diff --git a/morpheus-graphql-core.cabal b/morpheus-graphql-core.cabal
--- a/morpheus-graphql-core.cabal
+++ b/morpheus-graphql-core.cabal
@@ -1,11 +1,11 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.34.4.
+-- This file has been generated from package.yaml by hpack version 0.35.0.
 --
 -- see: https://github.com/sol/hpack
 
 name:           morpheus-graphql-core
-version:        0.23.0
+version:        0.24.0
 synopsis:       Morpheus GraphQL Core
 description:    Build GraphQL APIs with your favorite functional language!
 category:       web, graphql
@@ -21,7 +21,9 @@
     README.md
     changelog.md
 data-files:
+    test/query/parsing/selection-set/empty-selection-2/query.gql
     test/query/parsing/selection-set/empty-selection/query.gql
+    test/query/parsing/selection-set/non-empty-selection-2/query.gql
     test/query/parsing/selection-set/non-empty-selection/query.gql
     test/query/validation/__typename/arguments/query.gql
     test/query/validation/__typename/schema.gql
@@ -98,7 +100,9 @@
     "test/schema/validation/schema-definition/fail/required query/schema-with-query/schema.gql"
     test/schema/validation/schema-definition/fail/unknown-type/unknown/schema.gql
     test/schema/validation/schema-definition/ok/full/schema.gql
+    test/query/parsing/selection-set/empty-selection-2/response.json
     test/query/parsing/selection-set/empty-selection/response.json
+    test/query/parsing/selection-set/non-empty-selection-2/response.json
     test/query/parsing/selection-set/non-empty-selection/response.json
     test/query/validation/__typename/arguments/response.json
     test/query/validation/__typename/selection-set/response.json
@@ -270,7 +274,7 @@
     , hashable >=1.0.0 && <2.0.0
     , megaparsec >=7.0.0 && <10.0.0
     , morpheus-graphql-core
-    , morpheus-graphql-tests >=0.23.0 && <0.24.0
+    , morpheus-graphql-tests >=0.24.0 && <0.25.0
     , mtl >=2.0.0 && <3.0.0
     , relude >=0.3.0 && <2.0.0
     , scientific >=0.3.6.2 && <0.4.0
diff --git a/src/Data/Morpheus/Error.hs b/src/Data/Morpheus/Error.hs
--- a/src/Data/Morpheus/Error.hs
+++ b/src/Data/Morpheus/Error.hs
@@ -8,6 +8,8 @@
     subfieldsNotSelected,
     NameCollision (..),
     gqlWarnings,
+    printWarning,
+    printError,
   )
 where
 
diff --git a/src/Data/Morpheus/Error/Warning.hs b/src/Data/Morpheus/Error/Warning.hs
--- a/src/Data/Morpheus/Error/Warning.hs
+++ b/src/Data/Morpheus/Error/Warning.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE NoImplicitPrelude #-}
 
 module Data.Morpheus.Error.Warning
@@ -7,6 +8,8 @@
     deprecatedEnum,
     deprecatedField,
     gqlWarnings,
+    printWarning,
+    printError,
   )
 where
 
@@ -14,17 +17,20 @@
 import Data.ByteString.Lazy.Char8 (unpack)
 import Data.Morpheus.Types.Internal.AST.Base
   ( Description,
+    Position (..),
     Ref (..),
   )
 import Data.Morpheus.Types.Internal.AST.Error
-  ( GQLError,
+  ( GQLError (..),
     GQLErrors,
+    PropName (..),
     at,
     msg,
   )
 import Data.Morpheus.Types.Internal.AST.Name
   ( FieldName,
   )
+import qualified Data.Text as T
 import Language.Haskell.TH
 import Relude
 
