diff --git a/.vscode/launch.json b/.vscode/launch.json
index f03bfb9..d8957a8 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -7,7 +7,7 @@
             "request": "launch",
             "program": "${workspaceFolder}/bin/tcp-chat",
             "windows": { "program": "${workspaceFolder}/bin/tcp-chat.exe" },
-            "args": [ "-l" ],
+            // "args": [ "-l" ],
             "preLaunchTask": "build_exec_dbg",
             "stopAtEntry": false,
             "cwd": "${workspaceFolder}/bin",
diff --git a/dependencies/tlibc b/dependencies/tlibc
index 4257943..89aab2b 160000
--- a/dependencies/tlibc
+++ b/dependencies/tlibc
@@ -1 +1 @@
-Subproject commit 425794361bc52240bb50001becbb5fb6e9ebcf20
+Subproject commit 89aab2b5bffd46ec0538a5e7c2f1674d59d5677a
diff --git a/src/ClientCLI/ClientCLI.c b/src/ClientCLI/ClientCLI.c
new file mode 100644
index 0000000..28c2608
--- /dev/null
+++ b/src/ClientCLI/ClientCLI.c
@@ -0,0 +1,243 @@
+#include "ClientCLI/ClientCLI.h"
+#include "ClientCLI/db_tables.h"
+#include "term.h"
+#include "common_constants.h"
+#include "tlibc/time.h"
+#include "tlibc/filesystem.h"
+
+static const str greeting_art = STR(
+    "   ^,,^                           ╱|\n"
+    "  ( •·•)   Meum!                (o.o`7\n"
+    "  / ` |                 Meum...  |`˜ \\\n"
+    "\\(_,J J                          L l`,)/\n"
+);
+    
+static const str farewell_art = STR(
+    "   ^,,^                           ╱|\n"
+    "  ( -.-)                        (>,<`7\n"
+    "  / ` |        Goodbye!          |`˜ \\\n"
+    "\\(_,J J                          L l`,)/\n"
+);
+
+
+#define is_alias(LITERAL) str_equals(command, STR(LITERAL))
+
+static Result(void) ClientCLI_askUserNameAndPassword(str* username_out, str* password_out);
+static Result(void) ClientCLI_commandExec(ClientCLI* self, str command, bool* stop);
+static Result(void) ClientCLI_openUserDB(ClientCLI* self);
+static Result(void) ClientCLI_saveServerInfo(ClientCLI* self, cstr server_addr_cstr, cstr server_pk_base64);
+
+
+void ClientCLI_destroy(ClientCLI* self){
+    if(!self)
+        return;
+    Client_free(self->client);
+    idb_close(self->user_db);
+}
+void ClientCLI_construct(ClientCLI* self){
+    self->client = NULL;
+    self->user_db = NULL;
+}
+
+Result(void) ClientCLI_run(ClientCLI* self) {
+    Deferral(16);
+
+    try_void(term_init());
+    term_clear();
+    printf("%s\n", greeting_art.data);
+
+    // create Client
+    str username = str_null, password = str_null;
+    try_void(ClientCLI_askUserNameAndPassword(&username, &password));
+    Defer(
+        str_free(username);
+        str_free(password);
+    );
+    Client_free(self->client);
+    try(self->client, p, Client_create(username, password));
+    memset(password.data, 0, password.size);
+
+    // init db
+    try_void(ClientCLI_openUserDB(self));
+
+    char input_buf[1024];
+    str command_input = str_null;
+    bool stop = false;
+    while(!stop){
+        sleepMsec(50);
+        printf("> ");
+        try_void(term_readLine(input_buf, sizeof(input_buf)));
+        
+        command_input = str_from_cstr(input_buf);
+        str_trim(&command_input, true);
+        if(command_input.size == 0)
+            continue;
+        
+        ResultVar(void) com_result = ClientCLI_commandExec(self, command_input, &stop);
+        if(com_result.error){
+            str e_str = Error_toStr(com_result.error);
+            printf("%s\n", e_str.data);
+            str_free(e_str);
+            Error_free(com_result.error);
+        }
+    }
+
+    Return RESULT_VOID;
+}
+
+static Result(void) ClientCLI_askUserNameAndPassword(str* username_out, str* password_out){
+    Deferral(8);
+    bool success = false;
+
+    // ask username
+    Array(char) username_buf = Array_alloc_size(128);
+    Defer(if(!success) Array_free(username_buf));
+    str username = str_null;
+    while(true) {
+        printf("username: ");
+        try_void(term_readLine(username_buf.data, username_buf.size));
+        username = str_from_cstr(username_buf.data);
+        str_trim(&username, true);
+        if(username.size < USERNAME_SIZE_MIN || username.size > USERNAME_SIZE_MAX){
+            printf("ERROR: username length (in bytes) must be >= %i and <= %i\n", 
+                USERNAME_SIZE_MIN, USERNAME_SIZE_MAX);
+        }
+        else break;
+    }
+
+    // ask password
+    Array(char) password_buf = Array_alloc_size(128);
+    Defer(if(!success) Array_free(password_buf));
+    str password = str_null;
+    while(true) {
+        printf("password: ");
+        // TODO: hide password
+        try_void(term_readLineHidden(password_buf.data, password_buf.size));
+        password = str_from_cstr(password_buf.data);
+        str_trim(&password, true);
+        if(password.size < PASSWORD_SIZE_MIN || password.size > PASSWORD_SIZE_MAX){
+            printf("ERROR: password length (in bytes) must be >= %i and <= %i\n", 
+                PASSWORD_SIZE_MIN, PASSWORD_SIZE_MAX);
+        }
+        else break;
+    }
+
+    *username_out = username;
+    *password_out = password;
+    success = true;
+    Return RESULT_VOID;
+}
+
+static Result(void) ClientCLI_commandExec(ClientCLI* self, str command, bool* stop){
+    Deferral(64);
+
+    if(is_alias("q") || is_alias("quit") || is_alias("exit")){
+        printf("%s\n", farewell_art.data);
+        *stop = true;
+    }
+    else if(is_alias("clear")){
+        term_clear();
+    }
+    else if(is_alias("h") || is_alias("help")){
+        printf(
+            "COMMANDS:\n"
+            "h, help                        Show this message.\n"
+            "q, quit, exit                  Close the program.\n"
+            "clear                          Clear the screen.\n"
+            "j, join                        Join a server.\n"
+            "c, connect                     Connect to a server you joined.\n"
+        );
+    }
+    else if (is_alias("j") || is_alias("join")){
+        // ask server address
+        printf("Enter server address (ip:port):\n");
+        char server_addr_cstr[HOSTADDR_SIZE_MAX + 1];
+        try_void(term_readLine(server_addr_cstr, sizeof(server_addr_cstr)));
+        str server_addr_str = str_from_cstr(server_addr_cstr);
+        str_trim(&server_addr_str, true);
+
+        // ask server public key
+        printf("Enter server public key (RSA-Public-<SIZE>:<DATA_BASE64>):\n");
+        char server_pk_cstr[PUBLIC_KEY_BASE64_SIZE_MAX + 1];
+        try_void(term_readLine(server_pk_cstr, sizeof(server_pk_cstr)));
+        str server_pk_str = str_from_cstr(server_pk_cstr);
+        str_trim(&server_pk_str, true);
+        
+        // connect to server
+        printf("connecting to server...\n");
+        try_void(Client_connect(self->client, server_addr_cstr, server_pk_cstr));
+        printf("connection established\n");
+
+        // show server info
+        // printf("server name: %s\n", client->server_connection->server_name.data);
+        // printf("server description: %s\n", client->server_connection->server_description.data);
+        
+
+        try_void(ClientCLI_saveServerInfo(self, server_addr_cstr, server_pk_cstr));
+        // TODO: ask in loop: log in / register
+
+        //TODO: call Client_runIO(): 
+        //      function with infinite loop which sends and receives messages
+        //      with navigation across server channels
+    }
+    else if(is_alias("c") || is_alias("connect")){
+        // TODO: read saved servers from database
+        // TODO: show scrollable list of servers, get selected one
+        // TODO: ask in loop: log in / register
+    }
+    else {
+        printf("ERROR: unknown command.\n"
+            "Use 'h' to see list of avaliable commands\n");
+    }
+
+    Return RESULT_VOID;
+}
+
+static Result(void) ClientCLI_openUserDB(ClientCLI* self){
+    Deferral(8);
+
+    str username = Client_getUserName(self->client);
+    Array(u8) user_data_key = Client_getUserDataKey(self->client);
+    str user_db_dir = str_from_cstr(strcat_malloc("client-db", path_seps, username.data));
+    Defer(free(user_db_dir.data));
+    try(self->user_db, p, idb_open(user_db_dir, user_data_key));
+
+    Return RESULT_VOID;
+}
+
+static Result(void) ClientCLI_saveServerInfo(ClientCLI* self, cstr server_addr_cstr, cstr server_pk_base64){
+    Deferral(8);
+
+    ServerInfo si;
+    memset(&si, 0, sizeof(ServerInfo));
+    
+    // address
+    si.address_len = strlen(server_addr_cstr);
+    memcpy(si.address, server_addr_cstr, si.address_len);
+    si.address[si.address_len] = 0;
+    
+    // public key
+    si.pk_base64_len = strlen(server_pk_base64);
+    memcpy(si.pk_base64, server_addr_cstr, si.pk_base64_len);
+    si.pk_base64[si.pk_base64_len] = 0;
+
+    // name
+    str server_name = str_null;
+    try_void(Client_getServerName(self->client, &server_name));
+    si.name_len = server_name.size;
+    memcpy(si.name, server_name.data, si.name_len);
+    si.name[si.name_len] = 0;
+    
+    // description
+    str server_description = str_null;
+    try_void(Client_getServerName(self->client, &server_description));
+    si.desc_len = server_name.size;
+    memcpy(si.desc, server_description.data, si.desc_len);
+    si.desc[si.desc_len] = 0;
+    
+    // TODO: check cred->server_address_id_cache_map
+
+    // TODO: save server info to user's db
+
+    Return RESULT_VOID;
+}
diff --git a/src/ClientCLI/ClientCLI.h b/src/ClientCLI/ClientCLI.h
new file mode 100644
index 0000000..72f8cc3
--- /dev/null
+++ b/src/ClientCLI/ClientCLI.h
@@ -0,0 +1,12 @@
+#pragma once
+#include "client/client.h"
+#include "db/idb.h"
+
+typedef struct ClientCLI {
+    Client* client;
+    IncrementalDB* user_db;
+} ClientCLI;
+
+void ClientCLI_construct(ClientCLI* self);
+void ClientCLI_destroy(ClientCLI* self);
+Result(void) ClientCLI_run(ClientCLI* self);
diff --git a/src/ClientCLI/db_tables.h b/src/ClientCLI/db_tables.h
new file mode 100644
index 0000000..7861143
--- /dev/null
+++ b/src/ClientCLI/db_tables.h
@@ -0,0 +1,14 @@
+#pragma once
+#include "common_constants.h"
+#include "tlibc/time.h"
+
+typedef struct ServerInfo {
+    char address[HOSTADDR_SIZE_MAX + 1];
+    u16 address_len;
+    char pk_base64[PUBLIC_KEY_BASE64_SIZE_MAX + 1];
+    u32 pk_base64_len;
+    char name[CHANNEL_NAME_SIZE_MAX + 1];
+    u16 name_len;
+    char desc[CHANNEL_DESC_SIZE_MAX + 1];
+    u16 desc_len;
+} ATTRIBUTE_ALIGNED(16*1024) ServerInfo;
diff --git a/src/client/ClientCredentials.c b/src/client/ClientCredentials.c
deleted file mode 100644
index 4f7c5fa..0000000
--- a/src/client/ClientCredentials.c
+++ /dev/null
@@ -1,44 +0,0 @@
-#include "client.h"
-#include "tlibc/collections/List.h"
-
-void ClientCredentials_destroy(ClientCredentials* cred){
-    if(!cred)
-        return;
-    free(cred->username.data);
-    free(cred->user_data_key.data);
-    free(cred->token.data);
-}
-
-
-Result(void) ClientCredentials_tryConstruct(ClientCredentials* cred,
-    str username, str password)
-{
-    Deferral(8);
-    
-    memset(cred, 0, sizeof(ClientCredentials));
-    bool success = false;
-    Defer(if(!success) ClientCredentials_destroy(cred));
-
-    cred->username = str_copy(username);
-
-    // concat password and username
-    List(u8) data_to_hash = List_alloc_size(password.size + username.size + PASSWORD_HASH_SIZE);
-    Defer(free(data_to_hash.data));
-    List_push_size(&data_to_hash, password.data, password.size);
-    List_push_size(&data_to_hash, username.data, username.size);
-    
-    // lvl 1 hash - is used as AES key for user data
-    cred->user_data_key = Array_alloc(u8, PASSWORD_HASH_SIZE);
-    hash_password(List_castTo_Array(data_to_hash), cred->user_data_key.data, PASSWORD_HASH_LVL_ROUNDS);
-    // concat lvl 1 hash to data_to_hash
-    List_push_size(&data_to_hash, cred->user_data_key.data, cred->user_data_key.size);
-    // lvl 2 hash - is used for authentification
-    cred->token = Array_alloc(u8, PASSWORD_HASH_SIZE);
-    hash_password(List_castTo_Array(data_to_hash), cred->token.data, PASSWORD_HASH_LVL_ROUNDS);
-
-    AESBlockEncryptor_construct(&cred->user_data_aes_enc, cred->user_data_key, AESBlockEncryptor_DEFAULT_CLASS);
-    AESBlockDecryptor_construct(&cred->user_data_aes_dec, cred->user_data_key, AESBlockDecryptor_DEFAULT_CLASS);
-
-    success = true;
-    Return RESULT_VOID;
-}
diff --git a/src/client/ServerConnection.c b/src/client/ServerConnection.c
index 51c036d..896a2ef 100644
--- a/src/client/ServerConnection.c
+++ b/src/client/ServerConnection.c
@@ -1,4 +1,4 @@
-#include "client.h"
+#include "client_internal.h"
 #include "requests/requests.h"
 
 void ServerConnection_close(ServerConnection* conn){
@@ -6,44 +6,14 @@ void ServerConnection_close(ServerConnection* conn){
         return;
     RSA_destroyPublicKey(&conn->server_pk);
     EncryptedSocketTCP_destroy(&conn->sock);
-    free(conn->session_key.data);
-    free(conn->name.data);
-    free(conn->description.data);
+    Array_free(conn->session_key);
+    str_free(conn->server_name);
+    str_free(conn->server_description);
     free(conn);
 }
 
-/// @brief 
-/// @param server_link_cstr address:port:public_key
-/// @return 
-Result(void) ServerLink_parse(cstr server_link_cstr, EndpointIPv4* server_end_out, br_rsa_public_key* server_key_out){
-    Deferral(8);
-    str server_link_str = str_from_cstr(server_link_cstr);
-    
-    // parse address and port
-    i32 sep_pos = str_seekChar(server_link_str, ':', 0);
-    if(sep_pos == -1){
-        Return RESULT_ERROR_FMT("server link is invalid: %s", server_link_cstr);
-    }
-    *server_end_out = EndpointIPv4_INVALID;
-    try_void(EndpointIPv4_parse(server_link_cstr, server_end_out));    
-    if(EndpointIPv4_is_invalid(*server_end_out)){
-        Return RESULT_ERROR_FMT("server address or port is invalid: %s", server_link_cstr);
-    }
-
-    // parse public key
-    sep_pos = str_seekChar(server_link_str, ':', sep_pos + 1);
-    if(sep_pos == -1){
-        Return RESULT_ERROR_FMT("server link is invalid: %s", server_link_cstr);
-    }
-    str server_key_str = str_sliceAfter(server_link_str, sep_pos + 1);
-    char* server_key_cstr = str_copy(server_key_str).data;
-    Defer(free(server_key_cstr));
-    try_void(RSA_parsePublicKey_base64(server_key_cstr, server_key_out));
-    
-    Return RESULT_VOID;
-}
-
-Result(ServerConnection*) ServerConnection_open(cstr server_link_cstr){
+Result(ServerConnection*) ServerConnection_open(cstr server_addr_cstr, cstr server_pk_base64)
+{
     Deferral(16);
 
     ServerConnection* conn = (ServerConnection*)malloc(sizeof(ServerConnection));
@@ -51,7 +21,14 @@ Result(ServerConnection*) ServerConnection_open(cstr server_link_cstr){
     bool success = false;
     Defer(if(!success) ServerConnection_close(conn));
 
-    try_void(ServerLink_parse(server_link_cstr, &conn->server_end, &conn->server_pk));
+    // TODO: parse domain name and get ip from it
+    conn->server_end = EndpointIPv4_INVALID;
+    try_void(EndpointIPv4_parse(server_addr_cstr, &conn->server_end));    
+    if(EndpointIPv4_is_invalid(conn->server_end)){
+        Return RESULT_ERROR_FMT("server address or port is invalid: %s", server_addr_cstr);
+    }
+
+    try_void(RSA_parsePublicKey_base64(server_pk_base64, &conn->server_pk));
     RSAEncryptor_construct(&conn->rsa_enc, &conn->server_pk);
     
     conn->session_key = Array_alloc_size(AES_SESSION_KEY_SIZE);
@@ -82,6 +59,21 @@ Result(ServerConnection*) ServerConnection_open(cstr server_link_cstr){
     conn->session_id = server_handshake.session_id;
 
