curl -u <YOUR_KEY_ID>:<YOUR_KEY_SECRET> \
-X POST https://api.razorpay.com/v1/payments/pay_HKrqmsgBHbaeIM/refund \
-H "Content-Type: application/json" \

RazorpayClient razorpay = new RazorpayClient("[YOUR_KEY_ID]", "[YOUR_KEY_SECRET]");

String paymentId = "pay_29QQoUBi66xm2f";

JSONObject refundRequest = new JSONObject();
refundRequest.put("amount",100);
refundRequest.put("speed","normal");
JSONObject notes = new JSONObject();
notes.put("notes_key_1","Tea, Earl Grey, Hot");
notes.put("notes_key_2","Tea, Earl Grey… decaf.");
refundRequest.put("notes",notes);
refundRequest.put("receipt","Receipt No. #31");

Payment payment = razorpay.payments.refund(paymentId,refundRequest);

$api = new Api($key_id, $secret);

$api->payment->fetch($paymentId)->refund(array("amount"=> "100", "speed"=>"normal", "notes"=>array("notes_key_1"=>"Beam me up Scotty.", "notes_key_2"=>"Engage"), "receipt"=>"Receipt No. 31"));

import razorpay
client = razorpay.Client(auth=("YOUR_ID", "YOUR_SECRET"))

client.payment.refund(paymentId,{
  "amount": "100",
  "speed": "normal",
  "notes": {
    "notes_key_1": "Beam me up Scotty.",
    "notes_key_2": "Engage"
  },
  "receipt": "Receipt No. 31"
})

import ( razorpay "github.com/razorpay/razorpay-go" )
client := razorpay.NewClient("YOUR_KEY_ID", "YOUR_SECRET")

data := map[string]interface{}{
  "speed": "normal",
  "notes": map[string]interface{}{
    "key_1": "value1",
    "key_2": "value2",
  },
}
body, err := client.Payment.Refund("<paymentId>",1200, data, nil)

require 'razorpay'

Razorpay.setup("YOUR_KEY_ID", "YOUR_KEY_SECRET")
Razorpay::Payment.fetch("pay_29QQoUBi66xm2f").refund()

var instance = new Razorpay({ key_id: 'YOUR_KEY_ID', key_secret: 'YOUR_SECRET' })

instance.payments.refund(paymentId,{
  "amount": "100",
  "speed": "normal",
  "notes": {
    "notes_key_1": "Beam me up Scotty.",
    "notes_key_2": "Engage"
  },
  "receipt": "Receipt No. 31"
})

//initialize the SDK client
RazorpayClient client = new RazorpayClient("[YOUR_KEY_ID]", "[YOUR_KEY_SECRET]");

// payment to be refunded, payment must be a captured payment
Payment payment = client.Payment.Fetch(paymentId);

//Full Refund
Refund refund = payment.Refund();

//Partial Refund
Dictionary<string, object> data = new Dictionary<string, object>();
data.Add("amount", "500100");
Refund refund = payment.Refund(data);

{
  "id": "rfnd_HMtH2fBtD60QkX",
  "entity": "refund",
  "amount": 200,
  "currency": "INR",
  "payment_id": "pay_HKrqmsgBHbaeIM",
  "notes": [],
  "receipt": null,
  "acquirer_data": {
    "rrn": null
  },
  "created_at": 1623663010,
  "batch_id": null,
  "status": "processed",
  "speed_processed": "normal",
  "speed_requested": "normal"
}

{
    "error": {
        "code": "BAD_REQUEST_ERROR",
        "description": "Kbrq5xxQHR8 is not a valid id",
        "source": "business",
        "step": "payment_initiation",
        "reason": "input_validation_failed",
        "metadata": {}
    }
}