diff --git a/building/main.cpp b/building/main.cpp
index 5cc83b5..17f6fdb 100644
--- a/building/main.cpp
+++ b/building/main.cpp
@@ -95,7 +95,7 @@ struct CAWebChat {
                 "thread_synchronization.h",
                 "os_utils.h",
                 "connecting_assets/static_asset_manager.h",
-                "http_structures/client_request.h",
+                "http_structures/messages.h",
                 "http_structures/cookies.h",
                 "http_structures/response_gen.h",
                 "http_structures/accept_language.h",
diff --git a/src/http_server/engine_engine_number_9/http_structures/client_request_parse.h b/src/http_server/engine_engine_number_9/http_structures/client_request_parse.h
index ea6e559..0146257 100644
--- a/src/http_server/engine_engine_number_9/http_structures/client_request_parse.h
+++ b/src/http_server/engine_engine_number_9/http_structures/client_request_parse.h
@@ -4,7 +4,7 @@
 /* Do not export this file */
 
 #include "../baza.h"
-#include "client_request.h"
+#include "messages.h"
 #include <libregexis024vm/libregexis024vm_interface.h>
 
 namespace een9 {
diff --git a/src/http_server/engine_engine_number_9/http_structures/client_request.h b/src/http_server/engine_engine_number_9/http_structures/messages.h
similarity index 77%
rename from src/http_server/engine_engine_number_9/http_structures/client_request.h
rename to src/http_server/engine_engine_number_9/http_structures/messages.h
index 9760a2c..7409814 100644
--- a/src/http_server/engine_engine_number_9/http_structures/client_request.h
+++ b/src/http_server/engine_engine_number_9/http_structures/messages.h
@@ -17,6 +17,13 @@ namespace een9 {
         bool has_body = false;
         std::string body;
     };
+
+    struct ServerResponse {
+        std::string code;
+        std::string msg;
+        std::vector<std::pair<std::string, std::string>> headers;
+        std::string body;
+    };
 }
 
 #endif
diff --git a/src/http_server/engine_engine_number_9/http_structures/response_gen.cpp b/src/http_server/engine_engine_number_9/http_structures/response_gen.cpp
index 5b9e4aa..48eb7ba 100644
--- a/src/http_server/engine_engine_number_9/http_structures/response_gen.cpp
+++ b/src/http_server/engine_engine_number_9/http_structures/response_gen.cpp
@@ -5,50 +5,26 @@
 
