diff --git a/parser/src/main/scala/aqua/parser/lexer/NamedArg.scala b/parser/src/main/scala/aqua/parser/lexer/NamedArg.scala
new file mode 100644
index 00000000..c0d50dc1
--- /dev/null
+++ b/parser/src/main/scala/aqua/parser/lexer/NamedArg.scala
@@ -0,0 +1,59 @@
+package aqua.parser.lexer
+
+import aqua.parser.lift.Span.S
+import aqua.parser.lexer.Token.*
+
+import cats.data.NonEmptyList
+import cats.parse.Parser as P
+import cats.syntax.functor.*
+import cats.Comonad
+import cats.arrow.FunctionK
+
+enum NamedArg[F[_]] extends Token[F] {
+  // for `name = value`
+  case Full(name: Name[F], value: ValueToken[F])
+  // for just `name` (short for `name = name`)
+  case Short(variable: VarToken[F])
+
+  lazy val argName: Name[F] = this match {
+    case Full(name, _) => name
+    case Short(variable) => variable.name
+  }
+
+  lazy val argValue: ValueToken[F] = this match {
+    case Full(_, value) => value
+    case Short(variable) => variable
+  }
+
+  override def as[T](v: T): F[T] = this match {
+    case Full(name, value) => name.as(v)
+    case Short(variable) => variable.as(v)
+  }
+
+  override def mapK[K[_]: Comonad](fk: FunctionK[F, K]): NamedArg[K] =
+    this match {
+      case Full(name, value) => Full(name.mapK(fk), value.mapK(fk))
+      case Short(variable) => Short(variable.mapK(fk))
+    }
+}
+
+object NamedArg {
+
+  private val namedArgFull: P[NamedArg.Full[S]] =
+    P.defer(
+      (Name.p.between(` *`, `/s*`) <*
+        `=`.between(` *`, `/s*`)) ~
+        ValueToken.`value`.between(` *`, `/s*`)
+    ).map(NamedArg.Full.apply)
+
+  private val namedArgShort: P[NamedArg.Short[S]] =
+    P.defer(
+      VarToken.variable.between(` *`, `/s*`)
+    ).map(NamedArg.Short.apply)
+
+  val namedArg: P[NamedArg[S]] =
+    namedArgFull.backtrack | namedArgShort
+
+  val namedArgs: P[NonEmptyList[NamedArg[S]]] =
+    P.defer(` `.?.with1 ~ `(` ~ `/s*` *> comma(namedArg) <* `/s*` *> `)`)
+}
diff --git a/parser/src/main/scala/aqua/parser/lexer/PropertyOp.scala b/parser/src/main/scala/aqua/parser/lexer/PropertyOp.scala
index 6fa49a78..1e63f266 100644
--- a/parser/src/main/scala/aqua/parser/lexer/PropertyOp.scala
+++ b/parser/src/main/scala/aqua/parser/lexer/PropertyOp.scala
@@ -3,18 +3,19 @@ package aqua.parser.lexer
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.types.LiteralType
+import aqua.parser.lexer.CallArrowToken.CallBraces
+import aqua.parser.lexer.NamedArg.namedArgs
+
+import cats.~>
 import cats.data.{NonEmptyList, NonEmptyMap}
 import cats.parse.{Numbers, Parser as P, Parser0 as P0}
 import cats.syntax.comonad.*
 import cats.syntax.functor.*
 import cats.{Comonad, Functor}
-
 import scala.language.postfixOps
-import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
-import aqua.types.LiteralType
-import aqua.parser.lexer.CallArrowToken.CallBraces
 
 sealed trait PropertyOp[F[_]] extends Token[F] {
   def mapK[K[_]: Comonad](fk: F ~> K): PropertyOp[K]
@@ -47,12 +48,14 @@ case class IntoIndex[F[_]: Comonad](point: F[Unit], idx: Option[ValueToken[F]])
   override def mapK[K[_]: Comonad](fk: F ~> K): IntoIndex[K] = copy(fk(point), idx.map(_.mapK(fk)))
 }
 
