diff --git a/.env.sample b/.env.sample
index ff79a32..13a80bb 100644
--- a/.env.sample
+++ b/.env.sample
@@ -12,5 +12,9 @@ REDIRECT_URL=https://
 ## Redirect URI when the transaction fails
 ERROR_REDIRECT_URL=https://
 
+## Personal Access Token if you use $client->getTransactionDetail(), this token should be set.
+## See https://app.tendopay.ph/merchants/api-settings
+MERCHANT_PERSONAL_ACCESS_TOKEN=
+
 ## If you have own sandbox
 #SANDBOX_HOST_URL=https://
diff --git a/samples/notify.php b/samples/notify.php
new file mode 100644
index 0000000..d73568e
--- /dev/null
+++ b/samples/notify.php
@@ -0,0 +1,57 @@
+<?php
+require __DIR__ . '/../vendor/autoload.php';
+
+function dump()
+{
+    echo '<pre>';
+    array_map('print_r', func_get_args());
+    echo '</pre>';
+}
+
+use TendoPay\SDK\Constants;
+use TendoPay\SDK\Models\NotifyRequest;
+use TendoPay\SDK\TendoPayClient;
+
+
+$client = new TendoPayClient();
+$client->enableSandBox();
+
+try {
+    $notifyRequest = new NotifyRequest($_REQUEST);
+    $transaction = $client->getTransactionDetail($notifyRequest->getTransactionNumber());
+
+    $merchant_order_id = $transaction->getMerchantOrderId();
+    $status = $transaction->getStatus();
+    $amount = $transaction->getAmount();
+
+    // dump(compact('merchant_order_id', 'status', 'amount'));
+    // Search Merchant side transaction by $transaction->getMerchantOrderId()
+    // Check if the transaction is already processed
+    // The process should stop here if this transaction is already done.
+    // return 200 if this is a duplicated notification
+
+
+    switch ($status) {
+        case Constants::PURCHASE_TRANSACTION_SUCCESS:
+            // The transaction is successfully completed
+            // Do merchant job here
+            break;
+        case Constants::PURCHASE_TRANSACTION_FAILURE:
+            // The transaction is unsuccessfully completed.
+            // Do merchant job here
+            break;
+        case Constants::CANCEL_TRANSACTION_SUCCESS:
+            // the previous transaction is successfully cancelled
+            // Do merchant job here
+            break;
+    }
+
+    // After all merchant side process done, return 200
+    http_response_code(200);
+} catch (Exception $e) {
+    // other wise return error
+    dump($e->getMessage());
+    http_response_code(500);
+}
+
+
diff --git a/src/Constants.php b/src/Constants.php
index 285f6db..fa9c6f6 100644
--- a/src/Constants.php
+++ b/src/Constants.php
@@ -24,11 +24,16 @@ class Constants
     public const AUTHORIZATION_ENDPOINT_URI = 'payments/api/v1/authTokenRequest';
     public const DESCRIPTION_ENDPOINT_URI = 'payments/api/v1/paymentDescription';
     public const BEARER_TOKEN_ENDPOINT_URI = 'oauth/token';
-    public const ORDER_STATUS_TRANSITION_ENDPOINT_URL = 'payments/api/v1/orderUpdate';
+    public const ORDER_STATUS_TRANSITION_ENDPOINT_URI = 'payments/api/v1/orderUpdate';
+    /**
+     * Gets the transaction detail endpoint uri
+     */
+    public const TRANSACTION_DETAIL_ENDPOINT_URI = '/merchants/api/v1/transactions/{transactionNumber}';
 
     public const TENDOPAY_ICON = 'https://s3.ca-central-1.amazonaws.com/candydigital/images/tendopay/tp-icon-32x32.png';
     public const TENDOPAY_FAQ = 'https://tendopay.ph/page-faq.html';
 
+
     /**
      * Below public constant names are used as keys of data send to or received from TP API
      */
@@ -53,6 +58,37 @@ class Constants
     public const STATUS_SUCCESS = 'success';
     public const STATUS_FAILURE = 'failure';
 
