.info
@@ -84,7 +84,7 @@ pStakeAddressRegistrationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressRegistrationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "registration-certificate"
     $ Opt.info
@@ -99,7 +99,7 @@ pStakeAddressDeregistrationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressDeregistrationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "deregistration-certificate"
     $ Opt.info
@@ -114,7 +114,7 @@ pStakeAddressStakeDelegationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressStakeDelegationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "stake-delegation-certificate"
     $ Opt.info
@@ -133,7 +133,7 @@ pStakeAddressStakeAndVoteDelegationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressStakeAndVoteDelegationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "stake-and-vote-delegation-certificate"
     $ Opt.info
@@ -153,7 +153,7 @@ pStakeAddressVoteDelegationCertificateCmd :: ()
   => CardanoEra era
   -> Maybe (Parser (StakeAddressCmds era))
 pStakeAddressVoteDelegationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "vote-delegation-certificate"
     $ Opt.info
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Options/StakePool.hs b/cardano-cli/src/Cardano/CLI/EraBased/Options/StakePool.hs
index 2a019776ce..7625a641e3 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Options/StakePool.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Options/StakePool.hs
@@ -57,7 +57,7 @@ pStakePoolMetadataHashCmd =
 
 pStakePoolRegistrationCertificateCmd :: CardanoEra era -> EnvCli -> Maybe (Parser (StakePoolCmds era))
 pStakePoolRegistrationCertificateCmd era envCli = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "registration-certificate"
     $ Opt.info
@@ -78,7 +78,7 @@ pStakePoolRegistrationCertificateCmd era envCli = do
 
 pStakePoolDeregistrationCertificateCmd :: CardanoEra era -> Maybe (Parser (StakePoolCmds era))
 pStakePoolDeregistrationCertificateCmd era = do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
   pure
     $ subParser "deregistration-certificate"
     $ Opt.info
diff --git a/cardano-cli/src/Cardano/CLI/EraBased/Run/Transaction.hs b/cardano-cli/src/Cardano/CLI/EraBased/Run/Transaction.hs
index dc6c0b9450..e40774de03 100644
--- a/cardano-cli/src/Cardano/CLI/EraBased/Run/Transaction.hs
+++ b/cardano-cli/src/Cardano/CLI/EraBased/Run/Transaction.hs
@@ -203,17 +203,15 @@ runTxBuildCmd
   let filteredTxinsc = Set.toList $ Set.fromList txinsc
 
   -- We need to construct the txBodycontent outside of runTxBuild
-  BalancedTxBody txBodycontent balancedTxBody _ _ <-
+  BalancedTxBody txBodyContent balancedTxBody _ _ <-
     runTxBuild
       era socketPath consensusModeParams nid mScriptValidity inputsAndMaybeScriptWits readOnlyRefIns filteredTxinsc
       mReturnCollateral mTotCollateral txOuts changeAddr valuesWithScriptWits mLowBound
       mUpperBound certsAndMaybeScriptWits withdrawalsAndMaybeScriptWits
       requiredSigners txAuxScripts txMetadata mProp mOverrideWits votes proposals outputOptions
 
-  mScriptWits <-
-    case cardanoEraStyle era of
-      LegacyByronEra -> return []
-      ShelleyBasedEra sbe -> return $ collectTxBodyScriptWitnesses sbe txBodycontent
+  let mScriptWits =
+        forEraInEon era [] $ \sbe -> collectTxBodyScriptWitnesses sbe txBodyContent
 
   let allReferenceInputs = getAllReferenceInputs
                              inputsAndMaybeScriptWits
@@ -230,7 +228,7 @@ runTxBuildCmd
   -- the script cost vs having to build the tx body each time
   case outputOptions of
     OutputScriptCostOnly fp -> do
-      let BuildTxWith mTxProtocolParams = txProtocolParams txBodycontent
+      let BuildTxWith mTxProtocolParams = txProtocolParams txBodyContent
 
