## **API Integration**
The steps to integrate the Standard Checkout Page on the merchant's website.
[Step 1. Initiating Payment request](🔗)
[Step 2. Redirecting user to PhonePe Standard Checkout page](🔗)
[Step 3. Redirecting user to Merchant web page](🔗)
[Step 4. Status verification post redirection to merchant website](🔗)
[Step 5. Handling Payment Success, Pending and Failure](🔗)
[Step 6. Refund](🔗)
#### **Step 1. Initiating Payment request**
The merchant does a server-to-server call to initiate a payment request ([PAY API](🔗)). In response to this PAY API call, a URL for that particular transaction is returned for the PhonePe payment page.
Refer here for [PAY API - Pay Page](🔗)
#### **Step 2. Redirecting user to PhonePe Standard Checkout page**
The merchant does a client-side redirection to the URL returned in Step 1. This will take the customer to the PhonePe payment page.
#### **Step 3. Redirecting user to Merchant web page**
Once the user has completed the payment, PhonePe will redirect to the **redirectUrl** passed in the request body to give the UI control back to the merchant website.
#### ** Step 4. Status verification post redirection to merchant website**
The merchant should check with their server if the [S2S response](🔗) is received.
Refer here for [Server-to-Server Callback](🔗)
If S2S is received, the checksum and amount should be validated on the server side and the payment status has to be updated on the merchant website.
If S2S is not received, then the [PG Check Status API](🔗) should be called and the amount should be validated in the response. The order status should be updated based on the transaction status provided by PhonePe.
Refer here for [Check Status API](🔗)
#### ** Step 5. Handling Payment Success, Pending and Failure**
The S2S callback or PG Status API response will return the actual payment status. The payment status falls within these three categories and merchants should handle it.
**Payment Success** If success response is received in merchant's server, then the success status has to be passed to the website and notify the customer with Payment Success page.
**Payment Failure** If failure response is received in merchant's server, then the failure status has to be passed to the website and notify the customer with Payment Failure page & ask the customer to retry payment.
**Payment Pending** If pending response is received in merchant's server, then the merchant can handle it in two ways depending on the use case.
**Option 1:** Pending status can be passed to the website and notify the customer with Payment Pending page. Ask the customer to wait for the terminal status and the status of the transaction should be shown in the order history page.
**Option 2:** Even though the payment status is Pending, Failure status can be passed to the website and notify the customer with Payment Failure page along with the refund message(If any amount is debited, the amount will be refunded back).
#### **Step 6. Refund**
In case of cancellations or returns, the merchant can initiate a refund through Dashboard or Refund API. This refund will be done against the originalTransactionId (The actual transaction id of the forward payment). Refer here for the [Refund API](🔗)
Refer here for [Refund API](🔗)