diff --git a/internal/builtins/http.go b/internal/builtins/http.go
index 471cd11..82bab2e 100644
--- a/internal/builtins/http.go
+++ b/internal/builtins/http.go
@@ -178,6 +178,7 @@ func starlarkResponse(res *http.Response) *starlarkstruct.Struct {
 		"code":    starlark.MakeInt(res.StatusCode),
 		"headers": starlarkStringSliceMap(res.Header),
 		"body":    reader,
+		"url":     starlark.String(res.Request.URL.String()),
 		"json": starlark.NewBuiltin("response.json", func(thread *starlark.Thread, b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
 			return reader.readJSON(thread, b, args, kwargs)
 		}),
diff --git a/internal/convert/convert.go b/internal/convert/convert.go
index 4a1c75a..2deadfb 100644
--- a/internal/convert/convert.go
+++ b/internal/convert/convert.go
@@ -23,8 +23,16 @@ func Convert(v any) (starlark.Value, error) {
 }
 
 func convert(val reflect.Value) (starlark.Value, error) {
+	// Check for invalid or nil values
+	if !val.IsValid() {
+		return starlark.None, nil
+	}
+	
 	switch val.Kind() {
 	case reflect.Interface:
+		if val.IsNil() {
+			return starlark.None, nil
+		}
 		return convert(val.Elem())
 	case reflect.Int, reflect.Int64, reflect.Int32, reflect.Int16, reflect.Int8:
 		return starlark.MakeInt64(val.Int()), nil
@@ -37,9 +45,20 @@ func convert(val reflect.Value) (starlark.Value, error) {
 	case reflect.String:
 		return starlark.String(val.String()), nil
 	case reflect.Slice, reflect.Array:
+		if val.IsNil() {
+			return starlark.None, nil
+		}
 		return convertSlice(val)
 	case reflect.Map:
+		if val.IsNil() {
+			return starlark.None, nil
+		}
 		return convertMap(val)
+	case reflect.Ptr:
+		if val.IsNil() {
+			return starlark.None, nil
+		}
+		return convert(val.Elem())
 	default:
 		return nil, fmt.Errorf("%w: %s", ErrInvalidType, val.Type())
 	}