diff --git a/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/Interpreter.scala b/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/Interpreter.scala
index 2601f3e70..bf6926b63 100644
--- a/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/Interpreter.scala
+++ b/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/Interpreter.scala
@@ -106,21 +106,25 @@ case class Interpreter(vocabulary: List[Word]) {
     if (s.program.isEmpty) s.context else execute(nextStep(s))
   }
 
-  final def execute(program: List[Any], context: Context, unfreeze: Boolean = true): Context = {
+  final def executeProgram(
+    program: List[Any],
+    context: Context,
+    unfreeze: Boolean = true
+  ): Context = {
     val result = execute(Step(program, context))
     if (unfreeze) result.unfreeze else result
   }
 
-  final def execute(program: List[Any]): Context = {
-    execute(program, Context(this, Nil, Map.empty))
+  final def executeProgram(program: List[Any]): Context = {
+    executeProgram(program, Context(this, Nil, Map.empty))
   }
 
-  final def execute(program: String): Context = {
-    execute(splitAndTrim(program))
-  }
-
-  final def execute(program: String, vars: Map[String, Any], features: Features): Context = {
-    execute(splitAndTrim(program), Context(this, Nil, vars, vars, features = features))
+  final def execute(
+    program: String,
+    vars: Map[String, Any] = Map.empty,
+    features: Features = Features.STABLE
+  ): Context = {
+    executeProgram(splitAndTrim(program), Context(this, Nil, vars, vars, features = features))
   }
 
   @scala.annotation.tailrec
diff --git a/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/StandardVocabulary.scala b/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/StandardVocabulary.scala
index 6160d919c..6c19e1145 100644
--- a/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/StandardVocabulary.scala
+++ b/atlas-core/src/main/scala/com/netflix/atlas/core/stacklang/StandardVocabulary.scala
@@ -57,7 +57,7 @@ object StandardVocabulary extends Vocabulary {
     override def matches(stack: List[Any]): Boolean = true
 
     override def execute(context: Context): Context = {
-      context.interpreter.execute(body, context, unfreeze = false)
+      context.interpreter.executeProgram(body, context, unfreeze = false)
     }
 
     override def summary: String =
@@ -81,7 +81,7 @@ object StandardVocabulary extends Vocabulary {
     override def execute(context: Context): Context = {
       context.stack match {
         case (vs: List[_]) :: stack =>
-          context.interpreter.execute(vs, context.copy(stack = stack), unfreeze = false)
+          context.interpreter.executeProgram(vs, context.copy(stack = stack), unfreeze = false)
         case _ => invalidStack
       }
     }
@@ -198,7 +198,7 @@ object StandardVocabulary extends Vocabulary {
       context.stack match {
         case (f: List[_]) :: (vs: List[_]) :: stack =>
           vs.reverse.foldLeft(context.copy(stack = stack)) { (c, v) =>
-            c.interpreter.execute(f, c.copy(stack = v :: c.stack), unfreeze = false)
+            c.interpreter.executeProgram(f, c.copy(stack = v :: c.stack), unfreeze = false)
           }
         case _ => invalidStack
       }
@@ -362,7 +362,8 @@ object StandardVocabulary extends Vocabulary {
           val init = context.copy(stack = stack)
           val res = vs.foldLeft(List.empty[Any] -> init) {
             case ((rs, c), v) =>
-              val rc = c.interpreter.execute(f, c.copy(stack = v :: c.stack), unfreeze = false)
+              val rc =
+                c.interpreter.executeProgram(f, c.copy(stack = v :: c.stack), unfreeze = false)
               (rc.stack.head :: rs) -> rc.copy(stack = rc.stack.tail)
           }
           res._2.copy(stack = res._1.reverse :: res._2.stack)
diff --git a/atlas-core/src/test/scala/com/netflix/atlas/core/stacklang/InterpreterSuite.scala b/atlas-core/src/test/scala/com/netflix/atlas/core/stacklang/InterpreterSuite.scala
index bb41bcebb..f4631def8 100644
--- a/atlas-core/src/test/scala/com/netflix/atlas/core/stacklang/InterpreterSuite.scala
+++ b/atlas-core/src/test/scala/com/netflix/atlas/core/stacklang/InterpreterSuite.scala
@@ -40,28 +40,28 @@ class InterpreterSuite extends FunSuite {
   }
 
   test("empty") {
-    assertEquals(interpreter.execute(Nil), context(Nil))
+    assertEquals(interpreter.executeProgram(Nil), context(Nil))
   }
 