@@ -54,7 +60,38 @@
 
 gqlWarnings :: [GQLError] -> Q ()
 gqlWarnings [] = pure ()
-gqlWarnings warnings = traverse_ handleWarning warnings
+gqlWarnings warnings = traverse_ (reportWarning . printWarning) warnings
+
+printWarning :: GQLError -> String
+printWarning = printError "warning" "\x1b[33m"
+
+printError :: String -> String -> GQLError -> String
+printError label color warning =
+  withColor (label <> ":")
+    <> description
+    <> loc
+    <> printedPath
+    <> "\n"
   where
-    handleWarning warning =
-      reportWarning ("Morpheus GraphQL Warning: " <> (unpack . encode) warning)
+    propPath = concat $ toList $ path warning
+    propLoc = concat $ toList $ locations warning
+    description = indent <> withColor (toString (message warning))
+    loc
+      | null propPath = ""
+      | otherwise = indent <> "  locations: " <> concatMap printLocation propLoc
+    printedPath
+      | null propPath = ""
+      | otherwise = indent <> "  path: " <> intercalate "." (map printPath propPath)
+
+    withColor :: String -> String
+    withColor x = color <> x <> "\x1b[0m"
+
+indent :: String
+indent = "\n      "
+
+printPath :: PropName -> String
+printPath (PropIndex x) = show x
+printPath (PropName x) = T.unpack x
+
+printLocation :: Position -> String
+printLocation Position {..} = show line <> ":" <> show column
diff --git a/src/Data/Morpheus/Parsing/Request/Selection.hs b/src/Data/Morpheus/Parsing/Request/Selection.hs
--- a/src/Data/Morpheus/Parsing/Request/Selection.hs
+++ b/src/Data/Morpheus/Parsing/Request/Selection.hs
@@ -80,6 +80,7 @@
       <*> maybeArguments
       <*> optionalDirectives
       <*> parseSelectionContent
+      <*> pure empty
 
 parseSelectionContent :: Parser (SelectionContent RAW)
 parseSelectionContent =
diff --git a/src/Data/Morpheus/Types/Internal/AST/Error.hs b/src/Data/Morpheus/Types/Internal/AST/Error.hs
--- a/src/Data/Morpheus/Types/Internal/AST/Error.hs
+++ b/src/Data/Morpheus/Types/Internal/AST/Error.hs
@@ -18,7 +18,8 @@
     GQLErrors,
     GQLError
       ( message,
-        locations
+        locations,
+        path
       ),
     manyMsg,
     Msg (..),
@@ -80,7 +81,7 @@
 {-# INLINE atPositions #-}
 
 withExtensions :: GQLError -> Map Text Value -> GQLError
-withExtensions gqlerr ext = gqlerr {extensions = Just ext}
+withExtensions gqlErr ext = gqlErr {extensions = Just ext}
 
 withPath :: GQLError -> [PropName] -> GQLError
 withPath err [] = err
diff --git a/src/Data/Morpheus/Types/Internal/AST/Selection.hs b/src/Data/Morpheus/Types/Internal/AST/Selection.hs
--- a/src/Data/Morpheus/Types/Internal/AST/Selection.hs
+++ b/src/Data/Morpheus/Types/Internal/AST/Selection.hs
@@ -126,7 +126,7 @@
   SelectionField :: SelectionContent s
   SelectionSet :: SelectionSet s -> SelectionContent s
   UnionSelection ::
-    { defaultSelection :: SelectionSet VALID,
+    { defaultSelection :: Maybe (SelectionSet VALID),
       conditionalSelections :: UnionSelection VALID
     } ->
     SelectionContent VALID
@@ -142,7 +142,7 @@
     where
       unionSelectionElements :: [Either (Selection VALID) UnionTag]
       unionSelectionElements =
-        map Left (toList interfaceFields)
+        map Left (concatMap toList $ maybeToList interfaceFields)
           <> map Right (sortOn unionTagName $ toList unionSets)
 
 instance
@@ -153,7 +153,7 @@
   Merge (HistoryT m) (SelectionContent s)
   where
   merge (SelectionSet s1) (SelectionSet s2) = SelectionSet <$> merge s1 s2
-  merge (UnionSelection m1 u1) (UnionSelection m2 u2) = UnionSelection <$> merge m1 m2 <*> merge u1 u2
+  merge (UnionSelection m1 u1) (UnionSelection m2 u2) = UnionSelection <$> withMaybe m1 m2 <*> merge u1 u2
   merge oldC currentC
     | oldC == currentC = pure oldC
     | otherwise = do
@@ -163,6 +163,12 @@
               `atPositions` fmap refPosition path
           )
 
