💳 PhonePe Payment Gateway Integration – A Complete Guide

Aritra Dutta — Mon, 26 May 2025 19:55:38 +0000

In today’s digital-first world, enabling seamless online payments is a must-have for any modern application. Whether you're running an e-commerce platform, a service-based website, or a mobile app, integrating a reliable and secure payment gateway is crucial. PhonePe offers a robust Payment Gateway API for development and business purposes. Recently, I have integrated the same into my project, and I would like to share the steps to do it. I have shown the process using the UAT API and credentials of PhonePe, but I will also mention the steps to do the same using a merchant Id.

Prerequisites

Before starting with the integration steps, let's consider some of the prerequisites for the API to function properly.

A registered PhonePe business account.
A test API key and merchant credentials (from the PhonePe dashboard).
Basic understanding of REST APIs, Node.js/Java/PHP (or your preferred backend language).
Your application URL (for redirect and webhook setup).

Getting the credentials

Go to the PhonePe Business Dashboard and sign up as a merchant. On approval of your account, PhonePe will give you the following

Merchant ID
Salt Key
Salt Index
API Credentials

Payment API Integration

I will show the integration process step by step with UAT credentials. When integrating for a business application, replace the UAT credentials with those given by PhonePe.

Payment API URL for Testing -
https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/pay
Salt Key - 96434309-7796-489d-8924-ab56988a6076
PhonePe Merchannt Id - PGTESTPAYUAT86.

Request Headers -

Header Name	Header Value
Content-Type	X-VERIFY
application/json	SHA256(base64 encoded payload + “/pg/v1/pay” + salt key) + ### + salt index

Request/Payload Parameters-

Parameter Name	Datatype	Mandatory/Optional	Possible Values
merchantId	String	Mandatory	Unique MerchantID assigned to the merchant by PhonePe Note: merchantId length will be less than 38 characters.
merchantTransactionId	String	Mandatory	Unique TransactionID generated by the merchant to track request to PhonePe Note: – merchantTransactionId length should be less than 35 characters.
amount	Long	Mandatory	Transaction amount in Paise. Note: Amount should be greater than 100 (in Paise)
merchantUserId	String	Mandatory if paymentInstrument.type is: ● PAY_PAGE ● CARD ● SAVED_CARD Optional for if paymentInstrument.type is: ● UPI_INTENT ● UPI_COLLECT ● UPI_QR ● TOKEN ● NET_BANKING	Unique UserID of the users generated by the merchant. Note: – merchantUserId length should be less than 36 characters
redirectUrl	String	Mandatory	The url where the user will be redirected after transaction completion. Note - The redirectUrl should be an existing page of the application.
redirectMode	Enum	Mandatory	● REDIRECT and ● POST
callbackUrl	String	Mandatory	The URL where server to server callback will be posted. Always POST
paymentInstrument	Object	Mandatory	PayMent Details
paymentInstrument.type	Enum	Mandatory	● PAY_PAGE ● CARD ● UPI_INTENT ● SAVED_CARD ● TOKEN ● UPI_COLLECT ● UPI_QR ● NET_BANKING
mobileNumber	String	Optional	Mobile number of the user Note: There should not be any space.

Payload-
Firstly, we need to prepare the payload for the request. We will create an object with the fields which are mentioned above. Replace the PHONEPE_MERCHANT_ID with the merchant id provided by PhonePe. Also note that the amount should be in paise so we are multiplying it with 100.

let data = {
        merchantId: PHONEPE_MERCHANT_ID,
        merchantTransactionId: merchantTransactionId,
        name: customerName,
        mobileNumber: customerMobileNumber,
        amount: totalAmount * 100,
        redirectUrl:
          <YOUR_REDIRECT_URL>,
        callbackUrl:
          <YOUR_CALLBACK_URL>,
        redirectMode: "REDIRECT",
        paymentInstrument: {
          type: "PAY_PAGE",
        },
      };

Now we have to convert this data to a string and take the base64 encoded value.

const payload = JSON.stringify(data);
const payloadMain = Buffer.from(payload).toString("base64");

Next, we will concatenate the base64 encoded payload with "/pg/v1/pay" and the Salt key given by PhonePe. Now, hash the string using sha256 algorithm and prepare the checksum. The Salt index is 1 for UAT.

const string = payloadMain + "/pg/v1/pay" + PHONEPE_SALT_KEY;
let sha256hash = crypto.createHash("sha256").update(string).digest("hex");
let checkSum = sha256hash + "###" + process.env.SALT_INDEX;

Now, prepare an object for axios to hit the payment API.
Payment API URL for Testing -
https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/pay

let options = {
        method: "POST",
        URL: "https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/pay",
        headers: {
          accept: "application/json",
          "Content-Type": "application/json",
          "X-VERIFY": checkSum,
        },
        data: {
          request: payloadMain,
        },
      };
let phonePayRes = await axios(options);

Payment Status API Integration

Payment Staus API URL for Testing -
https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/status

Now, it's time to check the status of the payment made.
Create a string combining "/pg/v1/status/", the Merchant ID, and the transaction ID.

const string ="/pg/v1/status/" + PHONEPE_MERCHANT_ID + YOUR_TRANSACTION_ID + PHONEPE_SALT_KEY;

Similarly, we will create the hash and checksum.

let sha256hash = crypto.createHash("sha256").update(string).digest("hex");
let checkSum = sha256hash + "###" + process.env.SALT_INDEX;

Now, we will prepare the object to be passed to axios for hitting the API.

let options = {
        method: "GET",
        url: https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/status/{PHONEPE_MERCHANT_ID}/{YOUR_TRANSACTION_ID},
        headers: {
          accept: "application/json",
          "Content-Type": "application/json",
          "X-VERIFY": checkSum,
        },
      };

let phonePeStsRes = await axios(options);

This will give the status of the transaction, whether it was a failure or a success.

I hope this blog will help you integrate these APIs into your own application. I would be pleased to know if any points remained uncovered, so that I can further add them.

DEV Community: Aritra Dutta

💳 PhonePe Payment Gateway Integration – A Complete Guide

Prerequisites

Getting the credentials

Payment API Integration

Payment Status API Integration