     // get server name
+    try_void(ServerConnection_requestServerName(conn));
+    // get server description
+    try_void(ServerConnection_requestServerDescription(conn));
+
+    success = true;
+    Return RESULT_VALUE(p, conn);
+}
+
+Result(void) ServerConnection_requestServerName(ServerConnection* conn){
+    if(conn == NULL){
+        return RESULT_ERROR("Client is not connected to a server", false);
+    }
+    Deferral(4);
+
+    PacketHeader req_header, res_header;
     ServerPublicInfoRequest public_info_req;
     ServerPublicInfoResponse public_info_res;
     ServerPublicInfoRequest_construct(&public_info_req, &req_header,
@@ -89,16 +81,26 @@ Result(ServerConnection*) ServerConnection_open(cstr server_link_cstr){
     try_void(sendRequest(&conn->sock, &req_header, &public_info_req));
     try_void(recvResponse(&conn->sock, &res_header, &public_info_res,
         PacketType_ServerPublicInfoResponse));
-    try_void(recvStr(&conn->sock, public_info_res.data_size, &conn->name));
+    try_void(recvStr(&conn->sock, public_info_res.data_size, &conn->server_name));
 
-    // get server description
+    Return RESULT_VOID;
+}
+
+Result(void) ServerConnection_requestServerDescription(ServerConnection* conn){
+    if(conn == NULL){
+        return RESULT_ERROR("Client is not connected to a server", false);
+    }
+    Deferral(4);
+    
+    PacketHeader req_header, res_header;
+    ServerPublicInfoRequest public_info_req;
+    ServerPublicInfoResponse public_info_res;
     ServerPublicInfoRequest_construct(&public_info_req, &req_header,
         ServerPublicInfo_Description);
     try_void(sendRequest(&conn->sock, &req_header, &public_info_req));
     try_void(recvResponse(&conn->sock, &res_header, &public_info_res,
         PacketType_ServerPublicInfoResponse));
-    try_void(recvStr(&conn->sock, public_info_res.data_size, &conn->description));
+    try_void(recvStr(&conn->sock, public_info_res.data_size, &conn->server_description));
 
-    success = true;
-    Return RESULT_VALUE(p, conn);
-}
+    Return RESULT_VOID;
+}
\ No newline at end of file
diff --git a/src/client/client.c b/src/client/client.c
index 8352c8b..124d5dd 100644
--- a/src/client/client.c
+++ b/src/client/client.c
@@ -1,169 +1,79 @@
-#include "client.h"
-#include "term.h"
-#include "tlibc/time.h"
-#include "network/tcp-chat-protocol/v1.h"
+#include "client/client_internal.h"
 
-static const str greeting_art = STR(
-    "   ^,,^                           ╱|\n"
-    "  ( •·•)   Meum!                (o.o`7\n"
-    "  / ` |                 Meum...  |`˜ \\\n"
-    "\\(_,J J                          L l`,)/\n"
-);
-    
-static const str farewell_art = STR(
-    "   ^,,^                           ╱|\n"
-    "  ( -.-)                        (>,<`7\n"
-    "  / ` |        Goodbye!          |`˜ \\\n"
-    "\\(_,J J                          L l`,)/\n"
-);
-
-Result(void) Client_createFromConfig(cstr config_path){
-    Deferral(16);
-
-    Client* client = (Client*)malloc(sizeof(Client));
-    memset(client, 0, sizeof(Client));
-    bool success = false;
-    Defer(if(!success) Client_free(client));
-
-    (void)config_path;
-
-    success = true;
-    Return RESULT_VALUE(p, client);
-}
-
-void Client_free(Client* client){
-    if(!client)
+void Client_free(Client* self){
+    if(!self)
         return;
     
-    ClientCredentials_destroy(&client->cred);
-    ServerConnection_close(client->server_connection);
-    free(client);
+    str_free(self->username);
+    Array_free(self->token);
+    Array_free(self->user_data_key);
+    ServerConnection_close(self->server_connection);
+    free(self);
 }
 
-static Result(void) commandExec(Client* client, str command, bool* stop);
-
-static Result(void) askUserNameAndPassword(ClientCredentials* cred){
-    Deferral(8);
-
-    char username_buf[128];
-    str username = str_null;
-    while(true) {
-        printf("username: ");
-        try_void(term_readLine(username_buf, sizeof(username_buf)));
-        username = str_from_cstr(username_buf);
-        str_trim(&username, true);
-        if(username.size < USERNAME_SIZE_MIN || username.size > USERNAME_SIZE_MAX){
-            printf("ERROR: username length (in bytes) must be >= %i and <= %i\n", 
-                USERNAME_SIZE_MIN, USERNAME_SIZE_MAX);
-        }
-        else break;
-    }
-
-    char password_buf[128];
-    str password = str_null;
-    while(true) {
-        printf("password: ");
-        // TODO: hide password
-        try_void(term_readLineHidden(password_buf, sizeof(password_buf)));
-        password = str_from_cstr(password_buf);
-        str_trim(&password, true);
-        if(password.size < PASSWORD_SIZE_MIN || password.size > PASSWORD_SIZE_MAX){
-            printf("ERROR: password length (in bytes) must be >= %i and <= %i\n", 
-                PASSWORD_SIZE_MIN, PASSWORD_SIZE_MAX);
-        }
-        else break;
-    }
-
-    try_void(ClientCredentials_tryConstruct(cred, username, password));
-    Return RESULT_VOID;
-}
-
-Result(void) Client_run(Client* client) {
+Result(Client*) Client_create(str username, str password){
     Deferral(16);
-    try_void(term_init());
 
