diff --git a/postgrest.cabal b/postgrest.cabal
index fd5f3ec28..1f7b716c7 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -66,6 +66,7 @@ library
                       PostgREST.SchemaCache.Representations
                       PostgREST.SchemaCache.Table
                       PostgREST.Error
+                      PostgREST.Error.Types
                       PostgREST.Listener
                       PostgREST.Logger
                       PostgREST.MainTx
diff --git a/src/PostgREST/Error.hs b/src/PostgREST/Error.hs
index 57ba2b4b4..5890e4889 100644
--- a/src/PostgREST/Error.hs
+++ b/src/PostgREST/Error.hs
@@ -51,6 +51,9 @@ import PostgREST.SchemaCache.Relationship (Cardinality (..),
                                            RelationshipsMap)
 import PostgREST.SchemaCache.Routine      (Routine (..),
                                            RoutineParam (..))
+
+import PostgREST.Error.Types
+
 import Protolude
 
 class (ErrorBody a, JSON.ToJSON a) => PgrstError a where
@@ -75,48 +78,6 @@ class ErrorBody a where
   details :: a -> Maybe JSON.Value
   hint    :: a -> Maybe JSON.Value
 
-data ApiRequestError
-  = AggregatesNotAllowed
-  | MediaTypeError [ByteString]
-  | InvalidBody ByteString
-  | InvalidFilters
-  | InvalidPreferences [ByteString]
-  | InvalidRange RangeError
-  | InvalidRpcMethod ByteString
-  | NotEmbedded Text
-  | NotImplemented Text
-  | PutLimitNotAllowedError
-  | QueryParamError QPError
-  | RelatedOrderNotToOne Text Text
-  | UnacceptableFilter Text
-  | UnacceptableSchema Text [Text]
-  | UnsupportedMethod ByteString
-  | GucHeadersError
-  | GucStatusError
-  | PutMatchingPkError
-  | SingularityError Integer
-  | PGRSTParseError RaiseError
-  | MaxAffectedViolationError Integer
-  | InvalidResourcePath
-  | OpenAPIDisabled
-  | MaxAffectedRpcViolation
-  deriving Show
-
-data QPError = QPError Text Text
-  deriving Show
-
-data RaiseError
-  = MsgParseError ByteString
-  | DetParseError ByteString
-  | NoDetail
-  deriving Show
-
-data RangeError
-  = NegativeLimit
-  | LowerGTUpper
-  | OutOfBounds Text Text
-  deriving Show
-
 instance PgrstError ApiRequestError where
   status AggregatesNotAllowed{}      = HTTP.status400
   status MediaTypeError{}            = HTTP.status406
@@ -245,15 +206,6 @@ instance JSON.ToJSON ApiRequestError where
   toJSON err = toJsonPgrstError
     (code err) (message err) (details err) (hint err)
 
-data SchemaCacheError
-  = AmbiguousRelBetween Text Text [Relationship]
-  | AmbiguousRpc [Routine]
-  | NoRelBetween Text Text (Maybe Text) Text RelationshipsMap
-  | NoRpc Text Text [Text] MediaType Bool [QualifiedIdentifier] [Routine]
-  | ColumnNotFound Text Text
-  | TableNotFound Text Text SchemaCache
-  deriving Show
-
 instance PgrstError SchemaCacheError where
   status AmbiguousRelBetween{} = HTTP.status300
   status AmbiguousRpc{}        = HTTP.status300
@@ -486,11 +438,6 @@ pgrstParseErrorHint err = case err of
   MsgParseError _ -> "MESSAGE must be a JSON object with obligatory keys: 'code', 'message' and optional keys: 'details', 'hint'."
   _               -> "DETAIL must be a JSON object with obligatory keys: 'status', 'headers' and optional key: 'status_text'."
 
-data PgError = PgError Authenticated SQL.UsageError
-  deriving Show
-
-type Authenticated = Bool
-
 instance PgrstError PgError where
   status (PgError authed usageError) = pgErrorStatus authed usageError
 
@@ -637,43 +584,6 @@ pgErrorStatus authed (SQL.SessionUsageError (SQL.QueryError _ _ (SQL.ResultError
     _                       -> HTTP.status500
 
 
-data Error
-  = ApiRequestError ApiRequestError
-  | SchemaCacheErr SchemaCacheError
-  | JwtErr JwtError
-  | NoSchemaCacheError
-  | PgErr PgError
-  deriving Show
-
-data JwtError
-  = JwtDecodeErr JwtDecodeError
-  | JwtSecretMissing
-  | JwtTokenRequired
-  | JwtClaimsErr JwtClaimsError
-  deriving Show
-
-data JwtDecodeError
-  = EmptyAuthHeader
-  | UnexpectedParts Int
-  | KeyError Text
-  | BadAlgorithm Text
-  | BadCrypto
-  | UnsupportedTokenType
-  | UnreachableDecodeError
-  deriving Show
-
-data JwtClaimsError
-  = JWTExpired
-  | JWTNotYetValid
-  | JWTIssuedAtFuture
-  | JWTNotInAudience
-  | ParsingClaimsFailed
-  | ExpClaimNotNumber
-  | NbfClaimNotNumber
-  | IatClaimNotNumber
-  | AudClaimNotStringOrArray
-  deriving Show
-
 instance PgrstError Error where
   status (ApiRequestError err) = status err
   status (SchemaCacheErr err)  = status err
@@ -774,18 +684,6 @@ requiredTokenHeader :: Header
 requiredTokenHeader = ("WWW-Authenticate", "Bearer")
 
