diff --git a/include/tcp-chat/tcp-chat.h b/include/tcp-chat/tcp-chat.h
new file mode 100644
index 0000000..4f231e3
--- /dev/null
+++ b/include/tcp-chat/tcp-chat.h
@@ -0,0 +1,14 @@
+#pragma once
+#include "tlibc/errors.h"
+
+/// requires tlibc and tlibtoml init
+Result(void) TcpChat_init();
+void TcpChat_deinit();
+
+ErrorCodePage_declare(WINSOCK2);
+ErrorCodePage_declare(TcpChat);
+
+typedef enum TcpChatError {
+    TcpChatError_Unknown,
+    TcpChatError_RejectIncoming,
+} TcpChatError;
diff --git a/src/cli/main.c b/src/cli/main.c
index 3229afe..7df6eac 100644
--- a/src/cli/main.c
+++ b/src/cli/main.c
@@ -1,7 +1,8 @@
 #include "tlibc/tlibc.h"
-#include "network/network.h"
+#include "tlibtoml.h"
+#include "tcp-chat/tcp-chat.h"
 #include "cryptography/RSA.h"
-#include "modes/modes.h"
+#include "cli/modes/modes.h"
 
 #define _DEFAULT_CONFIG_PATH_CLIENT "tcp-chat-client.config"
 #define _DEFAULT_CONFIG_PATH_SERVER "tcp-chat-server.toml"
@@ -11,11 +12,12 @@
 
 int main(const int argc, cstr const* argv){
     Deferral(32);
-
     try_fatal_void(tlibc_init());
     Defer(tlibc_deinit());
-    try_fatal_void(network_init());
-    Defer(network_deinit());
+    try_fatal_void(tlibtoml_init());
+    Defer(tlibtoml_deinit());
+    try_fatal_void(TcpChat_init());
+    Defer(TcpChat_deinit());
 
     if(br_prng_seeder_system(NULL) == NULL){
         printfe("Can't get system random seeder. Bearssl is compiled incorrectly.");
diff --git a/src/network/internal.h b/src/network/internal.h
index 5a669a3..e79d725 100644
--- a/src/network/internal.h
+++ b/src/network/internal.h
@@ -1,7 +1,6 @@
 #pragma once
-#include "tlibc/errors.h"
+#include "tcp-chat/tcp-chat.h"
 #include "endpoint.h"
-#include "network.h"
 
 #if !defined(KN_USE_WINSOCK)
     #if defined(_WIN64) || defined(_WIN32)
diff --git a/src/network/network.h b/src/network/network.h
deleted file mode 100755
index 1eb807a..0000000
--- a/src/network/network.h
+++ /dev/null
@@ -1,7 +0,0 @@
-#pragma once
-#include "tlibc/errors.h"
-
-ErrorCodePage_declare(WINSOCK2);
-
-Result(void) network_init();
-void network_deinit();
diff --git a/src/network/tcp-chat-protocol/v1.c b/src/network/tcp-chat-protocol/v1.c
index 2758abf..be9fe4d 100644
--- a/src/network/tcp-chat-protocol/v1.c
+++ b/src/network/tcp-chat-protocol/v1.c
@@ -161,10 +161,11 @@ void SendMessageResponse_construct(SendMessageResponse *ptr, PacketHeader *heade
 }
 
 void GetMessageBlockRequest_construct(GetMessageBlockRequest *ptr, PacketHeader *header,
-    u64 first_message_id, u32 messages_count)
+    u64 channel_id, u64 first_message_id, u32 messages_count)
 {
     _PacketHeader_construct(GetMessageBlockRequest);
     zeroStruct(ptr);
+    ptr->channel_id = channel_id;
     ptr->first_message_id = first_message_id;
     ptr->messages_count = messages_count;
 }
diff --git a/src/network/tcp-chat-protocol/v1.h b/src/network/tcp-chat-protocol/v1.h
index d45f27a..a5db0c9 100644
--- a/src/network/tcp-chat-protocol/v1.h
+++ b/src/network/tcp-chat-protocol/v1.h
@@ -144,12 +144,13 @@ void SendMessageResponse_construct(SendMessageResponse* ptr, PacketHeader* heade
 