-    fputs(greeting_art.data, stdout);
-    try_void(askUserNameAndPassword(&client->cred));
+    Client* self = (Client*)malloc(sizeof(Client));
+    memset(self, 0, sizeof(Client));
+    bool success = false;
+    Defer(if(!success) Client_free(self));
 
-    Array(char) input_buf = Array_alloc(char, 10000);
-    Defer(free(input_buf.data));
-    str command_input = str_null;
-    bool stop = false;
-    while(!stop){
-        sleepMsec(50);
-        fputs("> ", stdout);
-        try_void(term_readLine(input_buf.data, input_buf.size));
-        
-        command_input = str_from_cstr(input_buf.data);
-        str_trim(&command_input, true);
-        if(command_input.size == 0)
-            continue;
-        
-        ResultVar(void) com_result = commandExec(client, command_input, &stop);
-        if(com_result.error){
-            str e_str = Error_toStr(com_result.error);
-            printf("%s\n", e_str.data);
-            free(e_str.data);
-            Error_free(com_result.error);
-        }
-    }
+    self->username = str_copy(username);
 
+    // concat password and username
+    List(u8) data_to_hash = List_alloc_size(password.size + username.size + PASSWORD_HASH_SIZE);
+    Defer(free(data_to_hash.data));
+    List_push_size(&data_to_hash, password.data, password.size);
+    List_push_size(&data_to_hash, username.data, username.size);
+    
+    // lvl 1 hash - is used as AES key for user data
+    self->user_data_key = Array_alloc(u8, PASSWORD_HASH_SIZE);
+    hash_password(List_castTo_Array(data_to_hash), self->user_data_key.data, PASSWORD_HASH_LVL_ROUNDS);
+    // concat lvl 1 hash to data_to_hash
+    List_push_size(&data_to_hash, self->user_data_key.data, self->user_data_key.size);
+    // lvl 2 hash - is used for authentification
+    self->token = Array_alloc(u8, PASSWORD_HASH_SIZE);
+    // TODO: generate different token for each server
+    hash_password(List_castTo_Array(data_to_hash), self->token.data, PASSWORD_HASH_LVL_ROUNDS);
+
+    success = true;
+    Return RESULT_VALUE(p, self);
+}
+
+Result(void) Client_connect(Client* self, cstr server_addr_cstr, cstr server_pk_base64){
+    Deferral(8);
+    Client_disconnect(self);
+    try(self->server_connection, p, 
+        ServerConnection_open(server_addr_cstr, server_pk_base64));
     Return RESULT_VOID;
 }
 
-#define is_alias(LITERAL) str_equals(command, STR(LITERAL))
-
-static Result(void) commandExec(Client* client, str command, bool* stop){
-    Deferral(64);
-    char answer_buf[10000];
-    if(is_alias("q") || is_alias("quit") || is_alias("exit")){
-        fputs(farewell_art.data, stdout);
-        *stop = true;
-    }
-    else if(is_alias("clear")){
-        term_clear();
-    }
-    else if(is_alias("h") || is_alias("help")){
-        puts(
-            "COMMANDS:\n"
-            "h, help                        Show this message.\n"
-            "q, quit, exit                  Close the program.\n"
-            "clear                          Clear the screen.\n"
-            "j, join                        Join a server.\n"
-            "c, connect                     Connect to a server you joined.\n"
-        );
-    }
-    else if (is_alias("j") || is_alias("join")){
-        ServerConnection_close(client->server_connection);
-
-        puts("Enter server address (ip:port:public_key): ");
-        try_void(term_readLine(answer_buf, sizeof(answer_buf)));
-        str new_server_link = str_from_cstr(answer_buf);
-        str_trim(&new_server_link, true);
-
-        printf("connecting to server...\n");
-        try(client->server_connection, p, 
-            ServerConnection_open(new_server_link.data));
-        printf("connection established\n");
-
-        // TODO: show server info
-        // TODO: save server info to user's db
-        // TODO: ask in loop: log in / register
-
-        //TODO: call Client_runIO(): 
-        //      function with infinite loop which sends and receives messages
-        //      with navigation across server channels
-    }
-    else if(is_alias("c") || is_alias("connect")){
-        // TODO: read saved servers from database
-        // TODO: show scrollable list of servers, get selected one
-        // TODO: ask in loop: log in / register
-    }
-    else {
-        printf("ERROR: unknown command.\n"
-            "Use 'h' to see list of avaliable commands\n");
-    }
-
-    Return RESULT_VOID;
+void Client_disconnect(Client* self){
+    ServerConnection_close(self->server_connection);
+    self->server_connection = NULL;
 }
 
+str Client_getUserName(Client* client){
+    return client->username;
+}
+
+Array(u8) Client_getUserDataKey(Client* client){
+    return client->user_data_key;
+}
+
+Result(void) Client_getServerName(Client* self, str* out_name){
+    if(self->server_connection == NULL){
+        return RESULT_ERROR("Client is not connected to a server", false);
+    }
+    *out_name = self->server_connection->server_name;
+    return RESULT_VOID;
+}
+
+Result(void) Client_getServerDescription(Client* self, str* out_desc){
+    if(self->server_connection == NULL){
+        return RESULT_ERROR("Client is not connected to a server", false);
+    }
+    *out_desc = self->server_connection->server_description;
+    return RESULT_VOID;
+}
diff --git a/src/client/client.h b/src/client/client.h
index 2d934b9..346268c 100644
--- a/src/client/client.h
+++ b/src/client/client.h
@@ -1,45 +1,28 @@
 #pragma once
-#include "cryptography/AES.h"
-#include "cryptography/RSA.h"
-#include "network/encrypted_sockets.h"
+#include "tlibc/errors.h"
 #include "tlibc/string/str.h"
 
 typedef struct Client Client;
 
