Payment API Service

The Payment API Service is the main gateway for processing payments. It orchestrates card tokenization, fraud detection, and transaction processing while providing a simple REST API for merchants.

Base URL: https://paymentgateway.redahaloubi.com/api/v1Public API: https://paymentgateway.redahaloubi.com/api/public

Authentication

The Payment API uses two different authentication methods depending on the endpoint:

API Key (Server-to-Server)
Client Secret (Browser)

Use for: Payment processing from your backend server

X-API-Key: pk_live_abc123def456...

Endpoints requiring API Key:

/api/v1/payments/* - All payment operations
/api/v1/transactions/* - Transaction queries
/api/v1/payment-intents - Create payment intent
/api/v1/payment-intents/:id/cancel - Cancel payment intent

How to get an API key: See Merchant API → Create API Key

Use for: Hosted checkout page (browser-based)

X-Client-Secret: pi_abc123_secret_xyz789...

Or as query parameter:

?client_secret=pi_abc123_secret_xyz789...

Endpoints requiring Client Secret:

/api/public/payment-intents/:id/confirm - Confirm payment

Security:

Client secrets are safe to use in browsers
They expire after 1 hour
They’re tied to a specific payment intent
Cannot be used to access other merchant data

Rate Limits

Payment Operations

20 requests per second per merchant10,000 requests per hour per merchant

Transaction Queries

100 requests per second per merchant

Public Endpoints

50 requests per second per IPUsed for hosted checkout page

Idempotency Cache

24 hour cache durationPrevents duplicate payments

Payment Flow Overview

Payment Operations

Authorize Payment

endpoint

/api/v1/payments/authorize

Authorize a payment by holding funds on the customer’s card without charging. Authorization is valid for 7 days. Authentication: API Key required Request Body

integer

required

Amount in cents (e.g., 9999 = $99.99)Min: 1 (0.01 in currency)Max: No limit (dependent on card)

string

required

Three-letter currency codeSupported: USD, EUR, MADLength: Exactly 3 characters

object

required

Card details

Show Card Object

string

required

Card number (13-19 digits, no spaces)

string

required

Name on card

integer

required

Expiration month (1-12)

integer

required

Expiration year (4 digits, e.g., 2027)

string

required

Card verification value (3-4 digits)

object

Customer information (optional)

Show Customer Object

string

Customer email (for receipts)

string

Customer full name

string

Payment description (e.g., “Order #12345”)

object

Custom key-value pairs for your referenceExample: {"order_id": "12345", "customer_id": "cus_abc"}

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payments/authorize \
  -H "X-API-Key: pk_live_your_api_key" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: order-12345-auth" \
  -d '{
    "amount": 9999,
    "currency": "USD",
    "card": {
      "number": "4242424242424242",
      "cardholder_name": "John Doe",
      "exp_month": 12,
      "exp_year": 2027,
      "cvv": "123"
    },
    "customer": {
      "email": "[email protected]",
      "name": "John Doe"
    },
    "description": "Order #12345 - Premium Plan",
    "metadata": {
      "order_id": "12345",
      "plan": "premium"
    }
  }'

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pay_abc123def456ghi789",
    "status": "authorized",
    "amount": 9999,
    "currency": "USD",
    "card_brand": "visa",
    "card_last4": "4242",
    "auth_code": "123456",
    "fraud_score": 15,
    "fraud_decision": "approve",
    "response_code": "00",
    "response_message": "Approved",
    "transaction_id": "txn_xyz789uvw012rst345",
    "created_at": "2026-01-24T10:00:00Z",
    "expires_at": "2026-01-31T10:00:00Z"
  }
}

Error Responses

400 Bad Request - Invalid Amount

{
  "success": false,
  "error": "invalid request: amount must be at least 1"
}

400 Bad Request - Unsupported Currency

{
  "success": false,
  "error": "unsupported currency (only USD, EUR, and MAD supported)"
}

402 Payment Required - Card Declined

{
  "success": false,
  "error": "payment declined: insufficient funds (code: 51)"
}

402 Payment Required - Fraud Declined

{
  "success": false,
  "error": "payment declined: high fraud risk (score: 85)"
}

409 Conflict - Idempotency Key Mismatch

{
  "success": false,
  "error": "idempotency key already used with different request data"
}

429 Too Many Requests

{
  "success": false,
  "error": "rate limit exceeded: 20 requests per second"
}

Idempotency: Include an Idempotency-Key header to safely retry requests. If the same key is used within 24 hours, the original response is returned without creating a new payment.

