diff --git a/.gitignore b/.gitignore
index fb75514..d84e34d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ iu9-ca-web-chat.db
 log/
 core
 
+config/example.json
\ No newline at end of file
diff --git a/assets/HypertextPages/chat-members.nytl.html b/assets/HypertextPages/chat-members.nytl.html
new file mode 100644
index 0000000..176acab
--- /dev/null
+++ b/assets/HypertextPages/chat-members.nytl.html
@@ -0,0 +1,29 @@
+{% ELDEF main JSON pres JSON userinfo JSON openedchat JSON initial_chatUpdResp %}
+<!DOCTYPE html>
+<html lang="ru">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Веб-Чат Members</title>
+    <link rel="stylesheet" href="/assets/css/chat.css">
+</head>
+<body>
+{% PUT chat.pass pres userinfo openedchat initial_chatUpdResp %}
+<!--TODO: ADD SOMETHING WRITE SOMETHING AAAAAA -->
+<div class="overlay" id="overlay">
+    <div class="members-list" id="members-list">
+        <div class="members-list-header">
+            <span class="close" onclick="closeMembersList()">&times;</span>
+            <h2 class="all-members">Все участники</h2>
+        </div>
+        <div class="members-list-body">
+            <ul id="members-list-body">
+                <!-- Список участников будет добавлен динамически -->
+            </ul>
+        </div>
+    </div>
+</div>
+<script src="/assets/js/chat-members.js"></script>
+</body>
+</html>
+{% ENDELDEF %}
diff --git a/assets/HypertextPages/chat.nytl.html b/assets/HypertextPages/chat.nytl.html
index cc6617b..3519f47 100644
--- a/assets/HypertextPages/chat.nytl.html
+++ b/assets/HypertextPages/chat.nytl.html
@@ -1,4 +1,13 @@
-{% ELDEF main JSON pres JSON userinfo %}
+{% ELDEF pass JSON pres JSON userinfo JSON openedchat JSON initial_chatUpdResp %}
+<script>
+    let pres = {% PUT jsinsert pres %};
+    let userinfo = {% PUT jsinsert userinfo %};
+    let openedchat = {% PUT jsinsert openedchat %};
+    let initial_chatUpdResp = {% PUT jsinsert initial_chatUpdResp %};
+</script>
+{% ENDELDEF %}
+
+{% ELDEF main JSON pres JSON userinfo JSON openedchat JSON initial_chatUpdResp %}
 <!DOCTYPE html>
 <html lang="ru">
 <head>
@@ -8,6 +17,8 @@
     <link rel="stylesheet" href="/assets/css/chat.css">
 </head>
 <body>
+{% PUT chat.pass pres userinfo openedchat initial_chatUpdResp %}
+<!-- TODO AAAAA-->
 <div class="chat-container">
     <div class="chat-header">
         <span class="room-name">Веб чат</span>
@@ -21,19 +32,6 @@
         <button class="chat-send-button" onclick="sendMessage()">Отправить</button>
     </div>
 </div>
-<div class="overlay" id="overlay">
-    <div class="members-list" id="members-list">
-        <div class="members-list-header">
-            <span class="close" onclick="closeMembersList()">&times;</span>
-            <h2 class="all-members">Все участники</h2>
-        </div>
-        <div class="members-list-body">
-            <ul id="members-list-body">
-                <!-- Список участников будет добавлен динамически -->
-            </ul>
-        </div>
-    </div>
-</div>
 <script src="/assets/js/chat.js"></script>
 </body>
 </html>
diff --git a/assets/HypertextPages/edit-profile.nytl.html b/assets/HypertextPages/edit-profile.nytl.html
new file mode 100644
index 0000000..63cfe07
--- /dev/null
+++ b/assets/HypertextPages/edit-profile.nytl.html
@@ -0,0 +1,42 @@
+{% ELDEF main JSON pres JSON userprofile JSON errors %}
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <link rel="stylesheet" href="/assets/css/profile.css">
+    <title>Профиль</title>
+</head>
+<body>
+    <div class="main-container">
+        {% FOR error IN errors %}
+            <div>
+                <p>{% WRITE error.text %}</p>
+            </div>
+        {% ENDFOR %}
+        <div class="profile-header">
+            <h1>Редактирование профиля</h1>
+        </div>
+        <form method="post" action="/user/{% WRITE userprofile.nickname %}">
+            <div class="columns">
+                <div class="column">
+                    <p>{% WRITE userprofile.name %} ( {% WRITE userprofile.nickname %} )</p>
+                    <label for="name"> Изменить имя </label>
+                    <input type="text" name="name" id="name">
+                    <br>
+                    <label for="password"> Изменить пароль </label>
+                    <input type="password" name="password" id="password">
+                    <br>
+                </div>
+            </div>
+            <div class="additional-info">
+                <p>О себе</p>
+                <p>{% WRITE userprofile.bio %}</p><br>
+                <label for="bio">Изменить</label>
+                <textarea name="bio" id="bio"></textarea>
+            </div>
+            <button class="save" type="submit">Сохранить изменения</button>
+        </form>
+    </div>
+</body>
+</html>
+{% ENDELDEF%}
diff --git a/assets/HypertextPages/err-404.html b/assets/HypertextPages/err-404.html
new file mode 100644
index 0000000..a54d561
--- /dev/null
+++ b/assets/HypertextPages/err-404.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Not found</title>
+</head>
+<body>
+    <h1>Page not found</h1>
+</body>
+</html>
diff --git a/assets/HypertextPages/list-rooms.nytl.html b/assets/HypertextPages/list-rooms.nytl.html
index ddc4923..ff71a87 100644
--- a/assets/HypertextPages/list-rooms.nytl.html
+++ b/assets/HypertextPages/list-rooms.nytl.html
@@ -1,4 +1,4 @@
-{% ELDEF main JSON pres JSON userinfo %}
+{% ELDEF main JSON pres JSON userinfo JSON initial_chatListUpdResp %}
 <!DOCTYPE html>
 <html lang="{% WRITE pres.lang %}">
 <head>
@@ -8,7 +8,11 @@
     <link rel="stylesheet" href="/assets/css/list-rooms.css">
 </head>
 <body>
-{% PUT pass-pres-userinfo pres userinfo %}
+<script>
+    let pres = {% PUT jsinsert pres %};
+    let userinfo = {% PUT jsinsert userinfo %};
+    let initial_chatListUpdResp = {% PUT jsinsert initial_chatListUpdResp %};
+</script>
 <div class="container">
     <h1 style="color: white;">Выберите Чат-Комнату</h1>
     <ul class="room-list">
diff --git a/assets/HypertextPages/login.nytl.html b/assets/HypertextPages/login.nytl.html
index 7428177..4089ae1 100644
--- a/assets/HypertextPages/login.nytl.html
+++ b/assets/HypertextPages/login.nytl.html
@@ -9,10 +9,9 @@
 </head>
 
 <body>
-{% PUT pass-pres-userinfo pres userinfo %}
 {% FOR msg IN errors %}
     <div class="error-msg">
-        {% WRITE msg %}
+        {% WRITE msg.text %}
     </div>
 {% ENDFOR %}
 <div class="form-container">
diff --git a/assets/HypertextPages/pass-pres-userinfo.nytl.html b/assets/HypertextPages/pass-pres-userinfo.nytl.html
deleted file mode 100644
index 8331b75..0000000
--- a/assets/HypertextPages/pass-pres-userinfo.nytl.html
+++ /dev/null
@@ -1,6 +0,0 @@
-{% ELDEF main JSON pres JSON userinfo %}
-<script>
-    let pres = {% PUT jsinsert pres %};
-    let userinfo = {% PUT jsinsert userinfo %};
-</script>
-{% ENDELDEF %}
diff --git a/assets/HypertextPages/profile.nytl.html b/assets/HypertextPages/profile.nytl.html
deleted file mode 100644
index 5c9505a..0000000
--- a/assets/HypertextPages/profile.nytl.html
+++ /dev/null
@@ -1,39 +0,0 @@
-{% ELDEF main JSON pres JSON userinfo %}
-<!DOCTYPE html>
-<html lang="en">
-<head>
-    <meta charset="UTF-8">
-    <link rel="stylesheet" href="/assets/css/profile.css">
-    <title>Профиль</title>
-</head>
-<body>
-<div class="main-container">
-    <div class="profile-header">
-        <h1 style="color: white; text-align: center;">Профиль пользователя</h1>
-        <a class="return" href="chat.nytl.html">Назад</a>
-    </div>
-    <form>
-        <div class="columns">
-            <div class="column">
-                <img class="avatar" src="/assets/img/empty_avatar.png" id="avatar" height="200" width="200"><br>
-                <input type="file" id="fileInput" style="display:none">
-                <button class="add" type="button" onclick="document.getElementById('fileInput').click();">Изменить фото</button><br>
-            </div>
-            <div class="column">
-                <input type="text" name="username" placeholder = "Имя пользователя" value="Some Name" id="username"><br>
-                <input type="text" name="login" placeholder="Логин" value="some_login123" id="login" readonly><br>
-            </div>
-        </div>
-        <h3 style="color:#007bb5;">О себе</h3>
-        <div class="additional-info">
-            <textarea name="bio" placeholder="Напишите о себе..." id="bio"></textarea>
-        </div>
-        <button class="save" type="submit">Сохранить изменения</button>
-    </form>
-</div>
-
-<script src="/assets/js/list-rooms.js"> </script>
-
-</body>
-</html>
-{% ENDELDEF%}
diff --git a/assets/HypertextPages/registration.nytl.html b/assets/HypertextPages/registration.nytl.html
deleted file mode 100644
index e9810ba..0000000
--- a/assets/HypertextPages/registration.nytl.html
+++ /dev/null
@@ -1,27 +0,0 @@
-{% ELDEF main JSON pres JSON userinfo %}
-<!DOCTYPE html>
-<html lang="ru">
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Страница Регистрации</title>
-    <link rel="stylesheet" href="/assets/css/registration.css">
-
-</head>
-
-<body>
-<div class="form-container">
-    <h1 class="hide-cursor no-select">Вход</h1>
-    <form action="assets/html/list-rooms.html" method="post">
-        <input type="text" name="username" placeholder="Имя пользователя" id="username"><br>
-        <input type="text" name="login" placeholder="Логин" id="login"><br>
-        <input type="password" name="password" placeholder="Пароль" id="password"><br>
-        <button type="submit" class="hide-cursor no-select">Зарегистрироваться</button>
-        <div id="error"></div>
-    </form>
-</div>
-
-<script src="assets/js/registration.js"></script>
-</body>
-</html>
-{% ENDELDEF %}
diff --git a/assets/HypertextPages/view-profile.nytl.html b/assets/HypertextPages/view-profile.nytl.html
new file mode 100644
index 0000000..ccfc0db
--- /dev/null
+++ b/assets/HypertextPages/view-profile.nytl.html
@@ -0,0 +1,26 @@
+{% ELDEF main JSON pres JSON userprofile %}
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <link rel="stylesheet" href="/assets/css/profile.css">
+    <title>Профиль</title>
+</head>
+<body>
+    <div class="main-container">
+        <div class="profile-header">
+            <h1>Профиль пользователя</h1>
+        </div>
+        <div class="columns">
+            <div class="column">
+                <p>{% WRITE userprofile.name %} ( {% WRITE userprofile.nickname %} )</p>
+            </div>
+        </div>
+        <div class="additional-info">
+            <p>О себе</p>
+            <p>{% WRITE userprofile.bio %}</p><br>
+        </div>
+    </div>
+</body>
+</html>
+{% ENDELDEF%}
diff --git a/assets/img/empty_avatar.png b/assets/img/empty_avatar.png
deleted file mode 100644
index c1aa714..0000000
Binary files a/assets/img/empty_avatar.png and /dev/null differ
diff --git a/assets/img/logo0.png b/assets/img/logo0.png
new file mode 100644
index 0000000..3cb5db2
Binary files /dev/null and b/assets/img/logo0.png differ
diff --git a/assets/js/chat-members.js b/assets/js/chat-members.js
new file mode 100644
index 0000000..e69de29
diff --git a/assets/js/profile.js b/assets/js/profile.js
deleted file mode 100644
index fc92988..0000000
--- a/assets/js/profile.js
+++ /dev/null
@@ -1,10 +0,0 @@
-document.getElementById('fileInput').addEventListener('change', function(event) {
-    const file = event.target.files[0];
-    if (file) {
-        const reader = new FileReader();
-        reader.onload = function(e) {
-            document.getElementById('avatar').src = e.target.result;
-        };
-        reader.readAsDataURL(file);
-    }
-});
\ No newline at end of file
diff --git a/building/main.cpp b/building/main.cpp
index 077885e..7ed5b24 100644
--- a/building/main.cpp
+++ b/building/main.cpp
@@ -149,23 +149,8 @@ struct CAWebChat {
                 "login_cookie.cpp",
                 "backend_logic/server_data_interact.cpp",
                 "backend_logic/client_server_interact.cpp",
-                "backend_logic/when_list_rooms.cpp",
-                "backend_logic/when_login.cpp",
-                "backend_logic/when_chat.cpp",
-                "backend_logic/when_user.cpp",
-                "backend_logic/api_pollevents.cpp",
-                "backend_logic/api_getchatlist.cpp",
-                "backend_logic/api_getchatinfo.cpp",
-                "backend_logic/api_getchatmemberlist.cpp",
-                "backend_logic/api_getuserinfo.cpp",
-                "backend_logic/api_getmessageinfo.cpp",
-                "backend_logic/api_getmessageneighbours.cpp",
-                "backend_logic/api_sendmessage.cpp",
-                "backend_logic/api_deletemessage.cpp",
-                "backend_logic/api_addmembertochat.cpp",
-                "backend_logic/api_removememberfromchat.cpp",
-                "backend_logic/api_createchat.cpp",
-                "backend_logic/api_removechat.cpp",
+
+                "backend_logic/polling.cpp",
             };
             for (std::string& u: T.units)
                 u = "web_chat/iu9_ca_web_chat_lib/" + u;
diff --git a/config/default.json b/config/default.json
new file mode 100644
index 0000000..e69de29
diff --git a/example/config.json b/example/config.json
index a884aea..7c8ba53 100644
--- a/example/config.json
+++ b/example/config.json
@@ -14,7 +14,9 @@
         "name-of-room": "Название комнаты",
         "create-room": "Создать комнату",
 
-        "incorrect-nickname-or-password": "Неправильный никнейм или пароль"
+        "incorrect-nickname-or-password": "Неправильный никнейм или пароль",
+
+        "incorrect-profile-data": "Неправильно заполнены поля профиля"
       },
       "ask" : {
         "select-chat-room": "Выберете чат комнату"
@@ -29,7 +31,7 @@
   },
   "assets": "./assets",
   "database": {
-    "type": "sqlite",
+    "type": "sqlite3",
     "file": "./iu9-ca-web-chat.db"
   },
   "limits": {
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 b5deb27..139c6e3 100644
--- a/src/http_server/engine_engine_number_9/running_mainloop.cpp
+++ b/src/http_server/engine_engine_number_9/running_mainloop.cpp
@@ -258,8 +258,8 @@ namespace een9 {
                 }
                 errno = 0;
                 ret = poll(pollfds.data(), Nip, params.mainloop_recheck_interval_us);
-                if (ret != 0) {
-                    printf("poll() error :> %d\n", errno);
+                if (ret != 0 && errno != 0) {
+                    printf("poll() error :> %s\n", een9::prettyprint_errno("").c_str());
                 }
                 ASSERT_on_iret(ret, "poll()");
                 for (size_t i = 0; i < Nip; i++) {
diff --git a/src/http_server/misc_tests/nytl_test1.cpp b/src/http_server/misc_tests/nytl_test1.cpp
index 6f7340c..e0937cd 100644
--- a/src/http_server/misc_tests/nytl_test1.cpp
+++ b/src/http_server/misc_tests/nytl_test1.cpp
@@ -18,7 +18,14 @@ int main(int argc, char** argv) {
     een9::readFile(config_file, config_text);
     const json::JSON config = json::parse_str_flawless(config_text);
 
-    std::string answer2 = templater.render("login", {&config["presentation"].g()});
+    json::JSON userprofile;
+    userprofile["uid"].asInteger() = json::Integer(0l);
+    userprofile["name"].asString() = "radasdasdasdadsdasd";
+    userprofile["nickname"].asString() = "root";
+    userprofile["bio"].asString() = "Your mother";
+    json::JSON errors;
+    errors = json::JSON(json::array);
+    std::string answer2 = templater.render("edit-profile", {&config["presentation"], &userprofile, &errors});
     printf("%s\n<a><f><t><e><r><><l><f>\n", answer2.c_str());
 
     return 0;
diff --git a/src/http_server/new_york_transit_line/parser.cpp b/src/http_server/new_york_transit_line/parser.cpp
index 69e4a78..808bd26 100644
--- a/src/http_server/new_york_transit_line/parser.cpp
+++ b/src/http_server/new_york_transit_line/parser.cpp
@@ -178,7 +178,7 @@ namespace nytl {
                 }
                 ASSERT(nm == "EL", "Type of argument variable is either JSON or EL(...signature)")
                 skip(ctx, '(');
-                result = json::JSON(json::array);
+                result.asArray();
                 assert(result.isArray());
             }
             skipWhitespace(ctx);
@@ -220,16 +220,16 @@ namespace nytl {
                 ASSERT(!first.empty(), "Expression should start with 'root' name of global package or local variable");
                 ASSERT(first != "_", "_ ??? ARE YOU KIDDING???");
                 if (local_var_names.count(first) == 1) {
-                    result["V"] = json::JSON(json::Integer((int64_t)local_var_names.at(first)));
+                    result["V"].asInteger() = json::Integer((int64_t)local_var_names.at(first));
                 } else {
-                    result["V"] = json::JSON(first);
+                    result["V"].asString() = first;
                 }
-                result["C"] = json::JSON(json::array);
+                result["C"].asArray();
             } else {
                 skipWhitespace(ctx);
                 skip(ctx, ']');
             }
-            std::vector<json::JSON>& chain = result["C"].g().asArray();
+            std::vector<json::JSON>& chain = result["C"].asArray();
             while (true) {
                 if (peep(ctx) == '.') {
                     skip(ctx, '.');
diff --git a/src/http_server/new_york_transit_line/rendering.cpp b/src/http_server/new_york_transit_line/rendering.cpp
index bbdddbc..bbbf1c7 100644
--- a/src/http_server/new_york_transit_line/rendering.cpp
+++ b/src/http_server/new_york_transit_line/rendering.cpp
@@ -56,18 +56,18 @@ namespace nytl {
                 descend(*(temp_ret.JSON_subval));
             } else {
                 assert(expr.isDictionary());
-                const json::JSON& val = expr["V"].g();
+                const json::JSON& val = expr["V"];
                 if (val.isInteger()) {
                     size_t lv_ind = val.asInteger().get_int();
                     assert(lv_ind < local_vars.size());
                     result = local_vars[lv_ind];
                 } else if (val.isString()) {
-                    std::string cur_el_name_str = expr["V"].g().asString();
+                    std::string cur_el_name_str = expr["V"].asString();
                     result = LocalVarValue{false, cur_el_name_str, NULL};
                 } else
                     assert(false);
             }
-            const std::vector<json::JSON>& chain = expr["C"].g().asArray();
+            const std::vector<json::JSON>& chain = expr["C"].asArray();
             while (true) {
                 if (chain_el >= chain.size())
                     return NULL;
@@ -211,7 +211,8 @@ namespace nytl {
     uptr<RFrame> RFrame_OverParts::toMe(bool returned, const global_elem_set_t &elem_ns, Ditch &result,
         const std::function<std::string(std::string)> &escape) {
         if (!returned)
-            ASSERT(elem_ns.count(name) == 1, "No such element");
+            if (elem_ns.count(name) != 1)
+                THROW("No such element");
         const Element& el = elem_ns.at(name);
         if (!returned) {
             /* Continue to do checks */
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/admin_control_procedure.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/admin_control_procedure.cpp
new file mode 100644
index 0000000..4d7a81d
--- /dev/null
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/admin_control_procedure.cpp
@@ -0,0 +1,30 @@
+#include "server_data_interact.h"
+#include <engine_engine_number_9/baza_throw.h>
+#include <engine_engine_number_9/baza.h>
+#include "../str_fields.h"
+
+namespace iu9cawebchat {
+    std::string admin_control_procedure(SqliteConnection& conn, const std::string& req, bool& termination) {
+        if (req == "hello") {
+            return ":0 omg! hiii!! Hewwou :3 !!!!\n";
+        }
+        if (req == "8") {
+            termination = true;
+            return "Bye\n";
+        }
+        std::string updaterootpw_pref = "updaterootpw";
+        if (een9::beginsWith(req, "updaterootpw")) {
+            size_t nid = updaterootpw_pref.size();
+            if (nid >= req.size() || !isSPACE(req[nid]))
+                return "Bad command syntax. Missing whitespace\n";
+            std::string new_password = req.substr(nid + 1);
+            if (!check_password(new_password))
+                een9_THROW("Bad password");
+            sqlite_nooutput(conn,
+                "UPDATE `user` SET `password` = ?1 WHERE `id` = 0 ",
+                {}, {{1, new_password}});
+            return "Successul update\n";
+        }
+        return "Incorrect command\n";
+    }
+}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_addmembertochat.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_addmembertochat.cpp
index b000e19..017fb50 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_addmembertochat.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_addmembertochat.cpp
@@ -1,15 +1,48 @@
 #include "server_data_interact.h"
 #include <engine_engine_number_9/baza_throw.h>
+#include <assert.h>
 
 namespace iu9cawebchat {
+    void make_her_a_member_of_the_midnight_crew(SqliteConnection& conn, int64_t chatId, int64_t alienUserId, int64_t role) {
+        assert(role != user_chat_role_deleted);
+        int64_t chat_HistoryId_BEFORE_EV = get_current_history_id_of_chat(conn, chatId);
+        int64_t alien_chatlist_HistoryId_BEFORE_EV = get_current_history_id_of_user_chatList(conn, alienUserId);
+        sqlite_nooutput(conn,
+            "INSERT INTO `user_chat_membership` (`userId`, `chatId`, `user_chatList_IncHistoryId`,"
+            "`chat_IncHistoryId`, `role`) VALUES (?1, ?2, ?3, ?4, ?5)",
+            {{1, alienUserId}, {2, chatId}, {3, alien_chatlist_HistoryId_BEFORE_EV + 1},
+            {4, chat_HistoryId_BEFORE_EV + 1}, {5, role}}, {});
+
+        sqlite_nooutput(conn,
+            "UPDATE `chat` SET `it_HistoryId` = ?1 WHERE `id` = ?2", {{1, chat_HistoryId_BEFORE_EV + 1},
+            {2, chatId}}, {});
+
+        sqlite_nooutput(conn,
+            "UPDATE `user` SET `chatList_HistoryId` = ?1 WHERE `id` = ?2",
+            {{1, alien_chatlist_HistoryId_BEFORE_EV + 1}, {2, alienUserId}}, {});
+    }
+
     json::JSON internalapi_addMemberToChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["chatId"].g().asInteger().get_int();
+        int64_t chatId = Sent["chatUpdReq"]["chatId"].asInteger().get_int();
         int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
-        if (my_role_here == user_chat_role_deleted)
-            een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
+        if (my_role_here != user_chat_role_admin)
+            een9_THROW("Non-admin user tries to access internalapi_getChatInfo");
+
+        std::string alien_nickname = Sent["nickname"].asString();
+        RowUser_Content alien;
+        try {
+            alien = lookup_user_content_by_nickname(conn, alien_nickname);
+        } catch (std::exception& e) {
+            return json::JSON(json::jdict{{"status", json::JSON(-1l)}});
+        }
+
+        int64_t aliens_old_role = get_role_of_user_in_chat(conn, alien.id, chatId);
+        if (aliens_old_role == user_chat_role_deleted) {
+            make_her_a_member_of_the_midnight_crew(conn, chatId, alien.id, user_chat_role_regular);
+        }
+
         json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        // todo: WRITE THIS MORBID THING
+        poll_update_chat(conn, Sent, Recv);
         return Recv;
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_createchat.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_createchat.cpp
index efaea56..0eaa384 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_createchat.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_createchat.cpp
@@ -1,11 +1,27 @@
 #include "server_data_interact.h"
 #include <engine_engine_number_9/baza_throw.h>
+#include "../str_fields.h"
 
 namespace iu9cawebchat {
     json::JSON internalapi_createChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        std::string new_chat_name = Sent["content"]["name"].asString();
+        std::string new_chat_nickname = Sent["content"]["nickname"].asString();
+        if (!check_nickname(new_chat_nickname) || !check_name(new_chat_name))
+            return json::JSON(json::jdict{{"status", json::JSON(-1l)}});
+        if (is_nickname_taken(conn, new_chat_nickname))
+            return json::JSON(json::jdict{{"status", json::JSON(-2l)}});
+        reserve_nickname(conn, new_chat_nickname);
+
+        sqlite_nooutput(conn,
+            "INSERT INTO `chat` (`nickname`, `name`, `it_HistoryId`, `lastMsgId`) VALUES (?1, ?2, 0, -1)");
+
+        int64_t CHAT_ID = sqlite_trsess_last_insert_rowid(conn);
+
+        make_her_a_member_of_the_midnight_crew(conn, CHAT_ID, uid, user_chat_role_admin);
+
+        // todo: send a message into chat
         json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        // todo: WRITE THIS MORBID THING
+        poll_update_chat_list(conn, uid, Sent, Recv);
         return Recv;
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_deletemessage.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_deletemessage.cpp
index fed1c2c..c2a1a66 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_deletemessage.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_deletemessage.cpp
@@ -3,13 +3,30 @@
 
