diff --git a/AlgebraicDataflowArchitectureModel/models/GroupChat.model b/AlgebraicDataflowArchitectureModel/models/GroupChat.model
new file mode 100644
index 0000000..d8b0c42
--- /dev/null
+++ b/AlgebraicDataflowArchitectureModel/models/GroupChat.model
@@ -0,0 +1,27 @@
+channel Signup {
+	out accounts(adb:Map, signUp(aid:Str)) = insert(adb, aid, {"notifications": nil})
+}
+
+channel HasRead(aid:Str) {
+	out accounts.{aid}.notifications(ntMap:Map, hasRead(gid:Str)) = delete(ntMap, gid)
+}
+
+channel CreateGroup {
+	out groups(gdb:Map, createGroup(gid:Str)) = insert(gdb, gid, {"members": nil, "messages": nil})
+}
+
+channel AddGroupMember(gid:Str) {
+	out groups.{gid}.members(memList:List, addGroupMember(aid:Str)) = append(memList, aid)
+}
+
+channel PostMessage(gid:Str) {
+	out groups.{gid}.messages(mesList:List, postMessage(message:Str)) = append(mesList, message)
+}
+
+channel Notify(gid:Str) {
+	in groups.{gid}.messages(prevMesList, notify(id)) = mesList
+	for EachMember(mno:Int) {
+		ref groups.{gid}.members.{mno}(id:Str, notify(id))
+		out accounts.{id}.notifications(prevNtMap:Map, notify(id)) = insert(prevNtMap, gid, true)
+	}
+}