diff --git a/spectrum_manager/src/APIServer.cpp b/spectrum_manager/src/APIServer.cpp
index 5af0fccd..357535dd 100644
--- a/spectrum_manager/src/APIServer.cpp
+++ b/spectrum_manager/src/APIServer.cpp
@@ -119,6 +119,7 @@ void APIServer::serve_instances(Server *server, Server::session *session, struct
 		usernames.push_back(username);
 		instance.AddMember("registered", !username.empty(), json.GetAllocator());
 		instance.AddMember("username", usernames.back().c_str(), json.GetAllocator());
+		instance.AddMember("frontend", is_slack(m_config, id) ? "slack" : "xmpp", json.GetAllocator());
 
 		instances.PushBack(instance, json.GetAllocator());
 	}
@@ -221,6 +222,50 @@ void APIServer::serve_instances_register(Server *server, Server::session *sessio
 	}
 }
 
+void APIServer::serve_instances_join_room(Server *server, Server::session *session, struct mg_connection *conn, struct http_message *hm) {
+	std::string uri(hm->uri.p, hm->uri.len);
+	std::string instance = uri.substr(uri.rfind("/") + 1);
+
+	UserInfo info;
+	m_storage->getUser(session->user, info);
+
+	std::string username = "";
+	int type = (int) TYPE_STRING;
+	m_storage->getUserSetting(info.id, instance, type, username);
+
+	if (username.empty()) {
+		send_ack(conn, true, "You are not registered to this Spectrum 2 instance.");
+		return;
+	}
+
+	std::string name = get_http_var(hm, "name");
+	std::string legacy_room = get_http_var(hm, "legacy_room");
+	std::string legacy_server = get_http_var(hm, "legacy_server");
+	std::string frontend_room = get_http_var(hm, "frontend_room");
+
+	std::string response = server->send_command(instance, "join_room " +
+		username + " " + name + " " + legacy_room + " " + legacy_server + " " + frontend_room);
+
+	if (response.find("Joined the room") == std::string::npos) {
+		send_ack(conn, true, response);
+	}
+	else {
+		send_ack(conn, false, response);
+	}
+}
+
+void APIServer::serve_instances_join_room_form(Server *server, Server::session *session, struct mg_connection *conn, struct http_message *hm) {
+	// So far we support just Slack here. For XMPP, it is up to user to initiate the join room request.
+	Document json;
+	json.SetObject();
+	json.AddMember("error", 0, json.GetAllocator());
+	json.AddMember("name_label", "Nickname in 3rd-party room", json.GetAllocator());
+	json.AddMember("legacy_room_label", "3rd-party room name", json.GetAllocator());
+	json.AddMember("legacy_server_label", "3rd-party server", json.GetAllocator());
+	json.AddMember("frontend_room_label", "Slack channel", json.GetAllocator());
+	send_json(conn, json);
+}
+
 void APIServer::serve_instances_register_form(Server *server, Server::session *session, struct mg_connection *conn, struct http_message *hm) {
 	std::string uri(hm->uri.p, hm->uri.len);
 	std::string instance = uri.substr(uri.rfind("/") + 1);
@@ -330,6 +375,12 @@ void APIServer::handleRequest(Server *server, Server::session *sess, struct mg_c
 	else if (has_prefix(&hm->uri, "/api/v1/instances/register/")) {
 		serve_instances_register(server, sess, conn, hm);
 	}
+	else if (has_prefix(&hm->uri, "/api/v1/instances/join_room_form/")) {
+		serve_instances_join_room_form(server, sess, conn, hm);
+	}
+	else if (has_prefix(&hm->uri, "/api/v1/instances/join_room/")) {
+		serve_instances_join_room(server, sess, conn, hm);
+	}
 	else if (has_prefix(&hm->uri, "/api/v1/users/remove/")) {
 		serve_users_remove(server, sess, conn, hm);
 	}
diff --git a/spectrum_manager/src/APIServer.h b/spectrum_manager/src/APIServer.h
index e649dd07..9971ecd0 100644
--- a/spectrum_manager/src/APIServer.h
+++ b/spectrum_manager/src/APIServer.h
@@ -58,6 +58,8 @@ class APIServer {
 		void serve_instances_unregister(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
 		void serve_instances_register(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
 		void serve_instances_register_form(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
+		void serve_instances_join_room(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
+		void serve_instances_join_room_form(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
 		void serve_users(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
 		void serve_users_add(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
 		void serve_users_remove(Server *server, Server::session *sess, struct mg_connection *conn, struct http_message *hm);
diff --git a/spectrum_manager/src/html/instances/join_room.shtml b/spectrum_manager/src/html/instances/join_room.shtml
new file mode 100644
index 00000000..a9bcbe29
--- /dev/null
+++ b/spectrum_manager/src/html/instances/join_room.shtml
@@ -0,0 +1,37 @@
+<!--#include virtual="/header.shtml" -->
+
+<h2>Join room</h2>
+<form action="/api/v1/instances/join_room" class="basic-grey" method="POST"> 
+<h1>Join room
+	<span id="description">Join the room using this Spectrum 2 instance.</span> 
+</h1> 
+<label> 
+	<span id="name_desc"></span> 
+	<input type="text" id="name" name="name" placeholder=""></textarea> 
+</label> 
+<label> 
+	<span id="legacy_room_desc"></span> 
+	<input type="text" id="legacy_room" name="legacy_name" placeholder=""></textarea> 
+</label> 
+<label>
+	<span id="legacy_server_desc"></span> 
+	<input type="text" id="legacy_server" name="legacy_server" placeholder=""></textarea> 
+</label>
+<label>
+	<span id="frontend_room_desc"></span> 
+	<input type="text" id="frontend_room" name="frontend_room" placeholder=""></textarea> 
+</label>
+<label> 
+	<span>&nbsp;</span> 
+	<input type="submit" class="button_command" value="Join room" />
+</label> 
+<input type="hidden" name="instance" id="instance" value=""></input> 
+</form><br/>
+
+<script type="text/javascript">
+$(function() {
+	fill_instances_join_room_form();
+});
+</script>
+
+<!--#include virtual="/footer.shtml" -->
diff --git a/spectrum_manager/src/html/js/app.js b/spectrum_manager/src/html/js/app.js
index b4098066..613049d9 100644
--- a/spectrum_manager/src/html/js/app.js
+++ b/spectrum_manager/src/html/js/app.js
@@ -34,7 +34,12 @@ function show_instances() {
 				$("#main_result  > tbody:last-child").append(row);
 			}
 			else {
-				row += '<td><a class="button_command" href="' + $.cookie("base_location") +  'api/v1/instances/' + command + '/' + instance.id + '">' + command + '</a>' + '</td></tr>';
+				row += '<td>';
+				if (command == 'unregister' && instance.frontend == "slack") {
+					row += '<a href="' + $.cookie("base_location") + 'instances/join_room.shtml?id=' + instance.id + '">Join room</a> | ';
+				}
+				row += '<a class="button_command" href="' + $.cookie("base_location") +  'api/v1/instances/' + command + '/' + instance.id + '">' + command + '</a>';
+				row += '</td></tr>';
 				$("#main_result  > tbody:last-child").append(row);
 				$(".button_command").click(function(e) {
 					e.preventDefault();
@@ -92,6 +97,39 @@ function getQueryParams(qs) {
 	return params;
 }
 