Sale Payment

endpoint

/api/v1/payments/sale

Process a sale (authorize + capture in one step). Funds are immediately charged to the customer’s card. Authentication: API Key required Request Body Same as Authorize Payment Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payments/sale \
  -H "X-API-Key: pk_live_your_api_key" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: order-12345-sale" \
  -d '{
    "amount": 4999,
    "currency": "USD",
    "card": {
      "number": "5555555555554444",
      "cardholder_name": "Jane Smith",
      "exp_month": 6,
      "exp_year": 2028,
      "cvv": "456"
    },
    "description": "Subscription - Monthly Plan"
  }'

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pay_def456ghi789jkl012",
    "status": "captured",
    "amount": 4999,
    "currency": "USD",
    "card_brand": "mastercard",
    "card_last4": "4444",
    "auth_code": "789012",
    "response_code": "00",
    "response_message": "Approved",
    "transaction_id": "txn_mno345pqr678stu901",
    "created_at": "2026-01-24T10:05:00Z",
    "captured_at": "2026-01-24T10:05:01Z"
  }
}

When to use Sale vs Authorize:Use Sale when:

Immediate charge is required (subscriptions, digital goods)
You ship goods immediately
Payment and fulfillment happen together

Use Authorize when:

You need to verify funds availability first
You ship physical goods later
You need to adjust the amount before capture
You want to manually review orders

Capture Payment

endpoint

/api/v1/payments/:id/capture

Capture a previously authorized payment. You can capture the full amount or a partial amount. Authentication: API Key required Path Parameters

string

required

Payment ID from authorization response

Request Body

integer

required

Amount to capture in centsMust be: ≤ authorized amountPartial captures: Allowed (e.g., capture

50 of

100 authorization)

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payments/pay_abc123def456/capture \
  -H "X-API-Key: pk_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 9999
  }'

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pay_abc123def456ghi789",
    "status": "captured",
    "amount": 9999,
    "currency": "USD",
    "captured_amount": 9999,
    "card_brand": "visa",
    "card_last4": "4242",
    "captured_at": "2026-01-24T15:30:00Z"
  }
}

Error Responses

400 Bad Request - Already Captured

{
  "success": false,
  "error": "payment already captured"
}

400 Bad Request - Amount Too High

{
  "success": false,
  "error": "capture amount exceeds authorized amount"
}

400 Bad Request - Authorization Expired

{
  "success": false,
  "error": "authorization expired (valid for 7 days)"
}

404 Not Found

{
  "success": false,
  "error": "payment not found"
}

Capture Deadline: Authorizations expire after 7 days. Capture before the expiration date or the authorization will be automatically voided.

Void Payment

endpoint

/api/v1/payments/:id/void

Cancel an authorized payment before it’s captured. This releases the hold on the customer’s card. Authentication: API Key required Path Parameters

string

required

Payment ID to void

Request Body

string

required

Reason for voiding (for audit logs)Example: “Customer requested cancellation”, “Order canceled”

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payments/pay_abc123def456/void \
  -H "X-API-Key: pk_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "reason": "Customer requested order cancellation"
  }'

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pay_abc123def456ghi789",
    "status": "voided",
    "amount": 9999,
    "currency": "USD",
    "voided_at": "2026-01-24T12:00:00Z",
    "void_reason": "Customer requested order cancellation"
  }
}