       pparams <- pure mTxProtocolParams & onNothing (left TxCmdProtocolParametersNotPresentInTxBody)
       executionUnitPrices <- pure (getExecutionUnitPrices era pparams) & onNothing (left TxCmdPParamExecutionUnitsNotAvailable)
@@ -595,8 +593,8 @@ runTxBuild
               , txUpdateProposal = validatedTxUpProp
               , txMintValue = validatedMintValue
               , txScriptValidity = validatedTxScriptValidity
-              , txProposalProcedures = inEraEonMaybe era (`Featured` validatedTxProposalProcedures)
-              , txVotingProcedures = inEraEonMaybe era (`Featured` validatedTxVotes)
+              , txProposalProcedures = forEraInEonMaybe era (`Featured` validatedTxProposalProcedures)
+              , txVotingProcedures = forEraInEonMaybe era (`Featured` validatedTxVotes)
               }
 
       firstExceptT TxCmdTxInsDoNotExist
@@ -661,21 +659,20 @@ validateTxInsCollateral :: CardanoEra era
                         -> [TxIn]
                         -> Either TxCmdError (TxInsCollateral era)
 validateTxInsCollateral _   []    = return TxInsCollateralNone
-validateTxInsCollateral era txins =
-    case collateralSupportedInEra era of
-      Nothing -> txFeatureMismatchPure era TxFeatureCollateral
-      Just supported -> return (TxInsCollateral supported txins)
+validateTxInsCollateral era txins = do
+  supported <- forEraMaybeEon era
+    & maybe (txFeatureMismatchPure era TxFeatureCollateral) Right
+  pure $ TxInsCollateral supported txins
 
 validateTxInsReference
   :: CardanoEra era
   -> [TxIn]
   -> Either TxCmdError (TxInsReference BuildTx era)
 validateTxInsReference _ []  = return TxInsReferenceNone
-validateTxInsReference era allRefIns =
-  caseByronToAlonzoOrBabbageEraOnwards
-    (const $ txFeatureMismatchPure era TxFeatureReferenceInputs)
-    (\w -> return $ TxInsReference w allRefIns)
-    era
+validateTxInsReference era allRefIns = do
+  supported <- forEraMaybeEon era
+    & maybe (txFeatureMismatchPure era TxFeatureReferenceInputs) Right
+  pure $ TxInsReference supported allRefIns
 
 getAllReferenceInputs
  :: [(TxIn, Maybe (ScriptWitness WitCtxTxIn era))]
@@ -733,24 +730,6 @@ toTxOutValueInAnyEra era val =
     (\w -> return (TxOutValue w val))
     era
 
--- TODO move this to cardano-api
-caseAlonzoOnlyOrBabbageEraOnwards :: ()
-  => (AlonzoEraOnly era -> a)
-  -> (BabbageEraOnwards era -> a)
-  -> AlonzoEraOnwards era
-  -> a
-caseAlonzoOnlyOrBabbageEraOnwards l r = \case
-  AlonzoEraOnwardsAlonzo -> l AlonzoEraOnlyAlonzo
-  AlonzoEraOnwardsBabbage -> r BabbageEraOnwardsBabbage
-  AlonzoEraOnwardsConway  -> r BabbageEraOnwardsConway
-
--- TODO move this to cardano-api
-alonzoEraOnlyToAlonzoEraOnwards :: ()
-  => AlonzoEraOnly era
-  -> AlonzoEraOnwards era
-alonzoEraOnlyToAlonzoEraOnwards = \case
-  AlonzoEraOnlyAlonzo -> AlonzoEraOnwardsAlonzo
-
 toTxOutInAnyEra :: CardanoEra era
                 -> TxOutAnyEra
                 -> ExceptT TxCmdError IO (TxOut CtxTx era)
diff --git a/cardano-cli/src/Cardano/CLI/Json/Friendly.hs b/cardano-cli/src/Cardano/CLI/Json/Friendly.hs
index 4036bb1084..e2f316119a 100644
--- a/cardano-cli/src/Cardano/CLI/Json/Friendly.hs
+++ b/cardano-cli/src/Cardano/CLI/Json/Friendly.hs
@@ -128,7 +128,7 @@ pattern ShelleyTtl
   :: SlotNo -> (TxValidityLowerBound era, TxValidityUpperBound era)
 pattern ShelleyTtl ttl <-
   ( TxValidityNoLowerBound
-  , TxValidityUpperBound ValidityUpperBoundInShelleyEra ttl
+  , TxValidityUpperBound _ ttl
   )
 
