SERVER 2 SERVER

S2S PayLater

Initiate PayLater payments from your server using a provider enabled for your FiatPe account.

Supported PayLater providers

Fetch the PayLater providers available to your account using the Methods API.

The paylater object contains only providers enabled for your account. Display the returned provider name and submit its corresponding object key as the provider code.

Open the Methods API guide

Test PayLater providers by response flow

Use these provider codes in the FiatPe UAT environment to validate both supported PayLater continuation flows.

Test flow	Provider	Provider code	Expected action
Redirect	Amazon Pay	`amazonpay`	`redirect`
HTML form	LazyPay	`lazypay`	`html_form`

Test every response flow in UAT before going live.

Your integration must successfully handle Redirect and HTML Form flows in the UAT environment. The flow returned for a transaction can vary based on the configured TID, acquiring bank, issuing bank, payment network, payment method, and other transaction parameters.

Do not hardcode a flow for a card, bank, wallet, or PayLater provider. Always inspect the returned next[].action value and process redirect or html_form as instructed by the API response.

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 PayLater payment

Send the payment request from your backend with the PayLater provider selected by the customer. Generate the Basic authorization value by Base64 encoding api_key:secret_key.

REQUEST

Curl

curl --location 'https://api.fiatpe.com/v1/payments/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_2129fc063f6a4e0b",
    "return_url": "https://example.com/payment/return",
    "callback_url": "https://api.example.com/webhooks/fiatpe",
    "description": "Test payment",
    "method": "paylater",
    "provider": "amazonpay",
    "metadata": {
      "note_key": "value1"
    }
  }'

Request fields

Field	Required	Description
`amount`	Yes	Payment amount in the currency’s smallest sub-unit.
`currency`	Yes	Three-letter currency code, such as `INR`.
`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 in Step 1.
`return_url`	Yes	HTTPS URL used after PayLater authorisation completes.
`callback_url`	No	Optional HTTPS endpoint on your server where FiatPe sends asynchronous payment updates.
`description`	No	Description associated with the payment.
`method`	Yes	Set to `paylater`.
`provider`	Yes	Provider code returned by the Methods API, for example `amazonpay` or `lazypay`.
`metadata`	No	Merchant-defined key-value data associated with the payment.

Response actions

Redirect flow

In UAT, amazonpay returns a redirect action. Navigate the customer’s browser to next[0].url so they can complete provider authentication.

200 OK

{
  "payment_id": "FIATPESTDS7GILWFCO1790705098",
  "next": [
    {
      "action": "redirect",
      "url": "https://api.fiatpe.com/v1/payments/FIATPESTDS7GILWFCO1790705098/authentication/"
    }
  ]
}

HTML form flow

Use lazypay in UAT to test the html_form response. Render next[0].html_content as a complete HTML document in the customer’s browser.

REQUEST

Curl

curl --location 'https://api.fiatpe.com/v1/payments/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_2129fc063f6a4e0b",
    "return_url": "https://example.com/payment/return",
    "callback_url": "https://api.example.com/webhooks/fiatpe",
    "description": "Test payment",
    "method": "paylater",
    "provider": "lazypay",
    "metadata": {
      "note_key": "value1"
    }
  }'

200 OK

{
  "payment_id": "FIATPEST5YW9DBBT041790704898",
  "next": [
    {
      "action": "html_form",
      "html_content": "<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n  <meta charset=\"UTF-8\">\n  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n  <title>Redirecting | FiatPe</title>\n  <script src=\"https://cdnjs.cloudflare.com/ajax/libs/lottie-web/5.12.2/lottie.min.js\"></script>\n</head>\n<body>\n  <div class=\"redirect-container\">\n    <div id=\"lottie-loader\"></div>\n    <h1>Redirecting...</h1>\n    <p>Please wait while we redirect you securely. Do not close this window.</p>\n    <form id=\"payment-form\" method=\"GET\"\n      action=\"https://api.fiatpe.com/v1/payments/FIATPEST5YW9DBBT041790704898/authentication/\"\n      hidden>\n      <input type=\"hidden\" name=\"paymentMode\" value=\"WALLET\">\n      <input type=\"hidden\" name=\"walletCode\" value=\"AIRTELMONEY\">\n    </form>\n    <noscript>\n      <button type=\"submit\" form=\"payment-form\">Continue to payment</button>\n    </noscript>\n  </div>\n  <script>\n    if (window.lottie) {\n      lottie.loadAnimation({\n        container: document.getElementById(\"lottie-loader\"),\n        renderer: \"svg\",\n        loop: true,\n        autoplay: true,\n        path: \"https://bucket.fiatpe.com/static/animation/lottie/fiatpe_pg_processing_loader.json\"\n      });\n    }\n    window.setTimeout(function () {\n      document.getElementById(\"payment-form\").submit();\n    }, 1000);\n  </script>\n</body>\n</html>"
    }
  ]
}

Treat html_content as an opaque document returned by FiatPe. Do not rewrite its form action, hidden fields, scripts, or provider values.

Handle the PayLater result

For a redirect action, navigate the customer’s browser to the returned URL.
For an html_form action, render the returned HTML as a complete browser document.
Do not treat the redirect or rendered form as proof of payment success.
Confirm the final payment status on your backend and process webhooks idempotently.
Verify the payment ID, order ID, amount, and currency before fulfilment.