Error Responses

400 Bad Request - Already Captured

{
  "success": false,
  "error": "cannot void captured payment (use refund instead)"
}

400 Bad Request - Already Voided

{
  "success": false,
  "error": "payment already voided"
}

Void vs Refund:Void: Cancel before capture (no money has been charged)
Refund: Return money after capture (money has been charged)

Refund Payment

endpoint

/api/v1/payments/:id/refund

Refund a captured payment. Supports full and partial refunds. Authentication: API Key required Path Parameters

string

required

Payment ID to refund

Request Body

integer

required

Amount to refund in centsFull refund: Original payment amountPartial refund: Less than original amount

string

required

Refund reason (for audit logs)Example: “Product returned”, “Service not delivered”

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payments/pay_abc123def456/refund \
  -H "X-API-Key: pk_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 2500,
    "reason": "Product damaged - partial refund"
  }'

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pay_abc123def456ghi789",
    "status": "partially_refunded",
    "amount": 9999,
    "currency": "USD",
    "refunded_amount": 2500,
    "remaining_amount": 7499,
    "refunded_at": "2026-01-24T16:00:00Z",
    "refund_reason": "Product damaged - partial refund"
  }
}

Error Responses

400 Bad Request - Not Captured

{
  "success": false,
  "error": "can only refund captured payments"
}

400 Bad Request - Amount Too High

{
  "success": false,
  "error": "refund amount exceeds available amount"
}

400 Bad Request - Already Refunded

{
  "success": false,
  "error": "payment already fully refunded"
}

Refund Processing:

Refunds are processed immediately
Funds typically appear in customer’s account within 5-10 business days
Multiple partial refunds are supported until full amount is refunded

Get Payment

endpoint

/api/v1/payments/:id

Retrieve details of a specific payment. Authentication: API Key required Path Parameters

string

required

Payment ID

Example Request

curl -X GET https://paymentgateway.redahaloubi.com/api/v1/payments/pay_abc123def456 \
  -H "X-API-Key: pk_live_your_api_key"

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pay_abc123def456ghi789",
    "status": "authorized",
    "amount": 9999,
    "currency": "USD",
    "card_brand": "visa",
    "card_last4": "4242",
    "auth_code": "123456",
    "description": "Order #12345 - Premium Plan",
    "customer": {
      "email": "[email protected]",
      "name": "John Doe"
    },
    "metadata": {
      "order_id": "12345",
      "plan": "premium"
    },
    "created_at": "2026-01-24T10:00:00Z",
    "expires_at": "2026-01-31T10:00:00Z"
  }
}

Error Responses

404 Not Found

{
  "success": false,
  "error": "payment not found"
}

401 Unauthorized - Wrong Merchant

{
  "success": false,
  "error": "payment not found"
}

Payment Intents

Payment Intents provide a hosted checkout solution where customers complete payment in a browser.

Create Payment Intent

endpoint

/api/v1/payment-intents

Create a payment intent for hosted checkout. Returns a checkout_url to redirect your customer. Authentication: API Key required Request Body

integer

required

Amount in cents

string

required

Currency code (USD, EUR, MAD)

string

required

URL to redirect after successful paymentMust be HTTPS (except localhost for testing)Supports placeholders: {CHECKOUT_SESSION_ID} will be replaced with payment intent ID

string

URL to redirect if customer cancelsDefault: Same as success_url

string

Your internal order ID

string

Payment description shown to customer

string

When to capture fundsValues: automatic (default), manual

automatic: Funds captured immediately after authorization
manual: You must manually capture later

string

Customer email (pre-filled on checkout page)

object

Custom metadata

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payment-intents \
  -H "X-API-Key: pk_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 9999,
    "currency": "USD",
    "success_url": "https://yourstore.com/order/success?session_id={CHECKOUT_SESSION_ID}",
    "cancel_url": "https://yourstore.com/order/cancel",
    "description": "Order #12345 - Premium Plan",
    "customer_email": "[email protected]",
    "metadata": {
      "order_id": "12345"
    }
  }'

