diff --git a/src/Connection.php b/src/Connection.php
index 42e3b5079..037e9a065 100644
--- a/src/Connection.php
+++ b/src/Connection.php
@@ -580,7 +580,7 @@ final class Connection
         }
         $this->pendingOutgoing[$this->pendingOutgoingKey++] = $message;
         $this->outgoingCtr?->inc();
-        $this->pendingOutgoingGauge?->set(count($this->pendingOutgoing));
+        $this->pendingOutgoingGauge?->set(\count($this->pendingOutgoing));
         if (isset($this->writer)) {
             $this->writer->resume();
         }
diff --git a/src/Loop/Connection/ReadLoop.php b/src/Loop/Connection/ReadLoop.php
index 652fd5d00..0f06dd2ab 100644
--- a/src/Loop/Connection/ReadLoop.php
+++ b/src/Loop/Connection/ReadLoop.php
@@ -139,10 +139,13 @@ final class ReadLoop extends Loop
             }
             throw $e;
         }
+        /** @var int $payload_length */
         if ($payload_length & (1 << 31)) {
             $this->API->logger("Received quick ACK $payload_length from DC ".$this->datacenter, Logger::ULTRA_VERBOSE);
+            $this->connection->incomingBytesCtr?->incBy(4);
             return null;
         }
+        $this->connection->incomingBytesCtr?->incBy(4+$payload_length);
         if ($payload_length <= 16) {
             $code = Tools::unpackSignedInt($buffer->bufferRead(4));
             if ($code === -1 && $payload_length >= 8) {
@@ -177,6 +180,7 @@ final class ReadLoop extends Loop
                     if ($left < (-$message_length & 15)) {
                         $this->API->logger('Protocol padded unencrypted message', Logger::ULTRA_VERBOSE);
                     }
+                    $this->connection->incomingBytesCtr?->incBy($left);
                     $buffer->bufferRead($left);
                 }
             } elseif ($auth_key_id === $this->shared->getTempAuthKey()->getID()) {
@@ -187,6 +191,7 @@ final class ReadLoop extends Loop
                 $payload_length -= $left;
                 $decrypted_data = Crypt::igeDecrypt($buffer->bufferRead($payload_length), $aes_key, $aes_iv);
                 if ($left) {
+                    $this->connection->incomingBytesCtr?->incBy($left);
                     $buffer->bufferRead($left);
                 }
                 if ($message_key != substr(hash('sha256', substr($this->shared->getTempAuthKey()->getAuthKey(), 96, 32).$decrypted_data, true), 8, 16)) {
diff --git a/src/Loop/Connection/WriteLoop.php b/src/Loop/Connection/WriteLoop.php
index b0b384c4b..66dd0b47f 100644
--- a/src/Loop/Connection/WriteLoop.php
+++ b/src/Loop/Connection/WriteLoop.php
@@ -102,7 +102,7 @@ final class WriteLoop extends Loop
                 }
                 if ($message->getState() & MTProtoOutgoingMessage::STATE_REPLIED) {
                     unset($this->connection->pendingOutgoing[$k]);
-                    $this->connection->pendingOutgoingGauge?->set(count($this->connection->pendingOutgoing));
+                    $this->connection->pendingOutgoingGauge?->set(\count($this->connection->pendingOutgoing));
                     continue;
                 }
                 $skipped_all = false;
@@ -112,14 +112,15 @@ final class WriteLoop extends Loop
                 $pad_length = -$length & 15;
                 $pad_length += 16 * Tools::randomInt(modulus: 16);
                 $pad = Tools::random($pad_length);
-                $buffer = $this->connection->stream->getWriteBuffer(8 + 8 + 4 + $pad_length + $length);
+                $buffer = $this->connection->stream->getWriteBuffer($total_len = 8 + 8 + 4 + $pad_length + $length);
                 $buffer->bufferWrite("\0\0\0\0\0\0\0\0".Tools::packSignedLong($message_id).Tools::packUnsignedInt($length).$message->getSerializedBody().$pad);
                 $this->connection->httpSent();
+                $this->connection->outgoingBytesCtr?->incBy($total_len);
 
                 $this->API->logger("Sent $message as unencrypted message to DC $this->datacenter!", Logger::ULTRA_VERBOSE);
 
                 unset($this->connection->pendingOutgoing[$k]);
-                $this->connection->pendingOutgoingGauge?->set(count($this->connection->pendingOutgoing));
+                $this->connection->pendingOutgoingGauge?->set(\count($this->connection->pendingOutgoing));
                 $message->setMsgId($message_id);
                 $this->connection->outgoing_messages[$message_id] = $message;
                 $this->connection->new_outgoing[$message_id] = $message;
@@ -162,13 +163,13 @@ final class WriteLoop extends Loop
                 }
                 if ($message->getState() & MTProtoOutgoingMessage::STATE_REPLIED) {
                     unset($this->connection->pendingOutgoing[$k]);
-                    $this->connection->pendingOutgoingGauge?->set(count($this->connection->pendingOutgoing));
+                    $this->connection->pendingOutgoingGauge?->set(\count($this->connection->pendingOutgoing));
                     $this->API->logger("Skipping resending of $message, we already got a reply in DC $this->datacenter");
                     continue;
                 }
                 if ($message instanceof Container) {
                     unset($this->connection->pendingOutgoing[$k]);
-                    $this->connection->pendingOutgoingGauge?->set(count($this->connection->pendingOutgoing));
+                    $this->connection->pendingOutgoingGauge?->set(\count($this->connection->pendingOutgoing));
                     continue;
                 }
                 $constructor = $message->constructor;
@@ -326,7 +327,7 @@ final class WriteLoop extends Loop
                 $message_id = $this->connection->msgIdHandler->generateMessageId();
                 $this->connection->pendingOutgoing[$this->connection->pendingOutgoingKey] = new Container(array_values($keys));
                 $this->connection->outgoingCtr?->inc();
-                $this->connection->pendingOutgoingGauge?->set(count($this->connection->pendingOutgoing));
+                $this->connection->pendingOutgoingGauge?->set(\count($this->connection->pendingOutgoing));
                 $keys[$this->connection->pendingOutgoingKey++] = $message_id;
                 $message_data = $this->API->getTL()->serializeObject(['type' => ''], ['_' => 'msg_container', 'messages' => $messages], 'container');
                 $message_data_length = \strlen($message_data);
@@ -353,9 +354,10 @@ final class WriteLoop extends Loop
             //$ack = unpack('V', substr($message_key_large, 0, 4))[1] | (1 << 31);
             [$aes_key, $aes_iv] = Crypt::kdf($message_key, $this->shared->getTempAuthKey()->getAuthKey());
             $message = $this->shared->getTempAuthKey()->getID().$message_key.Crypt::igeEncrypt($plaintext.$padding, $aes_key, $aes_iv);
-            $buffer = $this->connection->stream->getWriteBuffer(\strlen($message));
+            $buffer = $this->connection->stream->getWriteBuffer($total_len = \strlen($message));
             $buffer->bufferWrite($message);
             $this->connection->httpSent();
+            $this->connection->outgoingBytesCtr?->incBy($total_len);
             $this->API->logger("Sent encrypted payload to DC {$this->datacenter}", Logger::ULTRA_VERBOSE);
 
             if ($ackCount) {
@@ -380,7 +382,7 @@ final class WriteLoop extends Loop
                     }
                 });
             }
-            $this->connection->pendingOutgoingGauge?->set(count($this->connection->pendingOutgoing));
+            $this->connection->pendingOutgoingGauge?->set(\count($this->connection->pendingOutgoing));
         } while ($this->connection->pendingOutgoing && !$skipped);
         if (empty($this->connection->pendingOutgoing)) {
             $this->connection->pendingOutgoing = [];
diff --git a/src/MTProtoSession/ResponseHandler.php b/src/MTProtoSession/ResponseHandler.php
index e607e6e87..7b7e32b5e 100644
--- a/src/MTProtoSession/ResponseHandler.php
+++ b/src/MTProtoSession/ResponseHandler.php
@@ -145,7 +145,7 @@ trait ResponseHandler
             $this->checkInSeqNo($newMessage);
             $newMessage->setSeqNo(null);
             $tmp->enqueue($newMessage);
-            $this->connection->incomingCtr?->inc();