 
 namespace een9 {
-    std::string form_http_server_response_header(const char* code,
+    ServerResponse form_http_server_response_200(const std::string& Content_Type, const std::string& body) {
+        return een9::ServerResponse{"200", "OK",
+            {{"Content-Type", Content_Type}, {"Content-Length", std::to_string(body.size())}}, body};
+    }
+
+    ServerResponse form_http_server_response_404(const std::string& Content_Type, const std::string& body) {
+        return een9::ServerResponse{"404", "ERROR",
+            {{"Content-Type", Content_Type}, {"Content-Length", std::to_string(body.size())}}, body};
+    }
+
+    ServerResponse form_http_server_response_303(const std::string& Location) {
+        return een9::ServerResponse{"303", "Go here", {{"Location", Location}}, ""};
+    }
+
+
+    ServerResponse form_http_server_response_303_spec_head(const std::string &Location,
         const std::vector<std::pair<std::string, std::string>>& headers) {
-        assert(strlen(code) == 3);
-        std::string result = std::string("HTTP/1.0 ") + code + " " + (code[0] < '4' ? "OK" : "ERROR") + "\r\n";
-        for (auto& p: headers)
-            result += (p.first + ": " + p.second + "\r\n");
-        return result;
-    }
-
-    std::string form_http_server_response_header_only(const char* code,
-        const std::vector<std::pair<std::string, std::string>>& headers) {
-        return form_http_server_response_header(code, headers) + "\r\n";
-    }
-
-    std::string form_http_server_response_with_body(const char* code,
-        const std::vector<std::pair<std::string, std::string>>& headers,
-        const std::string& body)
-    {
-        std::string result = form_http_server_response_header(code, headers)
-        + "Content-Length: " + std::to_string(body.size()) + "\r\n\r\n" + body;
-        return result;
-    }
-
-    /* Message from server to client */
-    std::string form_http_server_response_200(const std::string& Content_Type, const std::string& body) {
-        return form_http_server_response_with_body("200", {
-            {"Content-Type", Content_Type}
-        }, body);
-    }
-
-    std::string form_http_server_response_404(const std::string& Content_Type, const std::string& body) {
-        return form_http_server_response_with_body("404", {
-            {"Content-Type", Content_Type}
-        }, body);
-    }
-
-    std::string form_http_server_response_303(const std::string& Location) {
-        return form_http_server_response_header_only("303", {{"Location", Location}});
-    }
-
-    std::string form_http_server_response_303_spec_head(const std::string &Location,
-        const std::vector<std::pair<std::string, std::string>>& headers) {
-        std::vector<std::pair<std::string, std::string>> cp = headers;
-        cp.emplace_back("Location", Location);
-        return form_http_server_response_header_only("303", cp);
+        ServerResponse r{"303", "Go here", {{"Location", Location}}, ""};
+        for (auto& hl: headers)
+            r.headers.push_back(hl);
+        return r;
     }
 }
diff --git a/src/http_server/engine_engine_number_9/http_structures/response_gen.h b/src/http_server/engine_engine_number_9/http_structures/response_gen.h
index da78bcb..bf0da65 100644
--- a/src/http_server/engine_engine_number_9/http_structures/response_gen.h
+++ b/src/http_server/engine_engine_number_9/http_structures/response_gen.h
@@ -3,26 +3,16 @@
 
 #include <vector>
 #include <string>
-
+#include "messages.h"
 
 namespace een9 {
-    std::string form_http_server_response_header(const char* code,
-        const std::vector<std::pair<std::string, std::string>>& headers);
+    ServerResponse form_http_server_response_200(const std::string& Content_Type, const std::string& body);
 
-    std::string form_http_server_reponse_header_only(const char* code,
-        const std::vector<std::pair<std::string, std::string>>& headers);
+    ServerResponse form_http_server_response_404(const std::string& Content_Type, const std::string& body);
 
-    std::string form_http_server_response_with_body(const char* code,
-        const std::vector<std::pair<std::string, std::string>>& headers,
-        const std::string& body);
+    ServerResponse form_http_server_response_303(const std::string& Location);
 
-    std::string form_http_server_response_200(const std::string& Content_Type, const std::string& body);
-
-    std::string form_http_server_response_404(const std::string& Content_Type, const std::string& body);
-
-    std::string form_http_server_response_303(const std::string& Location);
-
-    std::string form_http_server_response_303_spec_head(const std::string &Location,
+    ServerResponse form_http_server_response_303_spec_head(const std::string &Location,
         const std::vector<std::pair<std::string, std::string>>& headers);
 }
 
diff --git a/src/http_server/engine_engine_number_9/running_mainloop.cpp b/src/http_server/engine_engine_number_9/running_mainloop.cpp
index 7af1e4e..a5cbfdd 100644
--- a/src/http_server/engine_engine_number_9/running_mainloop.cpp
+++ b/src/http_server/engine_engine_number_9/running_mainloop.cpp
@@ -149,12 +149,22 @@ namespace een9 {
         return pctx.body;
     }
 