 namespace iu9cawebchat {
     json::JSON internalapi_deleteMessage(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["chatId"].g().asInteger().get_int();
+        int64_t chatId = Sent["chatUpdReq"].asInteger().get_int();
         int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
         if (my_role_here == user_chat_role_deleted)
             een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
+        if (my_role_here == user_chat_role_read_only)
+            een9_THROW("read-only user can't send messages");
+
+        int64_t LocalHistoryId = Sent["chatUpdReq"]["LocalHistoryId"].asInteger().get_int();
+        int64_t msgId = Sent["id"].asInteger().get_int();
+        RowMessage_Content msgInQuestion = lookup_message_content(conn, chatId, msgId);
+        if (!(!msgInQuestion.isSystem && (msgInQuestion.senderUserId == uid || my_role_here == user_chat_role_admin) ))
+            een9_THROW("Can't delete: permission denied");
+
+        int64_t chat_HistoryId_BEFORE_EV = get_current_history_id_of_chat(conn, chatId);
+
+        sqlite_nooutput(conn,
+            "UPDATE `message` SET `exists` = 0, `text` = NULL, `chat_IncHistoryId` = ?1 WHERE `id` = ?2",
+            {{1, chat_HistoryId_BEFORE_EV + 1}, {2, msgId}});
+
+        sqlite_nooutput(conn, "UPDATE `chat` SET `it_HistoryId` = ?1 WHERE `id` = ?2",
+            {{1, chat_HistoryId_BEFORE_EV + 1}, {2, chatId}}, {});
+
         json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        // todo: WRITE THIS MORBID THING
+        poll_update_chat(conn, Sent, Recv);
         return Recv;
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatinfo.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatinfo.cpp
deleted file mode 100644
index e60939b..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatinfo.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    json::JSON internalapi_getChatInfo(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["id"].g().asInteger().get_int();
-        int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
-        if (my_role_here == user_chat_role_deleted)
-            een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        RowChat_Content content = lookup_chat_content(conn, chatId);
-        Recv["name"] = json::JSON(content.name);
-        Recv["nickname"] = json::JSON(content.nickname);
-        Recv["lastMsgId"] = json::JSON(content.lastMsgId);
-        Recv["roleHere"] = json::JSON(stringify_user_chat_role(my_role_here));
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatlist.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatlist.cpp
deleted file mode 100644
index f5e13da..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatlist.cpp
+++ /dev/null
@@ -1,33 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    json::JSON internalapi_getChatList(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        Recv["chats"] = json::JSON(json::array);
-        std::vector<json::JSON>& chats = Recv["chats"].g().asArray();
-        SqliteStatement req(conn,
-            "SELECT `chat`.`id`, `chat`.`nickname`, `chat`.`name`, `chat`.`lastMsgId`, "
-            "`user_chat_membership`.`role` FROM `chat` "
-            "RIGHT JOIN `user_chat_membership` ON `chat`.`id` = `user_chat_membership`.`chatId` "
-            "WHERE `user_chat_membership`.`userId` = ?1 ", {{1, uid}}, {});
-        while (true) {
-            fsql_integer_or_null chat_id;
-            fsql_text8_or_null chat_nickname, chat_name;
-            fsql_integer_or_null chat_lastMsgId, role_here;
-            int status = sqlite_stmt_step(req, {{0, &chat_id}, {3, &chat_lastMsgId}, {4, &role_here}},
-                {{1, &chat_nickname}, {2, &chat_name}});
-            if (status != SQLITE_ROW)
-                break;
-            chats.emplace_back();
-            json::JSON& chat = chats.back();
-            chat["id"] = json::JSON(chat_id.value);
-            chat["content"]["nickname"] = json::JSON(chat_nickname.value);
-            chat["content"]["name"] = json::JSON(chat_name.value);
-            chat["content"]["lastMsgId"] = json::JSON(chat_lastMsgId.exist ? chat_lastMsgId.value : -1);
-            chat["content"]["roleHere"] = json::JSON(stringify_user_chat_role(role_here.value));
-        }
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatmemberlist.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatmemberlist.cpp
deleted file mode 100644
index 78f39b3..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getchatmemberlist.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    json::JSON internalapi_getChatMemberList(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["id"].g().asInteger().get_int();
-        int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
-        if (my_role_here == user_chat_role_deleted)
-            een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        Recv["members"] = json::JSON(json::array);
-        std::vector<json::JSON>& members = Recv["members"].g().asArray();
-        SqliteStatement req(conn,
-            "SELECT `user`.`id`, `user`.`nickname`, `user`.`name`, `user_chat_membership`.`role` FROM "
-            "`user` RIGHT JOIN `user_chat_membership` ON `user`.`id` = `user_chat_membership`.`userId` "
-            "WHERE `user_chat_membership`.`chatId` = ?1",
-            {{1, chatId}}, {});
-        while (true) {
-            fsql_integer_or_null this_user_id;
-            fsql_text8_or_null this_user_nickname, this_user_name;
-            fsql_integer_or_null this_users_role;
-            int status = sqlite_stmt_step(req, {{0, &this_user_id}, {3, &this_users_role}},
-                {{1, &this_user_nickname}, {2, &this_user_name}});
-            if (status != SQLITE_ROW)
-                break;
-            members.emplace_back();
-            json::JSON& member = members.back();
-            member["id"] = json::JSON(this_user_id.value);
-            member["content"]["nickname"] = json::JSON(this_user_nickname.value);
-            member["content"]["name"] = json::JSON(this_user_name.value);
-            member["content"]["role"] = json::JSON(this_users_role.value);
-        }
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getmessageinfo.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getmessageinfo.cpp
deleted file mode 100644
index e095fb9..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getmessageinfo.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    json::JSON internalapi_getMessageInfo(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["chatId"].g().asInteger().get_int();
-        int64_t msgId = Sent["id"].g().asInteger().get_int();
-        if (get_role_of_user_in_chat(conn, uid, chatId) == user_chat_role_deleted)
-            een9_THROW("Authentication failure");
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        RowMessage_Content content = lookup_message_content(conn, chatId, msgId);
-        Recv["text"] = json::JSON(content.text);
-        Recv["isSystem"] = json::JSON(content.isSystem);
-        Recv["sender"] = json::JSON(content.senderUserId);
-        // todo: sync that addition with api documentation
-        Recv["previous"] = json::JSON(content.previous);
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getmessageneighbours.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getmessageneighbours.cpp
deleted file mode 100644
index 5db5ff2..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getmessageneighbours.cpp
+++ /dev/null
@@ -1,52 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    /* This is literally the most dumb and useless query */
-    json::JSON internalapi_getMessageNeighbours(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["chatId"].g().asInteger().get_int();
-        if (get_role_of_user_in_chat(conn, uid, chatId) == user_chat_role_deleted)
-            een9_THROW("Authentication failure");
-        bool dir_forward = Sent["direction"].g().asString() == "forward";
-        int64_t amount = Sent["amount"].g().asInteger().get_int();
-        if (amount < 0)
-            een9_THROW("Incorrect amount");
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        Recv["messages"] = json::JSON(json::array);
-        std::vector<json::JSON>& messages = Recv["messages"].g().asArray();
-        if (dir_forward) {
-            int64_t curMsg = Sent["id"].g().asInteger().get_int();
-            if (curMsg < 0)
-                een9_THROW("forward message lookup from the beginning of chat is not supported yet");
-            while (true) {
-                /* At this point, curMsg is non-negative */
-                std::pair<int64_t, RowMessage_Content> nxt = lookup_message_content_rev_side(conn, chatId, curMsg);
-                if (nxt.first < 0)
-                    break;
-                messages.emplace_back();
-                json::JSON& message = messages.back();
-                message["id"] = json::JSON(nxt.first);
-                message["previous"] = json::JSON(curMsg);
-                message["content"]["text"] = json::JSON(nxt.second.text);
-                message["content"]["isSystem"] = json::JSON(nxt.second.isSystem);
-                message["content"]["sender"] = json::JSON(nxt.second.senderUserId);
-                curMsg = nxt.first;
-            }
-        } else {
-            int64_t curMsg = Sent["previousMsgId"].g().asInteger().get_int();
-            while (curMsg >= 0) {
-                RowMessage_Content curRow = lookup_message_content(conn, chatId, curMsg);
-                messages.emplace_back();
-                json::JSON& message = messages.back();
-                message["id"] = json::JSON(curMsg);
-                message["previous"] = json::JSON(curRow.previous);
-                message["content"]["text"] = json::JSON(curRow.text);
-                message["content"]["isSystem"] = json::JSON(curRow.isSystem);
-                message["content"]["sender"] = json::JSON(curRow.senderUserId);
-                curMsg = curRow.previous;
-            }
-        }
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getuserinfo.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getuserinfo.cpp
deleted file mode 100644
index 71816d8..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_getuserinfo.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "server_data_interact.h"
-
-namespace iu9cawebchat {
-    json::JSON internalapi_getUserInfo(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t otherUserId = Sent["id"].g().asInteger().get_int();
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        RowUser_Content content = lookup_user_content(conn, otherUserId);
-        Recv["name"] = json::JSON(content.name);
-        Recv["nickname"] = json::JSON(content.nickname);
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_leavechat.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_leavechat.cpp
new file mode 100644
index 0000000..7ed2be5
--- /dev/null
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_leavechat.cpp
@@ -0,0 +1,14 @@
+#include "server_data_interact.h"
+#include <engine_engine_number_9/baza_throw.h>
+
+namespace iu9cawebchat {
+    json::JSON internalapi_leaveChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        int64_t chatId = Sent["chatId"].asInteger().get_int();
+        if (get_role_of_user_in_chat(conn, uid, chatId) == user_chat_role_deleted)
+            een9_THROW("Not a member");
+        kick_from_chat(conn, uid, chatId);
+        json::JSON Recv;
+        poll_update_chat_list(conn, uid, Sent, Recv);
+        return Recv;
+    }
+}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_pollevents.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_pollevents.cpp
deleted file mode 100644
index d08c2c4..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_pollevents.cpp
+++ /dev/null
@@ -1,151 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    int64_t get_current_history_id_of_chat(SqliteConnection& conn, int64_t chatId) {
-        SqliteStatement req(conn, "SELECT `it_HistoryId` FROM `chat` WHERE `id` = ?1", {{1, chatId}}, {});
-        fsql_integer_or_null HistoryId;
-        int status = sqlite_stmt_step(req, {{0, &HistoryId}}, {});
-        een9_ASSERT_pl(status == SQLITE_ROW);
-        return HistoryId.value;
-    }
-
-    int64_t get_current_history_id_of_user_chatList(SqliteConnection& conn, int64_t userId) {
-        SqliteStatement req(conn, "SELECT `chatList_HistoryId` FROM `user` WHERE `id` = ?1", {{1, userId}}, {});
-        fsql_integer_or_null HistoryId;
-        int status = sqlite_stmt_step(req, {{0, &HistoryId}}, {});
-        een9_ASSERT_pl(status == SQLITE_ROW);
-        return HistoryId.value;
-    }
-
-    void internalapi_pollEvents_in_chat_collect_membership_events(SqliteConnection& conn,
-        std::vector<json::JSON>& events, int64_t chatId, int64_t LocalHistoryId) {
-        SqliteStatement membership_changes(conn,
-                    "SELECT `userId`, `role`, FROM `user_chat_membership` WHERE `chatId` = ?1 "
-                    "AND `chat_IncHistoryId` > ?2", {{1, chatId}, {2, LocalHistoryId}}, {});
-        fsql_integer_or_null ev_userId;
-        fsql_integer_or_null ev_user_role;
-        while (true) {
-            int status = sqlite_stmt_step(membership_changes,
-            {{0, &ev_userId}, {1, &ev_user_role}}, {});
-            if (status != SQLITE_ROW)
-                break;
-            events.emplace_back();
-            json::JSON& event = events.back();
-            event["member"] = json::JSON(ev_userId.value);
-            if (ev_user_role.value == user_chat_role_deleted) {
-                event["type"] = json::JSON("removedMember");
-            } else {
-                event["type"] = json::JSON("addedMember");
-                RowUser_Content USER = lookup_user_content(conn, ev_userId.value);
-                event["content"]["name"] = json::JSON(USER.name);
-                event["content"]["nickname"] = json::JSON(USER.nickname);
-                event["content"]["role"] = json::JSON(stringify_user_chat_role(ev_user_role.value));
-            }
-            events.push_back(event);
-        }
-    }
-
-    void internalapi_pollEvents_in_chat_collect_messages_events(SqliteConnection& conn,
-        std::vector<json::JSON>& events, int64_t chatId, int64_t LocalHistoryId) {
-        SqliteStatement messages_changes(conn,
-            "SELECT `id`, `previous`, `senderUserId`, `exists`, `isSystem`, `text` FROM `messages` WHERE "
-            "WHERE `chatId` = ?1 AND `chat_IncHistoryId` > ?2", {{1, chatId}, {2, LocalHistoryId}}, {});
-        fsql_integer_or_null ev_msgId, ev_previousMsgId, msgSenderUserId, msgExists, msgIsSystem;
-        fsql_text8_or_null msgText;
-        while (true) {
-            int status = sqlite_stmt_step(messages_changes,
-                {{0, &ev_msgId}, {1, &ev_previousMsgId}, {2, &msgSenderUserId}, {3, &msgExists}, {4, &msgIsSystem}},
-                {{5, &msgText}});
-            if (status != SQLITE_ROW)
-                break;
-            events.emplace_back();
-            json::JSON& event = events.back();
-            event["type"] = json::JSON("newMessage");
-            event["id"] = json::JSON(ev_msgId.value);
-            event["previous"] = json::JSON(ev_previousMsgId.value);
-            event["content"]["sender"] = json::JSON(msgSenderUserId.value);
-            event["content"]["isSystem"] = json::JSON((bool)msgIsSystem.value);
-            event["content"]["text"] = json::JSON(msgText.value);
-            events.push_back(event);
-        }
-    }
-
-    void internalapi_pollEvents_in_user_chatList_collect_events(SqliteConnection& conn,
-        std::vector<json::JSON>& events, int64_t userId, int64_t LocalHistoryId) {
-        SqliteStatement membership_changes(conn,
-            "SELECT `chatId`, `role` FROM `user_chat_membership` WHERE `userId` = ?1 "
-            "AND `user_chatList_IncHistoryId` > ?2", {{1, userId}, {2, LocalHistoryId}});
-        fsql_integer_or_null ev_chatId, usersRoleHere;
-        while (true) {
-            int status = sqlite_stmt_step(membership_changes, {{0, &ev_chatId}, {1, &usersRoleHere}}, {});
-            if (status != SQLITE_ROW)
-                break;
-            events.emplace_back();
-            json::JSON& event = events.back();
-            event["id"] = json::JSON(ev_chatId.value);
-            if (usersRoleHere.value == user_chat_role_deleted) {
-                event["type"] = json::JSON("removedChat");
-            } else {
-                event["type"] = json::JSON("addedChat");
-                RowChat_Content CHAT = lookup_chat_content(conn, ev_chatId.value);
-                event["content"]["name"] = json::JSON(CHAT.name);
-                event["content"]["nickname"] = json::JSON(CHAT.nickname);
-                event["content"]["lastMsgId"] = json::JSON(CHAT.lastMsgId);
-                event["content"]["roleHere"] = json::JSON(stringify_user_chat_role(usersRoleHere.value));
-            }
-        }
-    }
-
-    int64_t event_polling_fill_chat_hist_entity_response(SqliteConnection& conn, json::JSON& hist_entity_response,
-            int64_t uid, int64_t chatId, int64_t LocalHistoryId) {
-        hist_entity_response["type"] = json::JSON("chat");
-        if (get_role_of_user_in_chat(conn, uid, chatId) == user_chat_role_deleted)
-            een9_THROW("internalapi/pollEvents: trying to access chat that user does not belong to");
-        hist_entity_response["chatId"] = json::JSON(chatId);
-        int64_t NewHistoryId = get_current_history_id_of_chat(conn, chatId);
-        hist_entity_response["HistoryId"] = json::JSON(NewHistoryId);
-
-        hist_entity_response["events"] = json::JSON(json::array);
-        std::vector<json::JSON>& events = hist_entity_response["events"].g().asArray();
-        /* Two classes of 'real events' can happen to chat: membership table change, message table change */
-        /* Here, I collect membership changes (related to this chat) */
-        internalapi_pollEvents_in_chat_collect_membership_events(conn, events, chatId, LocalHistoryId);
-        /* Here, I collect message changes (related to this chat) */
-        internalapi_pollEvents_in_chat_collect_messages_events(conn, events, chatId, LocalHistoryId);
-        return NewHistoryId;
-    }
-
-    int64_t event_polling_fill_chatlist_hist_entity_response(SqliteConnection& conn, json::JSON& hist_entity_response,
-            int64_t uid, int64_t LocalHistoryId) {
-        hist_entity_response["type"] = json::JSON("chatlist");
-        int64_t NewHistoryId = get_current_history_id_of_user_chatList(conn, uid);
-        hist_entity_response["HistotyId"] = json::JSON(NewHistoryId);
-
-        hist_entity_response["events"] = json::JSON(json::array);
-        std::vector<json::JSON>& events = hist_entity_response["events"].g().asArray();
-        internalapi_pollEvents_in_user_chatList_collect_events(conn, events, uid, LocalHistoryId);
-        return NewHistoryId;
-    }
-
-    json::JSON internalapi_pollEvents(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        Recv["update"] = json::JSON(json::array);
-        const std::vector<json::JSON>& req_scope = Sent["scope"].g().asArray();
-        std::vector<json::JSON>& updated = Recv["update"].g().asArray();
-        for (const json::JSON& hist_entity_request: req_scope) {
-            updated.emplace_back();
-            json::JSON& hist_entity_response = updated.back();
-            const int64_t LocalHistoryId = hist_entity_request["LocalHistoryId"].g().asInteger().get_int();
-            if (hist_entity_request["type"].g().asString() == "chat") {
-                int64_t chatId = hist_entity_request["chatId"].g().asInteger().get_int();
-                event_polling_fill_chat_hist_entity_response(conn, hist_entity_response, uid, chatId, LocalHistoryId);
-            } else if (hist_entity_request["type"].g().asString() == "chatlist") {
-                event_polling_fill_chatlist_hist_entity_response(conn, hist_entity_response, uid, LocalHistoryId);
-            } else
-                een9_THROW("Bad request");
-        }
-        return Recv;
-    }
-}
\ No newline at end of file
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removechat.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removechat.cpp
deleted file mode 100644
index 5d00493..0000000
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removechat.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-#include "server_data_interact.h"
-#include <engine_engine_number_9/baza_throw.h>
-
-namespace iu9cawebchat {
-    json::JSON internalapi_removeChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        // todo: WRITE THIS MORBID THING
-        return Recv;
-    }
-}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removememberfromchat.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removememberfromchat.cpp
index 2c452f9..a2dc896 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removememberfromchat.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_removememberfromchat.cpp
@@ -2,14 +2,36 @@
 #include <engine_engine_number_9/baza_throw.h>
 
 namespace iu9cawebchat {
+    void kick_from_chat(SqliteConnection& conn, int64_t alienUserId, int64_t chatId) {
+        if (get_role_of_user_in_chat(conn, alienUserId, chatId) == user_chat_role_deleted)
+            een9_THROW("Can't delete a deleted member");
+        int64_t chat_HistoryId_BEFORE_EV = get_current_history_id_of_chat(conn, chatId);
+        int64_t alien_chatlist_HistoryId_BEFORE_EV = get_current_history_id_of_user_chatList(conn, alienUserId);
+
+        sqlite_nooutput(conn,
+        "UPDATE `user_chat_membership` SET `user_chatList_IncHistoryId` = ?3,"
+        "`chat_IncHistoryId` = ?4, `role` = ?5 WHERE `userId` = ?1 AND `chatId` = ?2",
+            {{1, alienUserId}, {2, chatId}, {3, alien_chatlist_HistoryId_BEFORE_EV + 1},
+            {4, chat_HistoryId_BEFORE_EV + 1}, {5, user_chat_role_deleted}}, {});
+
+        sqlite_nooutput(conn,
+            "UPDATE `chat` SET `it_HistoryId` = ?1 WHERE `id` = ?2", {{1, chat_HistoryId_BEFORE_EV + 1},
+            {2, chatId}}, {});
+
+        sqlite_nooutput(conn,
+            "UPDATE `user` SET `chatList_HistoryId` = ?1 WHERE `id` = ?2",
+            {{1, alien_chatlist_HistoryId_BEFORE_EV + 1}, {2, alienUserId}}, {});
+    }
+
     json::JSON internalapi_removeMemberFromChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["chatId"].g().asInteger().get_int();
+        int64_t chatId = Sent["chatUpdReq"]["chatId"].asInteger().get_int();
         int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
-        if (my_role_here == user_chat_role_deleted)
-            een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
+        if (my_role_here != user_chat_role_deleted)
+            een9_THROW("Only admin can delete members of chat");
+        int64_t badAlienId = Sent["chatUpdReq"]["userId"].asInteger().get_int();
+        kick_from_chat(conn, badAlienId, chatId);
         json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        // todo: WRITE THIS MORBID THING
+        poll_update_chat(conn, Sent, Recv);
         return Recv;
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_sendmessage.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_sendmessage.cpp
index de27b9c..8129027 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_sendmessage.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/api_sendmessage.cpp
@@ -3,46 +3,39 @@
 #include "../str_fields.h"
 
 namespace iu9cawebchat {
-    /* Throws excetion on failure
-     * Chat's HistoryId will increment after this operation, incremented
+    /* No authorization check is performed
+     * Chat's HistoryId will increment after this operation
      * if adding system message, uid is ignored
      */
-    int64_t insert_new_message(SqliteConnection& conn, int64_t uid, int64_t chatId,
+    void insert_new_message(SqliteConnection& conn, int64_t uid, int64_t chatId,
             const std::string& text, bool isSystem) {
         int64_t chat_HistoryId_BEFORE_MSG = get_current_history_id_of_chat(conn, chatId);
-        if (chat_HistoryId_BEFORE_MSG > INT64_MAX - 100)
-            een9_THROW("please no");
+        int64_t chat_lastMsgId = get_lastMsgId_of_chat(conn, chatId);
         SqliteStatement req(conn,
-            "INSERT INTO `message` (`chatId`, `previous`, `senderUserId`, `exists`, `isSystem`, `text`,"
-            "`chat_IncHistoryId`) VALUES (?1, ?2, ?3, 1, ?4, ?5, ?6)",
-            {{1, chatId}, {4, (int64_t)isSystem}, {6, chat_HistoryId_BEFORE_MSG + 1}}, {{5, text}});
-        int64_t chat_cur_last_msg_id = get_lastMsgId_of_chat(conn, chatId);
-        if (chat_cur_last_msg_id >= 0)
-            sqlite_stmt_bind_int64(req, 2, chat_cur_last_msg_id);
+            "INSERT INTO `message` (`chatId`, `id`, `senderUserId`, `exists`, `isSystem`, `chat_IncHistoryId`, "
+            "`text`) VALUES (?1, ?2, ?3 1, ?4, ?5, ?6)",
+            {{1, chatId}, {2, chat_lastMsgId + 1}, {4, (int64_t)isSystem}, {5, chat_HistoryId_BEFORE_MSG + 1}}, {{6, text}});
         if (!isSystem)
             sqlite_stmt_bind_int64(req, 3, uid);
-        int64_t MSG_ID = sqlite_trsess_last_insert_rowid(conn);
         sqlite_nooutput(conn, "UPDATE `chat` SET `lastMsgId` = ?1, `it_HistoryId` = ?2 WHERE `id` = ?3",
-            {{1, MSG_ID}, {2, chat_HistoryId_BEFORE_MSG + 1}, {3, chatId}}, {});
-        return MSG_ID;
+            {{1, chat_lastMsgId + 1}, {2, chat_HistoryId_BEFORE_MSG + 1}, {3, chatId}}, {});
     }
 
     json::JSON internalapi_sendMessage(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
-        int64_t chatId = Sent["chatId"].g().asInteger().get_int();
+        int64_t chatId = Sent["chatUpdReq"].asInteger().get_int();
         int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
         if (my_role_here == user_chat_role_deleted)
             een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
         if (my_role_here == user_chat_role_read_only)
             een9_THROW("read-only user can't send messages");
-        const int64_t LocalHistoryId = Sent["LocalHistoryId"].g().asInteger().get_int();
-        std::string text = Sent["content"]["text"].g().asString();
+
+        std::string text = Sent["content"]["text"].asString();
         if (!is_orthodox_string(text) || text.empty())
             een9_THROW("Bad input text");
-        int64_t MSG_ID = insert_new_message(conn, uid, chatId, text, false);
+        insert_new_message(conn, uid, chatId, text, false);
+
         json::JSON Recv;
-        Recv["status"] = json::JSON(0l);
-        json::JSON hist_ent_response = Recv["update"][0].g();
-        event_polling_fill_chat_hist_entity_response(conn, hist_ent_response, uid, chatId, LocalHistoryId);
+        poll_update_chat(conn, Sent, Recv);
         return Recv;
     }
 }
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 5fb613d..08add79 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
@@ -20,64 +20,45 @@ namespace iu9cawebchat {
             if (ret_logged_in_user >= 0) {
                 ret_userinfo["uid"] = json::JSON(ret_logged_in_user);
                 ret_userinfo["nickname"] = json::JSON(tried.nickname);
-                ret_userinfo["name"] = json::JSON(find_user_name(conn, ret_logged_in_user));
+                ret_userinfo["name"] = json::JSON(get_user_name(conn, ret_logged_in_user));
             }
         }
     }
 
-    std::string R200_pres_uinfo(const std::string& el_name, WorkerGuestData& wgd,
-                     const json::JSON& config_presentation,
-                     const json::JSON& userinfo) {
-
-        std::string page = wgd.templater->render(el_name, {&config_presentation, &userinfo});
+    std::string 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);
     }
 
-    std::string R200_pres_uinfo_msges(const std::string& el_name, WorkerGuestData& wgd,
-        const json::JSON& config_presentation,
-        const json::JSON& userinfo, const std::vector<HtmlMsgBox>& messages) {
-
-        json::JSON jmessages;
-        // todo: optimize
+    json::JSON jsonify_html_message_list(const std::vector<HtmlMsgBox>& messages) {
+        json::JSON jmessages(json::array);
         for (size_t i = 0; i < messages.size(); i++) {
-            jmessages[i]["class"] = json::JSON(messages[i].class_);
-            jmessages[i]["text"] = json::JSON(messages[i].text);
+            jmessages[i]["class"].asString() = messages[i].class_;
+            jmessages[i]["text"].asString() = messages[i].text;
         }
-        std::string page = wgd.templater->render(el_name, {&config_presentation, &userinfo, &jmessages});
-        return een9::form_http_server_response_200("text/html", page);
+        return jmessages;
+    }
+
+    std::string 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,
-        const std::function<json::JSON(SqliteConnection&, int64_t, const json::JSON&)>& F) {
+                                 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_pollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_pollEvents);
+    std::string when_internalapi_chatpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
+        return when_internalapi(wgd, req, uid, internalapi_chatPollEvents);
     }
 
-    std::string when_internalapi_getchatlist(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_getChatList);
-    }
-
-    std::string when_internalapi_getchatinfo(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_getChatInfo);
-    }
-
-    std::string when_internalapi_getchatmemberlist(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_getChatMemberList);
-    }
-
-    std::string when_internalapi_getuserinfo(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_getUserInfo);
-    }
-
-    std::string when_internalapi_getmessageinfo(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_getMessageInfo);
+    std::string 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) {
@@ -104,7 +85,7 @@ namespace iu9cawebchat {
         return when_internalapi(wgd, req, uid, internalapi_createChat);
     }
 
-    std::string when_internalapi_removechat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid) {
-        return when_internalapi(wgd, req, uid, internalapi_removeChat);
+    std::string 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 ab97249..70c173d 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
@@ -27,18 +27,17 @@ namespace iu9cawebchat {
             int64_t& ret_logged_in_user
         );
 
-    std::string R200_pres_uinfo(const std::string& el_name, WorkerGuestData& wgd,
-        const json::JSON& config_presentation,
-        const json::JSON& userinfo);
+    std::string http_R200(const std::string& el_name, WorkerGuestData& wgd,
+        const std::vector<const json::JSON*>& args);
 
     struct HtmlMsgBox {
         std::string class_;
         std::string text;
     };
 
-    std::string R200_pres_uinfo_msges(const std::string& el_name, WorkerGuestData& wgd,
-        const json::JSON& config_presentation,
-        const json::JSON& userinfo, const std::vector<HtmlMsgBox>& messages);
+    json::JSON jsonify_html_message_list(const std::vector<HtmlMsgBox>& messages);
+
+    std::string page_E404(WorkerGuestData& wgd);
 
     /*  ========================== PAGES ================================== */
 
@@ -52,22 +51,13 @@ namespace iu9cawebchat {
                                const een9::ClientRequest& req, const json::JSON& userinfo);
 
     std::string when_page_user(WorkerGuestData& wgd, const json::JSON& config_presentation,
-            const een9::ClientRequest& req, const json::JSON& userinfo);
+            const een9::ClientRequest& req, const std::vector<LoginCookie>& login_cookies, const json::JSON& userinfo);
 
 
     /* ========================  API  ============================== */
+    std::string when_internalapi_chatpollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
 
-    std::string when_internalapi_pollevents(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
-
-    std::string when_internalapi_getchatlist(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
-
-    std::string when_internalapi_getchatinfo(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
-
-    std::string when_internalapi_getchatmemberlist(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
-
-    std::string when_internalapi_getuserinfo(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
-
-    std::string when_internalapi_getmessageinfo(WorkerGuestData& wgd, const een9::ClientRequest& req, int64_t uid);
+    std::string 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);
 
@@ -81,7 +71,7 @@ namespace iu9cawebchat {
 
     std::string when_internalapi_createchat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
 
-    std::string when_internalapi_removechat(WorkerGuestData &wgd, const een9::ClientRequest &req, int64_t uid);
+    std::string 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/polling.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/polling.cpp
new file mode 100644
index 0000000..83902ff
--- /dev/null
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/polling.cpp
@@ -0,0 +1,196 @@
+#include "server_data_interact.h"
+#include <assert.h>
+#include <engine_engine_number_9/baza_throw.h>
+
+namespace iu9cawebchat {
+    json::JSON poll_update_chat_list_resp(SqliteConnection& conn, int64_t userId, int64_t LocalHistoryId) {
+        json::JSON chatListUpdResp;
+        SqliteStatement my_membership_changes(conn,
+           "SELECT `chatId`, `role` FROM `user_chat_membership` WHERE `userId` = ?1 "
+           "AND `user_chatList_IncHistoryId` > ?2", {{1, userId}, {2, LocalHistoryId}});
+        json::jarr myChats = chatListUpdResp["myChats"].asArray();
+        while (true) {
+            fsql_integer_or_null ev_chatId, usersRoleHere;
+            int status = sqlite_stmt_step(my_membership_changes, {{0, &ev_chatId}, {1, &usersRoleHere}}, {});
+            if (status != SQLITE_ROW)
+                break;
+            myChats.emplace_back();
+            json::JSON& myMembershipSt = myChats.back();
+            myMembershipSt["chatId"].asInteger() = json::Integer(ev_chatId.value);
+            myMembershipSt["myRoleHere"].asString() = stringify_user_chat_role(usersRoleHere.value);
+            if (usersRoleHere.value != user_chat_role_deleted) {
+                RowChat_Content CHAT = lookup_chat_content(conn, ev_chatId.value);
+                myMembershipSt["chatName"].asString() = CHAT.name;
+                myMembershipSt["chatNickname"].asString() = CHAT.nickname;
+            }
+        }
+        int64_t HistoryId = get_current_history_id_of_user_chatList(conn, userId);
+        chatListUpdResp["HistoryId"].asInteger() = json::Integer(HistoryId);
+        return chatListUpdResp;
+    }
+
+    void poll_update_chat_list(SqliteConnection& conn, int64_t userId, const json::JSON& Sent, json::JSON& Recv) {
+        Recv["status"].asInteger() = json::Integer(0l);
+        // todo: in libjsonincpp: get rid of Integer
+        poll_update_chat_list_resp(conn, userId, Sent["chatListUpdReq"]["LocalHistoryId"].asInteger().get_int());
+    }
+
+    json::JSON make_messageSt_obj(int64_t id, int64_t senderUserId, bool exists, bool isSystem, const std::string& text) {
+        json::JSON messageSt;
+        messageSt["id"].asInteger() = json::Integer(id);
+        if (!isSystem)
+            messageSt["senderUserId"].asInteger() = json::Integer(senderUserId);
+        messageSt["exists"] = json::JSON(exists);
+        messageSt["isSystem"] = json::JSON(isSystem);
+        if (exists)
+            messageSt["text"].asString() = text;
+        return messageSt;
+    }
+
+    json::jarr poll_update_chat_resp_messages(SqliteConnection& conn, int64_t chatId, int64_t LocalHistoryId,
+        int64_t QSEG_A, int64_t QSEG_B) {
+
+        json::jarr messages;
+        SqliteStatement messages_changes(conn,
+            "SELECT `id`, `senderUserId`, `exists`, `isSystem`, `text` FROM `messages` "
+            "WHERE `chatId` = ?1 AND ( `chat_IncHistoryId` > ?2 OR ( ?3 <= `id` AND `id` <= ?4 ) )",
+            {{1, chatId}, {2, LocalHistoryId}, {3, QSEG_A}, {4, QSEG_B}}, {});
+        while (true) {
+            fsql_integer_or_null msgId, msgSenderUserId, msgExists, msgIsSystem;
+            fsql_text8_or_null msgText;
+            int status = sqlite_stmt_step(messages_changes,
+                {{0, &msgId}, {1, &msgSenderUserId}, {2, &msgExists}, {3, &msgIsSystem}},
+                {{4, &msgText}});
+            if (status != SQLITE_ROW)
+                break;
+            messages.push_back(make_messageSt_obj(msgId.value, msgSenderUserId.value, msgExists.value,
+                msgIsSystem.value, msgText.value));
+        }
+        return messages;
+    }
+
+    json::jarr poll_update_chat_resp_members(SqliteConnection& conn, int64_t chatId, int64_t LocalHistoryId) {
+        json::jarr members;
+
+        SqliteStatement membership_changes(conn,
+                   "SELECT `userId`, `role`, FROM `user_chat_membership` WHERE `chatId` = ?1 "
+                   "AND `chat_IncHistoryId` > ?2", {{1, chatId}, {2, LocalHistoryId}}, {});
+        while (true) {
+            fsql_integer_or_null alienUserId;
+            fsql_integer_or_null alienRoleHere;
+            int status = sqlite_stmt_step(membership_changes,
+                {{0, &alienUserId}, {1, &alienRoleHere}}, {});
+            if (status != SQLITE_ROW)
+                break;
+            members.emplace_back();
+            json::JSON& memberSt = members.back();
+            memberSt["userId"].asInteger() = json::Integer(alienUserId.value);
+            memberSt["roleHere"].asString() = stringify_user_chat_role(alienRoleHere.value);
+            if (alienRoleHere.value != user_chat_role_deleted) {
+                RowUser_Content alien = lookup_user_content(conn, alienUserId.value);
+                memberSt["name"].asString() = alien.name;
+                memberSt["nickname"].asString() = alien.nickname;
+            }
+        }
+        return members;
+    }
+
+    json::JSON poll_update_chat_ONE_MSG_resp(SqliteConnection& conn, int64_t chatId, int64_t selectedMsg) {
+        json::JSON chatUpdResp;
+
+        chatUpdResp["members"].asArray() = poll_update_chat_resp_members(conn, chatId, 0);
+
+
+        json::jarr messages = chatUpdResp["messages"].asArray();
+        if (selectedMsg >= 0) {
+            RowMessage_Content msg = lookup_message_content(conn, chatId, selectedMsg);
+            messages.push_back(make_messageSt_obj(msg.id, msg.senderUserId, msg.exists, msg.isSystem, msg.text));
+        }
+
+        int64_t lastMsgId = get_lastMsgId_of_chat(conn, chatId);
+        chatUpdResp["lastMsgId"].asInteger() = json::Integer(lastMsgId);
+
+        int64_t HistoryId = get_current_history_id_of_chat(conn, chatId);
+        chatUpdResp["HistoryId"].asInteger() = json::Integer(HistoryId);
+        return chatUpdResp;
+    }
+
+    json::JSON poll_update_chat_important_segment_resp(SqliteConnection& conn, int64_t chatId, int64_t LocalHistoryId,
+        int64_t QSEG_A, int64_t QSEG_B) {
+
+        json::JSON chatUpdResp;
+
+        chatUpdResp["members"].asArray() = poll_update_chat_resp_members(conn, chatId, LocalHistoryId);
+        chatUpdResp["messages"].asArray() = poll_update_chat_resp_messages(conn, chatId, LocalHistoryId, QSEG_A, QSEG_B);
+
+        int64_t lastMsgId = get_lastMsgId_of_chat(conn, chatId);
+        chatUpdResp["lastMsgId"].asInteger() = json::Integer(lastMsgId);
+
+        int64_t HistoryId = get_current_history_id_of_chat(conn, chatId);
+        chatUpdResp["HistoryId"].asInteger() = json::Integer(HistoryId);
+        return chatUpdResp;
+    }
+
+    /* chat polling function MUST have one queer feature: it accepts a range of msgId, which are guaranteed to be
+     * lookud up. */
+    void poll_update_chat_important_segment(SqliteConnection& conn, const json::JSON& Sent, json::JSON& Recv,
+        int64_t QSEG_A, int64_t QSEG_B) {
+
+        Recv["status"].asInteger() = json::Integer(0l);
+        Recv["charUpdResp"] = poll_update_chat_important_segment_resp(conn,
+            Sent["chatUpdReq"]["chatId"].asInteger().get_int(),
+            Sent["chatUpdReq"]["LocalHistoryId"].asInteger().get_int(), QSEG_A, QSEG_B);
+    }
+
+    void poll_update_chat(SqliteConnection& conn, const json::JSON& Sent, json::JSON& Recv) {
+        poll_update_chat_important_segment(conn, Sent, Recv, -1, -2);
+    }
+
+    json::JSON internalapi_chatPollEvents(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        int64_t chatId = Sent["chatUpdReq"]["chatId"].asInteger().get_int();
+        if (get_role_of_user_in_chat(conn, uid, chatId) == user_chat_role_deleted)
+            een9_THROW("chatPollEvents: trying to access chat that user does not belong to");
+        json::JSON Recv;
+        poll_update_chat(conn, Sent, Recv);
+        return Recv;
+    }
+
+    json::JSON internalapi_chatListPollEvents(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        json::JSON Recv;
+        poll_update_chat_list(conn, uid, Sent, Recv);
+        return Recv;
+    }
+
+
+    /* Reznya */
+    json::JSON internalapi_getMessageNeighbours(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        int64_t chatId = Sent["chatId"].asInteger().get_int();
+        if (get_role_of_user_in_chat(conn, uid, chatId) == user_chat_role_deleted)
+            een9_THROW("Authentication failure");
+        int64_t lastMsgId = get_lastMsgId_of_chat(conn, chatId);
+        bool dir_forward = Sent["direction"].asString() == "forward";
+        int64_t amount = Sent["amount"].asInteger().get_int();
+        int64_t K = Sent["msgId"].asInteger().get_int();
+        if (amount <= 0 || amount > 15)
+            een9_THROW("Incorrect amount");
+        json::JSON Recv;
+        int64_t qBeg = -1;
+        int64_t qEnd = -2;
+        if (lastMsgId >= 0) {
+            if (K < 0) {
+                if (dir_forward)
+                    een9_THROW("Can't go from the top of chat");
+                qBeg = std::max(0l, lastMsgId - amount + 1);
+                qEnd = lastMsgId;
+            } else if (dir_forward) {
+                qBeg = K + 1;
+                qEnd = K + amount;
+            } else {
+                qBeg = K - amount;
+                qEnd = K - 1;
+            }
+        }
+        poll_update_chat_important_segment(conn, Sent, Recv, qBeg, qEnd);
+        return Recv;
+    }
+}
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.cpp b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.cpp
index 6ff0cbe..5fefcc1 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.cpp
@@ -2,6 +2,7 @@
 
 #include <engine_engine_number_9/baza_throw.h>
 #include <engine_engine_number_9/http_structures/cookies.h>
+#include "../str_fields.h"
 
 namespace iu9cawebchat {
     const char* stringify_user_chat_role(int64_t role) {
@@ -27,7 +28,7 @@ namespace iu9cawebchat {
         return -1;
     }
 
-    std::string find_user_name (SqliteConnection& conn, int64_t uid) {
+    std::string get_user_name (SqliteConnection& conn, int64_t uid) {
         een9_ASSERT(uid >= 0, "Are you crazy?");
         SqliteStatement sql_req(conn,
            "SELECT `name` FROM `user` WHERE `id` = ?1",
@@ -50,7 +51,20 @@ namespace iu9cawebchat {
         fsql_text8_or_null name_col;
         int status = sqlite_stmt_step(sql_req, {}, {{0, &nickname_col}, {1, &name_col}});
         if (status == SQLITE_ROW) {
-            return {std::move(nickname_col.value), std::move(name_col.value)};
+            return {uid, std::move(nickname_col.value), std::move(name_col.value)};
+        }
+        een9_THROW("No such user");
+    }
+
+    RowUser_Content lookup_user_content_by_nickname(SqliteConnection& conn, const std::string& nickname) {
+        SqliteStatement sql_req(conn,
+           "SELECT `id`, `name` FROM `user` WHERE `nickname` = ?1",
+           {}, {{1, nickname}});
+        fsql_integer_or_null id_col;
+        fsql_text8_or_null name_col;
+        int status = sqlite_stmt_step(sql_req, {{0, &id_col}}, {{1, &name_col}});
+        if (status == SQLITE_ROW) {
+            return {id_col.value, nickname, std::move(name_col.value)};
         }
         een9_THROW("No such user");
     }
@@ -65,7 +79,22 @@ namespace iu9cawebchat {
         fsql_integer_or_null last_msg_id_col;
         int status = sqlite_stmt_step(sql_req, {{2, &last_msg_id_col}}, {{0, &nickname_col}, {1, &name_col}});
         if (status == SQLITE_ROW) {
-            return {std::move(nickname_col.value), std::move(name_col.value),
+            return {chatId, std::move(nickname_col.value), std::move(name_col.value),
+                last_msg_id_col.exist ? last_msg_id_col.value : -1};
+        }
+        een9_THROW("No such chat");
+    }
+
+    RowChat_Content lookup_chat_content_by_nickname(SqliteConnection &conn, const std::string& nickname) {
+        SqliteStatement sql_req(conn,
+           "SELECT `id`, `name`, `lastMsgId` FROM `chat` WHERE `nickname` = ?1",
+           {}, {{1, nickname}});
+        fsql_integer_or_null id_col;
+        fsql_text8_or_null name_col;
+        fsql_integer_or_null last_msg_id_col;
+        int status = sqlite_stmt_step(sql_req, {{0, &id_col}, {2, &last_msg_id_col}}, {{1, &name_col}});
+        if (status == SQLITE_ROW) {
+            return {id_col.value, nickname, std::move(name_col.value),
                 last_msg_id_col.exist ? last_msg_id_col.value : -1};
         }
         een9_THROW("No such chat");
@@ -73,39 +102,21 @@ namespace iu9cawebchat {
 
     RowMessage_Content lookup_message_content(SqliteConnection& conn, int64_t chatId, int64_t msgId) {
         SqliteStatement req(conn,
-            "SELECT `previousId`, `senderUserId`, `exists`, `isSystem`, `text` FROM `message` WHERE "
+            "SELECT `senderUserId`, `exists`, `isSystem`, `text` FROM `message` WHERE "
             "`chatId` = ?1 AND `id` = ?2", {{1, chatId}, {2, msgId}}, {});
-        fsql_integer_or_null previousId, senderUserId, exists, isSystem;
+        fsql_integer_or_null senderUserId, exists, isSystem;
         fsql_text8_or_null msg_text;
-        int status = sqlite_stmt_step(req, {{0, &previousId}, {1, &senderUserId}, {2, &exists}, {3, &isSystem}},
-            {{4, &msg_text}});
+        int status = sqlite_stmt_step(req, {{0, &senderUserId}, {1, &exists}, {2, &isSystem}},
+            {{3, &msg_text}});
         if (status == SQLITE_ROW) {
             if (!(bool)exists.value)
-                een9_THROW("Message existed, but now it isn't");
-            return {(bool)isSystem.value, msg_text.value, senderUserId.exist ? senderUserId.value : -1,
-            previousId.exist ? previousId.value : -1};
+                een9_THROW("Message existed, but now it does not");
+            return {msgId, senderUserId.exist ? senderUserId.value : -1, (bool)exists.value,
+                (bool)isSystem.value, msg_text.value};
         }
         een9_THROW("No such message");
     }
 
-    std::pair<int64_t, RowMessage_Content> lookup_message_content_rev_side(SqliteConnection& conn, int64_t chatId, int64_t prevMsgId) {
-        een9_ASSERT(prevMsgId >= 0, "V durku dobro pozhalovat");
-        SqliteStatement req(conn,
-            "SELECT `id`, `senderUserId`, `exists`, `isSystem`, `text` FROM `message` WHERE "
-            "`chatId` = ?1 AND `previous` = ?2", {{1, chatId}, {2, prevMsgId}}, {});
-        fsql_integer_or_null id, senderUserId, exists, isSystem;
-        fsql_text8_or_null msg_text;
-        int status = sqlite_stmt_step(req, {{0, &id}, {1, &senderUserId}, {2, &exists}, {3, &isSystem}},
-            {{4, &msg_text}});
-        if (status == SQLITE_ROW) {
-            een9_ASSERT_pl(exists.value == 1);
-            return {id.value,
-                {(bool)isSystem.value, msg_text.value, senderUserId.exist ? senderUserId.value : -1, prevMsgId}};
-        }
-        return {-1, {}};
-    }
-
-
     int64_t get_role_of_user_in_chat(SqliteConnection& conn, int64_t userId, int64_t chatId) {
         SqliteStatement req(conn,
             "SELECT `role` FROM `user_chat_membership` WHERE `userId` = ?1 AND `chatId` = ?2",
@@ -132,4 +143,103 @@ namespace iu9cawebchat {
 
     /* All the api calls processing is done in dedicated files.
      * All functions related to polling are defined in api_pollevents.cpp */
+
+    // todo: move everything to dedicated files
+    int64_t get_current_history_id_of_chat(SqliteConnection& conn, int64_t chatId) {
+        SqliteStatement req(conn, "SELECT `it_HistoryId` FROM `chat` WHERE `id` = ?1", {{1, chatId}}, {});
+        fsql_integer_or_null HistoryId;
+        int status = sqlite_stmt_step(req, {{0, &HistoryId}}, {});
+        een9_ASSERT_pl(status == SQLITE_ROW);
+        return HistoryId.value;
+    }
+
+    int64_t get_current_history_id_of_user_chatList(SqliteConnection& conn, int64_t userId) {
+        SqliteStatement req(conn, "SELECT `chatList_HistoryId` FROM `user` WHERE `id` = ?1", {{1, userId}}, {});
+        fsql_integer_or_null HistoryId;
+        int status = sqlite_stmt_step(req, {{0, &HistoryId}}, {});
+        een9_ASSERT_pl(status == SQLITE_ROW);
+        return HistoryId.value;
+    }
+
+
+    // todo: extract useful clues from deprecated code.
+    // todo: deprecated code goes here:
+    /* !!! DEPRECATED FUNCTION */
+    json::JSON toremoveinternalapi_getChatList(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        json::JSON Recv;
+        Recv["status"] = json::JSON(0l);
+        Recv["chats"] = json::JSON(json::array);
+        std::vector<json::JSON>& chats = Recv["chats"].asArray();
+        SqliteStatement req(conn,
+            "SELECT `chat`.`id`, `chat`.`nickname`, `chat`.`name`, `chat`.`lastMsgId`, "
+            "`user_chat_membership`.`role` FROM `chat` "
+            "RIGHT JOIN `user_chat_membership` ON `chat`.`id` = `user_chat_membership`.`chatId` "
+            "WHERE `user_chat_membership`.`userId` = ?1 ", {{1, uid}}, {});
+        while (true) {
+            fsql_integer_or_null chat_id;
+            fsql_text8_or_null chat_nickname, chat_name;
+            fsql_integer_or_null chat_lastMsgId, role_here;
+            int status = sqlite_stmt_step(req, {{0, &chat_id}, {3, &chat_lastMsgId}, {4, &role_here}},
+                {{1, &chat_nickname}, {2, &chat_name}});
+            if (status != SQLITE_ROW)
+                break;
+            chats.emplace_back();
+            json::JSON& chat = chats.back();
+            chat["id"] = json::JSON(chat_id.value);
+            chat["content"]["nickname"] = json::JSON(chat_nickname.value);
+            chat["content"]["name"] = json::JSON(chat_name.value);
+            chat["content"]["lastMsgId"] = json::JSON(chat_lastMsgId.exist ? chat_lastMsgId.value : -1);
+            chat["content"]["roleHere"] = json::JSON(stringify_user_chat_role(role_here.value));
+        }
+        return Recv;
+    }
+
+    /* !!! DEPRECATED FUNCTION */
+    json::JSON toremoveinternalapi_getChatMemberList(SqliteConnection& conn, int64_t uid, const json::JSON& Sent) {
+        int64_t chatId = Sent["id"].asInteger().get_int();
+        int64_t my_role_here = get_role_of_user_in_chat(conn, uid, chatId);
+        if (my_role_here == user_chat_role_deleted)
+            een9_THROW("Unauthorized user tries to access internalapi_getChatInfo");
+        json::JSON Recv;
+        Recv["status"] = json::JSON(0l);
+        Recv["members"] = json::JSON(json::array);
+        std::vector<json::JSON>& members = Recv["members"].asArray();
+        SqliteStatement req(conn,
+            "SELECT `user`.`id`, `user`.`nickname`, `user`.`name`, `user_chat_membership`.`role` FROM "
+            "`user` RIGHT JOIN `user_chat_membership` ON `user`.`id` = `user_chat_membership`.`userId` "
+            "WHERE `user_chat_membership`.`chatId` = ?1",
+            {{1, chatId}}, {});
+        while (true) {
+            fsql_integer_or_null this_user_id;
+            fsql_text8_or_null this_user_nickname, this_user_name;
+            fsql_integer_or_null this_users_role;
+            int status = sqlite_stmt_step(req, {{0, &this_user_id}, {3, &this_users_role}},
+                {{1, &this_user_nickname}, {2, &this_user_name}});
+            if (status != SQLITE_ROW)
+                break;
+            members.emplace_back();
+            json::JSON& member = members.back();
+            member["id"] = json::JSON(this_user_id.value);
+            member["content"]["nickname"] = json::JSON(this_user_nickname.value);
+            member["content"]["name"] = json::JSON(this_user_name.value);
+            member["content"]["role"] = json::JSON(this_users_role.value);
+        }
+        return Recv;
+    }
+
+    bool is_nickname_taken(SqliteConnection& conn, const std::string& nickname) {
+        if (!check_nickname(nickname))
+            return true;
+        SqliteStatement req(conn, "SELECT EXISTS(SELECT 1 FROM `nickname` WHERE `it` = ?1)",
+            {}, {{1, nickname}});
+        fsql_integer_or_null r{true, 0};
+        int status = sqlite_stmt_step(req, {{0, &r}}, {});
+        return r.value;
+    }
+
+    void reserve_nickname(SqliteConnection& conn, const std::string& nickname) {
+        if (!check_nickname(nickname))
+            een9_THROW("PRECAUTION! Trying to insert incorrect nickname into nickname table");
+        sqlite_nooutput(conn, "INSERT INTO `nickname` (`it`) VALUES (?1)", {}, {{1, nickname}});
+    }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.h b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.h
index ef1eaa5..2d04c09 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.h
+++ b/src/web_chat/iu9_ca_web_chat_lib/backend_logic/server_data_interact.h
@@ -16,62 +16,70 @@ namespace iu9cawebchat {
     const char* stringify_user_chat_role(int64_t role);
 
     int64_t find_user_by_credentials (SqliteConnection& conn, const std::string& nickname, const std::string& password);
-    std::string find_user_name (SqliteConnection& conn, int64_t uid);
+    std::string get_user_name (SqliteConnection& conn, int64_t uid);
 
     struct RowUser_Content {
+        int64_t id;
         std::string nickname;
         std::string name;
     };
 
     struct RowChat_Content {
+        int64_t id;
         std::string nickname;
         std::string name;
         int64_t lastMsgId;  // Negative if it does not exist
     };
 
     RowUser_Content lookup_user_content(SqliteConnection& conn, int64_t uid);
+    RowUser_Content lookup_user_content_by_nickname(SqliteConnection& conn, const std::string& nickname);
     /* Does not make authorization check */
     RowChat_Content lookup_chat_content(SqliteConnection& conn, int64_t chatId);
+    RowChat_Content lookup_chat_content_by_nickname(SqliteConnection &conn, const std::string& nickname);
 
     struct RowMessage_Content {
+        int64_t id;
+        int64_t senderUserId;
+        bool exists;
         bool isSystem;
         std::string text;
-        int64_t senderUserId;
-        int64_t previous = -1;
     };
 
     RowMessage_Content lookup_message_content(SqliteConnection& conn, int64_t chatId, int64_t msgId);
 
-    /* If prevMsgId is id of the last message in chat, and there is no message ahead of it, .first = -1 */
-    std::pair<int64_t, RowMessage_Content> lookup_message_content_rev_side(SqliteConnection& conn, int64_t chatId, int64_t prevMsgId);
-
     /* Does not make authorization check */
     int64_t get_role_of_user_in_chat(SqliteConnection& conn, int64_t userId, int64_t chatId);
     /* Does not make authorization check */
     int64_t get_lastMsgId_of_chat(SqliteConnection& conn, int64_t chatId);
 