+            $this->incomingCtr?->inc();
             $this->incoming_messages[$msg['msg_id']] = $newMessage;
         }
         $this->checkInSeqNo($message);
@@ -161,7 +161,7 @@ trait ResponseHandler
         } else {
             $this->msgIdHandler->checkIncomingMessageId($referencedMsgId, true);
             $message = new MTProtoIncomingMessage($content['orig_message'], $referencedMsgId, $message->unencrypted);
-            $this->connection->incomingCtr?->inc();
+            $this->incomingCtr?->inc();
             $this->incoming_messages[$referencedMsgId] = $message;
             $this->handleMessages([$message]);
         }
@@ -276,10 +276,16 @@ trait ResponseHandler
         EventLoop::queue($request->reply(...), $response);
     }
     /**
+     * @param array{error_message: string, error_code: int} $response
      * @return (callable(): Throwable)|null
      */
     private function handleRpcError(MTProtoOutgoingMessage $request, array $response): ?callable
     {
+        if ($response['error_code'] === 420) {
+            $this->rpcErrors?->inc(['message' => preg_replace('/\d+/', '', $response['error_message']), 'code' => (string) $response['error_code']]);
+        } else {
+            $this->rpcErrors?->inc(['message' => $response['error_message'], 'code' => (string) $response['error_code']]);
+        }
         if ($request->isMethod
             && $request->constructor !== 'auth.bindTempAuthKey'
             && $this->shared->hasTempAuthKey()
diff --git a/src/MTProtoSession/Session.php b/src/MTProtoSession/Session.php
index 95d7f2e95..c33b64cdf 100644
--- a/src/MTProtoSession/Session.php
+++ b/src/MTProtoSession/Session.php
@@ -42,9 +42,12 @@ trait Session
     use SeqNoHandler;
     use CallHandler;
     use Reliable;
-    public ?BetterGauge $pendingOutgoingGauge;
-    public ?BetterCounter $incomingCtr;
-    public ?BetterCounter $outgoingCtr;
+    public ?BetterGauge $pendingOutgoingGauge = null;
+    public ?BetterCounter $incomingCtr = null;
+    public ?BetterCounter $outgoingCtr = null;
+    public ?BetterCounter $incomingBytesCtr = null;
+    public ?BetterCounter $outgoingBytesCtr = null;
+    public ?BetterCounter $rpcErrors = null;
     /**
      * Incoming message array.
      *
@@ -176,9 +179,13 @@ trait Session
      */
     public function createSession(): void
     {
-        $this->pendingOutgoingGauge = $this->API->getPromGauge("MadelineProto", "pending_outgoing_mtproto_messages", "Number of not-yet sent outgoing MTProto messages", ['datacenter' => $this->datacenter, 'connection' => $this->id]);
-        $this->incomingCtr = $this->API->getPromCounter("MadelineProto", "outgoing_mtproto_messages", "Number of received MTProto messages", ['datacenter' => $this->datacenter, 'connection' => $this->id]);
-        $this->outgoingCtr = $this->API->getPromCounter("MadelineProto", "incoming_mtproto_messages", "Number of sent MTProto messages", ['datacenter' => $this->datacenter, 'connection' => $this->id]);
+        $labels = ['datacenter' => (string) $this->datacenter, 'connection' => (string) $this->id];
+        $this->pendingOutgoingGauge = $this->API->getPromGauge("MadelineProto", "pending_outgoing_mtproto_messages", "Number of not-yet sent outgoing MTProto messages", $labels);
+        $this->incomingCtr = $this->API->getPromCounter("MadelineProto", "incoming_mtproto_messages", "Number of received MTProto messages", $labels);
+        $this->outgoingCtr = $this->API->getPromCounter("MadelineProto", "outgoing_mtproto_messages", "Number of sent MTProto messages", $labels);
+        $this->incomingBytesCtr = $this->API->getPromCounter("MadelineProto", "incoming_bytes", "Number of received bytes", $labels);
+        $this->outgoingBytesCtr = $this->API->getPromCounter("MadelineProto", "outgoing_bytes", "Number of sent bytes", $labels);
+        $this->rpcErrors = $this->API->getPromCounter("MadelineProto", "rpc_errors", "Number of received RPC errors by type", $labels);
         if ($this->session_id === null) {
             $this->resetSession("creating initial session");
         }