+withMaybe :: (Merge f a, Monad f) => Maybe a -> Maybe a -> f (Maybe a)
+withMaybe (Just x) (Just y) = Just <$> merge x y
+withMaybe (Just x) Nothing = pure $ Just x
+withMaybe Nothing (Just y) = pure $ Just y
+withMaybe Nothing Nothing = pure Nothing
+
 deriving instance Show (SelectionContent a)
 
 deriving instance Eq (SelectionContent a)
@@ -227,7 +233,8 @@
       selectionName :: FieldName,
       selectionArguments :: Arguments s,
       selectionDirectives :: Directives s,
-      selectionContent :: SelectionContent s
+      selectionContent :: SelectionContent s,
+      selectionOrigin :: Maybe FragmentName
     } ->
     Selection s
   InlineFragment :: Fragment RAW -> Selection RAW
@@ -287,6 +294,7 @@
             { selectionAlias = mergeAlias,
               selectionPosition = pos1,
               selectionDirectives = dirs,
+              selectionOrigin = Nothing,
               ..
             }
     where
diff --git a/src/Data/Morpheus/Types/SelectionTree.hs b/src/Data/Morpheus/Types/SelectionTree.hs
--- a/src/Data/Morpheus/Types/SelectionTree.hs
+++ b/src/Data/Morpheus/Types/SelectionTree.hs
@@ -86,7 +86,7 @@
     SelectionField -> mempty
     (SelectionSet deeperSel) -> toList deeperSel
     (UnionSelection interfaceSelection sel) ->
-      toList interfaceSelection
+      concatMap toList (toList interfaceSelection)
         <> concatMap
           (toList . unionTagSelection)
           (toList sel)
@@ -94,7 +94,7 @@
   getChild name node = case selectionContent node of
     SelectionField -> Nothing
     (SelectionSet deeperSel) -> __lookup name deeperSel
-    (UnionSelection interfaceSelection sel) -> select (interfaceSelection : map unionTagSelection (toList sel))
+    (UnionSelection interfaceSelection sel) -> select (toList interfaceSelection <> map unionTagSelection (toList sel))
       where
         select (x : xs) = __lookup name x <|> select xs
         select [] = Nothing
diff --git a/src/Data/Morpheus/Validation/Query/Fragment.hs b/src/Data/Morpheus/Validation/Query/Fragment.hs
--- a/src/Data/Morpheus/Validation/Query/Fragment.hs
+++ b/src/Data/Morpheus/Validation/Query/Fragment.hs
@@ -34,6 +34,7 @@
     Position,
     RAW,
     Ref (..),
+    Selection (..),
     SelectionSet,
     Stage,
     TypeDefinition,
@@ -71,8 +72,8 @@
   Ref FragmentName ->
   FragmentValidator s UnionTag
 validateSpread f allowedTargets ref = do
-  fragment@Fragment {fragmentType} <- resolveSpread allowedTargets ref
-  UnionTag fragmentType <$> validateFragmentSelection f fragment
+  fragment@Fragment {fragmentType, fragmentName} <- resolveSpread allowedTargets ref
+  UnionTag fragmentType . fmap (\s -> s {selectionOrigin = Just fragmentName}) <$> validateFragmentSelection f fragment
 
 validateFragment ::
   (Fragment RAW -> FragmentValidator s (SelectionSet VALID)) ->
diff --git a/src/Data/Morpheus/Validation/Query/UnionSelection.hs b/src/Data/Morpheus/Validation/Query/UnionSelection.hs
--- a/src/Data/Morpheus/Validation/Query/UnionSelection.hs
+++ b/src/Data/Morpheus/Validation/Query/UnionSelection.hs
@@ -14,6 +14,7 @@
   )
 where
 
