diff --git a/README b/README
index b04df7c..7a1300e 100644
--- a/README
+++ b/README
@@ -43,35 +43,41 @@ Installation:
 3. Apache setup:
 
 CentOS:
-   yum install httpd php php-mysqlnd mariadb-server
+   yum install httpd php php-mysqlnd php-redis redis mariadb-server
    cp configs/apache.conf.centos /etc/httpd/conf.d/text0nly.conf
    cp configs/php.ini /etc/php.ini
    chown -R apache:apache /var/www/html/main
    chmod -R 755 /var/www/html/main
+   systemctl start redis
+   systemctl enable redis
    systemctl start mariadb
    systemctl enable mariadb
    systemctl start httpd
    systemctl enable httpd
 
 Alpine:
-   apk add apache2 php php-mysql mariadb
+   apk add apache2 php php-mysql php-redis redis mariadb
    cp configs/apache.conf.debian /etc/apache2/sites-available/text0nly.conf
    cp configs/php.ini /etc/php/php.ini
    chown -R www-data:www-data /var/www/html/main
    chmod -R 755 /var/www/html/main
    ln -s /etc/apache2/sites-available/text0nly.conf /etc/apache2/sites-enabled/
+   rc-update add redis default
    rc-update add mariadb default
    rc-update add apache2 default
+   rc-service redis start
    rc-service mariadb start
    rc-service apache2 start
 
 Debian:
-   apt install apache2 php mariadb-server
+   apt install apache2 php php-mysql php-redis redis mariadb-server
    cp configs/apache.conf.debian /etc/apache2/sites-available/text0nly.conf
    cp configs/php.ini /etc/php/php.ini
    chown -R www-data:www-data /var/www/html/main
    chmod -R 755 /var/www/html/main
    a2ensite text0nly.conf
+   systemctl start redis
+   systemctl enable redis
    systemctl start mariadb
    systemctl enable mariadb
    systemctl start apache2
@@ -86,6 +92,7 @@ Files:
    main/config.php - Database configuration (create from config.php.example)
    main/create.sql - Initial database structure
    main/migrate.sql - Database migrations
+   main/RateLimiter.php - DoS protection
    main/index.php - Main page
    main/register.php - Registration
    main/api.php - Message API
diff --git a/main/RateLimiter.php b/main/RateLimiter.php
new file mode 100644
index 0000000..5dd489e
--- /dev/null
+++ b/main/RateLimiter.php
@@ -0,0 +1,32 @@
+<?php
+class RateLimiter {
+    private $redis;
+    private $maxRequests = 5;
+    private $timeWindow = 3;
+
+    public function __construct() {
+        $this->redis = new Redis();
+        $this->redis->connect('127.0.0.1', 6379);
+    }
+
+    public function isAllowed($ip) {
+        $key = "rate_limit:{$ip}";
+        $current = $this->redis->get($key);
+
+        if (!$current) {
+            $this->redis->setex($key, $this->timeWindow, 1);
+            return true;
+        }
+
+        if ($current >= $this->maxRequests) {
+            return false;
+        }
+
+        $this->redis->incr($key);
+        return true;
+    }
+
+    public function __destruct() {
+        $this->redis->close();
+    }
+} 
\ No newline at end of file
diff --git a/main/api.php b/main/api.php
index cbe3134..b8dfb7c 100644
--- a/main/api.php
+++ b/main/api.php
@@ -7,6 +7,14 @@ header('Content-Security-Policy: default-src \'self\'');
 
 session_start();
 
+require_once 'RateLimiter.php';
+$limiter = new RateLimiter();
+
+if (!$limiter->isAllowed($_SERVER['REMOTE_ADDR'])) {
+    http_response_code(429);
+    die(json_encode(['error' => 'Too many requests']));
+}
+
 if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     if (!isset($_SESSION['csrf_token']) || !isset($_SERVER['HTTP_X_CSRF_TOKEN']) || 
         $_SESSION['csrf_token'] !== $_SERVER['HTTP_X_CSRF_TOKEN']) {