 
 typedef struct GetMessageBlockRequest {
+    u64 channel_id;
     u64 first_message_id;
     u32 messages_count;
 } ALIGN_PACKET_STRUCT GetMessageBlockRequest;
 
 void GetMessageBlockRequest_construct(GetMessageBlockRequest* ptr, PacketHeader* header,
-    u64 first_message_id, u32 messages_count);
+    u64 channel_id, u64 first_message_id, u32 messages_count);
 
 
 typedef struct GetMessageBlockResponse {
diff --git a/src/server/Channel.c b/src/server/Channel.c
index 125988a..f128590 100644
--- a/src/server/Channel.c
+++ b/src/server/Channel.c
@@ -58,7 +58,7 @@ Result(Channel*) Channel_create(u64 chan_id, str name, str description,
     StringBuilder_removeFromEnd(&sb, message_blocks_str.len);
     StringBuilder_append_str(&sb, message_blocks_meta_str);
     try(self->messages.blocks_meta_table, p, 
-        idb_getOrCreateTable(db, subdir, StringBuilder_getStr(&sb), sizeof(MessageBlock), false)
+        idb_getOrCreateTable(db, subdir, StringBuilder_getStr(&sb), sizeof(MessageBlockMeta), false)
     );
     idb_lockTable(self->messages.blocks_meta_table);
     Defer(idb_unlockTable(self->messages.blocks_meta_table));
@@ -96,11 +96,27 @@ Result(Channel*) Channel_create(u64 chan_id, str name, str description,
     Return RESULT_VALUE(p, self);
 }
 
+void Channel_unloadExcessBlocks(Channel* self){
+    while(self->messages.blocks_queue.count > MESSAGE_BLOCKS_CACHE_COUNT){
+        LLNode(MessageBlock)* node = self->messages.blocks_queue.first;
+        LList_MessageBlock_detatch(&self->messages.blocks_queue, node);
+        free(node);
+    }
+}
 
 Result(void) Channel_saveMessage(Channel* self, Array(u8) message_data, u64 sender_id,
-    MessageMeta* out_message_meta)
+    MessageMeta* out_message_meta, bool lock_tables)
 {
-    Deferral(1);
+    Deferral(4);
+
+    if(lock_tables){
+        idb_lockTable(self->messages.blocks_table);
+        idb_lockTable(self->messages.blocks_meta_table);
+        Defer(
+            idb_unlockTable(self->messages.blocks_table);
+            idb_unlockTable(self->messages.blocks_meta_table);
+        );
+    }
 
     // create new block if message won't fit in the last existing
     MessageBlockMeta* incomplete_block_meta = self->messages.blocks_meta_list.data + self->messages.blocks_meta_list.len;
@@ -117,35 +133,54 @@ Result(void) Channel_saveMessage(Channel* self, Array(u8) message_data, u64 send
             &self->messages.blocks_queue,
             self->messages.blocks_queue.last, 
             LLNode_MessageBlock_createZero());
-        //TODO: save to DB
+        // unload old blocks from cache
+        Channel_unloadExcessBlocks(self);
     }
     
-    // copy message to message block
+    // create message meta
     out_message_meta->magic = MESSAGE_MAGIC;
     out_message_meta->data_size = message_data.len;
     out_message_meta->id = new_message_id;
     out_message_meta->sender_id = sender_id;
     DateTime_getUTC(&out_message_meta->receiving_time_utc);
 
+    // copy message data to message block
     MessageBlock* incomplete_block = &self->messages.blocks_queue.last->value;
     u8* data_ptr = incomplete_block->data + incomplete_block_meta->data_size;
     memcpy(data_ptr, out_message_meta, sizeof(MessageMeta));
     data_ptr += sizeof(MessageMeta);
     memcpy(data_ptr, message_data.data, message_data.len);
+    incomplete_block_meta->data_size += sizeof(MessageMeta) + ALIGN_TO(message_data.len, 8);
+    incomplete_block_meta->messages_count++;
+
+    // save to DB
+    try_void(idb_pushRow(self->messages.blocks_meta_table, incomplete_block_meta, false));
+    try_void(idb_pushRow(self->messages.blocks_table, incomplete_block, false));
 
