--- a/hgext3rd/topic/__init__.py	Tue Oct 09 15:14:32 2018 +0200
+++ b/hgext3rd/topic/__init__.py	Mon Oct 01 12:37:42 2018 +0530
@@ -546,11 +546,21 @@
         """:topic: String. The topic of the changeset"""
         ctx = context.resource(mapping, 'ctx')
         return ctx.topic()
+
+    @templatekeyword('topicidx', requires={'ctx'})
+    def topicidxkw(context, mapping):
+        """:topicidx: Integer. Index of the changeset as a stack alias"""
+        ctx = context.resource(mapping, 'ctx')
+        return ctx.topicidx()
 else:
     def topickw(**args):
         """:topic: String. The topic of the changeset"""
         return args['ctx'].topic()
 
+    def topicidxkw(**args):
+        """:topicidx: Integer. Index of the changeset as a stack alias"""
+        return args['ctx'].topicidx()
+
 def wrapinit(orig, self, repo, *args, **kwargs):
     orig(self, repo, *args, **kwargs)
     if constants.extrakey not in self._extra: