diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ae6b738
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+.idea
+composer.phar
+composer.lock
+vendor
+
diff --git a/README.md b/README.md
index c5cc090..9457c9c 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,53 @@
-# php-tracking
\ No newline at end of file
+# php-tracking
+
+## Installation
+
+```bash
+composer require affise/php-tracking:^1.0
+```
+
+## Documentation
+
+The links bellow should provide all the documentation needed to make the best
+use of the library:
+
+- [Documentation](https://help-center.affise.com/en/articles/6466563-postback-integration-s2s-admins)
+
+## Usage
+
+### Clicks
+
+```php
+<?php
+
+use Affise\Tracking\Cookie;
+use Affise\Tracking\CookieInvalidParamException;
+use Affise\Tracking\CookieUnsetException;
+
+try {
+    Cookie::set();
+}
+catch (CookieInvalidParamException $e) {
+    echo "Invalid click id param\n";
+}
+catch (CookieUnsetException $e) {
+    echo "Failed to set cookie\n";
+}
+```
+
+### Conversions
+
+```php
+<?php
+
+use Affise\Tracking\PostbackSender;
+
+$sender = new PostbackSender("example.com");
+
+try {
+    $sender->send(['clickID' => '111111111111111111111111']);
+}
+catch (PostbackInvalidClickIDException $e) {
+    echo "Invalid click id\n";
+} 
+```
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..619352f
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,21 @@
+{
+  "name": "affise/php-tracking",
+  "description": "Affise tracking SDK",
+  "minimum-stability": "stable",
+  "license": "MIT",
+  "authors": [
+    {
+      "name": "vladimirkoptev",
+      "email": "vk@affise.com"
+    }
+  ],
+  "require": {
+    "php": ">=7.4",
+    "guzzlehttp/guzzle": "^7.0"
+  },
+  "autoload": {
+    "psr-4": {
+      "Affise\\Tracking\\": "src"
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/Cookie.php b/src/Cookie.php
new file mode 100644
index 0000000..17d3372
--- /dev/null
+++ b/src/Cookie.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Affise\Tracking;
+
+class Cookie
+{
+    private const QUERY_PARAM = ["click_id", "clickid", "afclick"];
+    private const COOKIE_NAME = "afclick";
+
+    /**
+     * @return void
+     * @throws CookieInvalidParamException
+     * @throws CookieUnsetException
+     */
+    public static function set()
+    {
+        $val = "";
+        foreach ([$_GET, $_POST] as $src) {
+            foreach (self::QUERY_PARAM as $key) {
+                if (isset($src[$key])) {
+                    $val = $src[$key];
+                    break 2;
+                }
+            }
+        }
+
+        if ($val === "") {
+            throw new CookieInvalidParamException();
+        }
+
+        $r = setcookie(self::COOKIE_NAME, $val, time()+3600*24*365, "/", $_SERVER['HTTP_HOST'], true, false);
+        if (!$r) {
+            throw new CookieUnsetException();
+        }
+    }
+}
diff --git a/src/CookieInvalidParamException.php b/src/CookieInvalidParamException.php
new file mode 100644
index 0000000..6be672e
--- /dev/null
+++ b/src/CookieInvalidParamException.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Affise\Tracking;
+
+class CookieInvalidParamException extends \Exception
+{
+
+}
\ No newline at end of file
diff --git a/src/CookieUnsetException.php b/src/CookieUnsetException.php
new file mode 100644
index 0000000..9f4e2be
--- /dev/null
+++ b/src/CookieUnsetException.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Affise\Tracking;
+
+class CookieUnsetException extends \Exception
+{
+
+}
\ No newline at end of file
diff --git a/src/Postback.php b/src/Postback.php
new file mode 100644
index 0000000..aefda34
--- /dev/null
+++ b/src/Postback.php
@@ -0,0 +1,118 @@
+<?php
+
+namespace Affise\Tracking;
+
+class Postback
+{
+    public const CUSTOM_FIELDS_COUNT = 15;
+    protected string $domain = "";
+    protected bool $ssl = true;
+    protected ?string $clickID = null;
+    protected ?string $actionID = null;
+    protected ?string $goal = null;
+    protected ?float $sum = null;
+    protected ?string $IP = null;
+    protected ?PostbackStatus $status = null;
+    protected ?string $referrer = null;
+    protected ?string $comment = null;
+    protected ?string $secure = null;
+    protected ?string $fbClID = null;
+    protected ?string $deviceType = null;
+    protected ?string $userID = null;
+    /**
+     * @var array<string>
+     */
+    protected ?array $customFields = [];
+
+    protected array $propertyMap = [
+        "clickID" => "click_id",
+        "actionID" => "action_id",
+        "goal" => "goal",
+        "sum" => "sum",
+        "IP" => "ip",
+        "status" => "status",
+        "referrer" => "referrer",
+        "comment" => "comment",
+        "secure" => "secure",
+        "fbClID" => "fbclid",
+        "deviceType" => "device_type",
+        "userID" => "user_id",
+        "customFields" => "custom_field",
+    ];
+
+    /**
+     * @param string $domain
+     * @param bool $ssl
+     * @param array $options
+     * @throws PostbackInvalidDomainException
+     */
+    public function __construct(string $domain, bool $ssl = true, array $options = [])
+    {
+        if ($domain === "") {
+            throw new PostbackInvalidDomainException();
+        }
+
+        $this->domain = $domain;
+        $this->ssl = $ssl;
+
+        foreach ($options as $key => $value) {
+            if (in_array($key, ["domain", "ssl"])) {
+                continue;
+            }
+
+            if ($key === "customFields") {
+                for ($i = 1; $i <= self::CUSTOM_FIELDS_COUNT; $i++) {
+                    if (isset($value[$i])) {
+                        $this->customFields[$i] = $value[$i];
+                    }
+                }
+            }
+
+            if (property_exists($this, $key)) {
+                $this->$key = $value;
+            }
+        }
+    }
+
+    /**
+     * @return string
+     * @throws PostbackInvalidClickIDException
+     */
+    public function url(): string
+    {
+        if ($this->clickID === "" || !preg_match('/[0-9a-f]{24}/i', $this->clickID)) {
+            throw new PostbackInvalidClickIDException();
+        }
+
+        $url = "http" . ($this->ssl ? "s" : "") . "://" . $this->domain . "/postback?";
+        $query = [];
+
+        foreach ($this->propertyMap as $key => $param) {
+            $query = array_merge($query, $this->mapProperty($key));
+        }
+
+        return $url . http_build_query($query);
+    }
+
+    protected function mapProperty(string $key): array
+    {
+        $param = $this->propertyMap[$key] ?? $key;
+        $query = [];
+
+        switch ($key) {
+            case "status":
+                $query[$param] = $this->status->value();
+                break;
+            case "customFields":
+                foreach ($this->customFields as $i => $value) {
+                    $query[$param . $i] = $value;
+                }
+                break;
+            default:
+                $query[$param] = $this->$key;
+                break;
+        }
+
+        return $query;
+    }
+}
\ No newline at end of file
diff --git a/src/PostbackInvalidClickIDException.php b/src/PostbackInvalidClickIDException.php
new file mode 100644
index 0000000..5f06df3
--- /dev/null
+++ b/src/PostbackInvalidClickIDException.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Affise\Tracking;
+
+class PostbackInvalidClickIDException extends \Exception
+{
+
+}
\ No newline at end of file
diff --git a/src/PostbackInvalidDomainException.php b/src/PostbackInvalidDomainException.php
new file mode 100644
index 0000000..eaa71db
--- /dev/null
+++ b/src/PostbackInvalidDomainException.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Affise\Tracking;
+
+class PostbackInvalidDomainException extends \Exception
+{
+
+}
\ No newline at end of file
diff --git a/src/PostbackSender.php b/src/PostbackSender.php
new file mode 100644
index 0000000..731063e
--- /dev/null
+++ b/src/PostbackSender.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Affise\Tracking;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\Exception\GuzzleException;
+
+class PostbackSender
+{
+    private Client $client;
+    protected string $domain;
+    protected bool $ssl = true;
+
+    public function __construct(string $domain, bool $ssl = true)
+    {
+        $this->client = new Client();
+        $this->domain = $domain;
+        $this->ssl = $ssl;
+    }
+
+    /**
+     * @param array $options
+     * @return bool
+     * @throws GuzzleException
+     * @throws PostbackInvalidClickIDException
+     * @throws PostbackInvalidDomainException
+     */
+    public function send(array $options = []): bool
+    {
+        return $this->sendPostback(new Postback($this->domain, $this->ssl, $options));
+    }
+
+    /**
+     * @param Postback $p
+     * @return bool
+     * @throws GuzzleException
+     * @throws PostbackInvalidClickIDException
+     */
+    public function sendPostback(Postback $p): bool
+    {
+        $url = $p->url();
+        $resp = $this->client->get($url);
+        return $resp->getStatusCode() === 200;
+    }
+}
\ No newline at end of file
diff --git a/src/PostbackStatus.php b/src/PostbackStatus.php
new file mode 100644
index 0000000..273667e
--- /dev/null
+++ b/src/PostbackStatus.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace Affise\Tracking;
+
+/**
+ * Enum PostbackStatus
+ */
+final class PostbackStatus
+{
+    public const CONFIRMED = 1;
+    public const PENDING = 2;
+    public const DECLINED = 3;
+    public const HOLD = 5;
+
+    private int $value;
+
+    private static array $values = [
+        self::CONFIRMED => null,
+        self::PENDING => null,
+        self::DECLINED => null,
+        self::HOLD => null,
+    ];
+
+    public static function Confirmed(): PostbackStatus
+    {
+        if (self::$values[self::CONFIRMED] == null) {
+            self::$values[self::CONFIRMED] = new PostbackStatus(self::CONFIRMED);
+        }
+        return self::$values[self::CONFIRMED];
+    }
+
+    public static function Pending(): PostbackStatus
+    {
+        if (self::$values[self::PENDING] == null) {
+            self::$values[self::PENDING] = new PostbackStatus(self::PENDING);
+        }
+        return self::$values[self::PENDING];
+    }
+
+    public static function Declined(): PostbackStatus
+    {
+        if (self::$values[self::DECLINED] == null) {
+            self::$values[self::DECLINED] = new PostbackStatus(self::DECLINED);
+        }
+        return self::$values[self::DECLINED];
+    }
+
+    public static function Hold(): PostbackStatus
+    {
+        if (self::$values[self::HOLD] == null) {
+            self::$values[self::HOLD] = new PostbackStatus(self::HOLD);
+        }
+        return self::$values[self::HOLD];
+    }
+
+    /**
+     * @param int $status
+     */
+    private function __construct(int $status)
+    {
+        $this->value = $status;
+    }
+
+    public function value(): int
+    {
+        return $this->value;
+    }
+}
\ No newline at end of file