+    std::string server_response_to_str(const ServerResponse& cont) {
+        std::string result = "HTTP/1.0 " + cont.code + " " + cont.msg + "\r\n";
+        for (const std::pair<std::string, std::string>& hl: cont.headers) {
+            result += hl.first + ": " + hl.second + "\r\n";
+        }
+        result += "\r\n" + cont.body;
+        return result;
+    }
+
     void process_connection(const SlaveTask& task, WorkersEnv& wte) {
         if (task.conn_info.type == 0) {
             printf("%d::Got http reuest\n", wte.id);
             ClientRequest client_request = process_http_connection_input(task.fd(), task.s_tips, wte);
             printf("%d::Http request has been read\n", wte.id);
-            std::string server_response = wte.wtec.guest_core(task, client_request, wte.id);
+            ServerResponse server_response_content = wte.wtec.guest_core(task, client_request, wte.id);
+            std::string server_response = server_response_to_str(server_response_content);
             process_connection_output(task.fd(), server_response);
             printf("%d::Http response has been sent\n", wte.id);
         } else if (task.conn_info.type == 1) {
diff --git a/src/http_server/engine_engine_number_9/running_mainloop.h b/src/http_server/engine_engine_number_9/running_mainloop.h
index 4595dc2..2625846 100644
--- a/src/http_server/engine_engine_number_9/running_mainloop.h
+++ b/src/http_server/engine_engine_number_9/running_mainloop.h
@@ -5,7 +5,7 @@
 #include <functional>
 #include <sys/time.h>
 #include "os_utils.h"
-#include "http_structures/client_request.h"
+#include "http_structures/messages.h"
 #include <stdint.h>
 #include "socket_address.h"
 
@@ -34,7 +34,7 @@ namespace een9 {
     typedef int worker_id_t;
 
     /* guest_core function must not throw anything that is not derived from std::exception */
-    typedef std::function<std::string(const SlaveTask&, const ClientRequest&, worker_id_t worker_id)> guest_core_t;
+    typedef std::function<ServerResponse(const SlaveTask&, const ClientRequest&, worker_id_t worker_id)> guest_core_t;
     /* same as gurst_core_t, but it used not for http, but for een9 specific "admin-cmd" protocol */
     typedef std::function<std::string(const SlaveTask&, const std::string&, worker_id_t)> guest_core_admin_control_t;
 
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.cpp
index 08add79..04c2cc2 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.cpp
@@ -25,7 +25,7 @@ namespace iu9cawebchat {
         }
     }
 
-    std::string http_R200(const std::string &el_name, WorkerGuestData &wgd,
+    een9::ServerResponse http_R200(const std::string &el_name, WorkerGuestData &wgd,
         const std::vector<const json::JSON *> &args) {
         std::string page = wgd.templater->render(el_name, args);
         return een9::form_http_server_response_200("text/html", page);
@@ -40,52 +40,52 @@ namespace iu9cawebchat {
         return jmessages;
     }
 
-    std::string page_E404(WorkerGuestData &wgd) {
+    een9::ServerResponse page_E404(WorkerGuestData &wgd) {
         return een9::form_http_server_response_404("text/html",
             wgd.templater->render("err-404", {}));
     }
 
     /* ========================= API =========================*/
-    std::string when_internalapi(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid,
+    een9::ServerResponse when_internalapi(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid,
                                  const std::function<json::JSON(SqliteConnection&, int64_t, const json::JSON&)>& F) {
         const json::JSON& Sent = json::parse_str_flawless(req.body);
         std::string result = json::generate_str(F(*wgd.db, uid, Sent), json::print_pretty);
         return een9::form_http_server_response_200("text/json", result);
     }
 
-    std::string when_internalapi_chatpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
+    een9::ServerResponse when_internalapi_chatpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_chatPollEvents);
     }
 
-    std::string when_internalapi_chatlistpollevents(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_chatlistpollevents(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_chatListPollEvents);
     }
 
-    std::string when_internalapi_getmessageneighbours(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_getmessageneighbours(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_getMessageNeighbours);
     }
 
-    std::string when_internalapi_sendmessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_sendmessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_sendMessage);
     }
 
-    std::string when_internalapi_deletemessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_deletemessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_deleteMessage);
     }
 