Response (201 Created)

{
  "success": true,
  "data": {
    "id": "pi_abc123def456ghi789",
    "client_secret": "pi_abc123def456ghi789_secret_xyz789uvw456rst123",
    "checkout_url": "https://checkout-page-amber.vercel.app/checkout/pi_abc123def456ghi789?client_secret=pi_abc123def456ghi789_secret_xyz789uvw456rst123",
    "amount": 9999,
    "currency": "USD",
    "status": "created",
    "success_url": "https://yourstore.com/order/success?session_id={CHECKOUT_SESSION_ID}",
    "cancel_url": "https://yourstore.com/order/cancel",
    "description": "Order #12345 - Premium Plan",
    "expires_at": "2026-01-24T11:00:00Z",
    "created_at": "2026-01-24T10:00:00Z"
  }
}

Next Steps:

Redirect your customer to checkout_url
Customer completes payment on hosted page
Customer is redirected to your success_url with ?payment_intent=pi_abc123...
Verify payment status on your server

Get Payment Intent (Public)

endpoint

/api/public/payment-intents/:id

Get payment intent details (browser-safe, no sensitive data returned). Authentication: None required (public endpoint) Path Parameters

string

required

Payment intent ID

Example Request

curl -X GET https://paymentgateway.redahaloubi.com/api/public/payment-intents/pi_abc123def456

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pi_abc123def456ghi789",
    "status": "created",
    "amount": 9999,
    "currency": "USD",
    "success_url": "https://yourstore.com/order/success",
    "cancel_url": "https://yourstore.com/order/cancel",
    "expires_at": "2026-01-24T11:00:00Z"
  }
}

Security Note: This endpoint does NOT return client_secret. It only provides public information needed to display the checkout page.

Confirm Payment Intent

endpoint

/api/public/payment-intents/:id/confirm

Confirm a payment intent by submitting card details. This processes the actual payment. Authentication: Client Secret required (in header or query) Path Parameters

string

required

Payment intent ID

Headers or Query

string

required

Client secret from payment intent creationAlternative: ?client_secret=pi_abc123_secret_xyz789

Request Body

object

required

Card details

Show Card Object

string

required

Card number (13-19 digits)

string

required

Name on card

integer

required

Expiration month (1-12)

integer

required

Expiration year (e.g., 2027)

string

required

Card verification value (3-4 digits)

string

Customer email (optional if provided during intent creation)

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/public/payment-intents/pi_abc123def456/confirm \
  -H "Content-Type: application/json" \
  -H "X-Client-Secret: pi_abc123def456ghi789_secret_xyz789uvw456rst123" \
  -d '{
    "card": {
      "number": "4242424242424242",
      "cardholder_name": "John Doe",
      "exp_month": 12,
      "exp_year": 2027,
      "cvv": "123"
    },
    "customer_email": "[email protected]"
  }'

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "pi_abc123def456ghi789",
    "status": "authorized",
    "payment_id": "pay_xyz789uvw012rst345",
    "redirect_url": "https://yourstore.com/order/success?payment_intent=pi_abc123def456ghi789"
  }
}

Error Responses

401 Unauthorized - Invalid Client Secret

{
  "success": false,
  "error": {
    "code": "INVALID_CLIENT_SECRET",
    "message": "client secret is invalid or expired"
  }
}

410 Gone - Intent Expired

{
  "success": false,
  "error": {
    "code": "INTENT_EXPIRED",
    "message": "payment intent expired (valid for 1 hour)"
  }
}

402 Payment Required - Card Declined

{
  "success": false,
  "error": {
    "code": "PAYMENT_DECLINED",
    "message": "card declined: insufficient funds",
    "remaining_attempts": 3
  }
}

410 Gone - Max Attempts

{
  "success": false,
  "error": {
    "code": "MAX_ATTEMPTS_REACHED",
    "message": "maximum payment attempts reached (5)"
  }
}

Payment Attempt Limits:

Maximum 5 attempts per payment intent
Each failed attempt is tracked
After 5 failures, the intent is locked
Create a new payment intent for additional attempts

Cancel Payment Intent

endpoint

/api/v1/payment-intents/:id/cancel

Cancel a payment intent before it’s completed. Authentication: API Key required Path Parameters

string

required

Payment intent ID to cancel

Example Request

curl -X POST https://paymentgateway.redahaloubi.com/api/v1/payment-intents/pi_abc123def456/cancel \
  -H "X-API-Key: pk_live_your_api_key"

Response (200 OK)

{
  "success": true,
  "message": "payment intent canceled"
}

Error Responses

400 Bad Request - Already Completed

{
  "success": false,
  "error": "cannot cancel completed payment intent"
}

Transaction Endpoints

Get Transaction

endpoint

/api/v1/transactions/:id

Get details of a specific transaction. Authentication: API Key required Path Parameters

string

required

Transaction ID

Example Request

curl -X GET https://paymentgateway.redahaloubi.com/api/v1/transactions/txn_abc123def456 \
  -H "X-API-Key: pk_live_your_api_key"

Response (200 OK)

{
  "success": true,
  "data": {
    "id": "txn_abc123def456ghi789",
    "payment_id": "pay_xyz789uvw012rst345",
    "status": "authorized",
    "amount": 9999,
    "currency": "USD",
    "card_brand": "visa",
    "card_last4": "4242",
    "auth_code": "123456",
    "response_code": "00",
    "response_message": "Approved",
    "created_at": "2026-01-24T10:00:00Z"
  }
}

List Transactions

endpoint

/api/v1/transactions

List all transactions for your merchant account. Authentication: API Key required Query Parameters

string

Filter by statusValues: authorized, captured, voided, refunded, failed

integer

Number of results per pageDefault: 10Max: 100

integer

Number of results to skipDefault: 0

Example Request

curl -X GET "https://paymentgateway.redahaloubi.com/api/v1/transactions?status=authorized&limit=20&offset=0" \
  -H "X-API-Key: pk_live_your_api_key"

Response (200 OK)

{
  "success": true,
  "data": {
    "transactions": [
      {
        "id": "txn_abc123def456",
        "payment_id": "pay_xyz789uvw012",
        "status": "authorized",
        "amount": 9999,
        "currency": "USD",
        "created_at": "2026-01-24T10:00:00Z"
      },
      {
        "id": "txn_def456ghi789",
        "payment_id": "pay_rst345mno678",
        "status": "authorized",
        "amount": 4999,
        "currency": "EUR",
        "created_at": "2026-01-24T09:30:00Z"
      }
    ],
    "total": 47,
    "limit": 20,
    "offset": 0
  }
}

Test Cards

Use these test card numbers for development and testing:

✅ Visa - Approved

Card Number: 4242 4242 4242 4242Expiry: Any future date (e.g., 12/2027)CVV: Any 3 digits (e.g., 123)Result: Authorization approved

✅ Mastercard - Approved

Card Number: 5555 5555 5555 4444Expiry: Any future dateCVV: Any 3 digitsResult: Authorization approved

❌ Generic Decline

Card Number: 4000 0000 0000 0002Expiry: Any future dateCVV: Any 3 digitsResult: Declined (code 05 - Do not honor)

❌ Insufficient Funds

Card Number: 4000 0000 0000 9995Expiry: Any future dateCVV: Any 3 digitsResult: Declined (code 51)

❌ Expired Card

Card Number: 4000 0000 0000 0069Expiry: Any future dateCVV: Any 3 digitsResult: Declined (code 54)

❌ CVV Mismatch

Card Number: 4000 0000 0000 0127Expiry: Any future dateCVV: Any 3 digitsResult: Declined (code N7)

❌ Processing Error

Card Number: 4000 0000 0000 0119Expiry: Any future dateCVV: Any 3 digitsResult: Declined (code 96)