-case class IntoCopy[F[_]: Comonad](point: F[Unit], fields: NonEmptyMap[String, ValueToken[F]])
-    extends PropertyOp[F] {
+case class IntoCopy[F[_]: Comonad](
+  point: F[Unit],
+  args: NonEmptyList[NamedArg[F]]
+) extends PropertyOp[F] {
   override def as[T](v: T): F[T] = point.as(v)
 
   override def mapK[K[_]: Comonad](fk: F ~> K): IntoCopy[K] =
-    copy(fk(point), fields.map(_.mapK(fk)))
+    copy(fk(point), args.map(_.mapK(fk)))
 }
 
 object PropertyOp {
@@ -66,9 +69,7 @@ object PropertyOp {
     }
 
   val parseCopy: P[PropertyOp[Span.S]] =
-    (`.` *> (`copy`.lift ~ namedArgs)).map { case (point, fields) =>
-      IntoCopy(point, NonEmptyMap.of(fields.head, fields.tail: _*))
-    }
+    (`.` *> (`copy`.lift ~ namedArgs)).map(IntoCopy.apply)
 
   private val parseIdx: P[PropertyOp[Span.S]] =
     (P.defer(
diff --git a/parser/src/main/scala/aqua/parser/lexer/Token.scala b/parser/src/main/scala/aqua/parser/lexer/Token.scala
index 9eac6e85..8c44347a 100644
--- a/parser/src/main/scala/aqua/parser/lexer/Token.scala
+++ b/parser/src/main/scala/aqua/parser/lexer/Token.scala
@@ -1,6 +1,7 @@
 package aqua.parser.lexer
 
 import aqua.parser.lift.Span.S
+
 import cats.data.NonEmptyList
 import cats.parse.{Accumulator0, Parser as P, Parser0 as P0}
 import cats.{~>, Comonad, Functor}
@@ -120,18 +121,6 @@ object Token {
   val `<-` : P[Unit] = P.string("<-")
   val `/s*` : P0[Unit] = ` \n+`.backtrack | ` *`.void
 
-  val namedArg: P[(String, ValueToken[S])] =
-    P.defer(
-      `name`.between(` *`, `/s*`) ~
-        `=`.between(` *`, `/s*`).void ~
-        ValueToken.`value`.between(` *`, `/s*`)
-    ).map { case ((name, _), vt) =>
-      (name, vt)
-    }
-
-  val namedArgs: P[NonEmptyList[(String, ValueToken[S])]] =
-    P.defer(` `.?.with1 ~ `(` ~ `/s*` *> comma(namedArg) <* `/s*` *> `)`)
-
   case class LiftToken[F[_]: Functor, A](point: F[A]) extends Token[F] {
     override def as[T](v: T): F[T] = Functor[F].as(point, v)
 
diff --git a/parser/src/main/scala/aqua/parser/lexer/ValueToken.scala b/parser/src/main/scala/aqua/parser/lexer/ValueToken.scala
index afc42750..a4a818ad 100644
--- a/parser/src/main/scala/aqua/parser/lexer/ValueToken.scala
+++ b/parser/src/main/scala/aqua/parser/lexer/ValueToken.scala
@@ -3,6 +3,7 @@ package aqua.parser.lexer
 import aqua.parser.Expr
 import aqua.parser.head.FilenameExpr
 import aqua.parser.lexer.Token.*
+import aqua.parser.lexer.NamedArg.namedArgs
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.types.LiteralType
@@ -260,7 +261,7 @@ object CallArrowToken {
 
 case class NamedValueToken[F[_]: Comonad](
   typeName: NamedTypeToken[F],
-  fields: NonEmptyMap[String, ValueToken[F]]
+  fields: NonEmptyList[NamedArg[F]]
 ) extends ValueToken[F] {
 
   override def mapK[K[_]: Comonad](fk: F ~> K): NamedValueToken[K] =
@@ -277,7 +278,7 @@ object NamedValueToken {
         "Missing braces '()' after the struct type"
       )
       .map { case (dn, args) =>
-        NamedValueToken(NamedTypeToken(dn), args.toNem)
+        NamedValueToken(NamedTypeToken(dn), args)
       }
 }
 