+    /**
+     * Notification Parameters
+     */
+    public const TRANSACTION_STATUS = 'status';
+    public const NOTIFIED_AT = 'notified_at';
+    public const MERCHANT_ID = 'merchant_id';
+    public const MERCHANT_ORDER_ID = 'merchant_order_id';
+    public const AMOUNT = 'amount';
+    public const CREATED_AT = 'created_at';
+
+
+    /**
+     * Purchase Transaction successfully completed
+     */
+    public const PURCHASE_TRANSACTION_SUCCESS = 'PTOK';
+
+    /**
+     * Purchase Transaction not successfully completed
+     */
+    public const PURCHASE_TRANSACTION_FAILURE = 'PTNG';
+
+    /**
+     * Purchase Transaction has canceled
+     */
+    public const PURCHASE_TRANSACTION_CANCELED = 'PTCA';
+
+    /**
+     * Cancel previous purchase transaction successfully completed
+     */
+    public const CANCEL_TRANSACTION_SUCCESS = 'CTOK';
+
     /**
      * Below public constants are the keys of description object that is being sent during request to Description Endpoint
      */
@@ -153,4 +189,17 @@ private static function is_sandbox_enabled(): bool
         return (bool)getenv('TENDOPAY_SANDBOX_ENABLED', true);
     }
 
+    /**
+     * Gets the transaction detail endpoint uri
+     * @param string $transactionNumber
+     * @return string
+     */
+    public static function getTransactionDetailEndpointURI($transactionNumber): string
+    {
+        return str_replace(
+            '{transactionNumber}',
+            $transactionNumber,
+            self::TRANSACTION_DETAIL_ENDPOINT_URI
+        );
+    }
 }
diff --git a/src/Models/NotifyRequest.php b/src/Models/NotifyRequest.php
new file mode 100644
index 0000000..7529b11
--- /dev/null
+++ b/src/Models/NotifyRequest.php
@@ -0,0 +1,82 @@
+<?php
+
+
+namespace TendoPay\SDK\Models;
+
+use Prophecy\Doubler\Generator\Node\ClassNode;
+use TendoPay\SDK\Constants;
+use TendoPay\SDK\Exception\TendoPayParameterException;
+
+/**
+ * "transactionNumber":1184,
+ * "status":"PURCHASE_TRANSACTION_CANCELED",
+ * "notifiedAt":"2019-08-23T23:21:36+08:00"
+ * Class NotifyRequest
+ * @package TendoPay\SDK\Models
+ */
+class NotifyRequest
+{
+    /**
+     * The transaction number that status changed
+     * @var
+     */
+    protected $transactionNumber;
+
+    /**
+     * The transaction status
+     * @var
+     */
+    protected $status;
+
+    /**
+     * Notification datetime
+     * @var
+     */
+    protected $notifiedAt;
+
+    /**
+     * NotifyRequest constructor.
+     * @param array $request
+     * @throws TendoPayParameterException
+     */
+    public function __construct(array $request)
+    {
+        $this->transactionNumber = $request[Constants::TRANSACTION_NO_PARAM] ?? '';
+        $this->status = $request[Constants::TRANSACTION_STATUS] ?? '';
+        $this->notifiedAt = $request[Constants::NOTIFIED_AT] ?? '';
+
+        if (!$this->transactionNumber ||
+            !$this->status ||
+            !$this->notifiedAt) {
+            throw new TendoPayParameterException(sprintf('%s, %s, %s are required.',
+                Constants::TRANSACTION_NO_PARAM,
+                Constants::TRANSACTION_STATUS,
+                Constants::NOTIFIED_AT
+            ));
+        }
+    }
+
+    /**
+     * @return mixed|string
+     */
+    public function getTransactionNumber()
+    {
+        return $this->transactionNumber;
+    }
+
+    /**
+     * @return mixed|string
+     */
+    public function getStatus()
+    {
+        return $this->status;
+    }
+
+    /**
+     * @return mixed|string
+     */
+    public function getNotifiedAt()
+    {
+        return $this->notifiedAt;
+    }
+}
diff --git a/src/Models/Transaction.php b/src/Models/Transaction.php
new file mode 100644
index 0000000..22d266b
--- /dev/null
+++ b/src/Models/Transaction.php
@@ -0,0 +1,98 @@
+<?php
+
+
+namespace TendoPay\SDK\Models;
+
+use TendoPay\SDK\Constants;
+use TendoPay\SDK\Exception\TendoPayParameterException;
+
+/**
+ * Class Transaction
+ * @package TendoPay\SDK\Models
+ *
+ * #### Data Structure
+ * | Field | Data Type | Description |
+ * | --- | --- | --- |
+ * | merchant_id | Number | Merchant ID |
+ * | merchant_order_id | String | Merchant Order ID |
+ * | amount | Number | Request Amount |
+ * | tendopay_transaction_number | String | Transaction Number |
+ * | created_at | ISO8601 Datetime | Datetime of the transaction |
+ * | status | String | Status of the transaction |
+ */
+class Transaction
+{
+    protected $merchantId;
+    protected $merchantOrderId;
+    protected $amount;
+    protected $transactionNumber;
+    protected $createdAt;
+    protected $status;
+
+    public function __construct(array $response = [])
+    {
+        $this->merchantId = $response[Constants::MERCHANT_ID] ?? null;
+        $this->merchantOrderId = $response[Constants::MERCHANT_ORDER_ID] ?? null;
+        $this->amount = $response[Constants::AMOUNT] ?? null;
+        $this->transactionNumber = $response[Constants::TRANSACTION_NO_PARAM] ?? null;
+        $this->status = $response[Constants::TRANSACTION_STATUS] ?? null;
+        $this->createdAt = $response[Constants::CREATED_AT] ?? null;
+
+        if (!$this->transactionNumber || !$this->merchantOrderId) {
+            throw new TendoPayParameterException(sprintf('%s, %s cannot be null',
+                Constants::TRANSACTION_NO_PARAM,
+                Constants::MERCHANT_ORDER_ID
+            ));
+        }
+    }
+
+
+    /**
+     * @return null
+     */
+    public function getMerchantId()
+    {
+        return $this->merchantId;
+    }
+
+    /**
+     * @return null
+     */
+    public function getMerchantOrderId()
+    {
+        return $this->merchantOrderId;
+    }
+
+    /**
+     * @return null
+     */
+    public function getAmount()
+    {
+        return $this->amount;
+    }
+
+    /**
+     * @return null
+     */
+    public function getTransactionNumber()
+    {
+        return $this->transactionNumber;
+    }
+
+    /**
+     * @return null
+     */
+    public function getCreatedAt()
+    {
+        return $this->createdAt;
+    }
+
+    /**
+     * @return null
+     */
+    public function getStatus()
+    {
+        return $this->status;
+    }
+
+}
diff --git a/src/TendoPayClient.php b/src/TendoPayClient.php
index 16f7801..22e1f9f 100644
--- a/src/TendoPayClient.php
+++ b/src/TendoPayClient.php
@@ -3,12 +3,16 @@
 namespace TendoPay\SDK;
 
