diff --git a/omnisend/includes/Internal/V1/class-client.php b/omnisend/includes/Internal/V1/class-client.php
index 625a4dc..b650225 100644
--- a/omnisend/includes/Internal/V1/class-client.php
+++ b/omnisend/includes/Internal/V1/class-client.php
@@ -15,6 +15,8 @@
 use Omnisend\SDK\V1\SaveContactResponse;
 use Omnisend\SDK\V1\GetContactResponse;
 use Omnisend\Internal\ContactFactory;
+use Omnisend\SDK\V1\SendBatchResponse;
+use Omnisend\SDK\V1\Batch;
 use WP_Error;
 
 defined( 'ABSPATH' ) || die( 'no direct access' );
@@ -296,6 +298,57 @@ public function connect_store( $platform ): ConnectStoreResponse {
 		return new ConnectStoreResponse( $error );
 	}
 
+	public function send_batch( Batch $batch ): SendBatchResponse {
+		$error = new WP_Error();
+		$error->merge_from( $this->check_setup() );
+
+		if ( $error->has_errors() ) {
+			return new SendBatchResponse( $error );
+		}
+
+		$response = wp_remote_post(
+			OMNISEND_CORE_API_V5 . '/batches',
+			array(
+				'body'    => wp_json_encode( $batch->to_array() ),
+				'headers' => array(
+					'Content-Type'          => 'application/json',
+					'X-API-Key'             => $this->api_key,
+					'X-INTEGRATION-NAME'    => $this->plugin_name,
+					'X-INTEGRATION-VERSION' => $this->plugin_version,
+				),
+				'timeout' => 10,
+			)
+		);
+
+		$http_code = wp_remote_retrieve_response_code( $response );
+
+		if ( $http_code >= 400 ) {
+			$body    = wp_remote_retrieve_body( $response );
+			$err_msg = "HTTP error: {$http_code} - " . wp_remote_retrieve_response_message( $response ) . " - {$body}";
+			$error->add( 'omnisend_api', $err_msg );
+
+			return new SendBatchResponse( $error );
+		}
+
+		$body = wp_remote_retrieve_body( $response );
+
+		if ( ! $body ) {
+			$error->add( 'omnisend_api', 'empty response' );
+
+			return new SendBatchResponse( $error );
+		}
+
+		$arr = json_decode( $body, true );
+
+		if ( empty( $arr['batchID'] ) ) {
+			$error->add( 'omnisend_api', 'batchID not found in response.' );
+
+			return new SendBatchResponse( $error );
+		}
+
+		return new SendBatchResponse( $error, $arr['batchID'] );
+	}
+
 	/**
 	 * @return WP_Error
 	 */
diff --git a/omnisend/includes/SDK/V1/class-batch.php b/omnisend/includes/SDK/V1/class-batch.php
new file mode 100644
index 0000000..b21340c
--- /dev/null
+++ b/omnisend/includes/SDK/V1/class-batch.php
@@ -0,0 +1,207 @@
+<?php
+/**
+ * Omnisend Client
+ *
+ * @package OmnisendClient
+ */
+
+namespace Omnisend\SDK\V1;
+
+use Omnisend\Internal\Utils;
+use WP_Error;
+
+defined( 'ABSPATH' ) || die( 'no direct access' );
+
+/**
+ * Omnisend Batch class. It should be used with Omnisend Client.
+ *
+ */
+class Batch {
+	public const PRODUCTS_ENDPOINT   = 'products';
+	public const CATEGORIES_ENDPOINT = 'categories';
+	public const EVENTS_ENDPOINT     = 'events';
+	public const CONTACTS_ENDPOINT   = 'contacts';
+	public const POST_METHOD         = 'POST';
+	public const PUT_METHOD          = 'PUT';
+
+	private const REQUIRED_PROPERTIES = array(
+		'endpoint',
+		'items',
+		'method',
+	);
+	private const STRING_PROPERTIES   = array(
+		'endpoint',
+		'method',
+		'origin',
+	);
+	private const ARRAY_PROPERTIES    = array(
+		'items',
+	);
+	private const AVAILABLE_ENDPOINTS = array(
+		self::PRODUCTS_ENDPOINT,
+		self::CATEGORIES_ENDPOINT,
+		self::EVENTS_ENDPOINT,
+		self::CONTACTS_ENDPOINT,
+	);
+	private const AVAILABLE_METHODS   = array(
+		self::POST_METHOD,
+		self::PUT_METHOD,
+	);
+
+	/**
+	 * @var string $endpoint
+	 */
+	private $endpoint = null;
+
+	/**
+	 * @var array $items
+	 */
+	private $items = null;
+
+	/**
+	 * @var string $method
+	 */
+	private $method = null;
+
+	/**
+	 * @var string $origin
+	 */
+	private $origin = null;
+
+	/**
+	 * Validate batch properties.