diff --git a/parser/src/test/scala/aqua/parser/AbilityValueExprSpec.scala b/parser/src/test/scala/aqua/parser/AbilityValueExprSpec.scala
index 26c4d6a3..b0dd4dcc 100644
--- a/parser/src/test/scala/aqua/parser/AbilityValueExprSpec.scala
+++ b/parser/src/test/scala/aqua/parser/AbilityValueExprSpec.scala
@@ -19,11 +19,14 @@ class AbilityValueExprSpec extends AnyFlatSpec with Matchers with AquaSpec {
     parseData(str) should be(
       NamedValueToken(
         NamedTypeToken[Id]("AbilityA"),
-        NonEmptyMap.of(
-          "v1" -> toNumber(1),
-          "f1" -> PropertyToken[Id](
-            VarToken(toName("input")),
-            NonEmptyList.one(IntoField("arrow"))
+        NonEmptyList.of(
+          NamedArg.Full(toName("v1"), toNumber(1)),
+          NamedArg.Full(
+            toName("f1"),
+            PropertyToken(
+              VarToken(toName("input")),
+              NonEmptyList.one(IntoField("arrow"))
+            )
           )
         )
       )
diff --git a/parser/src/test/scala/aqua/parser/StructValueExprSpec.scala b/parser/src/test/scala/aqua/parser/StructValueExprSpec.scala
index b487a28a..b237a5fb 100644
--- a/parser/src/test/scala/aqua/parser/StructValueExprSpec.scala
+++ b/parser/src/test/scala/aqua/parser/StructValueExprSpec.scala
@@ -4,21 +4,10 @@ import aqua.AquaSpec
 import aqua.AquaSpec.{toNumber, toStr, toVar}
 import aqua.parser.expr.ConstantExpr
 import aqua.parser.expr.func.AssignmentExpr
-import aqua.parser.lexer.{
-  CallArrowToken,
-  CollectionToken,
-  IntoArrow,
-  LiteralToken,
-  Name,
-  NamedTypeToken,
-  NamedValueToken,
-  PropertyToken,
-  Token,
-  ValueToken,
-  VarToken
-}
+import aqua.parser.lexer.*
 import aqua.parser.lexer.CollectionToken.Mode.ArrayMode
 import aqua.types.LiteralType
+
 import cats.Id
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
@@ -32,52 +21,67 @@ class StructValueExprSpec extends AnyFlatSpec with Matchers with AquaSpec {
     val one = toNumber(1)
     val two = toNumber(2)
     val three = toNumber(3)
-    val a = LiteralToken[Id]("\"a\"", LiteralType.string)
-    val b = LiteralToken[Id]("\"b\"", LiteralType.string)
-    val c = LiteralToken[Id]("\"c\"", LiteralType.string)
+    val a = toStr("a")
+    val b = toStr("b")
+    val c = toStr("c")
 
     parseData(
       str
     ) should be(
       NamedValueToken(
         NamedTypeToken[Id]("Obj"),
-        NonEmptyMap.of(
-          "f1" -> one,
-          "f2" -> a,
-          "f3" -> CollectionToken[Id](ArrayMode, List(one, two, three)),
-          "f4" -> CollectionToken[Id](ArrayMode, List(b, c)),
-          "f5" -> NamedValueToken(
-            NamedTypeToken[Id]("NestedObj"),
-            NonEmptyMap.of(
-              "i1" -> two,
-              "i2" -> b,
-              "i3" -> CallArrowToken(Name[Id]("funcCall"), List(three)),
-              "i4" -> VarToken[Id](Name[Id]("value"))
+        NonEmptyList.of(
+          NamedArg.Full(toName("f1"), one),
+          NamedArg.Full(toName("f2"), a),
+          NamedArg.Full(toName("f3"), CollectionToken[Id](ArrayMode, List(one, two, three))),
+          NamedArg.Full(toName("f4"), CollectionToken[Id](ArrayMode, List(b, c))),
+          NamedArg.Full(
+            toName("f5"),
+            NamedValueToken(
+              NamedTypeToken[Id]("NestedObj"),
+              NonEmptyList.of(
+                NamedArg.Full(toName("i1"), two),
+                NamedArg.Full(toName("i2"), b),
+                NamedArg.Full(toName("i3"), CallArrowToken(toName("funcCall"), List(three))),
+                NamedArg.Full(toName("i4"), VarToken(toName("value")))
+              )
             )
           ),
-          "f6" -> CallArrowToken(Name[Id]("funcCall"), List(one)),
-          "f7" -> PropertyToken[Id](
-            VarToken[Id](Name[Id]("Serv")),
-            NonEmptyList.one(IntoArrow[Id](Name[Id]("call"), List(two)))
+          NamedArg.Full(toName("f6"), CallArrowToken(Name[Id]("funcCall"), List(one))),
+          NamedArg.Full(
+            toName("f7"),
+            PropertyToken[Id](
+              VarToken[Id](Name[Id]("Serv")),
+              NonEmptyList.one(IntoArrow[Id](Name[Id]("call"), List(two)))
+            )
           )
         )
       )
     )
   }
 