-typedef struct ClientCredentials {
-    str username;
-    Array(u8) user_data_key;
-    Array(u8) token;
-    AESBlockEncryptor user_data_aes_enc;
-    AESBlockDecryptor user_data_aes_dec;
-} ClientCredentials;
-
-Result(void) ClientCredentials_tryConstruct(ClientCredentials* cred,
-    str username, str password);
-
-void ClientCredentials_destroy(ClientCredentials* cred);
-
-
-typedef struct ServerConnection {
-    EndpointIPv4 server_end;
-    br_rsa_public_key server_pk;
-    RSAEncryptor rsa_enc;
-    u64 session_id;
-    Array(u8) session_key;
-    EncryptedSocketTCP sock;
-    str name;
-    str description;
-} ServerConnection;
-
-Result(ServerConnection*) ServerConnection_open(cstr server_link_cstr);
-void ServerConnection_close(ServerConnection* conn);
-
-
-typedef struct Client {
-    ClientCredentials cred;
-    ServerConnection* server_connection;
-} Client;
-
-Result(void) Client_createFromConfig(cstr config_path);
+Result(Client*) Client_create(str username, str password);
 void Client_free(Client* client);
-Result(void) Client_run(Client* client);
+
+/// @return username saved during client initialization
+str Client_getUserName(Client* client);
+
+/// @return AES key calculated from password that can be used to encrypt user data
+Array(u8) Client_getUserDataKey(Client* client);
+
+/// @param server_addr_cstr ip:port
+/// @param server_pk_base64 public key encoded by `RSA_serializePublicKey_base64()`
+Result(void) Client_connect(Client* client, cstr server_addr_cstr, cstr server_pk_base64);
+/// disconnect from current server
+void Client_disconnect(Client* client);
+
+/// @param self connected client
+/// @param out_name owned by Client, fetched from server during Client_connect
+Result(void) Client_getServerName(Client* self, str* out_name);
+
+/// @param self connected client
+/// @param out_name owned by Client, fetched from server during Client_connect
+Result(void) Client_getServerDescription(Client* self, str* out_desc);
diff --git a/src/client/client_internal.h b/src/client/client_internal.h
new file mode 100644
index 0000000..258bd72
--- /dev/null
+++ b/src/client/client_internal.h
@@ -0,0 +1,36 @@
+#pragma once
+#include "client.h"
+#include "cryptography/AES.h"
+#include "cryptography/RSA.h"
+#include "network/encrypted_sockets.h"
+
+typedef struct ServerConnection ServerConnection;
+
+typedef struct Client {
+    str username;
+    Array(u8) user_data_key;
+    Array(u8) token;
+    ServerConnection* server_connection;
+} Client;
+
+
+typedef struct ServerConnection {
+    EndpointIPv4 server_end;
+    br_rsa_public_key server_pk;
+    RSAEncryptor rsa_enc;
+    u64 session_id;
+    Array(u8) session_key;
+    EncryptedSocketTCP sock;
+    str server_name;
+    str server_description;
+} ServerConnection;
+
+/// @param server_addr_cstr 
+/// @param server_pk_base64 public key encoded by `RSA_serializePublicKey_base64()`
+Result(ServerConnection*) ServerConnection_open(cstr server_addr_cstr, cstr server_pk_base64);
+void ServerConnection_close(ServerConnection* conn);
+
+/// updates conn->server_name
+Result(void) ServerConnection_requestServerName(ServerConnection* conn);
+/// updates conn->server_description
+Result(void) ServerConnection_requestServerDescription(ServerConnection* conn);
diff --git a/src/client/requests/requests.h b/src/client/requests/requests.h
index abd5bf4..37857c4 100644
--- a/src/client/requests/requests.h
+++ b/src/client/requests/requests.h
@@ -1,6 +1,6 @@
 #pragma once
 #include "network/tcp-chat-protocol/v1.h"
-#include "client/client.h"
+#include "client/client_internal.h"
 
 
 Result(void) recvErrorMessage(EncryptedSocketTCP* sock, PacketHeader* res_header,
diff --git a/src/common_constants.h b/src/common_constants.h
index a2b8ec6..c86f78e 100644
--- a/src/common_constants.h
+++ b/src/common_constants.h
@@ -6,6 +6,10 @@
 #define PASSWORD_SIZE_MIN 8
 #define PASSWORD_SIZE_MAX 31
 #define PASSWORD_HASH_SIZE 32
-#define CHANNEL_NAME_MIN 1
-#define CHANNEL_NAME_MAX 127
-#define CHANNEL_DESC_MAX 4095
+#define CHANNEL_NAME_SIZE_MIN 1
+#define CHANNEL_NAME_SIZE_MAX 127
+#define CHANNEL_DESC_SIZE_MAX 1023
+#define PRIVATE_KEY_BASE64_SIZE_MAX 1724
+#define PUBLIC_KEY_BASE64_SIZE_MAX 699
+#define HOSTADDR_SIZE_MIN 4
+#define HOSTADDR_SIZE_MAX 255
diff --git a/src/db/idb.c b/src/db/idb.c
index f06bf8c..82e8af6 100644
--- a/src/db/idb.c
+++ b/src/db/idb.c
@@ -43,11 +43,11 @@ void Table_close(Table* t){
         return;
     fclose(t->table_file);
     fclose(t->changes_file);
-    free(t->name.data);
-    free(t->table_file_path.data);
-    free(t->changes_file_path.data);
+    str_free(t->name);
+    str_free(t->table_file_path);
+    str_free(t->changes_file_path);
     pthread_mutex_destroy(&t->mutex);
-    free(t->enc_buf.data);
+    Array_free(t->enc_buf);
     free(t);
 }
 