+	 *
+	 * It ensures that required properties are set and that they are valid.
+	 *
+	 * @return WP_Error
+	 */
+	public function validate(): WP_Error {
+		$error = new WP_Error();
+		$error = $this->validate_properties( $error );
+
+		if ( $error->has_errors() ) {
+			return $error;
+		}
+
+		$error = $this->validate_values( $error );
+
+		return $error;
+	}
+
+	/**
+	 * Convert batch to array
+	 *
+	 * If batch is valid it will be transformed to array that can be sent to Omnisend.
+	 *
+	 * @return array
+	 */
+	public function to_array(): array {
+		if ( $this->validate()->has_errors() ) {
+			return array();
+		}
+
+		$arr = array(
+			'endpoint' => $this->endpoint,
+			'items'    => $this->items,
+			'method'   => $this->method,
+		);
+
+		if ( ! empty( $this->origin ) ) {
+			$arr['origin'] = $this->origin;
+		}
+
+		return $arr;
+	}
+
+	/**
+	 * Sets endpoint
+	 *
+	 * @param string $endpoint
+	 *
+	 * @return void
+	 */
+	public function set_endpoint( $endpoint ): void {
+		$this->endpoint = $endpoint;
+	}
+
+	/**
+	 * Sets batch items
+	 *
+	 * @param array $items
+	 *
+	 * @return void
+	 */
+	public function set_items( $items ): void {
+		$this->items = $items;
+	}
+
+	/**
+	 * Sets method, it can be "PUT" or "POST"
+	 *
+	 * @param string $method
+	 *
+	 * @return void
+	 */
+	public function set_method( $method ): void {
+		$this->method = $method;
+	}
+
+	/**
+	 * Sets origin of request
+	 *
+	 * @param string $origin
+	 *
+	 * @return void
+	 */
+	public function set_origin( $origin ): void {
+		$this->origin = $origin;
+	}
+
+	/**
+	 * Validates property type
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_properties( WP_Error $error ): WP_Error {
+		foreach ( $this as $property_key => $property_value ) {
+			if ( in_array( $property_key, self::REQUIRED_PROPERTIES ) && empty( $property_value ) ) {
+				$error->add( $property, $property_key . ' is a required property.' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::STRING_PROPERTIES ) && ! is_string( $property_value ) ) {
+				$error->add( $property, $property_key . ' must be a string.' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::ARRAY_PROPERTIES ) && ! is_array( $property_value ) ) {
+				$error->add( $property, $property_key . ' must be an array.' );
+			}
+		}
+
+		return $error;
+	}
+
+	/**
+	 * Validates property value
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_values( WP_Error $error ): WP_Error {
+		if ( ! in_array( $this->endpoint, self::AVAILABLE_ENDPOINTS ) ) {
+			$error->add( 'endpoint', sprintf( 'Endpoint must be one of the following: %s', implode( ', ', self::AVAILABLE_ENDPOINTS ) ) );
+		}
+
+		if ( ! in_array( $this->method, self::AVAILABLE_METHODS ) ) {
+			$error->add( 'method', sprintf( 'Method must be on of the following: %s', implode( ', ', self::AVAILABLE_METHODS ) ) );
+		}
+
+		if ( empty( $this->items ) || count( $this->items ) > 1000 ) {
+			$error->add( 'items', sprintf( 'Items are empty or batch size limit: %s was exceeded', 1000 ) );
+		}
+
+		return $error;
+	}
+}
diff --git a/omnisend/includes/SDK/V1/class-category.php b/omnisend/includes/SDK/V1/class-category.php
new file mode 100644
index 0000000..7fbb910
--- /dev/null
+++ b/omnisend/includes/SDK/V1/class-category.php
@@ -0,0 +1,140 @@
+<?php
+/**
+ * Omnisend Client
+ *
+ * @package OmnisendClient
+ */
+
+namespace Omnisend\SDK\V1;
+
+use Omnisend\Internal\Utils;
+use WP_Error;
+
+defined( 'ABSPATH' ) || die( 'no direct access' );
+
+/**
+ * Omnisend Batch class. It should be used with Omnisend Client.