 -- For parsing byteString to JSON Object, used for allowing full response control
-data PgRaiseErrMessage = PgRaiseErrMessage {
-  getCode    :: Text,
-  getMessage :: Text,
-  getDetails :: Maybe Text,
-  getHint    :: Maybe Text
-}
-
-data PgRaiseErrDetails = PgRaiseErrDetails {
-  getStatus     :: Int,
-  getStatusText :: Maybe Text,
-  getHeaders    :: Map Text Text
-}
 
 instance JSON.FromJSON PgRaiseErrMessage where
   parseJSON (JSON.Object m) =
diff --git a/src/PostgREST/Error/Types.hs b/src/PostgREST/Error/Types.hs
new file mode 100644
index 000000000..ae4e2924f
--- /dev/null
+++ b/src/PostgREST/Error/Types.hs
@@ -0,0 +1,139 @@
+{-|
+Module      : PostgREST.Error.Types
+Description : PostgREST Error Data Types
+-}
+module PostgREST.Error.Types
+  ( ApiRequestError(..)
+  , QPError(..)
+  , RangeError(..)
+  , RaiseError(..)
+  , SchemaCacheError(..)
+  , PgError(..)
+  , Error(..)
+  , JwtError (..)
+  , JwtDecodeError(..)
+  , JwtClaimsError(..)
+  , PgRaiseErrMessage(..)
+  , PgRaiseErrDetails(..)
+  ) where
+
+import qualified Hasql.Pool as SQL
+
+import PostgREST.MediaType                (MediaType (..))
+import PostgREST.SchemaCache              (SchemaCache (..))
+import PostgREST.SchemaCache.Identifiers  (QualifiedIdentifier (..))
+import PostgREST.SchemaCache.Relationship (Relationship (..),
+                                           RelationshipsMap)
+import PostgREST.SchemaCache.Routine      (Routine (..))
+
+import Protolude
+
+data Error
+  = ApiRequestError ApiRequestError
+  | SchemaCacheErr SchemaCacheError
+  | JwtErr JwtError
+  | NoSchemaCacheError
+  | PgErr PgError
+  deriving Show
+
+-- API REQUEST ERRORS: PGRST1XX
+data ApiRequestError
+  = AggregatesNotAllowed
+  | MediaTypeError [ByteString]
+  | InvalidBody ByteString
+  | InvalidFilters
+  | InvalidPreferences [ByteString]
+  | InvalidRange RangeError
+  | InvalidRpcMethod ByteString
+  | NotEmbedded Text
+  | NotImplemented Text
+  | PutLimitNotAllowedError
+  | QueryParamError QPError
+  | RelatedOrderNotToOne Text Text
+  | UnacceptableFilter Text
+  | UnacceptableSchema Text [Text]
+  | UnsupportedMethod ByteString
+  | GucHeadersError
+  | GucStatusError
+  | PutMatchingPkError
+  | SingularityError Integer
+  | PGRSTParseError RaiseError
+  | MaxAffectedViolationError Integer
+  | InvalidResourcePath
+  | OpenAPIDisabled
+  | MaxAffectedRpcViolation
+  deriving Show
+
+data QPError = QPError Text Text
+  deriving Show
+
+data RaiseError
+  = MsgParseError ByteString
+  | DetParseError ByteString
+  | NoDetail
+  deriving Show
+
+data RangeError
+  = NegativeLimit
+  | LowerGTUpper
+  | OutOfBounds Text Text
+  deriving Show
+
+-- SCHEMA CACHE ERRORS: PGRST2XX
+data SchemaCacheError
+  = AmbiguousRelBetween Text Text [Relationship]
+  | AmbiguousRpc [Routine]
+  | NoRelBetween Text Text (Maybe Text) Text RelationshipsMap
+  | NoRpc Text Text [Text] MediaType Bool [QualifiedIdentifier] [Routine]
+  | ColumnNotFound Text Text
+  | TableNotFound Text Text SchemaCache
+  deriving Show
+
+-- JWT ERRORS: PGRST3XX
+data JwtError
+  = JwtDecodeErr JwtDecodeError
+  | JwtSecretMissing
+  | JwtTokenRequired
+  | JwtClaimsErr JwtClaimsError
+  deriving Show
+
+data JwtDecodeError
+  = EmptyAuthHeader
+  | UnexpectedParts Int
+  | KeyError Text
+  | BadAlgorithm Text
+  | BadCrypto
+  | UnsupportedTokenType
+  | UnreachableDecodeError
+  deriving Show
+
+data JwtClaimsError
+  = JWTExpired
+  | JWTNotYetValid
+  | JWTIssuedAtFuture
+  | JWTNotInAudience
+  | ParsingClaimsFailed
+  | ExpClaimNotNumber
+  | NbfClaimNotNumber
+  | IatClaimNotNumber
+  | AudClaimNotStringOrArray
+  deriving Show
+
+-- PG ERRORS
+type Authenticated = Bool
+data PgError = PgError Authenticated SQL.UsageError
+  deriving Show
+
+-- For parsing byteString to JSON Object, used for allowing full response control
+data PgRaiseErrMessage = PgRaiseErrMessage {
+  getCode    :: Text,
+  getMessage :: Text,
+  getDetails :: Maybe Text,
+  getHint    :: Maybe Text
+}
+
+data PgRaiseErrDetails = PgRaiseErrDetails {
+  getStatus     :: Int,
+  getStatusText :: Maybe Text,
+  getHeaders    :: Map Text Text
+}