@@ -201,8 +201,8 @@ Result(IncrementalDB*) idb_open(str db_dir, NULLABLE(Array(u8) aes_key)){
 void idb_close(IncrementalDB* db){
     if(db == NULL)
         return;
-    free(db->db_dir.data);
-    free(db->aes_key.data);
+    str_free(db->db_dir);
+    Array_free(db->aes_key);
     HashMap_destroy(&db->tables_map);
     pthread_mutex_destroy(&db->mutex);
     free(db);
diff --git a/src/main.c b/src/main.c
index e5e83f3..1d0744f 100755
--- a/src/main.c
+++ b/src/main.c
@@ -1,5 +1,5 @@
 #include "network/network.h"
-#include "client/client.h"
+#include "ClientCLI/ClientCLI.h"
 #include "server/server.h"
 #include "tlibc/tlibc.h"
 #include "tlibc/base64.h"
@@ -141,9 +141,10 @@ int main(const int argc, cstr const* argv){
             if(!config_path)
                 config_path = _DEFAULT_CONFIG_PATH_CLIENT;
             
-            try_fatal(Client* client, p, Client_createFromConfig(config_path));
-            Defer(Client_free(client));
-            try_fatal_void(Client_run(client));
+            ClientCLI client;
+            ClientCLI_construct(&client);
+            Defer(ClientCLI_destroy(&client));
+            try_fatal_void(ClientCLI_run(&client));
             break;
         }
 
@@ -160,7 +161,7 @@ int main(const int argc, cstr const* argv){
         case RsaGenStdin: {
             printfe("reading stdin...\n");
             Array(u8) input_buf = Array_alloc_size(64*1024);
-            Defer(free(input_buf.data));
+            Defer(Array_free(input_buf));
             br_hmac_drbg_context rng = { .vtable = &br_hmac_drbg_vtable };
             br_hmac_drbg_init(&rng, &br_sha256_vtable, NULL, 0);
             i64 read_n = 0;
@@ -184,11 +185,11 @@ int main(const int argc, cstr const* argv){
             
             str sk_str = RSA_serializePrivateKey_base64(&sk);
             printf("rsa_private_key = %s\n", sk_str.data);
-            free(sk_str.data);
+            str_free(sk_str);
             
             str pk_str = RSA_serializePublicKey_base64(&pk);
             printf("\nrsa_public_key = %s\n", pk_str.data);
-            free(pk_str.data);
+            str_free(pk_str);
             break;
         }
         
@@ -204,11 +205,11 @@ int main(const int argc, cstr const* argv){
 
             str sk_str = RSA_serializePrivateKey_base64(&sk);
             printf("rsa_private_key = %s\n", sk_str.data);
-            free(sk_str.data);
+            str_free(sk_str);
             
             str pk_str = RSA_serializePublicKey_base64(&pk);
             printf("\nrsa_public_key = %s\n", pk_str.data);
-            free(pk_str.data);
+            str_free(pk_str);
             break;
         }
         
diff --git a/src/network/encrypted_sockets.c b/src/network/encrypted_sockets.c
index cb82553..ac32b38 100644
--- a/src/network/encrypted_sockets.c
+++ b/src/network/encrypted_sockets.c
@@ -18,8 +18,8 @@ void EncryptedSocketTCP_destroy(EncryptedSocketTCP* ptr){
     if(!ptr)
         return;
     socket_close(ptr->sock);
-    free(ptr->recv_buf.data);
-    free(ptr->send_buf.data);
+    Array_free(ptr->recv_buf);
+    Array_free(ptr->send_buf);
 }
 
 void EncryptedSocketTCP_changeKey(EncryptedSocketTCP* ptr, Array(u8) aes_key){
@@ -171,8 +171,8 @@ void EncryptedSocketUDP_destroy(EncryptedSocketUDP* ptr){
     if(!ptr)
         return;
     socket_close(ptr->sock);
-    free(ptr->recv_buf.data);
-    free(ptr->send_buf.data);
+    Array_free(ptr->recv_buf);
+    Array_free(ptr->send_buf);
 }
 
 void EncryptedSocketUDP_changeKey(EncryptedSocketUDP* ptr, Array(u8) aes_key){
diff --git a/src/server/ClientConnection.c b/src/server/ClientConnection.c
index 4dc07a4..01a7a7c 100644
--- a/src/server/ClientConnection.c
+++ b/src/server/ClientConnection.c
@@ -5,7 +5,7 @@ void ClientConnection_close(ClientConnection* conn){
     if(!conn)
         return;
     EncryptedSocketTCP_destroy(&conn->sock);
-    free(conn->session_key.data);
+    Array_free(conn->session_key);
     free(conn);
 }
 
@@ -29,7 +29,7 @@ Result(ClientConnection*) ClientConnection_accept(ConnectionHandlerArgs* args)
     
     // decrypt the rsa messages using server private key
     RSADecryptor rsa_dec;
-    RSADecryptor_construct(&rsa_dec, &args->server->cred.rsa_sk);
+    RSADecryptor_construct(&rsa_dec, &args->server->rsa_sk);
 
     // receive PacketHeader
     PacketHeader packet_header;
diff --git a/src/server/ServerCredentials.c b/src/server/ServerCredentials.c
deleted file mode 100644
index 29c2e81..0000000
--- a/src/server/ServerCredentials.c
+++ /dev/null
@@ -1,26 +0,0 @@
-#include "server.h"
-
-
-
-Result(void) ServerCredentials_tryConstruct(ServerCredentials* cred,
-    cstr rsa_sk_base64, cstr rsa_pk_base64)
-{
-    Deferral(4);
-    
-    memset(cred, 0, sizeof(*cred));
-    bool success = false;
-    Defer(if(!success) ServerCredentials_destroy(cred));
-
-    try_void(RSA_parsePrivateKey_base64(rsa_sk_base64, &cred->rsa_sk));
-    try_void(RSA_parsePublicKey_base64(rsa_pk_base64, &cred->rsa_pk));
-    
-    success = true;
-    Return RESULT_VOID;
-}
-
-void ServerCredentials_destroy(ServerCredentials* cred){
-    if(!cred)
-        return;
-    RSA_destroyPrivateKey(&cred->rsa_sk);
-    RSA_destroyPublicKey(&cred->rsa_pk);
-}
diff --git a/src/server/db_tables.h b/src/server/db_tables.h
index 6833893..77a7baa 100644
--- a/src/server/db_tables.h
+++ b/src/server/db_tables.h
@@ -3,15 +3,15 @@
 #include "tlibc/time.h"
 