   test("push items") {
-    assertEquals(interpreter.execute(List("foo", "bar")), context(List("bar", "foo")))
+    assertEquals(interpreter.executeProgram(List("foo", "bar")), context(List("bar", "foo")))
   }
 
   test("execute word") {
-    assertEquals(interpreter.execute(List(":push-foo")), context(List("foo")))
+    assertEquals(interpreter.executeProgram(List(":push-foo")), context(List("foo")))
   }
 
   test("overloaded word") {
-    assertEquals(interpreter.execute(List(":overloaded")), context(List("one")))
+    assertEquals(interpreter.executeProgram(List(":overloaded")), context(List("one")))
   }
 
   test("overloaded word and some don't match") {
-    assertEquals(interpreter.execute(List(":overloaded2")), context(List("two")))
+    assertEquals(interpreter.executeProgram(List(":overloaded2")), context(List("two")))
   }
 
   test("word with no matches") {
     val e = intercept[IllegalStateException] {
-      interpreter.execute(List(":no-match"))
+      interpreter.executeProgram(List(":no-match"))
     }
     val expected = "no matches for word ':no-match' with stack [], candidates: [exception]"
     assertEquals(e.getMessage, expected)
@@ -69,7 +69,7 @@ class InterpreterSuite extends FunSuite {
 
   test("using unstable word fails by default") {
     val e = intercept[IllegalStateException] {
-      interpreter.execute(List(":unstable"))
+      interpreter.executeProgram(List(":unstable"))
     }
     val expected = "to use :unstable enable unstable features"
     assertEquals(e.getMessage, expected)
@@ -77,45 +77,45 @@ class InterpreterSuite extends FunSuite {
 
   test("unknown word") {
     val e = intercept[IllegalStateException] {
-      interpreter.execute(List("foo", ":unknown"))
+      interpreter.executeProgram(List("foo", ":unknown"))
     }
     assertEquals(e.getMessage, "unknown word ':unknown'")
   }
 
   test("unmatched closing paren") {
     val e = intercept[IllegalStateException] {
-      interpreter.execute(List(")"))
+      interpreter.executeProgram(List(")"))
     }
     assertEquals(e.getMessage, "unmatched closing parenthesis")
   }
 
   test("unmatched closing paren 2") {
     val e = intercept[IllegalStateException] {
-      interpreter.execute(List("(", ")", ")"))
+      interpreter.executeProgram(List("(", ")", ")"))
     }
     assertEquals(e.getMessage, "unmatched closing parenthesis")
   }
 
   test("unmatched opening paren") {
     val e = intercept[IllegalStateException] {
-      interpreter.execute(List("("))
+      interpreter.executeProgram(List("("))
     }
     assertEquals(e.getMessage, "unmatched opening parenthesis")
   }
 
   test("list") {
     val list = List("(", "1", ")")
-    assertEquals(interpreter.execute(list), context(List(List("1"))))
+    assertEquals(interpreter.executeProgram(list), context(List(List("1"))))
   }
 
   test("nested list") {
     val list = List("(", "1", "(", ")", ")")
-    assertEquals(interpreter.execute(list), context(List(List("1", "(", ")"))))
+    assertEquals(interpreter.executeProgram(list), context(List(List("1", "(", ")"))))
   }
 
   test("multiple lists") {
     val list = List("(", "1", ")", "(", "2", ")")
-    assertEquals(interpreter.execute(list), context(List(List("2"), List("1"))))
+    assertEquals(interpreter.executeProgram(list), context(List(List("2"), List("1"))))
   }
 
   test("debug") {
diff --git a/atlas-webapi/src/main/scala/com/netflix/atlas/webapi/ExprApi.scala b/atlas-webapi/src/main/scala/com/netflix/atlas/webapi/ExprApi.scala
index abf966dd6..451e8d3bb 100644
--- a/atlas-webapi/src/main/scala/com/netflix/atlas/webapi/ExprApi.scala
+++ b/atlas-webapi/src/main/scala/com/netflix/atlas/webapi/ExprApi.scala
@@ -154,7 +154,7 @@ class ExprApi extends WebApi {
   // macros it alwasy returns true. This ensures the operation will actually be successful before
   // returning to a user.
   private def execWorks(interpreter: Interpreter, w: Word, ctxt: Context): Boolean = {
-    Try(interpreter.execute(List(s":${w.name}"), ctxt)).isSuccess
+    Try(interpreter.executeProgram(List(s":${w.name}"), ctxt)).isSuccess
   }
 
   private def matches(interpreter: Interpreter, w: Word, ctxt: Context): Boolean = {