util.stanza: New :get_meta()/:set_meta() API to attach custom properties to stanza objects These properties do not carry through clone(), and this is an intentional decision (for now, at least). My feeling is that it is the cloner that knows what metadata should be carried across to the clone, and the answer is usually not "all of it". Metadata is not persisted or serialized. It is designed to last only as long as the in-memory stanza object, to communicate properties to code that is processing that stanza object. Although the API does not currently distinguish between stanzas and child elements, it is recommended to refrain from setting metadata properties on child elements as this ability may be removed in the future.

--- a/util/stanza.lua	Sat Dec 06 16:00:22 2025 +0000
+++ b/util/stanza.lua	Sat Dec 06 17:27:59 2025 +0000
@@ -300,6 +300,27 @@
 	until not self
 end
 
+function stanza_mt:set_meta(k, v)
+	local meta = self.meta;
+	if not meta then
+		if v == nil then
+			return; -- no need to unset something that isn't set
+		end
+		meta = {};
+		self.meta = meta;
+	end
+	meta[k] = v;
+	return self;
+end
+
+function stanza_mt:get_meta(k)
+	local meta = self.meta;
+	if not meta then
+		return nil;
+	end
+	return meta[k];
+end
+
 local function _clone(stanza, only_top)
 	local attr = {};
 	for k,v in pairs(stanza.attr) do attr[k] = v; end