 typedef struct User {
-    u16 name_len;
     char name[USERNAME_SIZE_MAX + 1];  // null-terminated
+    u16 name_len;
     u8 token_hash[PASSWORD_HASH_SIZE]; // token is hashed again on server side
     DateTime registration_time;
 } ATTRIBUTE_ALIGNED(256) User;
 
 typedef struct Channel {
+    char name[CHANNEL_NAME_SIZE_MAX + 1];
     u16 name_len;
+    char desc[CHANNEL_DESC_SIZE_MAX + 1];
     u16 desc_len;
-    char name[CHANNEL_NAME_MAX + 1];
-    char desc[CHANNEL_DESC_MAX + 1];
-} ATTRIBUTE_ALIGNED(16*1024) Channel;
+} ATTRIBUTE_ALIGNED(4*1024) Channel;
diff --git a/src/server/request_handlers/Register.c b/src/server/request_handlers/Register.c
index b6d6eac..640383f 100644
--- a/src/server/request_handlers/Register.c
+++ b/src/server/request_handlers/Register.c
@@ -34,13 +34,17 @@ declare_RequestHandler(Register)
     // initialize new user
     User user;
     memset(&user, 0, sizeof(User));
-    memcpy(user.name, username_str.data, username_str.size + 1);
+
+    memcpy(user.name, username_str.data, username_str.size);
     user.name_len = username_str.size;
+    user.name[user.name_len] = 0;
+
     hash_password(
         Array_construct_size(req.token, sizeof(req.token)), 
         user.token_hash,
         PASSWORD_HASH_LVL_ROUNDS
     );
+    
     DateTime_getUTC(&user.registration_time);
     
     // save new user to db and cache
diff --git a/src/server/server.c b/src/server/server.c
index d13208c..695d7f7 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -11,16 +11,19 @@
 static void* handleConnection(void* _args);
 static Result(void) try_handleConnection(ConnectionHandlerArgs* args, cstr log_ctx);
 
-void Server_free(Server* server){
-    if(!server)
+void Server_free(Server* self){
+    if(!self)
         return;
-    free(server->name.data);
-    free(server->description.data);
-    ServerCredentials_destroy(&server->cred);
-    idb_close(server->db);
-    pthread_mutex_destroy(&server->users_cache_mutex);
-    free(server->users_cache_list.data);
-    HashMap_destroy(&server->users_name_id_map);
+    
+    str_free(self->name);
+    str_free(self->description);
+    RSA_destroyPrivateKey(&self->rsa_sk);
+    RSA_destroyPublicKey(&self->rsa_pk);
+
+    idb_close(self->db);
+    pthread_mutex_destroy(&self->users_cache_mutex);
+    List_destroy(self->users_cache_list);
+    HashMap_destroy(&self->users_name_id_map);
 }
 
 Result(Server*) Server_createFromConfig(cstr config_path){
@@ -76,11 +79,13 @@ Result(Server*) Server_createFromConfig(cstr config_path){
     char* pk_base64_cstr = str_copy(tmp_str).data;
     Defer(free(pk_base64_cstr));
     
-    try_void(ServerCredentials_tryConstruct(&server->cred, sk_base64_cstr, pk_base64_cstr));
+    try_void(RSA_parsePrivateKey_base64(sk_base64_cstr, &server->rsa_sk));
+    try_void(RSA_parsePublicKey_base64(pk_base64_cstr, &server->rsa_pk));
     
     // parse db_aes_key
     try_void(config_findValue(config_str, STR("db_aes_key"), &tmp_str, true));
     Array(u8) db_aes_key = Array_alloc_size(base64_decodedSize(tmp_str.data, tmp_str.size));
+    Defer(free(db_aes_key.data));
     base64_decode(tmp_str.data, tmp_str.size, db_aes_key.data);
 
     // parse db_dir and open db
@@ -147,7 +152,7 @@ static void* handleConnection(void* _args){
     if(r.error){
         str e_str = Error_toStr(r.error);
         logError(log_ctx, "%s", e_str.data);
-        free(e_str.data);
+        str_free(e_str);
         Error_free(r.error);
     }
     
diff --git a/src/server/server.h b/src/server/server.h
index c6ab4e4..9f38cd7 100644
--- a/src/server/server.h
+++ b/src/server/server.h
@@ -10,17 +10,6 @@
 
 typedef struct Server Server;
 
-typedef struct ServerCredentials {
-    br_rsa_private_key rsa_sk;
-    br_rsa_public_key rsa_pk;
-} ServerCredentials;
-
-Result(void) ServerCredentials_tryConstruct(ServerCredentials* cred,
-    cstr rsa_sk_base64, cstr rsa_pk_base64);
-
-void ServerCredentials_destroy(ServerCredentials* cred);
-
-
 typedef struct ClientConnection {
     u64 session_id;
     EndpointIPv4 client_end;
@@ -29,7 +18,6 @@ typedef struct ClientConnection {
     bool authorized;
 } ClientConnection;
 
-
 typedef struct ConnectionHandlerArgs {
     Server* server;
     Socket accepted_socket_tcp;
@@ -47,7 +35,9 @@ typedef struct Server {
     str description;
     u64 landing_channel_id;
     EndpointIPv4 local_end;
-    ServerCredentials cred;
+    br_rsa_private_key rsa_sk;
+    br_rsa_public_key rsa_pk;
+
     IncrementalDB* db;
     Table* db_users_table;
     pthread_mutex_t users_cache_mutex;