 friendlyValidityRange
@@ -151,8 +151,8 @@ friendlyValidityRange era = \case
           ]
     | otherwise -> Null
  where
-  isLowerBoundSupported = isJust $ validityLowerBoundSupportedInEra era
-  isUpperBoundSupported = isJust $ validityUpperBoundSupportedInEra era
+  isLowerBoundSupported = isJust $ inEonForEraMaybe TxValidityLowerBound era
+  isUpperBoundSupported = isJust $ inEonForEraMaybe TxValidityUpperBound era
 
 friendlyWithdrawals :: TxWithdrawals ViewTx era -> Aeson.Value
 friendlyWithdrawals TxWithdrawalsNone = Null
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Commands/Governance.hs b/cardano-cli/src/Cardano/CLI/Legacy/Commands/Governance.hs
index f992246456..de02b24a27 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Commands/Governance.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Commands/Governance.hs
@@ -14,18 +14,18 @@ import           Data.Text (Text)
 
 data LegacyGovernanceCmds
   = GovernanceMIRPayStakeAddressesCertificate
-      AnyShelleyToBabbageEra
+      (AnyEraInEon ShelleyToBabbageEra)
       MIRPot
       [StakeAddress]
       [Lovelace]
       (File () Out)
   | GovernanceMIRTransfer
-      AnyShelleyToBabbageEra
+      (AnyEraInEon ShelleyToBabbageEra)
       Lovelace
       (File () Out)
       TransferDirection
   | GovernanceGenesisKeyDelegationCertificate
-      AnyShelleyBasedEra
+      (AnyEraInEon ShelleyBasedEra)
       (VerificationKeyOrHashOrFile GenesisKey)
       (VerificationKeyOrHashOrFile GenesisDelegateKey)
       (VerificationKeyOrHashOrFile VrfKey)
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakeAddress.hs b/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakeAddress.hs
index 00d33d86be..f5b665f3bc 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakeAddress.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakeAddress.hs
@@ -29,17 +29,17 @@ data LegacyStakeAddressCmds
       NetworkId
       (Maybe (File () Out))
   | StakeAddressRegistrationCertificateCmd
-      AnyShelleyBasedEra
+      (AnyEraInEon ShelleyBasedEra)
       StakeIdentifier
       (Maybe Lovelace)
       (File () Out)
   | StakeAddressDelegationCertificateCmd
-      AnyShelleyBasedEra
+      (AnyEraInEon ShelleyBasedEra)
       StakeIdentifier
       (VerificationKeyOrHashOrFile StakePoolKey)
       (File () Out)
   | StakeAddressDeregistrationCertificateCmd
-      AnyShelleyBasedEra
+      (AnyEraInEon ShelleyBasedEra)
       StakeIdentifier
       (Maybe Lovelace)
       (File () Out)
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakePool.hs b/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakePool.hs
index 9824f098cb..453176cef4 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakePool.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Commands/StakePool.hs
@@ -17,7 +17,7 @@ import           Data.Text (Text)
 
 data LegacyStakePoolCmds
   = StakePoolDeregistrationCertificateCmd
-      AnyShelleyBasedEra
+      (AnyEraInEon ShelleyBasedEra)
       -- ^ Era in which to retire the stake pool.
       (VerificationKeyOrFile StakePoolKey)
       -- ^ Stake pool verification key.
@@ -32,7 +32,7 @@ data LegacyStakePoolCmds
       (StakePoolMetadataFile In)
       (Maybe (File () Out))
   | StakePoolRegistrationCertificateCmd
-      AnyShelleyBasedEra
+      (AnyEraInEon ShelleyBasedEra)
       -- ^ Era in which to register the stake pool.
       (VerificationKeyOrFile StakePoolKey)
       -- ^ Stake pool verification key.
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Options.hs b/cardano-cli/src/Cardano/CLI/Legacy/Options.hs
index f27e4d78fa..5ea8b4df51 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Options.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Options.hs
@@ -1463,5 +1463,6 @@ pLegacyCardanoEra envCli =
     , pure $ pure defaultCardanoEra
   ]
     where
-      defaultCardanoEra = defaultShelleyBasedEra & \(AnyShelleyBasedEra era) ->
-        AnyCardanoEra (shelleyBasedToCardanoEra era)
+      defaultCardanoEra = defaultShelleyBasedEra & \(AnyEraInEon era) ->
+        let cera = toCardanoEra era
+         in cardanoEraConstraints cera (AnyCardanoEra cera)
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Run/Governance.hs b/cardano-cli/src/Cardano/CLI/Legacy/Run/Governance.hs
index 7e4f1e05a7..21e896cf31 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Run/Governance.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Run/Governance.hs
@@ -56,32 +56,32 @@ runLegacyGovernanceCmds = \case
     runLegacyGovernanceVerifyPoll poll metadata mOutFile
 