     Return RESULT_VOID;
 }
 
-// Result(void) Channel_loadMessage(Channel* self, u64 id, 
-//     MessageMeta* out_message_meta, u8* out_data)
-// {
-//     Deferral(1);
-//     Return RESULT_VOID;
-// }
+Result(void) Channel_loadMessageBlock(Channel* self, u64 fisrt_message_id, u32 count,
+    MessageBlockMeta* out_meta, NULLABLE(Array(u8)*) out_block, bool lock_tables)
+{
+    Deferral(4);
 
-// Result(void) Channel_loadMessageBlock(Channel* self, u64 fisrt_message_id, u32 count,
-//     MessageBlockMeta* out_message_meta, MessageBlock* out_block)
-// {
-//     Deferral(1);
-//     Return RESULT_VOID;
-// }
+    if(lock_tables){
+        idb_lockTable(self->messages.blocks_table);
+        idb_lockTable(self->messages.blocks_meta_table);
+        Defer(
+            idb_unlockTable(self->messages.blocks_table);
+            idb_unlockTable(self->messages.blocks_meta_table);
+        );
+    }
+
+    // TODO: Maybe it's better to request message block id directly? Client doesn't know how much bytes `count` messages will take, this can lead to severe lags on slow internet
+
+    // TODO: binary search in list of blocks meta
+    // TODO: return if out_block == NULL
+    // TODO: check if block is in N_LAST_BLOCKS
+    // TODO: load block
+    // TODO: insert block in queue and keep it sorted
+
+    Return RESULT_VOID;
+}
diff --git a/src/server/responses/GetMessageBlock.c b/src/server/responses/GetMessageBlock.c
index 2379308..07ac415 100644
--- a/src/server/responses/GetMessageBlock.c
+++ b/src/server/responses/GetMessageBlock.c
@@ -9,18 +9,40 @@ declare_RequestHandler(GetMessageBlock)
 {
     Deferral(4);
     logInfo("requested %s", req_type_name);
-    
+
     // receive request
     GetMessageBlockRequest req;
     try_void(PacketHeader_validateContentSize(req_head, sizeof(req)));
     try_void(EncryptedSocketTCP_recvStruct(&conn->sock, &req));
 
-    (void)res_head;
+    if(!conn->authorized){
+        try_void(sendErrorMessage(log_ctx, conn, res_head,
+            LogSeverity_Warn, STR("not authorized") ));
+        Return RESULT_VOID;
+    }
+
+    // get message block from channel
+    Channel* ch = Server_tryGetChannel(conn->server, req.channel_id);
+    if(ch == NULL){
+        try_void(sendErrorMessage(log_ctx, conn, res_head,
+            LogSeverity_Warn, STR("invalid channel id") ));
+        Return RESULT_VOID;
+    }
+    MessageBlockMeta meta;
+    Array(u8) block_data;
+    try_void(Channel_loadMessageBlock(ch, req.first_message_id, req.messages_count, 
+        &meta, &block_data, true));
+    Defer(Array_u8_destroy(&block_data));
+
     // send response
-    // GetMessageBlockResponse res;
-    // GetMessageBlockResponse_construct(&res, res_head, );
-    // try_void(EncryptedSocketTCP_sendStruct(&conn->sock, res_head));
-    // try_void(EncryptedSocketTCP_sendStruct(&conn->sock, &res));
+    GetMessageBlockResponse res;
+    GetMessageBlockResponse_construct(&res, res_head, 
+        meta.first_message_id, meta.messages_count, meta.data_size);
+    try_void(EncryptedSocketTCP_sendStruct(&conn->sock, res_head));
+    try_void(EncryptedSocketTCP_sendStruct(&conn->sock, &res));
+    if(block_data.len != 0){
+        try_void(EncryptedSocketTCP_send(&conn->sock, block_data));
+    }
 
     Return RESULT_VOID;
 }
diff --git a/src/server/responses/Login.c b/src/server/responses/Login.c
index 68df2da..4d62d4a 100644
--- a/src/server/responses/Login.c
+++ b/src/server/responses/Login.c
@@ -17,9 +17,7 @@ declare_RequestHandler(Login)
 
     if(conn->authorized){
         try_void(sendErrorMessage(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            STR("is authorized in already")
-        ));
+            LogSeverity_Warn, STR("is authorized in already") ));
         Return RESULT_VOID;
     }
 