+import Control.Monad.Except (MonadError (throwError))
 import qualified Data.HashMap.Lazy as HM
 import Data.Mergeable (OrdMap)
 import Data.Morpheus.Internal.Utils
@@ -23,7 +24,6 @@
     selectOr,
     startHistory,
   )
-import Data.Morpheus.Types.Internal.AST.Base (Position (..))
 import Data.Morpheus.Types.Internal.AST.Name (TypeName)
 import Data.Morpheus.Types.Internal.AST.Selection
   ( Fragment (..),
@@ -82,23 +82,13 @@
   ) ->
   OrdMap TypeName (TypeDefinition IMPLEMENTABLE VALID) ->
   SelectionSet RAW ->
-  FragmentValidator s ([UnionTag], SelectionSet RAW)
+  FragmentValidator s ([UnionTag], Maybe (SelectionSet RAW))
 exploreFragments validateFragment types selectionSet = do
   (tags, selections) <- partitionEithers <$> traverse (splitFragment validateFragment (toList types)) (toList selectionSet)
-  selectionPosition <- fromMaybe (Position 0 0) <$> asksScope position
   (tags,)
-    <$> fromElems
-      ( ( Selection
-            { selectionName = "__typename",
-              selectionAlias = Nothing,
-              selectionPosition,
-              selectionArguments = empty,
-              selectionContent = SelectionField,
-              selectionDirectives = empty
-            }
-        )
-          : selections
-      )
+    <$> if null selections
+      then pure Nothing
+      else Just <$> fromElems selections
 
 -- sorts Fragment by conditional Types
 -- [
@@ -134,18 +124,25 @@
 getCompatibleTypes TypeDefinition {typeName, typeContent = DataObject {objectImplements}} = typeName : objectImplements
 getCompatibleTypes TypeDefinition {typeName} = [typeName]
 
+maybeMerge :: [SelectionSet VALID] -> FragmentValidator s (Maybe (SelectionSet VALID))
+maybeMerge [] = pure Nothing
+maybeMerge (x : xs) = Just <$> startHistory (mergeConcat (x :| xs))
+
+noEmptySelection :: FragmentValidator s a
+noEmptySelection = throwError "empty selection sets are not supported."
+
 joinClusters ::
-  SelectionSet VALID ->
+  Maybe (SelectionSet VALID) ->
   HashMap TypeName [SelectionSet VALID] ->
   FragmentValidator s (SelectionContent VALID)
-joinClusters selSet typedSelections
-  | null typedSelections = pure (SelectionSet selSet)
+joinClusters maybeSelSet typedSelections
+  | null typedSelections = maybe noEmptySelection (pure . SelectionSet) maybeSelSet
   | otherwise =
       traverse mkUnionTag (HM.toList typedSelections)
-        >>= fmap (UnionSelection selSet) . startHistory . fromElems
+        >>= fmap (UnionSelection maybeSelSet) . startHistory . fromElems
   where
     mkUnionTag :: (TypeName, [SelectionSet VALID]) -> FragmentValidator s UnionTag
-    mkUnionTag (typeName, fragments) = UnionTag typeName <$> startHistory (mergeConcat (selSet :| fragments))
+    mkUnionTag (typeName, fragments) = UnionTag typeName <$> (maybeMerge (toList maybeSelSet <> fragments) >>= maybe noEmptySelection pure)
 