+ *
+ */
+class Category {
+	private const REQUIRED_PROPERTIES = array(
+		'category_id',
+		'title',
+	);
+	private const STRING_PROPERTIES   = array(
+		'category_id',
+		'title',
+	);
+
+	/**
+	 * @var string $category_id
+	 */
+	private $category_id = null;
+
+	/**
+	 * @var string $title
+	 */
+	private $title = null;
+
+	/**
+	 * Validates category properties
+	 *
+	 * It ensures that required properties are set and that they are valid.
+	 *
+	 * @return WP_Error
+	 */
+	public function validate(): WP_Error {
+		$error = new WP_Error();
+		$error = $this->validate_properties( $error );
+
+		if ( $error->has_errors() ) {
+			return $error;
+		}
+
+		$error = $this->validate_values( $error );
+
+		return $error;
+	}
+
+	/**
+	 * Convert category to array
+	 *
+	 * If category is valid it will be transformed to array that can be sent to Omnisend.
+	 *
+	 * @return array
+	 */
+	public function to_array(): array {
+		if ( $this->validate()->has_errors() ) {
+			return array();
+		}
+
+		$data = array(
+			'categoryId' => $this->category_id,
+			'title'      => $this->title,
+		);
+
+		return $data;
+	}
+
+	/**
+	 * Sets category id
+	 *
+	 * @param string $category_id
+	 *
+	 * @return void
+	 */
+	public function set_category_id( $category_id ): void {
+		$this->category_id = $category_id;
+	}
+
+	/**
+	 * Sets category title
+	 *
+	 * @param string $title
+	 *
+	 * @return void
+	 */
+	public function set_title( $title ): void {
+		$this->title = $title;
+	}
+
+	/**
+	 * Validates property type
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_properties( WP_Error $error ): WP_Error {
+		foreach ( $this as $property_key => $property_value ) {
+			if ( in_array( $property_key, self::REQUIRED_PROPERTIES ) && empty( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' is a required property.' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::STRING_PROPERTIES ) && ! is_string( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' must be a string' );
+			}
+		}
+
+		return $error;
+	}
+
+	/**
+	 * Validates property value
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_values( WP_Error $error ): WP_Error {
+		if ( strlen( $this->category_id ) > 100 ) {
+			$error->add( 'category_id', 'Category ID must be under 100 characters' );
+		}
+
+		if ( strlen( $this->title ) > 100 ) {
+			$error->add( 'title', 'Title must be under 100 characters' );
+		}
+
+		return $error;
+	}
+}
diff --git a/omnisend/includes/SDK/V1/class-client.php b/omnisend/includes/SDK/V1/class-client.php
index 9572e6c..312cd20 100644
--- a/omnisend/includes/SDK/V1/class-client.php
+++ b/omnisend/includes/SDK/V1/class-client.php
@@ -60,4 +60,12 @@ public function get_contact_by_email( string $email ): GetContactResponse;
 	 * @return ConnectStoreResponse
 	 */
 	public function connect_store( string $platform ): ConnectStoreResponse;
+
+	/**
+	 * Send batch of categories/products/events/contacts
+	 * @param Batch $batch
+	 *
+	 * @return SendBatchResponse
+	 */
+	public function send_batch( Batch $batch ): SendBatchResponse;
 }
diff --git a/omnisend/includes/SDK/V1/class-event.php b/omnisend/includes/SDK/V1/class-event.php
index ece56bf..ad2d070 100644
--- a/omnisend/includes/SDK/V1/class-event.php
+++ b/omnisend/includes/SDK/V1/class-event.php
@@ -17,7 +17,6 @@
  *
  */
 class Event {
-
 	private $contact          = null;
 	private $event_name       = null;
 	private $event_version    = null;
@@ -32,8 +31,8 @@ class Event {
 	 * @return WP_Error
 	 */
 	public function validate(): WP_Error {
-
 		$error = new WP_Error();
+
 		if ( $this->contact instanceof Contact ) {
 			$error->merge_from( $this->contact->validate() );
 		}
@@ -54,12 +53,6 @@ public function validate(): WP_Error {
 			$error->add( 'origin', 'Not a string.' );
 		}
 
-		foreach ( $this->properties as $name ) {
-			if ( ! is_string( $name ) ) {
-				$error->add( $name, 'Not a string.' );
-			}
-		}
-
 		return $error;
 	}
 
@@ -111,6 +104,17 @@ public function add_properties( $key, $value ): void {
 		$this->properties[ $key ] = $value;
 	}
 
+	/**
+	 * Sets properties
+	 *
+	 * @param array $properties
+	 *
+	 * @return void
+	 */
+	public function set_properties( $properties ): void {
+		$this->properties = $properties;
+	}
+
 	/**
 	 * Sets contact.