 runLegacyGovernanceMIRCertificatePayStakeAddrs
-  :: AnyShelleyToBabbageEra
+  :: AnyEraInEon ShelleyToBabbageEra
   -> Ledger.MIRPot
   -> [StakeAddress] -- ^ Stake addresses
   -> [Lovelace]     -- ^ Corresponding reward amounts (same length)
   -> File () Out
   -> ExceptT GovernanceCmdError IO ()
-runLegacyGovernanceMIRCertificatePayStakeAddrs (AnyShelleyToBabbageEra w) =
+runLegacyGovernanceMIRCertificatePayStakeAddrs (AnyEraInEon w) =
   runGovernanceMIRCertificatePayStakeAddrs w
 
 runLegacyGovernanceMIRCertificateTransfer
-  :: AnyShelleyToBabbageEra
+  :: AnyEraInEon ShelleyToBabbageEra
   -> Lovelace
   -> File () Out
   -> TransferDirection
   -> ExceptT GovernanceCmdError IO ()
-runLegacyGovernanceMIRCertificateTransfer (AnyShelleyToBabbageEra w) =
+runLegacyGovernanceMIRCertificateTransfer (AnyEraInEon w) =
   runGovernanceMIRCertificateTransfer w
 
 runLegacyGovernanceGenesisKeyDelegationCertificate
-  :: AnyShelleyBasedEra
+  :: AnyEraInEon ShelleyBasedEra
   -> VerificationKeyOrHashOrFile GenesisKey
   -> VerificationKeyOrHashOrFile GenesisDelegateKey
   -> VerificationKeyOrHashOrFile VrfKey
   -> File () Out
   -> ExceptT GovernanceCmdError IO ()
-runLegacyGovernanceGenesisKeyDelegationCertificate (AnyShelleyBasedEra sbe)
+runLegacyGovernanceGenesisKeyDelegationCertificate (AnyEraInEon sbe)
                                              genVkOrHashOrFp
                                              genDelVkOrHashOrFp
                                              vrfVkOrHashOrFp
@@ -102,6 +102,7 @@ runLegacyGovernanceGenesisKeyDelegationCertificate (AnyShelleyBasedEra sbe)
   firstExceptT GovernanceCmdTextEnvWriteError
     . newExceptT
     $ writeLazyByteStringFile oFp
+    $ shelleyBasedEraConstraints sbe
     $ textEnvelopeToJSON (Just genKeyDelegCertDesc) genKeyDelegCert
   where
     genKeyDelegCertDesc :: TextEnvelopeDescr
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Run/StakeAddress.hs b/cardano-cli/src/Cardano/CLI/Legacy/Run/StakeAddress.hs
index c537e57ee2..a1e06d244c 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Run/StakeAddress.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Run/StakeAddress.hs
@@ -57,16 +57,16 @@ runLegacyStakeAddressBuildCmd =
   runStakeAddressBuildCmd
 
 runLegacyStakeAddressRegistrationCertificateCmd :: ()
-  => AnyShelleyBasedEra
+  => AnyEraInEon ShelleyBasedEra
   -> StakeIdentifier
   -> Maybe Lovelace -- ^ Deposit required in conway era
   -> File () Out
   -> ExceptT StakeAddressCmdError IO ()
-runLegacyStakeAddressRegistrationCertificateCmd (AnyShelleyBasedEra sbe) =
+runLegacyStakeAddressRegistrationCertificateCmd (AnyEraInEon sbe) =
   runStakeAddressRegistrationCertificateCmd sbe
 