+function fill_instances_join_room_form() {
+	var query = getQueryParams(document.location.search);
+	$("#instance").attr("value", query.id);
+
+	$(".button_command").click(function(e) {
+		e.preventDefault();
+		$(this).parent().empty().progressbar( {value: false} ).css('height', '1em');
+
+		var postdata ={
+			"name": $("#name").val(),
+			"legacy_room": $("#legacy_room").val(),
+			"legacy_server": $("#legacy_server").val()
+			"frontend_room": $("#frontend_room").val()
+		};
+
+		$.post($.cookie("base_location") + "api/v1/instances/join_room/" + $("#instance").val(), postdata, function(data) {
+			window.location.replace("index.shtml");
+		});
+	})
+	
+	$.get($.cookie("base_location") + "api/v1/instances/join_room_form/" + query.id, function(data) {
+		$("#name_desc").html(data.name_label + ":");
+		$("#legacy_room_desc").html(data.legacy_room_label + ":");
+		$("#legacy_server_desc").html(data.legacy_server_label + ":");
+		$("#frontend_room_desc").html(data.frontend_room_desc + ":");
+
+		$("#name").attr("placeholder", data.name_label + ":");
+		$("#legacy_room").attr("placeholder", data.legacy_room_label + ":");
+		$("#legacy_server").attr("placeholder", data.legacy_server_label + ":");
+		$("#frontend_room").attr("placeholder", data.frontend_room_desc + ":");
+	});
+}
+
 function fill_instances_register_form() {
 	var query = getQueryParams(document.location.search);
 	$("#instance").attr("value", query.id);