 validateInterfaceSelection ::
   ValidateFragmentSelection s =>
@@ -161,10 +158,9 @@
   inputSelectionSet = do
     possibleTypes <- askInterfaceTypes typeDef
     (spreads, selectionSet) <- exploreFragments validateFragment possibleTypes inputSelectionSet
-    validSelectionSet <- validate typeDef selectionSet
+    validSelectionSet <- traverse (validate typeDef) selectionSet
     let tags = tagUnionFragments spreads possibleTypes
-    let interfaces = selectOr [] id typeName tags
-    defaultSelection <- startHistory $ mergeConcat (validSelectionSet :| interfaces)
+    defaultSelection <- maybeMerge (toList validSelectionSet <> selectOr [] id typeName tags)
     joinClusters defaultSelection (HM.delete typeName tags)
 
 mkUnionRootType :: FragmentValidator s (TypeDefinition IMPLEMENTABLE VALID)
@@ -177,9 +173,10 @@
   UnionTypeDefinition OUT VALID ->
   SelectionSet RAW ->
   FragmentValidator s (SelectionContent VALID)
-validateUnionSelection validateFragment validate members selectionSet = do
-  unionTypes <- traverse (fmap toCategory . askTypeMember) members
-  (spreads, selSet) <- exploreFragments validateFragment unionTypes selectionSet
+validateUnionSelection validateFragment validate members inputSelectionSet = do
   typeDef <- mkUnionRootType
-  validSelection <- validate typeDef selSet
-  joinClusters validSelection (tagUnionFragments spreads unionTypes)
+  possibleTypes <- traverse (fmap toCategory . askTypeMember) members
+  (spreads, selectionSet) <- exploreFragments validateFragment possibleTypes inputSelectionSet
+  validSelectionSet <- traverse (validate typeDef) selectionSet
+  let tags = tagUnionFragments spreads possibleTypes
+  joinClusters validSelectionSet tags
diff --git a/test/query/parsing/selection-set/empty-selection-2/query.gql b/test/query/parsing/selection-set/empty-selection-2/query.gql
new file mode 100644
--- /dev/null
+++ b/test/query/parsing/selection-set/empty-selection-2/query.gql
@@ -0,0 +1,6 @@
+query {
+  field1 {
+    ... on X {
+    }
+  }
+}
diff --git a/test/query/parsing/selection-set/empty-selection-2/response.json b/test/query/parsing/selection-set/empty-selection-2/response.json
new file mode 100644
--- /dev/null
+++ b/test/query/parsing/selection-set/empty-selection-2/response.json
@@ -0,0 +1,5 @@
+[
+  {
+    "message": "empty selection sets are not supported."
+  }
+]
diff --git a/test/query/parsing/selection-set/non-empty-selection-2/query.gql b/test/query/parsing/selection-set/non-empty-selection-2/query.gql
new file mode 100644
--- /dev/null
+++ b/test/query/parsing/selection-set/non-empty-selection-2/query.gql
@@ -0,0 +1,7 @@
+query {
+  field1 {
+    ... on X {
+      name
+    }
+  }
+}
diff --git a/test/query/parsing/selection-set/non-empty-selection-2/response.json b/test/query/parsing/selection-set/non-empty-selection-2/response.json
new file mode 100644
--- /dev/null
+++ b/test/query/parsing/selection-set/non-empty-selection-2/response.json
@@ -0,0 +1,1 @@
+"OK"
diff --git a/test/rendering/union/interface/rendering.gql b/test/rendering/union/interface/rendering.gql
--- a/test/rendering/union/interface/rendering.gql
+++ b/test/rendering/union/interface/rendering.gql
@@ -1,9 +1,7 @@
 query {
   character {
-    __typename
     name
     ... on Hero {
-      __typename
       name
       hobby
     }
diff --git a/test/rendering/union/union/rendering.gql b/test/rendering/union/union/rendering.gql
--- a/test/rendering/union/union/rendering.gql
+++ b/test/rendering/union/union/rendering.gql
@@ -1,12 +1,9 @@
 query {
   mortal {
-    __typename
     ... on Animal {
-      __typename
       weight
     }
     ... on Human {
-      __typename
       name
     }
   }