SERVER 2 SERVER

S2S UPI Intent

Initiate a UPI Intent payment from your backend and launch the returned intent on the customer’s device.

STEP 1

Create the order on your server

Create a new FiatPe order for each payment attempt. Amounts use the smallest currency sub-unit: for INR, 5000 represents ₹50.00. Store the returned order ID against your internal order before using it in the S2S payment request.

Open the Create Order API reference

Server request example

Use your FiatPe credentials only from a trusted backend environment.

REQUEST

Curl

curl --request POST \
  --url https://api.fiatpe.com/v1/orders/ \
  --header "Authorization: Basic YOUR_BASE64_CREDENTIALS" \
  --header "Content-Type: application/json" \
  --data '{
    "amount": 5000,
    "currency": "INR"
  }'

Response

Store the returned data.id and pass it as the order_id in Step 2.

200 OK

{
  "data": {
    "id": "order_2f40f08f4baa4e5b",
    "amount": 5000,
    "entity": "order",
    "status": "created",
    "currency": "INR",
    "metadata": {},
    "created_at": 1788148983,
    "return_url": null,
    "amount_paid": 0,
    "bank_details": null,
    "return_method": "POST",
    "amount_pending": 5000
  },
  "message": "order created successfully."
}

STEP 2

Initiate a payment

Send this request from your backend. Generate the Basic authorization value by Base64 encoding api_key:secret_key. Theupi.flow value must be intent.

REQUEST

Curl

curl --location 'https://api.fiatpe.com/v1/payments/create/s2s/' \
  --header 'Authorization: Basic <base64(api_key:secret_key)>' \
  --header 'Content-Type: application/json' \
  --data-raw '{
    "amount": 5000,
    "currency": "INR",
    "contact": "+919898989898",
    "name": "Aftab Hussain",
    "email": "customer@example.com",
    "order_id": "order_75db8a5703ba4d3a",
    "return_url": "https://example.com/payment/return",
    "description": "Test payment",
    "method": "upi",
    "upi": {
      "flow": "intent",
      "expiry_time": 5
    },
    "metadata": {
      "note_key": "value1"
    }
  }'

Request fields

Field	Required	Description
`amount`	Yes	Payment amount in the currency’s smallest sub-unit. For INR, `5000` represents ₹50.00.
`currency`	Yes	Three-letter currency code. Use `INR` for Indian Rupees.
`contact`	Yes	Customer phone number including the country code.
`name`	Yes	Customer’s full name.
`email`	Yes	Customer email address.
`order_id`	Yes	Order ID returned by the Create Order API.
`return_url`	Yes	HTTPS URL used after the payment flow completes.
`description`	No	Description associated with the payment.
`method`	Yes	Set to `upi`.
`upi.flow`	Yes	Set to `intent`.
`upi.expiry_time`	Yes	Expiry value for the UPI Intent payment request.
`metadata`	No	Merchant-defined key-value data associated with the payment.

Response

Open the returned link for the customer to continue the UPI Intent flow. Store the payment_id for status checks, webhook reconciliation, and support.

200 OK

{
  "link": "https://api.fiatpe.com/simulation/<token>/",
  "payment_id": "FIATPESTO339JBX1411790703644"
}

Handle the final result

Opening the returned link does not prove that the payment succeeded.
Confirm the final status from your backend after the customer returns.
Process FiatPe webhook deliveries idempotently and allow delayed or duplicate events.
Match the payment ID, order ID, amount, and currency before fulfilment.