 	 *
diff --git a/omnisend/includes/SDK/V1/class-product.php b/omnisend/includes/SDK/V1/class-product.php
new file mode 100644
index 0000000..9601909
--- /dev/null
+++ b/omnisend/includes/SDK/V1/class-product.php
@@ -0,0 +1,463 @@
+<?php
+/**
+ * Omnisend Client
+ *
+ * @package OmnisendClient
+ */
+
+namespace Omnisend\SDK\V1;
+
+use Omnisend\Internal\Utils;
+use WP_Error;
+
+defined( 'ABSPATH' ) || die( 'no direct access' );
+
+/**
+ * Omnisend Batch class. It should be used with Omnisend Client.
+ *
+ */
+class Product {
+	public const STATUS_IN_STOCK      = 'inStock';
+	public const STATUS_OUT_OF_STOCK  = 'outOfStock';
+	public const STATUS_NOT_AVAILABLE = 'notAvailable';
+	public const AVAILABLE_STATUS     = array(
+		self::STATUS_IN_STOCK,
+		self::STATUS_OUT_OF_STOCK,
+		self::STATUS_NOT_AVAILABLE,
+	);
+
+	private const REQUIRED_PROPERTIES = array(
+		'currency',
+		'id',
+		'status',
+		'title',
+		'url',
+	);
+	private const STRING_PROPERTIES   = array(
+		'created_at',
+		'currency',
+		'default_image_url',
+		'description',
+		'id',
+		'status',
+		'title',
+		'type',
+		'updated_at',
+		'url',
+		'vendor',
+	);
+	private const ARRAY_PROPERTIES    = array(
+		'variants',
+		'images',
+	);
+
+	/**
+	 * @var array $category_ids
+	 */
+	private $category_ids = null;
+
+	/**
+	 * @var string $created_at
+	 */
+	private $created_at = null;
+
+	/**
+	 * @var string $currency
+	 */
+	private $currency = null;
+
+	/**
+	 * @var string $default_image_url
+	 */
+	private $default_image_url = null;
+
+	/**
+	 * @var string $description
+	 */
+	private $description = null;
+
+	/**
+	 * @var string $id
+	 */
+	private $id = null;
+
+	/**
+	 * @var array $images
+	 */
+	private $images = null;
+
+	/**
+	 * @var string $status
+	 */
+	private $status = null;
+
+	/**
+	 * @var string $title
+	 */
+	private $title = null;
+
+	/**
+	 * @var string $type
+	 */
+	private $type = null;
+
+	/**
+	 * @var string $updated_at
+	 */
+	private $updated_at = null;
+
+	/**
+	 * @var string $url
+	 */
+	private $url = null;
+
+	/**
+	 * @var array $variants
+	 */
+	private $variants = null;
+
+	/**
+	 * @var string $vendor
+	 */
+	private $vendor = null;
+
+	/**
+	 * @var array $tags
+	 */
+	private array $tags = array();
+
+	/**
+	 * Validates product properties
+	 *
+	 * It ensures that required properties are set and that they are valid.
+	 *
+	 * @return WP_Error
+	 */
+	public function validate(): WP_Error {
+		$error = new WP_Error();
+		$error = $this->validate_properties( $error );
+
+		if ( $error->has_errors() ) {
+			return $error;
+		}
+
+		$error = $this->validate_values( $error );
+
+		return $error;
+	}
+
+	/**
+	 * Convert product to array
+	 *
+	 * If product is valid it will be transformed to array that can be sent to Omnisend.
+	 *
+	 * @return array
+	 */
+	public function to_array(): array {
+		if ( $this->validate()->has_errors() ) {
+			return array();
+		}
+
+		$arr = array(
+			'currency' => $this->currency,
+			'id'       => $this->id,
+			'status'   => $this->status,
+			'title'    => $this->title,
+			'url'      => $this->url,
+		);
+
+		if ( ! empty( $this->category_ids ) ) {
+			$arr['categoryIDs'] = $this->category_ids;
+		}
+
+		if ( ! empty( $this->created_at ) ) {
+			$arr['createdAt'] = $this->created_at;
+		}
+
+		if ( ! empty( $this->default_image_url ) ) {
+			$arr['defaultImageUrl'] = $this->default_image_url;
+		}
+
+		if ( ! empty( $this->description ) ) {
+			$arr['description'] = $this->description;
+		}
+
+		if ( ! empty( $this->images ) ) {
+			$arr['images'] = $this->images;
+		}
+
+		if ( ! empty( $this->tags ) ) {
+			$arr['tags'] = $this->tags;
+		}
+
+		if ( ! empty( $this->type ) ) {
+			$arr['type'] = $this->type;
+		}
+
+		if ( ! empty( $this->updated_at ) ) {
+			$arr['updatedAt'] = $this->updated_at;
+		}
+
+		if ( ! empty( $this->vendor ) ) {
+			$arr['vendor'] = $this->vendor;
+		}
+
+		if ( ! empty( $this->variants ) ) {
+			$arr['variants'] = $this->variants;
+		}
+
+		return $arr;
+	}
+
+	/**
+	 * Sets category ids
+	 *
+	 * @param array $category_ids
+	 *
+	 * @return void
+	 */
+	public function set_category_ids( $category_ids ): void {
+		$this->category_ids = $category_ids;
+	}
+
+	/**
+	 * Sets product created date, format: "Y-m-d\Th:i:s\Z"
+	 *
+	 * @param string $created_at
+	 *
+	 * @return void
+	 */
+	public function set_created_at( $created_at ): void {
+		$this->created_at = $created_at;
+	}
+
+	/**
+	 * Sets currency
+	 *
+	 * @param string $currency
+	 *
+	 * @return void
+	 */
+	public function set_currency( $currency ): void {
+		$this->currency = $currency;
+	}
+
+	/**
+	 * Sets product default image URL
+	 *
+	 * @param string $default_image_url
+	 *
+	 * @return void
+	 */
+	public function set_default_image_url( $default_image_url ): void {
+		$this->default_image_url = $default_image_url;
+	}
+
+	/**
+	 * Sets product description
+	 *
+	 * @param string $description
+	 *
+	 * @return void
+	 */
+	public function set_descripton( $description ): void {
+		$this->description = $description;
+	}
+
+	/**
+	 * Sets product id
+	 *
+	 * @param string $id
+	 *
+	 * @return void
+	 */
+	public function set_id( $id ): void {
+		$this->id = $id;
+	}
+
+	/**
+	 * Sets product images, should not contain "default image url"
+	 *
+	 * @param array $images
+	 *
+	 * @return void
+	 */
+	public function set_images( $images ): void {
+		$this->images = $images;
+	}
+
+	/**
+	 * Sets product status
+	 *
+	 * @param string $status
+	 *
+	 * @return void
+	 */
+	public function set_status( $status ): void {
+		$this->status = $status;
+	}
+
+	/**
+	 * Adds new tag to tag array
+	 *
+	 * @param mixed $tag
+	 * @param bool $clean_up_tag clean up tag to be compatible with Omnisend
+	 *
+	 * @return void
+	 */
+	public function add_tag( $tag, $clean_up_tag = true ): void {
+		if ( $clean_up_tag ) {
+			$tag = Utils::clean_up_tag( $tag );
+		}
+
+		if ( $tag == '' ) {
+			return;
+		}
+
+		$this->tags[] = $tag;
+	}
+
+	/**
+	 * Sets product title
+	 *
+	 * @param string $title
+	 *
+	 * @return void
+	 */
+	public function set_title( $title ): void {
+		$this->title = $title;
+	}
+
+	/**
+	 * Sets product type
+	 *
+	 * @param string $type
+	 *
+	 * @return void
+	 */
+	public function set_type( $type ): void {
+		$this->type = $type;
+	}
+
+	/**
+	 * Sets product updated date, format: "Y-m-d\Th:i:s\Z"
+	 *