-    /* ============================= API ====================================*/
     int64_t get_current_history_id_of_chat(SqliteConnection& conn, int64_t chatId);
     int64_t get_current_history_id_of_user_chatList(SqliteConnection& conn, int64_t userId);
-    /* Returns HistoryId of chat (latest) */
-    int64_t event_polling_fill_chat_hist_entity_response(SqliteConnection& conn, json::JSON& hist_entity_response,
-            int64_t uid, int64_t chatId, int64_t LocalHistoryId);
-    /* Returns HistoryId of chat list (latest) */
-    int64_t event_polling_fill_chatlist_hist_entity_response(SqliteConnection& conn, json::JSON& hist_entity_response,
-            int64_t uid, int64_t LocalHistoryId);
-    json::JSON internalapi_pollEvents(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
-    json::JSON internalapi_getChatList(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
-    json::JSON internalapi_getChatInfo(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
-    json::JSON internalapi_getChatMemberList(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
-    json::JSON internalapi_getUserInfo(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
-    json::JSON internalapi_getMessageInfo(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
+
+    json::JSON poll_update_chat_list_resp(SqliteConnection& conn, int64_t userId, int64_t LocalHistoryId);
+    void poll_update_chat_list(SqliteConnection& conn, int64_t userId, const json::JSON& Sent, json::JSON& Recv);
+
+    json::JSON poll_update_chat_ONE_MSG_resp(SqliteConnection& conn, int64_t chatId, int64_t selectedMsg);
+    void poll_update_chat(SqliteConnection& conn, const json::JSON& Sent, json::JSON& Recv);
+
+    void make_her_a_member_of_the_midnight_crew(SqliteConnection& conn, int64_t chatId, int64_t alienUserId, int64_t role);
+    void kick_from_chat(SqliteConnection& conn, int64_t alienUserId, int64_t chatId);
+
+    bool is_nickname_taken(SqliteConnection& conn, const std::string& nickname);
+    void reserve_nickname(SqliteConnection& conn, const std::string& nickname);
+
+    /* ============================= API ==================================== */
+    json::JSON internalapi_chatPollEvents(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
+    json::JSON internalapi_chatListPollEvents(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
     json::JSON internalapi_getMessageNeighbours(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
     json::JSON internalapi_sendMessage(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
     json::JSON internalapi_deleteMessage(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
     json::JSON internalapi_addMemberToChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
     json::JSON internalapi_removeMemberFromChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
     json::JSON internalapi_createChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
-    json::JSON internalapi_removeChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
+    json::JSON internalapi_leaveChat(SqliteConnection& conn, int64_t uid, const json::JSON& Sent);
+
+    /**/
+    std::string admin_control_procedure(SqliteConnection& conn, const std::string& req, bool& termination);
 }
 
 #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 125cbe9..c0481ba 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
@@ -1,8 +1,54 @@
 #include "client_server_interact.h"
 
+#include <engine_engine_number_9/baza_throw.h>
+#include "../str_fields.h"
+
 namespace iu9cawebchat {
     std::string when_page_chat(WorkerGuestData& wgd, const json::JSON& config_presentation,
-            const een9::ClientRequest& req, const json::JSON& userinfo) {
-        return R200_pres_uinfo("chat", config_presentation, wgd, userinfo);
+        const een9::ClientRequest& req, const json::JSON& userinfo) {
+
+        std::vector<std::string> path_segs = {""};
+        path_segs.reserve(4);
+        for (char ch: req.uri_path) {
+            if (ch == '/')
+                path_segs.emplace_back();
+            else
+                path_segs.back() += ch;
+        }
+        // Parameter, passed from server to javascript
+        std::string chat_nickname;
+        int64_t selected_message_id = -1;
+        if (path_segs.size() >= 2) {
+            chat_nickname = std::move(path_segs[1]);
+        }
+        if (!check_nickname(chat_nickname))
+            return page_E404(wgd);
+        if (path_segs.size() == 2) {
+        } else if (path_segs.size() == 4) {
+            if (path_segs[2] != "m")
+                return page_E404(wgd);
+            selected_message_id = std::stoll(path_segs[3]);
+            return page_E404(wgd);
+        } else
+            return page_E404(wgd);
+
+        bool chat_members = (path_segs[0] == "chat-members");
+
+
+        // todo: do not throw id chat not found, catch exception and return 404
+        json::JSON openedchat;
+        RowChat_Content chatInfo = lookup_chat_content_by_nickname(*wgd.db, chat_nickname);
+        if (get_role_of_user_in_chat(*wgd.db, userinfo["id"].asInteger().get_int(), chatInfo.id) == user_chat_role_deleted) {
+            return page_E404(wgd);
+        }
+
+        openedchat["name"] = json::JSON(chatInfo.name);
+        openedchat["nickname"] = json::JSON(chatInfo.nickname);
+        openedchat["id"] = json::JSON(chatInfo.id);
+        openedchat["selectedMessageId"] = json::JSON(selected_message_id);  // -1 means that nothing was selected
+        json::JSON initial_chatUpdResp = poll_update_chat_ONE_MSG_resp(*wgd.db, chatInfo.id, selected_message_id);
+        if (chat_members)
+            return http_R200("chat", wgd, {&config_presentation, &userinfo, &openedchat, &initial_chatUpdResp});
+        return http_R200("chat", wgd, {&config_presentation, &userinfo, &openedchat, &initial_chatUpdResp});
     }
-}
\ No newline at end of file
+}
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 eb761f3..27b44ed 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
@@ -6,6 +6,8 @@ namespace iu9cawebchat {
         if (userinfo.isNull()) {
             return een9::form_http_server_response_303("/login");
         }
-        return R200_pres_uinfo("list-rooms", config_presentation, wgd, userinfo);
+        json::JSON initial_chatListUpdResp = poll_update_chat_list_resp(*wgd.db,
+            userinfo["uid"].asInteger().get_int(), 0);
+        return http_R200("list-rooms", wgd, {&config_presentation, &userinfo, &initial_chatListUpdResp});
     }
 }
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 11b658a..ba792f0 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
@@ -25,15 +25,18 @@ namespace iu9cawebchat {
             } catch(const std::exception& e){}
             if (uid < 0) {
                 printf("Redirecting back to /login because of incorrect credentials\n");
-                // class will be successfully ignored
-                return R200_pres_uinfo_msges("login", wgd, config_presentation, userinfo, {{"",
-                    config_presentation["phr"]["decl"]["incorrect-nickname-or-password"].g().asString()}});
+                json::JSON msg_list = jsonify_html_message_list({{"",
+                    config_presentation["phr"]["decl"]["incorrect-nickname-or-password"].asString()}});
+                return http_R200("login", wgd, {&config_presentation, &userinfo, &msg_list});
             }
             std::vector<std::pair<std::string, std::string>> response_hlines;
             LoginCookie new_login_cookie = create_login_cookie(nickname, password);
             add_set_cookie_headers_to_login(login_cookies, response_hlines, new_login_cookie);
             return een9::form_http_server_response_303_spec_head("/", response_hlines);
         }
-        return R200_pres_uinfo_msges("login", wgd, config_presentation, userinfo, {});
+        if (req.method != "GET")
+            een9_THROW("Bad method");
+        json::JSON empty_msg_list = json::JSON(json::array);
+        return http_R200("login", wgd, {&config_presentation, &userinfo, &empty_msg_list});
     }
 }
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 fc6db3d..d101165 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
@@ -1,8 +1,111 @@
 #include "client_server_interact.h"
+#include <engine_engine_number_9/form_data_structure/urlencoded_query.h>
+#include <engine_engine_number_9/baza_throw.h>
+#include <string.h>
+#include "../str_fields.h"
+#include "../login_cookie.h"
 
 namespace iu9cawebchat {
+    std::string get_user_bio(SqliteConnection& conn, int64_t userId) {
+        een9_ASSERT(userId >= 0, "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}});
+        if (status == SQLITE_ROW)
+            return bio_col.value;
+        een9_THROW("No such user");
+    }
+
+    static const char* pr_path = "/user/";
+
+    bool is_page_of_certain_user(const std::string& path) {
+        if (!een9::beginsWith(path, pr_path))
+            return false;
+        std::string r = path.substr(strlen(pr_path));
+        return check_nickname(r);
+    }
+
+    std::string obtain_nickname_in_user_page_path(const std::string& path) {
+        return path.substr(strlen(pr_path));
+    }
+
+    json::JSON user_row_to_userprofile_obj(SqliteConnection& conn, const RowUser_Content& alien) {
+        return json::JSON(json::jdict{
+            {"name", json::JSON(alien.name)},
+            {"nickname", json::JSON(alien.nickname)},
+            {"bio", json::JSON(get_user_bio(conn, alien.id))}
+        });
+    }
+
     std::string when_page_user(WorkerGuestData& wgd, const json::JSON& config_presentation,
-                const een9::ClientRequest& req, const json::JSON& userinfo) {
-        return R200_pres_uinfo("profile", config_presentation, wgd, userinfo);
+                const een9::ClientRequest& req, const std::vector<LoginCookie>& login_cookies, const json::JSON& userinfo) {
+        SqliteConnection& conn = *wgd.db;
+        if (!is_page_of_certain_user(req.uri_path))
+            return page_E404(wgd);
+        std::string alien_nickname = obtain_nickname_in_user_page_path(req.uri_path);
+        RowUser_Content alien;
+        try {
+            alien = lookup_user_content_by_nickname(conn, alien_nickname);
+        } catch (const std::exception& e) {
+            return page_E404(wgd);
+        }
+        // todo: in libjsonincpp: fix '999999 problem'
+        int64_t myuid = userinfo["uid"].asInteger().get_int();
+        bool can_edit = (alien.id == myuid);
+        if (req.method == "POST") {
+            std::vector<std::pair<std::string, std::string>> response_hlines;
+            try {
+                if (!can_edit)
+                    een9_THROW("Unauthorized access");
+                std::vector<std::pair<std::string, std::string>> query = een9::split_html_query(req.body);
+                // Profile update processing
+                std::string bio;
+                std::string name;
+                std::string password;
+                for (const std::pair<std::string, std::string>& p: query) {
+                    if (p.first == "bio")
+                        bio = p.second;
+                    else if (p.first == "name")
+                        name = p.second;
+                    else if (p.first == "password")
+                        password = p.second;
+                }
+                if (!bio.empty()) {
+                    if (!is_orthodox_string(bio) || bio.size() > 100000)
+                        een9_THROW("Incorrect `bio`");
+                    sqlite_nooutput(conn, "UPDATE `user` SET `bio` = ?1", {}, {{1, bio}});
+                }
+                if (!name.empty()) {
+                    if (!check_name(name))
+                        een9_THROW("Incorrect `name`");
+                    sqlite_nooutput(conn, "UPDATE `user` SET `name` = ?1", {}, {{1, name}});
+                }
+                if (!password.empty()) {
+                    if (!check_strong_password(password))
+                        een9_THROW("Incorrect `password`");
+                    sqlite_nooutput(conn, "UPDATE `user` SET `password` = ?1", {}, {{1, password}});
+                    if (alien.id == myuid) {
+                        LoginCookie new_login_cookie = create_login_cookie(userinfo["nickname"].asString(), password);
+                        add_set_cookie_headers_to_login(login_cookies, response_hlines, new_login_cookie);
+                    }
+                }
+            } catch (const std::exception& e) {
+                printf("Redirecting back to /user/... because of incorrect credentials\n");
+                json::JSON msg_list = jsonify_html_message_list({{"",
+                    config_presentation["phr"]["decl"]["incorrect-profile-data"].asString()}});
+                json::JSON alien_userprofile = user_row_to_userprofile_obj(conn, alien);
+                return http_R200("edit-profile", wgd, {&config_presentation, &alien_userprofile, &msg_list});
+            }
+            return een9::form_http_server_response_303_spec_head("/user/" + alien_nickname, response_hlines);
+        }
+        if (req.method == "GET") {
+            json::JSON alien_userprofile = user_row_to_userprofile_obj(conn, alien);
+            if (can_edit) {
+                json::JSON empty_msg_list = jsonify_html_message_list({});
+                return http_R200("edit-profile", wgd, {&config_presentation, &alien_userprofile, &empty_msg_list});
+            }
+            return http_R200("view-profile", wgd, {&config_presentation, &alien_userprofile});
+        }
+        een9_THROW("Bad method");
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/find_db.cpp b/src/web_chat/iu9_ca_web_chat_lib/find_db.cpp
index 56e39e4..5d5f050 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/find_db.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/find_db.cpp
@@ -2,15 +2,17 @@
 