@@ -29,9 +27,7 @@ declare_RequestHandler(Login)
     if(name_error_str.data){
         Defer(str_destroy(name_error_str));
         try_void(sendErrorMessage(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            name_error_str
-        ));
+            LogSeverity_Warn, name_error_str));
         Return RESULT_VOID;
     }
 
@@ -46,11 +42,8 @@ declare_RequestHandler(Login)
     // try get id from name cache
     u64* id_ptr = HashMap_tryGetPtr(&srv->users.name_id_map, username_str);
     if(id_ptr == NULL){
-        try_void(sendErrorMessage_f(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            "Username '%s' is not registered", 
-            username_str.data
-        ));
+        try_void(sendErrorMessage(log_ctx, conn, res_head,
+            LogSeverity_Warn, STR("Username is not registered") ));
         Return RESULT_VOID;
     }
     u64 user_id = *id_ptr;
@@ -62,9 +55,7 @@ declare_RequestHandler(Login)
     // validate token hash
     if(memcmp(req.token, u->token, sizeof(req.token)) != 0){
         try_void(sendErrorMessage(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            STR("wrong password")
-        ));
+            LogSeverity_Warn, STR("wrong password") ));
         Return RESULT_VOID;
     }
 
diff --git a/src/server/responses/Register.c b/src/server/responses/Register.c
index 243485e..c0eb0ca 100644
--- a/src/server/responses/Register.c
+++ b/src/server/responses/Register.c
@@ -17,9 +17,7 @@ declare_RequestHandler(Register)
 
     if(conn->authorized){
         try_void(sendErrorMessage(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            STR("is authorized in already")
-        ));
+            LogSeverity_Warn, STR("is authorized in already") ));
         Return RESULT_VOID;
     }
 
@@ -29,9 +27,7 @@ declare_RequestHandler(Register)
     if(name_error_str.data){
         Defer(str_destroy(name_error_str));
         try_void(sendErrorMessage(log_ctx, conn, res_head, 
-            LogSeverity_Warn,
-            name_error_str
-        ));
+            LogSeverity_Warn, name_error_str));
         Return RESULT_VOID;
     }
 
@@ -46,10 +42,8 @@ declare_RequestHandler(Register)
 
     // check if name is taken
     if(HashMap_tryGetPtr(&srv->users.name_id_map, username_str) != NULL){
-        try_void(sendErrorMessage_f(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            "Username '%s' already exists", 
-            username_str.data));
+        try_void(sendErrorMessage(log_ctx, conn, res_head,
+            LogSeverity_Warn, STR("Username already exists") ));
         Return RESULT_VOID;
     }
 
diff --git a/src/server/responses/SendMessage.c b/src/server/responses/SendMessage.c
index 04477e5..e742b90 100644
--- a/src/server/responses/SendMessage.c
+++ b/src/server/responses/SendMessage.c
@@ -17,20 +17,15 @@ declare_RequestHandler(SendMessage)
     
     if(!conn->authorized){
         try_void(sendErrorMessage(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            STR("is not authorized")
-        ));
+            LogSeverity_Warn, STR("not authorized") ));
         Return RESULT_VOID;
     }
 
     if(req.data_size < MESSAGE_SIZE_MIN || req.data_size > MESSAGE_SIZE_MAX){
-        try_void(sendErrorMessage_f(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            "message size must be >= %i and <= %i",
-            MESSAGE_SIZE_MIN, MESSAGE_SIZE_MAX
-        ));
-        // this will close socket connection
-        Return RESULT_ERROR("invalid message size", false);
+        try_void(sendErrorMessage(log_ctx, conn, res_head,
+            LogSeverity_Warn, STR("invalid message size") ));
+        // close socket connection to reject incoming data
+        Return RESULT_ERROR_CODE_FMT(TcpChat, TcpChatError_RejectIncoming, "invalid message size: %u", req.data_size);
     }
     