+	 * @param string $updated_at
+	 *
+	 * @return void
+	 */
+	public function set_updated_at( $updated_at ): void {
+		$this->updated_at = $updated_at;
+	}
+
+	/**
+	 * Sets product URL
+	 *
+	 * @param string $url
+	 *
+	 * @return void
+	 */
+	public function set_url( $url ): void {
+		$this->url = $url;
+	}
+
+	/**
+	 * Sets product variants
+	 *
+	 * @param array $variants
+	 *
+	 * @return void
+	 */
+	public function set_variants( $variants ): void {
+		$this->variants = $variants;
+	}
+
+	/**
+	 * Sets product vendor
+	 *
+	 * @param string $vendor
+	 *
+	 * @return void
+	 */
+	public function set_vendor( $vendor ): void {
+		$this->vendor = $vendor;
+	}
+
+	/**
+	 * Validates property type
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_properties( WP_Error $error ): WP_Error {
+		foreach ( $this as $property_key => $property_value ) {
+			if ( in_array( $property_key, self::REQUIRED_PROPERTIES ) && empty( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' is a required property' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::ARRAY_PROPERTIES ) && ! is_array( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' must be an array' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::STRING_PROPERTIES ) && ! is_string( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' must be a string' );
+			}
+		}
+
+		return $error;
+	}
+
+	/**
+	 * Validates property value
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_values( WP_Error $error ): WP_Error {
+		foreach ( $this->tags as $tag ) {
+			if ( ! Utils::is_valid_tag( $tag ) ) {
+				$error->add( 'tags', 'Tag "' . $tag . '" is not valid. Please cleanup it before setting it.' );
+			}
+		}
+
+		if ( ! in_array( $this->status, self::AVAILABLE_STATUS ) ) {
+			$error->add( 'status', sprintf( 'Status must be one of the following: %s', implode( ',', self::AVAILABLE_STATUS ) ) );
+		}
+
+		if ( strlen( $this->id ) > 100 ) {
+			$error->add( 'id', 'ID must be under 100 characters' );
+		}
+
+		if ( strlen( $this->title ) > 100 ) {
+			$error->add( 'title', 'Title must be under 100 characters' );
+		}
+
+		if ( ! ctype_upper( $this->currency ) ) {
+			$error->add( 'currency', 'Currency code must be all uppercase' );
+		}
+
+		if ( $this->description !== null && strlen( $this->description ) > 300 ) {
+			$error->add( 'description', 'Description must be under 300 characters' );
+		}
+
+		if ( $this->type !== null && strlen( $this->type ) > 100 ) {
+			$error->add( 'type', 'Type must be under 100 characters' );
+		}
+
+		if ( $this->vendor !== null && strlen( $this->vendor ) > 100 ) {
+			$error->add( 'vendor', 'Vendor must be under 100 characters' );
+		}
+
+		if ( $this->default_image_url !== null && ! empty( $this->default_image_url ) && ! filter_var( $this->default_image_url, FILTER_VALIDATE_URL ) ) {
+			$error->add( 'default_image_url', 'Default image must contain a valid URL' );
+		}
+
+		if ( ! filter_var( $this->url, FILTER_VALIDATE_URL ) ) {
+			$error->add( 'url', 'Url must contain a valid URL' );
+		}
+
+		return $error;
+	}
+}
diff --git a/omnisend/includes/SDK/V1/class-productvariant.php b/omnisend/includes/SDK/V1/class-productvariant.php
new file mode 100644
index 0000000..2febaa1
--- /dev/null
+++ b/omnisend/includes/SDK/V1/class-productvariant.php
@@ -0,0 +1,335 @@
+<?php
+/**
+ * Omnisend Client
+ *
+ * @package OmnisendClient
+ */
+
+namespace Omnisend\SDK\V1;
+
+use Omnisend\SDK\V1\Product;
+use WP_Error;
+
+defined( 'ABSPATH' ) || die( 'no direct access' );
+
+/**
+ * Omnisend ProductVariant class. It should be used with Omnisend Product.