-    std::string when_internalapi_addmembertochat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_addmembertochat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_addMemberToChat);
     }
 
-    std::string when_internalapi_removememberfromchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_removememberfromchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_removeMemberFromChat);
     }
 
-    std::string when_internalapi_createchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_createchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_createChat);
     }
 
-    std::string when_internalapi_leavechat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
+    een9::ServerResponse when_internalapi_leavechat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
         return when_internalapi(wgd, req, uid, internalapi_leaveChat);
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.h b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.h
index 13fa046..d6ceaac 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.h
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.h
@@ -4,7 +4,7 @@
 #include "server_data_interact.h"
 
 #include "../sqlite3_wrapper.h"
-#include <engine_engine_number_9/http_structures/client_request.h>
+#include <engine_engine_number_9/http_structures/messages.h>
 #include <engine_engine_number_9/http_structures/response_gen.h>
 #include "../login_cookie.h"
 
@@ -29,7 +29,7 @@ namespace iu9cawebchat {
             int64_t& ret_logged_in_user
         );
 
-    std::string http_R200(const std::string& el_name, WorkerGuestData& wgd,
+    een9::ServerResponse http_R200(const std::string& el_name, WorkerGuestData& wgd,
         const std::vector<const json::JSON*>& args);
 
     struct HtmlMsgBox {
@@ -39,43 +39,43 @@ namespace iu9cawebchat {
 
     json::JSON jsonify_html_message_list(const std::vector<HtmlMsgBox>& messages);
 
-    std::string page_E404(WorkerGuestData& wgd);
+    een9::ServerResponse page_E404(WorkerGuestData& wgd);
 
     /*  ========================== PAGES ================================== */
 
-    std::string when_page_list_rooms(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_list_rooms(WorkerGuestData& wgd, const json::JSON& config_presentation,
                                      const een9::ClientRequest& req, const json::JSON& userinfo);
 
-    std::string when_page_login(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_login(WorkerGuestData& wgd, const json::JSON& config_presentation,
                                 const een9::ClientRequest& req, const std::vector<LoginCookie>& login_cookies, const json::JSON& userinfo);
 
-    std::string when_page_chat(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_chat(WorkerGuestData& wgd, const json::JSON& config_presentation,
                                const een9::ClientRequest& req, const json::JSON& userinfo);
 
-    std::string when_page_user(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_user(WorkerGuestData& wgd, const json::JSON& config_presentation,
             const een9::ClientRequest& req, const std::vector<LoginCookie>& login_cookies, const json::JSON& userinfo);
 
-    std::string when_page_register(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_register(WorkerGuestData& wgd, const json::JSON& config_presentation,
                     const een9::ClientRequest& req, const json::JSON& userinfo);
 
     /* ========================  API  ============================== */
-    std::string when_internalapi_chatpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
+    een9::ServerResponse when_internalapi_chatpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
 
-    std::string when_internalapi_chatlistpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
+    een9::ServerResponse when_internalapi_chatlistpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
 
-    std::string when_internalapi_getmessageneighbours(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
+    een9::ServerResponse when_internalapi_getmessageneighbours(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
 
-    std::string when_internalapi_sendmessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    een9::ServerResponse when_internalapi_sendmessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 
-    std::string when_internalapi_deletemessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    een9::ServerResponse when_internalapi_deletemessage(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 
-    std::string when_internalapi_addmembertochat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    een9::ServerResponse when_internalapi_addmembertochat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 
-    std::string when_internalapi_removememberfromchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    een9::ServerResponse when_internalapi_removememberfromchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 
-    std::string when_internalapi_createchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    een9::ServerResponse when_internalapi_createchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 
-    std::string when_internalapi_leavechat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    een9::ServerResponse when_internalapi_leavechat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 }
 