-  "one named arg" should "be parsed" in {
-    val result = aqua.parser.lexer.Token.namedArg
+  "named args" should "parse one full named arg" in {
+    val result = NamedArg.namedArg
       .parseAll("""  a
                   | =
                   |  3""".stripMargin)
-      .map(v => (v._1, v._2.mapK(spanToId)))
+      .map(_.mapK(spanToId))
       .value
 
-    result should be(("a", toNumber(3)))
+    result should be(NamedArg.Full(toName("a"), toNumber(3)))
   }
 
-  "named args" should "be parsed" in {
-    val result = Token.namedArgs
+  it should "parse one short named arg" in {
+    val result = NamedArg.namedArg
+      .parseAll("  b ")
+      .map(_.mapK(spanToId))
+      .value
+
+    result should be(NamedArg.Short(toVar("b")))
+  }
+
+  it should "parse a few full named args" in {
+    val result = NamedArg.namedArgs
       .parseAll("""(
                   |a = "str",
                   |b = 3,
@@ -86,16 +90,61 @@ class StructValueExprSpec extends AnyFlatSpec with Matchers with AquaSpec {
                   |    5
                   |)""".stripMargin)
       .value
-      .map { case (str, vt) => (str, vt.mapK(spanToId)) }
+      .map(_.mapK(spanToId))
 
     result should be(
-      NonEmptyList[(String, ValueToken[Id])](
-        ("a", toStr("str")),
-        ("b", toNumber(3)) :: ("c", toNumber(5)) :: Nil
+      NonEmptyList.of(
+        NamedArg.Full(toName("a"), toStr("str")),
+        NamedArg.Full(toName("b"), toNumber(3)),
+        NamedArg.Full(toName("c"), toNumber(5))
       )
     )
   }
 
+  it should "parse a few short named args" in {
+    val result = NamedArg.namedArgs
+      .parseAll("""(
+                  |a,
+                  | b ,
+                  |c
+                  |
+                  |)""".stripMargin)
+      .value
+      .map(_.mapK(spanToId))
+
+    result should be(
+      NonEmptyList.of(
+        NamedArg.Short(toVar("a")),
+        NamedArg.Short(toVar("b")),
+        NamedArg.Short(toVar("c"))
+      )
+    )
+  }
+
+  it should "parse mixed named args" in {
+    val args = List(
+      "meaning = 42" -> NamedArg.Full(toName("meaning"), toNumber(42)),
+      "variable" -> NamedArg.Short(toVar("variable")),
+      "col = [1,2,3]" -> NamedArg.Full(
+        toName("col"),
+        CollectionToken[Id](ArrayMode, List(toNumber(1), toNumber(2), toNumber(3)))
+      ),
+      "arrow" -> NamedArg.Short(toVar("arrow"))
+    )
+
+    args.permutations.foreach(perm =>
+      val str = perm.map(_._1).mkString("(", ", ", ")")
+      val expected = NonEmptyList.fromListUnsafe(perm.map(_._2))
+
+      val result = NamedArg.namedArgs
+        .parseAll(str)
+        .value
+        .map(_.mapK(spanToId))
+
+      result should be(expected)
+    )
+  }
+
   "one line struct value" should "be parsed" in {
     parseAndCheckStruct(
       """Obj(f1 = 1, f2 = "a", f3 = [1,2,3], f4=["b", "c"], f5 =NestedObj(i1 = 2, i2 = "b", i3= funcCall(3), i4 = value), f6=funcCall(1), f7 = Serv.call(2))"""
diff --git a/parser/src/test/scala/aqua/parser/lexer/PropertyOpSpec.scala b/parser/src/test/scala/aqua/parser/lexer/PropertyOpSpec.scala
index 14dbb5e0..21f86cef 100644
--- a/parser/src/test/scala/aqua/parser/lexer/PropertyOpSpec.scala
+++ b/parser/src/test/scala/aqua/parser/lexer/PropertyOpSpec.scala
@@ -42,39 +42,59 @@ class PropertyOpSpec extends AnyFlatSpec with Matchers with EitherValues {
     PropertyOp.ops.parseAll("!-1").isLeft shouldBe true
   }
 