+ */
+class ProductVariant {
+	private const REQUIRED_PROPERTIES = array(
+		'id',
+		'price',
+		'title',
+		'url',
+	);
+	private const STRING_PROPERTIES   = array(
+		'default_image_url',
+		'description',
+		'sku',
+		'status',
+		'id',
+		'title',
+		'url',
+	);
+	private const NUMERIC_PROPERTIES  = array(
+		'price',
+		'strike_through_price',
+	);
+	private const ARRAY_PROPERTIES    = array(
+		'images',
+	);
+
+	/**
+	 * @var string $default_image_url
+	 */
+	private $default_image_url = null;
+
+	/**
+	 * @var string $description
+	 */
+	private $description = null;
+
+	/**
+	 * @var string $id
+	 */
+	private $id = null;
+
+	/**
+	 * @var array $images
+	 */
+	private $images = null;
+
+	/**
+	 * @var mixed $price
+	 */
+	private $price = null;
+
+	/**
+	 * @var string $sku
+	 */
+	private $sku = null;
+
+	/**
+	 * @var string $status
+	 */
+	private $status = null;
+
+	/**
+	 * @var mixed $strike_through_price
+	 */
+	private $strike_through_price = null;
+
+	/**
+	 * @var string $title
+	 */
+	private $title = null;
+
+	/**
+	 * @var string $url
+	 */
+	private $url = null;
+
+	/**
+	 * Validates product variation properties
+	 *
+	 * It ensures that required properties are set and that they are valid.
+	 *
+	 * @return WP_Error
+	 */
+	public function validate(): WP_Error {
+		$error = new WP_Error();
+		$error = $this->validate_properties( $error );
+
+		if ( $error->has_errors() ) {
+			return $error;
+		}
+
+		$error = $this->validate_values( $error );
+
+		return $error;
+	}
+
+	/**
+	 * Convert product variants to array
+	 *
+	 * If variants are valid it will be transformed to array that can be sent with Product to Omnisend.
+	 *
+	 * @return array
+	 */
+	public function to_array(): array {
+		if ( $this->validate()->has_errors() ) {
+			return array();
+		}
+
+		$arr = array(
+			'id'    => $this->id,
+			'price' => $this->price,
+			'title' => $this->title,
+			'url'   => $this->url,
+		);
+
+		if ( ! empty( $this->default_image_url ) ) {
+			$arr['default_image_url'] = $this->default_image_url;
+		}
+
+		if ( ! empty( $this->description ) ) {
+			$arr['description'] = $this->description;
+		}
+
+		if ( ! empty( $this->images ) ) {
+			$arr['images'] = $this->images;
+		}
+
+		if ( ! empty( $this->sku ) ) {
+			$arr['sku'] = $this->sku;
+		}
+
+		if ( ! empty( $this->status ) ) {
+			$arr['status'] = $this->status;
+		}
+
+		if ( ! empty( $this->strike_through_price ) ) {
+			$arr['strikeThroughPrice'] = $this->strike_through_price;
+		}
+
+		return $arr;
+	}
+
+	/**
+	 * Sets variant default image URL
+	 *
+	 * @param string $default_image_url
+	 *
+	 * @return void
+	 */
+	public function set_default_image_url( $default_image_url ): void {
+		$this->default_image_url = $default_image_url;
+	}
+
+	/**
+	 * Sets variant description
+	 *
+	 * @param string $description
+	 *
+	 * @return void
+	 */
+	public function set_descripton( $description ): void {
+		$this->description = $description;
+	}
+
+	/**
+	 * Sets variant ID
+	 *
+	 * @param string $id
+	 *
+	 * @return void
+	 */
+	public function set_id( $id ): void {
+		$this->id = $id;
+	}
+
+	/**
+	 * Sets variant images
+	 *
+	 * @param array $images
+	 *
+	 * @return void
+	 */
+	public function set_images( $images ): void {
+		$this->images = $images;
+	}
+
+	/**
+	 * Sets variant price
+	 *
+	 * @param mixed $price
+	 *
+	 * @return void
+	 */
+	public function set_price( $price ): void {
+		$this->price = $price;
+	}
+
+	/**
+	 * Sets variant SKU
+	 *
+	 * @param string $sku
+	 *
+	 * @return void
+	 */
+	public function set_sku( $sku ): void {
+		$this->sku = $sku;
+	}
+
+	/**
+	 * Sets variant status
+	 *
+	 * @param string $status
+	 *
+	 * @return void
+	 */
+	public function set_status( $status ): void {
+		$this->status = $status;
+	}
+
+	/**
