Define CustomField

thrift/src/main/thrift/atoms/interactive.thrift

@@ -3,6 +3,25 @@ namespace java com.gu.contentatom.thrift.atom.interactive
 #@namespace scala com.gu.contentatom.thrift.atom.interactive
 #@namespace typescript _at_guardian.content_atom_model.interactive
 
+union AnyValue {
+    1: bool bool
+    2: byte byte
+    3: i16 i16
+    4: i32 i32
+    5: i64 i64
+    6: double double
+    7: string string
+    8: list<AnyValue> list
+    9: set<AnyValue> set
+    10: map<string, AnyValue> map
+}
+
+struct CustomField {
+  1: required string fieldName
+  2: required string fieldType
+  3: required AnyValue defaultValue
+}
+
 struct InteractiveAtom {
   /* the unique ID will be stored in the `atom` data*/
   1: required string type
@@ -18,4 +37,5 @@ struct InteractiveAtom {
   See here: https://amp.dev/documentation/components/amp-iframe/ for more information.
    */
   7: optional string placeholderUrl
+  8: optional list<CustomField> customFields = []
 }