-  "copy ops" should "parse" in {
-    val opsP = (s: String) => PropertyOp.ops.parseAll(s).value.map(_.mapK(spanToId))
+  def copyOpsP(s: String) = PropertyOp.ops.parseAll(s).value.map(_.mapK(spanToId))
 
-    opsP(".copy(a = \"str\", b = 12)") should be(
+  "copy ops" should "parse one copy" in {
+    copyOpsP(".copy(a = \"str\", b = 12)") should be(
       NonEmptyList.of(
         IntoCopy[Id](
           (),
-          NonEmptyMap.of(
-            "a" -> LiteralToken("\"str\"", LiteralType.string),
-            "b" -> toNumber(12)
-          )
-        )
-      )
-    )
-
-    opsP(".copy(a = \"str\", b = 12).copy(c = 54, d = someVar)") should be(
-      NonEmptyList.of(
-        IntoCopy[Id](
-          (),
-          NonEmptyMap.of(
-            "a" -> LiteralToken("\"str\"", LiteralType.string),
-            "b" -> toNumber(12)
-          )
-        ),
-        IntoCopy[Id](
-          (),
-          NonEmptyMap.of(
-            "c" -> toNumber(54),
-            "d" -> VarToken("someVar")
+          NonEmptyList.of(
+            NamedArg.Full(toName("a"), toStr("str")),
+            NamedArg.Full(toName("b"), toNumber(12))
           )
         )
       )
     )
   }
 
+  it should "parse sequential copy" in {
+    copyOpsP(".copy(a = \"str\", b = 12).copy(c = 54, d = someVar)") should be(
+      NonEmptyList.of(
+        IntoCopy[Id](
+          (),
+          NonEmptyList.of(
+            NamedArg.Full(toName("a"), toStr("str")),
+            NamedArg.Full(toName("b"), toNumber(12))
+          )
+        ),
+        IntoCopy[Id](
+          (),
+          NonEmptyList.of(
+            NamedArg.Full(toName("c"), toNumber(54)),
+            NamedArg.Full(toName("d"), toVar("someVar"))
+          )
+        )
+      )
+    )
+  }
+
+  it should "parse mixed args in copy" in {
+    val args = List(
+      "a = \"str\"" -> NamedArg.Full(toName("a"), toStr("str")),
+      "b = 12" -> NamedArg.Full(toName("b"), toNumber(12)),
+      "c" -> NamedArg.Short(toVar("c")),
+      "d" -> NamedArg.Short(toVar("d"))
+    )
+
+    args.toSet.subsets().filter(_.nonEmpty).flatMap(_.toList.permutations).foreach { args =>
+      val str = args.map(_._1).mkString(".copy(", ", ", ")")
+      val expected = NonEmptyList.of(
+        IntoCopy[Id]((), NonEmptyList.fromListUnsafe(args.map(_._2)))
+      )
+
+      copyOpsP(str) should be(expected)
+    }
+  }
+
 }
diff --git a/semantics/src/main/scala/aqua/semantics/rules/ValuesAlgebra.scala b/semantics/src/main/scala/aqua/semantics/rules/ValuesAlgebra.scala
index 21ba297c..02806643 100644
--- a/semantics/src/main/scala/aqua/semantics/rules/ValuesAlgebra.scala
+++ b/semantics/src/main/scala/aqua/semantics/rules/ValuesAlgebra.scala
@@ -34,6 +34,23 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
   report: ReportAlgebra[S, Alg]
 ) extends Logging {
 
