diff --git a/TODO.md b/TODO.md
index cbafcce..06d3e14 100644
--- a/TODO.md
+++ b/TODO.md
@@ -27,3 +27,5 @@ Local topic history retention and browsing
 
 For topic creation: allow creation of distinct read and write URLs for
 one topic, to allow cap-style control of write- and read-permission.
+
+WebSockets: allow subscribe/unsubscribe along the websocket.