 runLegacyStakeAddresslDelegationCertificateCmd :: ()
-  => AnyShelleyBasedEra
+  => AnyEraInEon ShelleyBasedEra
   -> StakeIdentifier
   -- ^ Delegator stake verification key, verification key file or script file.
   -> VerificationKeyOrHashOrFile StakePoolKey
@@ -74,14 +74,14 @@ runLegacyStakeAddresslDelegationCertificateCmd :: ()
   -- verification key hash.
   -> File () Out
   -> ExceptT StakeAddressCmdError IO ()
-runLegacyStakeAddresslDelegationCertificateCmd (AnyShelleyBasedEra sbe) =
+runLegacyStakeAddresslDelegationCertificateCmd (AnyEraInEon sbe) =
   runStakeAddressStakeDelegationCertificateCmd sbe
 
 runLegacyStakeAddressDeregistrationCertificateCmd :: ()
-  => AnyShelleyBasedEra
+  => AnyEraInEon ShelleyBasedEra
   -> StakeIdentifier
   -> Maybe Lovelace -- ^ Deposit required in conway era
   -> File () Out
   -> ExceptT StakeAddressCmdError IO ()
-runLegacyStakeAddressDeregistrationCertificateCmd (AnyShelleyBasedEra sbe) =
+runLegacyStakeAddressDeregistrationCertificateCmd (AnyEraInEon sbe) =
   runStakeAddressDeregistrationCertificateCmd sbe
diff --git a/cardano-cli/src/Cardano/CLI/Legacy/Run/StakePool.hs b/cardano-cli/src/Cardano/CLI/Legacy/Run/StakePool.hs
index 61044cdf3f..841113972a 100644
--- a/cardano-cli/src/Cardano/CLI/Legacy/Run/StakePool.hs
+++ b/cardano-cli/src/Cardano/CLI/Legacy/Run/StakePool.hs
@@ -35,7 +35,7 @@ runLegacyStakePoolCmds = \case
 -- TODO: Metadata and more stake pool relay support to be
 -- added in the future.
 runLegacyStakePoolRegistrationCertificateCmd :: ()
-  => AnyShelleyBasedEra
+  => AnyEraInEon ShelleyBasedEra
   -> VerificationKeyOrFile StakePoolKey
   -- ^ Stake pool verification key.
   -> VerificationKeyOrFile VrfKey
@@ -58,17 +58,17 @@ runLegacyStakePoolRegistrationCertificateCmd :: ()
   -> File () Out
   -> ExceptT StakePoolCmdError IO ()
 runLegacyStakePoolRegistrationCertificateCmd = \case
-  AnyShelleyBasedEra sbe ->
+  AnyEraInEon sbe ->
     runStakePoolRegistrationCertificateCmd sbe
 
 runLegacyStakePoolDeregistrationCertificateCmd :: ()
-  => AnyShelleyBasedEra
+  => AnyEraInEon ShelleyBasedEra
   -> VerificationKeyOrFile StakePoolKey
   -> Shelley.EpochNo
   -> File () Out
   -> ExceptT StakePoolCmdError IO ()
 runLegacyStakePoolDeregistrationCertificateCmd = \case
-  AnyShelleyBasedEra sbe ->
+  AnyEraInEon sbe ->
     runStakePoolRetirementCertificateCmd sbe
 
 runLegacyStakePoolIdCmd :: ()
diff --git a/cardano-cli/src/Cardano/CLI/Read.hs b/cardano-cli/src/Cardano/CLI/Read.hs
index 65e186e8ed..ca5491fc8f 100644
--- a/cardano-cli/src/Cardano/CLI/Read.hs
+++ b/cardano-cli/src/Cardano/CLI/Read.hs
@@ -176,7 +176,7 @@ readTxMetadata :: CardanoEra era
                -> IO (Either MetadataError (TxMetadataInEra era))
 readTxMetadata _ _ [] = return $ Right TxMetadataNone
 readTxMetadata era schema files = cardanoEraConstraints era $ runExceptT $ do
-  supported <- maybeEonInEra era
+  supported <- forEraMaybeEon era
     & hoistMaybe (MetadataErrorNotAvailableInEra $ AnyCardanoEra era)
   metadata  <- mapM (readFileTxMetadata schema) files
   pure $ TxMetadataInEra supported $ mconcat metadata
@@ -796,7 +796,7 @@ readTxGovernanceActions
   -> IO (Either ConstitutionError [Proposal era])
 readTxGovernanceActions _ [] = return $ Right []
 readTxGovernanceActions era files = runExceptT $ do
-  w <- maybeEonInEra era
+  w <- forEraMaybeEon era
     & hoistMaybe (ConstitutionNotSupportedInEra $ cardanoEraConstraints era $ AnyCardanoEra era)
   newExceptT $ sequence <$> mapM (readProposal w) files
 
diff --git a/cardano-cli/src/Cardano/CLI/Types/Errors/StakeAddressDelegationError.hs b/cardano-cli/src/Cardano/CLI/Types/Errors/StakeAddressDelegationError.hs
index 8de937f6b0..cc5ab81f7e 100644
--- a/cardano-cli/src/Cardano/CLI/Types/Errors/StakeAddressDelegationError.hs
+++ b/cardano-cli/src/Cardano/CLI/Types/Errors/StakeAddressDelegationError.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeApplications #-}
 
 module Cardano.CLI.Types.Errors.StakeAddressDelegationError
   ( StakeAddressDelegationError(..)
@@ -10,12 +9,11 @@ import           Cardano.Api
 
 import qualified Data.Text as Text
 
-newtype StakeAddressDelegationError = VoteDelegationNotSupported AnyShelleyToBabbageEra deriving Show
+newtype StakeAddressDelegationError = VoteDelegationNotSupported (AnyEraInEon ShelleyToBabbageEra) deriving Show
 
 instance Error StakeAddressDelegationError where
   displayError = \case
-    VoteDelegationNotSupported (AnyShelleyToBabbageEra stbe) -> "Vote delegation not supported in " <> eraTxt stbe <> " era."
+    VoteDelegationNotSupported (AnyEraInEon eraInEon) -> "Vote delegation not supported in " <> eraTxt <> " era."
       where
-        eraTxt :: forall era. ShelleyToBabbageEra era -> String
-        eraTxt stbe' = shelleyToBabbageEraConstraints stbe' $
-          Text.unpack . renderEra $ AnyCardanoEra (cardanoEra @era)
+        cEra = toCardanoEra eraInEon
+        eraTxt = cardanoEraConstraints cEra $ Text.unpack . renderEra $ AnyCardanoEra cEra
diff --git a/cardano-cli/src/Cardano/CLI/Types/Errors/TxValidationError.hs b/cardano-cli/src/Cardano/CLI/Types/Errors/TxValidationError.hs
index 068a634b45..952870dfe9 100644
--- a/cardano-cli/src/Cardano/CLI/Types/Errors/TxValidationError.hs
+++ b/cardano-cli/src/Cardano/CLI/Types/Errors/TxValidationError.hs
@@ -6,6 +6,7 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
 
 module Cardano.CLI.Types.Errors.TxValidationError
   ( TxAuxScriptsValidationError(..)
@@ -41,7 +42,6 @@ import           Cardano.Api.Shelley
 import           Prelude
 
 import           Data.Bifunctor (first)
-import           Data.Function
 import qualified Data.Map.Strict as Map
 import           Data.Maybe
 import qualified Data.Text as Text
@@ -104,12 +104,9 @@ validateTxTotalCollateral :: CardanoEra era
                           -> Maybe Lovelace
                           -> Either TxTotalCollateralValidationError (TxTotalCollateral era)
 validateTxTotalCollateral _ Nothing = return TxTotalCollateralNone
-validateTxTotalCollateral era (Just coll) =
-  case totalAndReturnCollateralSupportedInEra era of
-    Just supp -> return $ TxTotalCollateral supp coll
-    Nothing -> Left $ TxTotalCollateralNotSupported
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
+validateTxTotalCollateral era (Just coll) = do
+  supported <- conjureWitness era TxTotalCollateralNotSupported
+  pure $ TxTotalCollateral supported coll
 
 newtype TxReturnCollateralValidationError
   = TxReturnCollateralNotSupported AnyCardanoEra
@@ -124,11 +121,8 @@ validateTxReturnCollateral :: CardanoEra era
                            -> Either TxReturnCollateralValidationError (TxReturnCollateral CtxTx era)
 validateTxReturnCollateral _ Nothing = return TxReturnCollateralNone
 validateTxReturnCollateral era (Just retColTxOut) = do
-  case totalAndReturnCollateralSupportedInEra era of
-    Just supp -> return $ TxReturnCollateral supp retColTxOut
-    Nothing -> Left $ TxReturnCollateralNotSupported
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
+  supported <- conjureWitness era TxReturnCollateralNotSupported
+  pure $ TxReturnCollateral supported retColTxOut
 
 newtype TxValidityLowerBoundValidationError
   = TxValidityLowerBoundNotSupported AnyCardanoEra
@@ -143,12 +137,9 @@ validateTxValidityLowerBound :: CardanoEra era
                              -> Maybe SlotNo
                              -> Either TxValidityLowerBoundValidationError (TxValidityLowerBound era)
 validateTxValidityLowerBound _ Nothing = return TxValidityNoLowerBound
-validateTxValidityLowerBound era (Just slot) =
-    case validityLowerBoundSupportedInEra era of
-      Nothing -> Left $ TxValidityLowerBoundNotSupported
-                      $ cardanoEraConstraints era
-                      $ AnyCardanoEra era
-      Just supported -> return (TxValidityLowerBound supported slot)
+validateTxValidityLowerBound era (Just slot) = do
+  supported <- conjureWitness era TxValidityLowerBoundNotSupported
+  pure $ TxValidityLowerBound supported slot
 
 newtype TxValidityUpperBoundValidationError
   = TxValidityUpperBoundNotSupported AnyCardanoEra
@@ -162,18 +153,13 @@ validateTxValidityUpperBound
   :: CardanoEra era
   -> Maybe SlotNo
   -> Either TxValidityUpperBoundValidationError (TxValidityUpperBound era)
-validateTxValidityUpperBound era Nothing =
-  case validityNoUpperBoundSupportedInEra era of
-    Nothing -> Left $ TxValidityUpperBoundNotSupported
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
-    Just supported -> return (TxValidityNoUpperBound supported)
-validateTxValidityUpperBound era (Just slot) =
-  case validityUpperBoundSupportedInEra era of
-    Nothing -> Left $ TxValidityUpperBoundNotSupported
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
-    Just supported -> return (TxValidityUpperBound supported slot)
+validateTxValidityUpperBound era = \case
+  Just slot -> do
+    supported <- conjureWitness era TxValidityUpperBoundNotSupported
+    pure $ TxValidityUpperBound supported slot
+  Nothing -> do
+    supported <- conjureWitness era TxValidityUpperBoundNotSupported
+    pure $ TxValidityNoUpperBound supported
 
 data TxAuxScriptsValidationError
   = TxAuxScriptsNotSupportedInEra AnyCardanoEra
@@ -191,14 +177,10 @@ validateTxAuxScripts
   -> [ScriptInAnyLang]
   -> Either TxAuxScriptsValidationError (TxAuxScripts era)
 validateTxAuxScripts _ [] = return TxAuxScriptsNone
-validateTxAuxScripts era scripts =
-  case auxScriptsSupportedInEra era of
-    Nothing -> Left $ TxAuxScriptsNotSupportedInEra
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
-    Just supported -> do
-      scriptsInEra <- mapM (first TxAuxScriptsLanguageError . validateScriptSupportedInEra era) scripts
-      return $ TxAuxScripts supported scriptsInEra
+validateTxAuxScripts era scripts = do
+  supported <- conjureWitness era TxAuxScriptsNotSupportedInEra
+  scriptsInEra <- mapM (first TxAuxScriptsLanguageError . validateScriptSupportedInEra era) scripts
+  pure $ TxAuxScripts supported scriptsInEra
 
 newtype TxRequiredSignersValidationError
   = TxRequiredSignersValidationError AnyCardanoEra
@@ -213,12 +195,9 @@ validateRequiredSigners
   -> [Hash PaymentKey]
   -> Either TxRequiredSignersValidationError (TxExtraKeyWitnesses era)
 validateRequiredSigners _ [] = return TxExtraKeyWitnessesNone
-validateRequiredSigners era reqSigs =
-  case extraKeyWitnessesSupportedInEra era of
-    Nothing -> Left $ TxRequiredSignersValidationError
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
-    Just supported -> return $ TxExtraKeyWitnesses supported reqSigs
+validateRequiredSigners era reqSigs = do
+  supported <- conjureWitness era TxRequiredSignersValidationError
+  pure $ TxExtraKeyWitnesses supported reqSigs
 