 namespace iu9cawebchat{
     int find_db_sqlite_file_path(const json::JSON& config, std::string& res_path) {
-        const json::JSON& type = config["database"]["type"].g();
-        if (!type.isString() && type.asString() == "sqlite3")
+        try {
+            const std::string& type = config["database"]["type"].asString();
+            if (type != "sqlite3")
+                return -1;
+            const std::string& path = config["database"]["file"].asString();
+            if (path.empty() || path[0] == ':')
+                return -1;
+            res_path = path;
+        } catch (const json::misuse& e) {
             return -1;
-        const json::JSON& path = config["database"]["file"].g();
-        if (!path.isString())
-            return -1;
-        if (path.asString().empty() || path.asString()[0] == ':')
-            return -1;
-        res_path = path.asString();
+        }
         return 0;
     }
 }
diff --git a/src/web_chat/iu9_ca_web_chat_lib/initialize.cpp b/src/web_chat/iu9_ca_web_chat_lib/initialize.cpp
index dafc910..bbfb084 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/initialize.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/initialize.cpp
@@ -44,36 +44,38 @@ namespace iu9cawebchat {
                                              "`nickname` TEXT UNIQUE REFERENCES `nickname` NOT NULL,"
                                              "`name` TEXT NOT NULL,"
                                              "`chatList_HistoryId` INTEGER NOT NULL,"
-                                             "`password` TEXT NOT NULL"
+                                             "`password` TEXT NOT NULL,"
+                                             "`bio` TEXT NOT NULL"
                                              ")");
             sqlite_nooutput(conn, "CREATE TABLE `chat` ("
                                              "`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"
                                              "`nickname` TEXT UNIQUE REFERENCES `nickname` NOT NULL,"
                                              "`name` TEXT NOT NULL,"
                                              "`it_HistoryId` INTEGER NOT NULL,"
-                                             "`lastMsgId` INTEGER REFERENCES `message`"
+                                             "`lastMsgId` INTEGER NOT NULL"
                                              ")");
             sqlite_nooutput(conn, "CREATE TABLE `user_chat_membership` ("
                                              "`userId` INTEGER REFERENCES `user` NOT NULL,"
                                              "`chatId` INTEGER REFERENCES `chat` NOT NULL,"
                                              "`user_chatList_IncHistoryId` INTEGER NOT NULL,"
                                              "`chat_IncHistoryId` INTEGER NOT NULL,"
-                                             "`role` INTEGER NOT NULL"
+                                             "`role` INTEGER NOT NULL,"
+                                             "UNIQUE (`userId`, `chatId`)"
                                              ")");
             sqlite_nooutput(conn, "CREATE TABLE `message` ("
-                                             "`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"
                                              "`chatId` INTEGER REFERENCES `chat` NOT NULL,"
-                                             "`previous` INTEGER REFERENCES `message`,"
+                                             "`id` INTEGER NOT NULL,"
                                              "`senderUserId` INTEGER REFERENCES `user`,"
                                              "`exists` BOOLEAN NOT NULL,"
                                              "`isSystem` BOOLEAN NOT NULL,"
-                                             "`text` TEXT NOT NULL,"
-                                             "`chat_IncHistoryId` INTEGER NOT NULL"
+                                             "`text` TEXT,"
+                                             "`chat_IncHistoryId` INTEGER NOT NULL,"
+                                             "PRIMARY KEY (`chatId`, `id`)"
                                              ")");
             sqlite_nooutput(conn, "INSERT INTO `nickname` VALUES (?1)", {}, {{1, "root"}});
-            sqlite_nooutput(conn, "INSERT INTO `user` (`id`, `nickname`, `name`, `chatList_HistoryId`, `password`) VALUES "
-                                             "(0, ?1, ?2, 0, ?3)", {},
-                                             {{1, "root"}, {2, "Rootov Root Rootovich"}, {3, root_pw}});
+            sqlite_nooutput(conn, "INSERT INTO `user` (`id`, `nickname`, `name`, `chatList_HistoryId`, `password`, "
+                                  "`bio` ) VALUES (0, ?1, ?2, 0, ?3, ?4)", {},
+                    {{1, "root"}, {2, "Rootov Root Rootovich"}, {3, root_pw}, {4, "One admin to rule them all"}});
             sqlite_nooutput(conn, "END");
         } catch (const std::exception& e) {
             sqlite_nooutput(conn, "ROLLBACK", {}, {});
diff --git a/src/web_chat/iu9_ca_web_chat_lib/login_cookie.cpp b/src/web_chat/iu9_ca_web_chat_lib/login_cookie.cpp
index 193a8e5..571d85d 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/login_cookie.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/login_cookie.cpp
@@ -23,8 +23,8 @@ namespace iu9cawebchat {
         uint64_t nsec = std::stoull(ft.substr(s_ + 1, ft.size() - s_ - 1));
         een9_ASSERT_pl(nsec < 1000000000);
         const json::JSON cnt = json::parse_str_flawless(base64_decode(login_cookie_encoded.second));
-        std::string nickname = cnt[0].g().asString();
-        std::string password = cnt[1].g().asString();
+        std::string nickname = cnt[0].asString();
+        std::string password = cnt[1].asString();
         return LoginCookie{{(time_t)sec, (time_t)nsec}, nickname, password};
     }
 
@@ -37,8 +37,8 @@ namespace iu9cawebchat {
 
     std::pair<std::string, std::string> encode_login_cookie(const LoginCookie& cookie) {
             json::JSON cnt;
-            cnt[1].g() = cookie.password;
-            cnt[0].g() = cookie.nickname;
+            cnt[1].asString() = cookie.password;
+            cnt[0].asString() = cookie.nickname;
         return {"login_" + std::to_string(cookie.login_time.tv_sec) + "_" + std::to_string(cookie.login_time.tv_nsec),
             base64_encode(json::generate_str(cnt, json::print_compact))};
     }
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 b0a2cd7..ad05db5 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/run.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/run.cpp
@@ -16,9 +16,25 @@ namespace iu9cawebchat {
         termination = true;
     }
 
+    struct ONE_SQLITE_TRANSACTION_GUARD {
+        SqliteConnection& conn;
+        bool rollback = false;
+
+        explicit ONE_SQLITE_TRANSACTION_GUARD(SqliteConnection& conn_) : conn(conn_) {
+            sqlite_nooutput(conn, "BEGIN", {}, {});
+        }
+
+        ~ONE_SQLITE_TRANSACTION_GUARD() {
+            if (rollback)
+                sqlite_nooutput(conn, "ROLLBACK", {}, {});
+            else
+                sqlite_nooutput(conn, "END", {}, {});
+        }
+    };
+
     void run_website(const json::JSON& config) {
-        een9_ASSERT(config["assets"].g().isString(), "config[\"assets\"] is not string");
-        std::string assets_dir = config["assets"].g().asString();
+        een9_ASSERT(config["assets"].isString(), "config[\"assets\"] is not string");
+        const std::string& assets_dir = config["assets"].asString();
         een9_ASSERT(een9::isDirectory(assets_dir), "\"" + assets_dir + "\" is not a directory");
 
         een9::StaticAssetManagerSlaveModule samI;
@@ -30,8 +46,8 @@ namespace iu9cawebchat {
             } },
         });
 
-        const json::JSON& config_presentation = config["presentation"].g();
-        int64_t slave_number = config["server"]["workers"].g().asInteger().get_int();
+        const json::JSON& config_presentation = config["presentation"];
+        int64_t slave_number = config["server"]["workers"].asInteger().get_int();
         een9_ASSERT(slave_number > 0 && slave_number <= 200, "E");
 
         std::string sqlite_db_path;
@@ -52,13 +68,7 @@ namespace iu9cawebchat {
             een9_ASSERT_pl(0 <= worker_id && worker_id < worker_guest_data.size());
             WorkerGuestData& wgd = worker_guest_data[worker_id];
             een9::StaticAsset sa;
-            sqlite_nooutput(*wgd.db, "BEGIN", {}, {});
-            struct guard {SqliteConnection& conn; bool rollback = false; ~guard() {
-                if (rollback)
-                    sqlite_nooutput(conn, "ROLLBACK", {}, {});
-                else
-                    sqlite_nooutput(conn, "END", {}, {});
-                }} guard_{*wgd.db};
+            ONE_SQLITE_TRANSACTION_GUARD conn_guard(*wgd.db);
             try {
                 std::vector<std::pair<std::string, std::string>> cookies;
                 std::vector<LoginCookie> login_cookies;
@@ -72,53 +82,42 @@ namespace iu9cawebchat {
                 if (req.uri_path == "/login") {
                     return when_page_login(wgd, config_presentation, req, login_cookies, userinfo);
                 }
-                if (een9::beginsWith(req.uri_path, "/chat")) {
+                // todo: split
+                if (een9::beginsWith(req.uri_path, "/chat/") || een9::beginsWith(req.uri_path, "/chat-members/")) {
                     return when_page_chat(wgd, config_presentation, req, userinfo);
                 }
-                if (req.uri_path == "/user") {
-                    return when_page_user(wgd, config_presentation, req, userinfo);
+                if (een9::beginsWith(req.uri_path, "/user/")) {
+                    return when_page_user(wgd, config_presentation, req, login_cookies, userinfo);
                 }
-                if (req.uri_path == "/internalapi/pollEvents") {
-                    return when_internalapi_pollevents(wgd, req, logged_in_user);
+                if (req.uri_path == "/api/chatPollEvents") {
+                    return when_internalapi_chatpollevents(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/getChatList") {
-                    return  when_internalapi_getchatlist(wgd, req, logged_in_user);
+                if (req.uri_path == "/api/chatListPollEvents") {
+                    return  when_internalapi_chatlistpollevents(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/getChatInfo") {
-                    return when_internalapi_getchatinfo(wgd, req, logged_in_user);
-                }
-                if (req.uri_path == "/internalapi/getChatMemberList") {
-                    return when_internalapi_getchatmemberlist(wgd, req, logged_in_user);
-                }
-                if (req.uri_path == "/internalapi/getUserInfo") {
-                    return when_internalapi_getuserinfo(wgd, req, logged_in_user);
-                }
-                if (req.uri_path == "/internalapi/getMessageInfo") {
-                    return when_internalapi_getmessageinfo(wgd, req, logged_in_user);
-                }
-                if (req.uri_path == "/internalapi/getMessageNeighbours") {
+                if (req.uri_path == "/api/getMessageNeighbours") {
                     return when_internalapi_getmessageneighbours(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/sendMessage") {
+                if (req.uri_path == "/api/sendMessage") {
                     return when_internalapi_sendmessage(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/deleteMessage") {
+                if (req.uri_path == "/api/deleteMessage") {
                     return when_internalapi_deletemessage(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/addMemberToChat") {
+                if (req.uri_path == "/api/addMemberToChat") {
                     return when_internalapi_addmembertochat(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/removeMemberFromChat") {
+                if (req.uri_path == "/api/removeMemberFromChat") {
                     return when_internalapi_removememberfromchat(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/createChat") {
+                if (req.uri_path == "/api/createChat") {
                     return when_internalapi_createchat(wgd, req, logged_in_user);
                 }
-                if (req.uri_path == "/internalapi/removeChat") {
-                    return when_internalapi_removechat(wgd, req, logged_in_user);
+                if (req.uri_path == "/api/leaveChat") {
+                    return when_internalapi_leavechat(wgd, req, logged_in_user);
                 }
             } catch (const std::exception& e) {
-                guard_.rollback = true;
+                conn_guard.rollback = true;
                 throw;
             }
             /* Trying to interpret request as asset lookup */
@@ -133,29 +132,11 @@ namespace iu9cawebchat {
         (const een9::SlaveTask& task, const std::string& req, een9::worker_id_t worker_id) -> std::string {
             een9_ASSERT_pl(0 <= worker_id && worker_id < worker_guest_data.size());
             WorkerGuestData& wgd = worker_guest_data[worker_id];
+            ONE_SQLITE_TRANSACTION_GUARD conn_guad(*wgd.db);
             try {
-                if (req == "hello") {
-                    return ":0 omg! hiii!! Hewwou :3 !!!!\n";
-                }
-                if (req == "8") {
-                    termination = true;
-                    return "Bye\n";
-                }
-                std::string updaterootpw_pref = "updaterootpw";
-                if (een9::beginsWith(req, "updaterootpw")) {
-                    size_t nid = updaterootpw_pref.size();
-                    if (nid >= req.size() || !isSPACE(req[nid]))
-                        return "Bad command syntax. Missing whitespace\n";
-                    std::string new_password = req.substr(nid + 1);
-                    if (!check_password(new_password))
-                        een9_THROW("Bad password");
-                    sqlite_nooutput(*wgd.db,
-                        "UPDATE `user` SET `password` = ?1 WHERE `id` = 0 ",
-                        {}, {{1, new_password}});
-                    return "Successul update\n";
-                }
-                return "Incorrect command\n";
+                return admin_control_procedure(*wgd.db, req, termination);
             } catch (std::exception& e) {
+                conn_guad.rollback = true;
                 return std::string("Server error\n") + e.what();
             }
         };
@@ -171,8 +152,8 @@ namespace iu9cawebchat {
                 een9_ASSERT(ret == 0, "Incorrect ear address: " + source[i].asString());
             }
         };
-        translate_addr_list_conf(params.client_regular_listened, config["server"]["http-listen"].g().asArray());
-        translate_addr_list_conf(params.admin_control_listened, config["server"]["admin-command-listen"].g().asArray());
+        translate_addr_list_conf(params.client_regular_listened, config["server"]["http-listen"].asArray());
+        translate_addr_list_conf(params.admin_control_listened, config["server"]["admin-command-listen"].asArray());
 
         signal(SIGINT, sigterm_action);
         signal(SIGTERM, sigterm_action);
diff --git a/src/web_chat/iu9_ca_web_chat_lib/str_fields.cpp b/src/web_chat/iu9_ca_web_chat_lib/str_fields.cpp
index 0c3aba5..9f77d40 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/str_fields.cpp
+++ b/src/web_chat/iu9_ca_web_chat_lib/str_fields.cpp
@@ -28,11 +28,15 @@ namespace iu9cawebchat {
     }
 
     bool check_password(const std::string &pwd) {
-        return is_orthodox_string(pwd) && pwd.size() >= 8;
+        return is_orthodox_string(pwd) && pwd.size() <= 150;
+    }
+
+    bool check_strong_password(const std::string& pwd) {
+        return check_password(pwd) && pwd.size() >= 8;
     }
 
     bool check_name(const std::string &name) {
-        return is_orthodox_string(name);
+        return is_orthodox_string(name) && name.size() <= 150;
     }
 
     bool check_nickname(const std::string &nickname) {
@@ -42,7 +46,7 @@ namespace iu9cawebchat {
             if (!isUNCHAR(ch))
                 return false;
         }
-        return true;
+        return nickname.size() <= 150;
     }
 
     /* Yeah baby, it's base64 time!!! */
diff --git a/src/web_chat/iu9_ca_web_chat_lib/str_fields.h b/src/web_chat/iu9_ca_web_chat_lib/str_fields.h
index c6cc2bd..642f5ae 100644
--- a/src/web_chat/iu9_ca_web_chat_lib/str_fields.h
+++ b/src/web_chat/iu9_ca_web_chat_lib/str_fields.h
@@ -13,6 +13,7 @@ namespace iu9cawebchat {
     bool is_orthodox_string(const std::string& str);
 
     bool check_password(const std::string& pwd);
+    bool check_strong_password(const std::string& pwd);
     bool check_name(const std::string& name);
     bool check_nickname(const std::string& nickname);
 