+  private def reportNamedArgsDuplicates(
+    args: NonEmptyList[NamedArg[S]]
+  ): Alg[Unit] = args
+    .groupBy(_.argName.value)
+    .filter { case (_, group) =>
+      group.size > 1
+    }
+    .toList
+    .traverse_ { case (name, group) =>
+      group.traverse_ { arg =>
+        report.error(
+          arg.argName,
+          s"Duplicate argument `$name`"
+        )
+      }
+    }
+
   private def resolveSingleProperty(rootType: Type, op: PropertyOp[S]): Alg[Option[PropertyRaw]] =
     op match {
       case op: IntoField[S] =>
@@ -46,12 +63,13 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
           )
         } yield arrowProp
       case op: IntoCopy[S] =>
-        for {
-          maybeFields <- op.fields.traverse(valueToRaw)
-          copyProp <- maybeFields.sequence.flatTraverse(
-            T.resolveCopy(rootType, op, _)
+        (for {
+          _ <- OptionT.liftF(
+            reportNamedArgsDuplicates(op.args)
           )
-        } yield copyProp
+          fields <- op.args.traverse(arg => OptionT(valueToRaw(arg.argValue)).map(arg -> _))
+          prop <- OptionT(T.resolveCopy(op, rootType, fields))
+        } yield prop).value
       case op: IntoIndex[S] =>
         for {
           maybeIdx <- op.idx.fold(LiteralRaw.Zero.some.pure)(valueToRaw)
@@ -102,7 +120,13 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
       case dvt @ NamedValueToken(typeName, fields) =>
         (for {
           resolvedType <- OptionT(T.resolveType(typeName))
-          fieldsGiven <- fields.traverse(value => OptionT(valueToRaw(value)))
+          // Report duplicate fields
+          _ <- OptionT.liftF(
+            reportNamedArgsDuplicates(fields)
+          )
+          fieldsGiven <- fields
+            .traverse(arg => OptionT(valueToRaw(arg.argValue)).map(arg.argName.value -> _))
+            .map(_.toNem) // Take only last value for a field
           fieldsGivenTypes = fieldsGiven.map(_.`type`)
           generated <- OptionT.fromOption(
             resolvedType match {
@@ -297,7 +321,8 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
     valueToRaw(v).flatMap(
       _.flatTraverse {
         case ca: CallArrowRaw => (ca, ca.baseType).some.pure[Alg]
-        case apr@ApplyPropertyRaw(_, IntoArrowRaw(_, arrowType, _)) => (apr, arrowType).some.pure[Alg]
+        case apr @ ApplyPropertyRaw(_, IntoArrowRaw(_, arrowType, _)) =>
+          (apr, arrowType).some.pure[Alg]
         // TODO: better error message (`raw` formatting)
         case raw => report.error(v, s"Expected arrow call, got $raw").as(none)
       }
diff --git a/semantics/src/main/scala/aqua/semantics/rules/types/TypesAlgebra.scala b/semantics/src/main/scala/aqua/semantics/rules/types/TypesAlgebra.scala
index 3fc8476b..40409769 100644
--- a/semantics/src/main/scala/aqua/semantics/rules/types/TypesAlgebra.scala
+++ b/semantics/src/main/scala/aqua/semantics/rules/types/TypesAlgebra.scala
@@ -37,10 +37,11 @@ trait TypesAlgebra[S[_], Alg[_]] {
   def resolveIndex(rootT: Type, op: IntoIndex[S], idx: ValueRaw): Alg[Option[PropertyRaw]]
 
   def resolveCopy(
+    token: IntoCopy[S],
     rootT: Type,
-    op: IntoCopy[S],
-    fields: NonEmptyMap[String, ValueRaw]
+    fields: NonEmptyList[(NamedArg[S], ValueRaw)]
   ): Alg[Option[PropertyRaw]]
+
   def resolveField(rootT: Type, op: IntoField[S]): Alg[Option[PropertyRaw]]
 