     // receive message data
@@ -41,13 +36,12 @@ declare_RequestHandler(SendMessage)
     Channel* ch = Server_tryGetChannel(conn->server, req.channel_id);
     if(ch == NULL){
         try_void(sendErrorMessage(log_ctx, conn, res_head,
-            LogSeverity_Warn,
-            STR("invalid channel id")
-        ));
+            LogSeverity_Warn, STR("invalid channel id") ));
         Return RESULT_VOID;
     }
     MessageMeta message_meta;
-    try_void(Channel_saveMessage(ch, message_data, conn->user_id, &message_meta));
+    try_void(Channel_saveMessage(ch, message_data, conn->user_id, 
+        &message_meta, true));
 
     // send response
     SendMessageResponse res;
diff --git a/src/server/server.c b/src/server/server.c
index c74526a..77ee057 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -221,7 +221,15 @@ static void* handleConnection(void* _args){
     if(r.error){
         Error_addCallPos(r.error, ErrorCallPos_here());
         str e_str = Error_toStr(r.error);
-        logError(FMT_str, e_str.len, e_str.data);
+        LogSeverity severity = LogSeverity_Error;
+
+        if(r.error->error_code_page == ErrorCodePage_TcpChat){
+            if(r.error->error_code == TcpChatError_RejectIncoming){
+                severity = LogSeverity_Debug;
+            }
+        }
+        
+        log(severity, FMT_str, e_str.len, e_str.data);
         str_destroy(e_str);
         Error_free(r.error);
     }
diff --git a/src/server/server_internal.h b/src/server/server_internal.h
index 8709182..df5ef80 100644
--- a/src/server/server_internal.h
+++ b/src/server/server_internal.h
@@ -2,6 +2,7 @@
 #include "tlibc/collections/HashMap.h"
 #include "tlibc/collections/List.h"
 #include "tlibc/collections/LList.h"
+#include "tcp-chat/tcp-chat.h"
 #include "tcp-chat/server.h"
 #include "cryptography/AES.h"
 #include "cryptography/RSA.h"
@@ -41,14 +42,13 @@ Result(Channel*) Channel_create(u64 id, str name, str description,
 void Channel_free(Channel* self);
 
 Result(void) Channel_saveMessage(Channel* self, Array(u8) message_data, u64 sender_id,
-    MessageMeta* out_message_meta);
-
-/// @param out_data buffer of size >= MESSAGE_SIZE_MAX
-Result(void) Channel_loadMessage(Channel* self, u64 id, 
-    MessageMeta* out_meta, u8* out_data);
+    MessageMeta* out_message_meta, bool lock_tables);
 
+/// @brief try to find `count` messages starting from `fisrt_message_id`
+/// @param out_meta information about found messages, .count can be 0 if no messages found
+/// @param out_block allocates buffer on heap and copies them there, .len can be 0 if no messages found
 Result(void) Channel_loadMessageBlock(Channel* self, u64 fisrt_message_id, u32 count,
-    MessageBlockMeta* out_meta, MessageBlock* out_block);
+    MessageBlockMeta* out_meta, NULLABLE(Array(u8)*) out_block, bool lock_tables);
 
 
 typedef struct Server {
diff --git a/src/network/network.c b/src/tcp-chat.c
old mode 100755
new mode 100644
similarity index 50%
rename from src/network/network.c
rename to src/tcp-chat.c
index e1392ed..5e76214
--- a/src/network/network.c
+++ b/src/tcp-chat.c
@@ -1,21 +1,27 @@
-#include "internal.h"
+#include "network/internal.h"
 
 ErrorCodePage_define(WINSOCK2);
+ErrorCodePage_define(TcpChat);
+
+Result(void) TcpChat_init(){
+    Deferral(4);
+
+    ErrorCodePage_register(TcpChat);
 
-Result(void) network_init(){
 #if _WIN32
     ErrorCodePage_register(WINSOCK2);
+
     // Initialize Winsock
     WSADATA wsaData = {0};
     int result = WSAStartup(MAKEWORD(2,2), &wsaData);
     if (result != 0) {
-        return RESULT_ERROR_FMT("WSAStartup failed with error code 0x%X", result);
+        Return RESULT_ERROR_CODE_FMT(WINSOCK2, result, "WSAStartup failed with error code %i", result);
     }
 #endif
-    return RESULT_VOID;
+    Return RESULT_VOID;
 }
 
-void network_deinit(){
+void TcpChat_deinit(){
 #if _WIN32
     // Deinitialize Winsock
     (void)WSACleanup();