 use Dotenv\Dotenv;
+use Exception;
 use GuzzleHttp\Client;
 use GuzzleHttp\Exception\GuzzleException;
+use InvalidArgumentException;
 use TendoPay\SDK\Exception\TendoPayConnectionException;
 use TendoPay\SDK\Exception\VerifyTransactionException;
 use TendoPay\SDK\Models\AccessToken;
 use TendoPay\SDK\Models\Payment;
+use TendoPay\SDK\Models\PurchaseTransaction;
+use TendoPay\SDK\Models\Transaction;
 use TendoPay\SDK\Models\VerifyTransactionRequest;
 use TendoPay\SDK\Models\VerifyTransactionResponse;
 use TendoPay\SDK\Traits\TendoPayHelper;
@@ -135,13 +139,18 @@ protected function request($method, $requestURI, $params, $headers = []): string
     }
 
     /**
+     * @param bool $usePersonalAccessToken
      * @return array
      * @throws TendoPayConnectionException
      */
-    protected function getAuthorizationHeader(): array
+    protected function getAuthorizationHeader($usePersonalAccessToken = false): array
     {
+        $accessToken = $usePersonalAccessToken ?
+            $this->getPersonalAccessToken() :
+            $this->getAccessToken();
+
         return [
-            'Authorization' => 'Bearer ' . $this->getAccessToken(),
+            'Authorization' => 'Bearer ' . $accessToken,
         ];
     }
 
@@ -171,6 +180,19 @@ protected function getAccessToken(): string
         return $this->accessToken->getToken();
     }
 
+    /**
+     * Return Personal Access Token
+     * @return string
+     */
+    protected function getPersonalAccessToken(): string
+    {
+        $token = (string)getenv('MERCHANT_PERSONAL_ACCESS_TOKEN', true);
+        if (!$token) {
+            throw new InvalidArgumentException('MERCHANT_PERSONAL_ACCESS_TOKEN does not exists');
+        }
+        return $token;
+    }
+
     /**
      * @param $params
      * @return mixed|string
@@ -333,6 +355,23 @@ public static function isCallbackRequest($request): bool
         );
     }
 
+    /**
+     * Retrieve Transaction Details with the transactionNumber
+     * @param $transactionNumber
+     * @return Transaction
+     * @throws Exception
+     */
+    public function getTransactionDetail($transactionNumber): Transaction
+    {
+        $params = [];
+        $response = $this->request('GET',
+            Constants::getTransactionDetailEndpointURI($transactionNumber),
+            $params,
+            $this->getAuthorizationHeader(true));
+
+        $transaction = json_decode($response, true);
+        return new Transaction($transaction);
+    }
 }