diff --git a/lib/Tinify.php b/lib/Tinify.php
index 80f533f..fe1ceef 100644
--- a/lib/Tinify.php
+++ b/lib/Tinify.php
@@ -5,36 +5,89 @@
 const VERSION = "1.6.4";
 
 class Tinify {
+    /**
+     * @var string|null API key.
+     */
     private static $key = NULL;
+
+    /**
+     * @var string|null Identifier used for requests.
+     */
     private static $appIdentifier = NULL;
+
+    /**
+     * @var string|null URL to the compression API.
+     */
     private static $proxy = NULL;
 
+    /**
+     * @var int|null The number of compressions.
+     */
     private static $compressionCount = NULL;
+
+    /**
+     * @var Client|null Tinify client.
+     */
     private static $client = NULL;
 
+    /**
+     * Sets the key and resets the client.
+     *
+     * @param string $key The API key.
+     * @return void
+     */
     public static function setKey($key) {
         self::$key = $key;
         self::$client = NULL;
     }
 
+    /**
+     * Sets the app identifier and resets the client.
+     *
+     * @param string $appIdentifier The app identifier.
+     * @return void
+     */
     public static function setAppIdentifier($appIdentifier) {
         self::$appIdentifier = $appIdentifier;
         self::$client = NULL;
     }
 
+    /**
+     * Sets the proxy and resets the client.
+     *
+     * @param string $proxy URL to the proxy server.
+     * @return void
+     */
     public static function setProxy($proxy) {
         self::$proxy = $proxy;
         self::$client = NULL;
     }
 
+    /**
+     * Retrieves the compression count.
+     *
+     * @return int|null
+     */
     public static function getCompressionCount() {
         return self::$compressionCount;
     }
 
+    /**
+     * Sets the compression count
+     *
+     * @param int $compressionCount
+     * @return void
+     */
     public static function setCompressionCount($compressionCount) {
         self::$compressionCount = $compressionCount;
     }
 
+    /**
+     * Retrieves the tinify client.
+     * Will initiate a new client with the current key, identifier and proxy.
+     *
+     * @return Client
+     */
     public static function getClient() {
         if (!self::$key) {
             throw new AccountException("Provide an API key with Tinify\setKey(...)");
@@ -47,6 +100,12 @@ public static function getClient() {
         return self::$client;
     }
 
+    /**
+     * Sets a new client
+     *
+     * @param Client $client
+     * @return void
+     */
     public static function setClient($client) {
         self::$client = $client;
     }
diff --git a/lib/Tinify/Client.php b/lib/Tinify/Client.php
index 0d8ed0c..e0afd49 100644
--- a/lib/Tinify/Client.php
+++ b/lib/Tinify/Client.php
@@ -3,22 +3,54 @@
 namespace Tinify;
 
 class Client {
+    /**
+     * The default endpoint
+     */
     const API_ENDPOINT = "https://api.tinify.com";
 
+    /**
+     * Number of retries on failure
+     */
     const RETRY_COUNT = 1;
+
+    /**
+     * The time between retrieves
+     */
     const RETRY_DELAY = 500;
 
     private $options;
 
+    /**
+     * Retrieves the user agent identifier
+     * contains client version, php version and curl version
+     *
+     * @return string
+     */
     public static function userAgent() {
         $curl = curl_version();
         return "Tinify/" . VERSION . " PHP/" . PHP_VERSION . " curl/" . $curl["version"];
     }
 
+    /**
+     * Path the the certificates
+     *
+     * @return string
+     */
     private static function caBundle() {
         return __DIR__ . "/../data/cacert.pem";
     }
 
+    /**
+     * Constructor for client
+     * validates if curl meets requirements,
+     *
+     * @param string $key api key
+     * @param string|null $app_identifier identifier for the client
+     * @param string|null $proxy an optional proxy url to go to first
+     * @return void
+     * 
+     * @throws ClientException when curl version is not supported
+     */
     function __construct($key, $app_identifier = NULL, $proxy = NULL) {
         $curl = curl_version();
 
@@ -70,6 +102,17 @@ function __construct($key, $app_identifier = NULL, $proxy = NULL) {
         }
     }
 
+    /**
+     * Makes an HTTP request to the API.
+     *
+     * @param string $method The HTTP method (GET, POST, etc.).
+     * @param string $url The endpoint path.
+     * @param array|string|null $body Optional. The request body. Default null.
+     * @return object An object with 'body' and 'headers' properties.
+     *
+     * @throws ConnectionException If the connection fails.
+     * @throws Exception If the API returns an error response.
+     */
     function request($method, $url, $body = NULL) {
         $header = array();
         if (is_array($body)) {
@@ -155,6 +198,12 @@ function request($method, $url, $body = NULL) {
         }
     }
 
+    /**
+     * Parses HTTP headers
+     *
+     * @param array|string $headers The request headers
+     * @return array lowercased headers
+     */
     protected static function parseHeaders($headers) {
         if (!is_array($headers)) {
             $headers = explode("\r\n", $headers);
diff --git a/lib/Tinify/Result.php b/lib/Tinify/Result.php
index 86ce892..1088d93 100644
--- a/lib/Tinify/Result.php
+++ b/lib/Tinify/Result.php
@@ -2,34 +2,88 @@
 
 namespace Tinify;
 
+/**
+ * Represents a compressed image result from the Tinify API.
+ * Contains the compressed image data and metadata such as content type and size.
+ *
+ * @see ResultMeta
+ */
 class Result extends ResultMeta {
+    /**
+     * The compressed image data.
+     * 
+     * @var string $data
+     */
     protected $data;
 
+    /**
+     * Constructs a Result with metadata and image data.
+     *
+     * @param array $meta The response headers containing metadata.
+     * @param string $data The compressed image data.
+     * @return void
+     */
     public function __construct($meta, $data) {
         $this->meta = $meta;
         $this->data = $data;
     }
 
+    /**
+     * Retrieves the compressed image data.
+     *
+     * @return string The compressed image data.
+     */
     public function data() {
         return $this->data;
     }
 
+    /**
+     * Retrieves the compressed image as a buffer.
+     *
+     * Alias for data()
+     * @see data()
+     * 
+     * @return string The compressed image data.
+     */
     public function toBuffer() {
         return $this->data;
     }
 
+    /**
+     * Writes the compressed image to a file.
+     *
+     * @param string $path The file path where the image should be written.
+     * @return int|false The bytes written, or false on failure.
+     */
     public function toFile($path) {
         return file_put_contents($path, $this->toBuffer());
     }
 
+    /**
+     * Retrieves the size of the compressed image in bytes.
+     * @return int The size of the compressed image.
+     */
     public function size() {
         return intval($this->meta["content-length"]);
     }
 
+    /**
+     * Retrieves the media type of the compressed image.
+     *
+     * @return string The media type eg 'image/png' or 'image/jpeg'.
+     */
     public function mediaType() {
         return $this->meta["content-type"];
     }
 
+    /**
+     * Retrieves the content type of the compressed image.
+     *
+     * Alias for mediaType()
+     * @see mediaType()
+     * 
+     * @return string The content type e.g. 'image/png' or 'image/jpeg'.
+     */
     public function contentType() {
         return $this->mediaType();
     }
diff --git a/lib/Tinify/ResultMeta.php b/lib/Tinify/ResultMeta.php
index 27aba0e..988c7dc 100644
--- a/lib/Tinify/ResultMeta.php
+++ b/lib/Tinify/ResultMeta.php
@@ -2,25 +2,55 @@
 
 namespace Tinify;
 
+/**
+ * Class containing compressed image meta data
+ */
 class ResultMeta {
+    /**
+     * The response headers containing image metadata.
+     *
+     * @var array $meta
+     */
     protected $meta;
 
+    /**
+     * Constructs a ResultMeta with response metadata.
+     *
+     * @param array $meta The response headers containing image metadata.
+     */
     public function __construct($meta) {
         $this->meta = $meta;
     }
 
+    /**
+     * Width of the image in pixels.
+     * @return int The image width.
+     */
     public function width() {
         return intval($this->meta["image-width"]);
     }
 
+    /**
+     * Height of the image in pixels.
+     * @return int The image height.
+     */
     public function height() {
         return intval($this->meta["image-height"]);
     }
 
+    /**
+     * Location of the compressed image.
+     * @return string|null The URL to the compressed image, or null if not available.
+     */
     public function location() {
         return isset($this->meta["location"]) ? $this->meta["location"] : null;
     }
 
+    /**
+     * Retrieves the file extension of the image.
+     * Extracts the extension from the content-type header.
+     * @return string|null The file extension or null if not available.
+     */
     public function extension() {
         if (isset($this->meta["content-type"])) {
             $parts = explode("/", $this->meta["content-type"]);
diff --git a/lib/Tinify/Source.php b/lib/Tinify/Source.php
index ef7c6a1..96fde9a 100644
--- a/lib/Tinify/Source.php
+++ b/lib/Tinify/Source.php
@@ -2,56 +2,132 @@
 
 namespace Tinify;
 