   def resolveArrow(
diff --git a/semantics/src/main/scala/aqua/semantics/rules/types/TypesInterpreter.scala b/semantics/src/main/scala/aqua/semantics/rules/types/TypesInterpreter.scala
index af088c17..474b5d70 100644
--- a/semantics/src/main/scala/aqua/semantics/rules/types/TypesInterpreter.scala
+++ b/semantics/src/main/scala/aqua/semantics/rules/types/TypesInterpreter.scala
@@ -216,7 +216,7 @@ class TypesInterpreter[S[_], X](using
             )
             .as(None)
         ) {
-          case at@ArrowType(_, _) =>
+          case at @ ArrowType(_, _) =>
             locations
               .pointFieldLocation(name, op.name.value, op)
               .as(Some(IntoArrowRaw(op.name.value, at, arguments)))
@@ -245,22 +245,33 @@ class TypesInterpreter[S[_], X](using
 
   // TODO actually it's stateless, exists there just for reporting needs
   override def resolveCopy(
+    token: IntoCopy[S],
     rootT: Type,
-    op: IntoCopy[S],
-    fields: NonEmptyMap[String, ValueRaw]
+    args: NonEmptyList[(NamedArg[S], ValueRaw)]
   ): State[X, Option[PropertyRaw]] =
     rootT match {
       case st: StructType =>
-        fields.toSortedMap.toList.traverse { case (fieldName, value) =>
+        args.forallM { case (arg, value) =>
+          val fieldName = arg.argName.value
           st.fields.lookup(fieldName) match {
             case Some(t) =>
-              ensureTypeMatches(op.fields.lookup(fieldName).getOrElse(op), t, value.`type`)
-            case None => report.error(op, s"No field with name '$fieldName' in $rootT").as(false)
+              ensureTypeMatches(arg.argValue, t, value.`type`)
+            case None =>
+              report.error(arg.argName, s"No field with name '$fieldName' in $rootT").as(false)
           }
-        }.map(res => if (res.forall(identity)) Some(IntoCopyRaw(st, fields)) else None)
+        }.map(
+          Option.when(_)(
+            IntoCopyRaw(
+              st,
+              args.map { case (arg, value) =>
+                arg.argName.value -> value
+              }.toNem
+            )
+          )
+        )
 
       case _ =>
-        report.error(op, s"Expected $rootT to be a data type").as(None)
+        report.error(token, s"Expected $rootT to be a data type").as(None)
     }
 
   // TODO actually it's stateless, exists there just for reporting needs
@@ -339,12 +350,12 @@ class TypesInterpreter[S[_], X](using
               )
               .as(false)
           } else {
-            valueFields.toSortedMap.toList.traverse { (name, `type`) =>
+            valueFields.toSortedMap.toList.forallM { (name, `type`) =>
               typeFields.lookup(name) match {
                 case Some(t) =>
                   val nextToken = token match {
                     case NamedValueToken(_, fields) =>
-                      fields.lookup(name).getOrElse(token)
+                      fields.find(_.argName.value == name).getOrElse(token)
                     // TODO: Is it needed?
                     case PropertyToken(_, properties) =>
                       properties.last
@@ -359,7 +370,7 @@ class TypesInterpreter[S[_], X](using
                     )
                     .as(false)
               }
-            }.map(_.forall(identity))
+            }
           }
         case _ =>
           val notes =
diff --git a/semantics/src/test/scala/aqua/semantics/SemanticsSpec.scala b/semantics/src/test/scala/aqua/semantics/SemanticsSpec.scala
index ff327b1c..04147a4b 100644
--- a/semantics/src/test/scala/aqua/semantics/SemanticsSpec.scala
+++ b/semantics/src/test/scala/aqua/semantics/SemanticsSpec.scala
@@ -5,7 +5,7 @@ import aqua.parser.Ast
 import aqua.raw.ops.{Call, CallArrowRawTag, FuncOp, OnTag, ParTag, RawTag, SeqGroupTag, SeqTag}
 import aqua.parser.Parser
 import aqua.parser.lift.{LiftParser, Span}
-import aqua.raw.value.{ApplyBinaryOpRaw, LiteralRaw, ValueRaw, VarRaw}
+import aqua.raw.value.*
 import aqua.types.*
 import aqua.raw.ops.*
 