+	 * Sets variant price before discount
+	 *
+	 * @param mixed $strike_through_price
+	 *
+	 * @return void
+	 */
+	public function set_strike_through_price( $strike_through_price ): void {
+		$this->strike_through_price = $strike_through_price;
+	}
+
+	/**
+	 * Sets variant title
+	 *
+	 * @param string $title
+	 *
+	 * @return void
+	 */
+	public function set_title( $title ): void {
+		$this->title = $title;
+	}
+
+	/**
+	 * Sets variant URL
+	 *
+	 * @param string $url
+	 *
+	 * @return void
+	 */
+	public function set_url( $url ): void {
+		$this->url = $url;
+	}
+
+	/**
+	 * Validates property type
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_properties( WP_Error $error ): WP_Error {
+		foreach ( $this as $property_key => $property_value ) {
+			if ( in_array( $property_key, self::REQUIRED_PROPERTIES ) && empty( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' is a required property' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::NUMERIC_PROPERTIES ) && ! is_numeric( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' must be a number' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::STRING_PROPERTIES ) && ! is_string( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' must be a string' );
+			}
+
+			if ( $property_value !== null && in_array( $property_key, self::ARRAY_PROPERTIES ) && ! is_array( $property_value ) ) {
+				$error->add( $property_key, $property_key . ' must be an array' );
+			}
+		}
+
+		return $error;
+	}
+
+	/**
+	 * Validates property value
+	 *
+	 * @param WP_Error $error
+	 *
+	 * @return WP_Error $error
+	 */
+	private function validate_values( WP_Error $error ): WP_Error {
+		if ( $this->status !== null && ! in_array( $this->status, Product::AVAILABLE_STATUS ) ) {
+			$error->add( 'status', sprintf( 'Status must be one of the following: %s', implode( ',', Product::AVAILABLE_STATUS ) ) );
+		}
+
+		if ( strlen( $this->id ) > 100 ) {
+			$error->add( 'id', 'ID must be under 100 characters' );
+		}
+
+		if ( strlen( $this->title ) > 100 ) {
+			$error->add( 'title', 'Title must be under 100 characters' );
+		}
+
+		if ( $this->description !== null && strlen( $this->description ) > 300 ) {
+			$error->add( 'description', 'Description must be under 300 characters' );
+		}
+
+		if ( $this->sku !== null && strlen( $this->sku ) > 100 ) {
+			$error->add( 'default_image_url', 'SKU must be under 100 characters' );
+		}
+
+		if ( $this->default_image_url !== null && ! empty( $this->default_image_url ) && ! filter_var( $this->default_image_url, FILTER_VALIDATE_URL ) ) {
+			$error->add( 'default_image_url', 'Default image URL must contain a valid URL' );
+		}
+
+		if ( ! filter_var( $this->url, FILTER_VALIDATE_URL ) ) {
+			$error->add( 'url', 'Url must contain a valid URL' );
+		}
+
+		return $error;
+	}
+}
diff --git a/omnisend/includes/SDK/V1/class-sendbatchresponse.php b/omnisend/includes/SDK/V1/class-sendbatchresponse.php
new file mode 100644
index 0000000..65a31cc
--- /dev/null
+++ b/omnisend/includes/SDK/V1/class-sendbatchresponse.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * Omnisend Client
+ *
+ * @package OmnisendClient
+ */
+
+namespace Omnisend\SDK\V1;
+
+use WP_Error;
+
+defined( 'ABSPATH' ) || die( 'no direct access' );
+
+class SendBatchResponse {
+	private WP_Error $wp_error;
+	private string $batch_id;
+
+	public function __construct( WP_Error $wp_error, string $batch_id = '' ) {
+		$this->wp_error = $wp_error;
+		$this->batch_id = $batch_id;
+	}
+
+	/**
+	 * Use to retrieve errors
+	 *
+	 * @return WP_error $wp_error
+	 */
+	public function get_wp_error(): WP_Error {
+		return $this->wp_error;
+	}
+
+	/**
+	 * Use to retrieve batch ID
+	 *
+	 * @return string $batch_id
+	 */
+	public function get_batch_id(): string {
+		return $this->batch_id;
+	}
+}