diff --git a/config/option.go b/config/option.go
index 0a5ac5c..e391768 100644
--- a/config/option.go
+++ b/config/option.go
@@ -16,6 +16,7 @@ type OptionType uint8
 
 // Various attribute options. Use ExternalOptType for extended types in the frontend.
 const (
+	optTypeAny         OptionType = 0
 	OptTypeString      OptionType = 1
 	OptTypeStringArray OptionType = 2
 	OptTypeInt         OptionType = 3
@@ -24,6 +25,8 @@ const (
 
 func getTypeName(t OptionType) string {
 	switch t {
+	case optTypeAny:
+		return "any"
 	case OptTypeString:
 		return "string"
 	case OptTypeStringArray:
diff --git a/config/perspective.go b/config/perspective.go
index ea2b25d..ba4b428 100644
--- a/config/perspective.go
+++ b/config/perspective.go
@@ -75,7 +75,7 @@ func (p *Perspective) getPerspectiveValueCache(name string, requestedType Option
 	}
 
 	// check type
-	if requestedType != pOption.option.OptType {
+	if requestedType != pOption.option.OptType && requestedType != optTypeAny {
 		log.Errorf("config: bad type: requested %s as %s, but is %s", name, getTypeName(requestedType), getTypeName(pOption.option.OptType))
 		return nil
 	}
@@ -88,6 +88,12 @@ func (p *Perspective) getPerspectiveValueCache(name string, requestedType Option
 	return pOption.valueCache
 }
 
+// Has returns whether the given option is set in the perspective.
+func (p *Perspective) Has(name string) bool {
+	valueCache := p.getPerspectiveValueCache(name, optTypeAny)
+	return valueCache != nil
+}
+
 // GetAsString returns a function that returns the wanted string with high performance.
 func (p *Perspective) GetAsString(name string) (value string, ok bool) {
 	valueCache := p.getPerspectiveValueCache(name, OptTypeString)