+/**
+ * Represents a compressed image source.
+ */
 class Source {
     private $url, $commands;
 
+    /**
+     * Shrinks the file at the given path
+     * - reads the file from disk
+     * - uses fromBuffer to make the API request
+     *
+     * @param string $path The path to the file
+     * @return Source
+     */
     public static function fromFile($path) {
         return self::fromBuffer(file_get_contents($path));
     }
 
+    /**
+     * Shrinks the given string.
+     * Will upload and compress the image to Tinify
+     * 
+     *
+     * @param string $string the raw body
+     * @return Source
+     */
     public static function fromBuffer($string) {
         $response = Tinify::getClient()->request("post", "/shrink", $string);
         return new self($response->headers["location"]);
     }
 
+    /**
+     * Shrinks the image on the given url
+     *
+     * @param string $url url to the subject to shrink
+     * @return Source
+     */
     public static function fromUrl($url) {
         $body = array("source" => array("url" => $url));
         $response = Tinify::getClient()->request("post", "/shrink", $body);
         return new self($response->headers["location"]);
     }
 
+    /**
+     * Constructor for the image source that has been compressed.
+     *
+     * @param string $url url to the compressed image
+     * @param array $commands Array of actions to apply on the compressed image.
+     * @return void
+     */
     public function __construct($url, $commands = array()) {
         $this->url = $url;
         $this->commands = $commands;
     }
 
+    /**
+     * Will add preserve command. This will keep meta data on the compressed image.
+     * https://tinypng.com/developers/reference#preserving-metadata
+     *
+     * @return Source
+     */
     public function preserve() {
         $options = $this->flatten(func_get_args());
         $commands = array_merge($this->commands, array("preserve" => $options));
         return new self($this->url, $commands);
     }
 
+    /**
+     * Will add resize command to the compressed image.
+     * https://tinypng.com/developers/reference#resizing-images
+     *
+     * @param array $options resize options
+     * @return Source
+     */
     public function resize($options) {
         $commands = array_merge($this->commands, array("resize" => $options));
         return new self($this->url, $commands);
     }
 
+    /**
+     * Will save the image to cloud storage
+     * https://tinypng.com/developers/reference#saving-to-amazon-s3
+     * Supports GCP, S3 and any other S3 API compatible storage.
+     *
+     * @param array $options store options
+     * @return Result The stored image
+     */
     public function store($options) {
         $response = Tinify::getClient()->request("post", $this->url,
             array_merge($this->commands, array("store" => $options)));
         return new Result($response->headers, $response->body);
     }
 
+    /**
+     * Will add convert command to the image
+     * https://tinypng.com/developers/reference#converting-images
+     *
+     * @param array $options conversion options
+     * @return Source
+     */
     public function convert($options) {
         $commands = array_merge($this->commands, array("convert" => $options));
         return new self($this->url, $commands);
     }
 
+    /**
+     * Will add transform commands to the image
+     * https://tinypng.com/developers/reference#converting-images
+     * The transform object specifies the stylistic transformations that will be applied to your image.
+     *
+     * @param array $options
+     * @return Source
+     */
     public function transform($options) {
         $commands = array_merge($this->commands, array("transform" => $options));
         return new self($this->url, $commands);
     }
 
+    /**
+     * Retrieves the compressed image as a Result object.
+     *
+     * Sends a GET request if no commands have been applied,
+     * or a POST request if commands are present.
+     *
+     * @return Result The compressed image with metadata.
+     */
     public function result() {
         $has_commands  = !empty($this->commands);
         $method = $has_commands ? "post" : "get";
@@ -60,14 +136,32 @@ public function result() {
         return new Result($response->headers, $response->body);
     }
 
+    /**
+     * Retrieves the compressed image and stores it on the given path
+     * 
+     *
+     * @param string $path Local file path
+     * @return int|false Returns positive int if successful
+     */
     public function toFile($path) {
         return $this->result()->toFile($path);
     }
 
+    /**
+     * Retrieves the raw image data
+     *
+     * @return string Raw result body
+     */
     public function toBuffer() {
         return $this->result()->toBuffer();
     }
 
+    /**
+     * Flattens an array of options.
+     *
+     * @param array $options An array that may contain mixed values and nested arrays.
+     * @return array A flattened array with all nested arrays merged.
+     */
     private static function flatten($options) {
         $flattened = array();
         foreach ($options as $option) {