@@ -674,4 +674,126 @@ class SemanticsSpec extends AnyFlatSpec with Matchers with Inside {
       warnings.exists(_.hints.exists(_.contains("used"))) should be(true)
     }
   }
+
+  {
+    val fieldCases = List(
+      "field = 42" -> "field = field",
+      "field = 42" -> "field",
+      "integer = 42" -> "field = integer",
+      "" -> "field = 42"
+    )
+
+    val strCases = List(
+      "str = \"str\"" -> "str = str",
+      "str = \"str\"" -> "str",
+      "string = \"str\"" -> "str = string",
+      "" -> "str = \"str\""
+    )
+
+    it should "handle struct creation" in {
+      for {
+        fieldCase <- fieldCases
+        (fieldDef, fieldArg) = fieldCase
+        strCase <- strCases
+        (strDef, strArg) = strCase
+      } {
+        val defs = List(fieldDef, strDef).filter(_.nonEmpty).mkString("\n  ")
+        val args = List(fieldArg, strArg).filter(_.nonEmpty).mkString(", ")
+        val script = s"""|data Struct:
+                         |  field: i8
+                         |  str: string
+                         |
+                         |func main() -> Struct:
+                         |  $defs
+                         |  <- Struct($args)
+                         |""".stripMargin
+
+        insideBody(script) { body =>
+          matchSubtree(body) { case (ReturnTag(vals), _) =>
+            inside(vals.head) { case MakeStructRaw(fields, _) =>
+              fields.contains("field") should be(true)
+              fields.contains("str") should be(true)
+            }
+          }
+        }
+      }
+    }
+
+    it should "handle ability creation" in {
+      def arrow(name: String) =
+        s"""|$name = (x: i8) -> bool:
+            |    <- x > 0
+            |""".stripMargin
+      val arrowCases = List(
+        arrow("arrow") -> "arrow = arrow",
+        arrow("arrow") -> "arrow",
+        arrow("closure") -> "arrow = closure"
+      )
+
+      for {
+        arrowCase <- arrowCases
+        (arrowDef, arrowArg) = arrowCase
+        fieldCase <- fieldCases
+        (fieldDef, fieldArg) = fieldCase
+        strCase <- strCases
+        (strDef, strArg) = strCase
+      } {
+        val defs = List(arrowDef, fieldDef, strDef).filter(_.nonEmpty).mkString("\n  ")
+        val args = List(arrowArg, fieldArg, strArg).filter(_.nonEmpty).mkString(", ")
+        val script = s"""|ability Ab:
+                         |  field: i8
+                         |  str: string
+                         |  arrow(x: i8) -> bool
+                         |
+                         |func main() -> Ab:
+                         |  $defs
+                         |  <- Ab($args)
+                         |""".stripMargin
+
+        insideBody(script) { body =>
+          matchSubtree(body) { case (ReturnTag(vals), _) =>
+            inside(vals.head) { case AbilityRaw(fields, _) =>
+              fields.contains("arrow") should be(true)
+              fields.contains("field") should be(true)
+              fields.contains("str") should be(true)
+            }
+          }
+        }
+      }
+    }
+  }
+
+  it should "forbid duplicate fields in data or ability creation" in {
+    List("data", "ability").foreach { form =>
+
+      val script = s"""|$form StructOrAb:
+                       |  field: i8
+                       |
+                       |func main() -> StructOrAb:
+                       |  field = 24
+                       |  <- StructOrAb(field = 42, field)
+                       |""".stripMargin
+
+      insideSemErrors(script) { errors =>
+        atLeast(1, errors.toChain.toList) shouldBe a[RulesViolated[Span.S]]
+      }
+    }
+  }
+
+  it should "forbid duplicate fields in data copy" in {
+
+    val script = """|data Struct:
+                    |  field: i8
+                    |
+                    |func main() -> Struct:
+                    |  st = Struct(field = 24)
+                    |  field = 37
+                    |  <- st.copy(field = 42, field)
+                    |""".stripMargin
+
+    insideSemErrors(script) { errors =>
+      atLeast(1, errors.toChain.toList) shouldBe a[RulesViolated[Span.S]]
+    }
+
+  }
 }