 newtype TxWithdrawalsValidationError
   = TxWithdrawalsNotSupported AnyCardanoEra
@@ -235,8 +214,7 @@ validateTxWithdrawals
   -> Either TxWithdrawalsValidationError (TxWithdrawals BuildTx era)
 validateTxWithdrawals _ [] = return TxWithdrawalsNone
 validateTxWithdrawals era withdrawals = do
-  supported <- maybeEonInEra era
-    & maybe (cardanoEraConstraints era $ Left . TxWithdrawalsNotSupported $ AnyCardanoEra era) Right
+  supported <- conjureWitness era TxWithdrawalsNotSupported
   let convWithdrawals = map convert withdrawals
   pure $ TxWithdrawals supported convWithdrawals
  where
@@ -264,8 +242,7 @@ validateTxCertificates
   -> Either TxCertificatesValidationError (TxCertificates BuildTx era)
 validateTxCertificates _ [] = return TxCertificatesNone
 validateTxCertificates era certsAndScriptWitnesses = cardanoEraConstraints era $ do
-  supported <- maybeEonInEra era
-    & maybe (Left . TxCertificatesValidationNotSupported $ AnyCardanoEra era) Right
+  supported <- conjureWitness era TxCertificatesValidationNotSupported
   let certs = map fst certsAndScriptWitnesses
       reqWits = Map.fromList $ mapMaybe convert certsAndScriptWitnesses
   pure $ TxCertificates supported certs $ BuildTxWith reqWits
@@ -308,12 +285,9 @@ validateProtocolParameters
   -> Maybe (LedgerProtocolParameters era)
   -> Either TxProtocolParametersValidationError (BuildTxWith BuildTx (Maybe (LedgerProtocolParameters era)))
 validateProtocolParameters _ Nothing = return (BuildTxWith Nothing)
-validateProtocolParameters era (Just pparams) =
-    case cardanoEraStyle era of
-      LegacyByronEra -> Left $ ProtocolParametersNotSupported
-                      $ cardanoEraConstraints era
-                      $ AnyCardanoEra era
-      ShelleyBasedEra _  -> return . BuildTxWith $ Just pparams
+validateProtocolParameters era (Just pparams) = do
+  _ <- conjureWitness @ShelleyBasedEra era ProtocolParametersNotSupported
+  pure . BuildTxWith $ Just pparams
 
 newtype TxUpdateProposalValidationError
   = TxUpdateProposalNotSupported AnyCardanoEra
@@ -329,8 +303,7 @@ validateTxUpdateProposal
   -> Either TxUpdateProposalValidationError (TxUpdateProposal era)
 validateTxUpdateProposal _ Nothing = return TxUpdateProposalNone
 validateTxUpdateProposal era (Just prop) = do
-  supported <- maybeEonInEra era
-    & maybe (cardanoEraConstraints era $ Left . TxUpdateProposalNotSupported $ AnyCardanoEra era) Right
+  supported <- conjureWitness era TxUpdateProposalNotSupported
   pure $ TxUpdateProposal supported prop
 
 newtype TxScriptValidityValidationError
@@ -346,9 +319,15 @@ validateTxScriptValidity
   -> Maybe ScriptValidity
   -> Either TxScriptValidityValidationError (TxScriptValidity era)
 validateTxScriptValidity _ Nothing = pure TxScriptValidityNone
-validateTxScriptValidity era (Just scriptValidity) =
-  case txScriptValiditySupportedInCardanoEra era of
-    Nothing -> Left $ ScriptValidityNotSupported
-                    $ cardanoEraConstraints era
-                    $ AnyCardanoEra era
-    Just supported -> pure $ TxScriptValidity supported scriptValidity
+validateTxScriptValidity era (Just scriptValidity) = do
+  supported <- conjureWitness era ScriptValidityNotSupported
+  pure $ TxScriptValidity supported scriptValidity
+
+
+conjureWitness :: Eon eon
+               => CardanoEra era -- ^ era to try to conjure eon from
+               -> (AnyCardanoEra -> e)  -- ^ error wrapper function
+               -> Either e (eon era) -- ^ eon if it includes the era, an error otherwise
+conjureWitness era errF =
+  maybe (cardanoEraConstraints era $ Left . errF $ AnyCardanoEra era) Right $
+    forEraMaybeEon era