 #endif
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_chat.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_chat.cpp
index 6fa5cdc..4e04490 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_chat.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_chat.cpp
@@ -4,7 +4,7 @@
 #include "../str_fields.h"
 
 namespace iu9cawebchat {
-    std::string when_page_chat(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_chat(WorkerGuestData& wgd, const json::JSON& config_presentation,
         const een9::ClientRequest& req, const json::JSON& userinfo) {
 
         std::vector<std::string> path_segs = {};
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_list_rooms.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_list_rooms.cpp
index 39898ab..4e5aa04 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_list_rooms.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_list_rooms.cpp
@@ -1,7 +1,7 @@
 #include "client_server_interact.h"
 
 namespace iu9cawebchat {
-    std::string when_page_list_rooms(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_list_rooms(WorkerGuestData& wgd, const json::JSON& config_presentation,
             const een9::ClientRequest& req, const json::JSON& userinfo) {
         if (userinfo.isNull()) {
             return een9::form_http_server_response_303("/login");
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_login.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_login.cpp
index 4828bcd..e40a342 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_login.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_login.cpp
@@ -4,7 +4,7 @@
 #include "../str_fields.h"
 
 namespace iu9cawebchat {
-    std::string when_page_login(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_login(WorkerGuestData& wgd, const json::JSON& config_presentation,
         const een9::ClientRequest& req, const std::vector<LoginCookie>& login_cookies, const json::JSON& userinfo) {
         if (req.method == "POST") {
             std::vector<std::pair<std::string, std::string>> query = een9::split_html_query(req.body);
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_register.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_register.cpp
index 2fbc733..56a079f 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_register.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_register.cpp
@@ -5,7 +5,7 @@
 #include "../str_fields.h"
 
 namespace iu9cawebchat {
-    std::string when_page_register(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_register(WorkerGuestData& wgd, const json::JSON& config_presentation,
                 const een9::ClientRequest& req, const json::JSON& userinfo) {
 
         const json::JSON& reg_pres = config_presentation["register"];
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_user.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_user.cpp
index 2137387..34e6753 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_user.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/when_user.cpp
@@ -7,7 +7,8 @@
 
 namespace iu9cawebchat {
     std::string get_user_bio(SqliteConnection& conn, int64_t userId) {
-        een9_ASSERT(userId >= 0, "Are you crazy?");
+        if (userId < 0)
+            een9_THROW("Are you crazy?");
         SqliteStatement sql_req(conn, "SELECT `bio` FROM `user` WHERE `id` = ?1", {{1, userId}}, {});
         fsql_text8_or_null bio_col;
         int status = sqlite_stmt_step(sql_req, {}, {{0, &bio_col}});
@@ -37,7 +38,7 @@ namespace iu9cawebchat {
         });
     }
 
-    std::string when_page_user(WorkerGuestData& wgd, const json::JSON& config_presentation,
+    een9::ServerResponse when_page_user(WorkerGuestData& wgd, const json::JSON& config_presentation,
                 const een9::ClientRequest& req, const std::vector<LoginCookie>& login_cookies, const json::JSON& userinfo) {
         if (userinfo.isNull())
             return een9::form_http_server_response_303("/");
diff --git a/src/web_chat/iu9_ca_web_chat_lib/run.cpp b/src/web_chat/iu9_ca_web_chat_lib/run.cpp
index 5c7340e..5e31ebb 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/run.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/run.cpp
@@ -78,7 +78,7 @@ namespace iu9cawebchat {
 
         een9::MainloopParameters params;
         params.guest_core = [&samI, &worker_guest_data]
-        (const een9::SlaveTask& task, const een9::ClientRequest& req, een9::worker_id_t worker_id) -> std::string {
+        (const een9::SlaveTask& task, const een9::ClientRequest& req, een9::worker_id_t worker_id) -> een9::ServerResponse {
             een9_ASSERT_pl(0 <= worker_id && worker_id < worker_guest_data.size());
             WorkerGuestData& wgd = worker_guest_data[worker_id];
             een9::StaticAsset sa;