⚠️ High Fraud Risk

Card Number: 4000 0000 0000 0259Expiry: Any future dateCVV: Any 3 digitsResult: Declined (fraud score > 70)

Test Card Rules:

All test cards use the same validation rules as real cards
Use any valid future expiry date (e.g., 12/2027)
Use any 3-digit CVV (except for CVV mismatch test)
Cardholder name can be anything
No real money is charged

Payment Status Lifecycle

Status Descriptions

created

Payment Intent StatusPayment intent created but no payment attempt yet.Next actions: Confirm payment intent, Cancel

authorized

Funds held on customer’s cardAuthorization is valid for 7 days. No money has been charged yet.Next actions: Capture, Void

captured

Payment completedFunds have been charged to the customer’s card.Next actions: Refund

voided

Authorization canceledHold released on customer’s card. No money was charged.Final state - No further actions possible

refunded

Fully refundedAll captured funds returned to customer.Final state - No further actions possible

partially_refunded

Partially refundedSome funds returned to customer, remaining amount still captured.Next actions: Additional refunds (up to remaining amount)

failed

Payment failedAuthorization attempt declined by issuer or fraud system.Final state - Create new payment for retry

expired

Authorization expiredAuthorization not captured within 7 days. Automatically voided.Final state - Create new payment for retry

Error Codes

Bad Request

Invalid request format or validation errorCommon causes:

Missing required fields
Invalid amount (must be positive integer)
Unsupported currency
Invalid card format

Unauthorized

Authentication failedCommon causes:

Missing API key or client secret
Invalid API key
Expired client secret
API key from different merchant

Payment Required

Payment declinedCommon causes:

Card declined by issuer (insufficient funds, expired, etc.)
Fraud risk too high
CVV verification failed
Card reported lost/stolen

Not Found

Resource not foundCommon causes:

Invalid payment ID
Invalid transaction ID
Payment belongs to different merchant

Conflict

Request conflicts with current stateCommon causes:

Idempotency key already used with different data
Payment already captured/voided/refunded
Cannot perform action in current status

Gone

Resource expired or no longer availableCommon causes:

Payment intent expired (1 hour)
Authorization expired (7 days)
Maximum payment attempts reached

Too Many Requests

Rate limit exceededLimits:

Payments: 20/sec, 10,000/hour
Transactions: 100/sec
Public endpoints: 50/sec per IP

Idempotency

Idempotency prevents duplicate payments caused by network retries or accidental double-clicks.

How It Works

Include Idempotency Key

Send a unique key in the Idempotency-Key header

-H "Idempotency-Key: order-12345-payment-attempt-1"

First Request Processed

The payment is processed normally and response is cached for 24 hours

Duplicate Requests Return Cached Response

If the same key is used again within 24 hours with the same request body, the original response is returned immediately without creating a new payment

Different Request Body = Error

If the same key is used with a different request body, you’ll get a 409 Conflict error

Best Practices

Use Unique Keys

Include order ID, user ID, timestamp, or attempt numberExample: order-{order_id}-{attempt}

Consistent Keys

Use the same key for all retry attempts of the same payment

24-Hour Expiry

Keys expire after 24 hours. After expiry, a new payment will be created

Test Retries

Test your retry logic in development to ensure proper idempotency handling

Webhooks

Payment API sends webhooks for payment events to keep your server updated in real-time.

Webhook Events

payment.authorized

Payment authorized successfully

payment.captured

Payment captured (charged)

payment.voided

Payment voided (canceled)

payment.refunded

Payment refunded (full or partial)

payment.failed

Payment authorization failed

payment_intent.created

Payment intent created

payment_intent.succeeded

Payment intent completed successfully

payment_intent.canceled

Payment intent canceled

Webhook Payload

{
  "event": "payment.authorized",
  "timestamp": "2026-01-24T10:00:00Z",
  "id": "evt_abc123def456",
  "data": {
    "payment_id": "pay_xyz789uvw012",
    "merchant_id": "merchant_abc123",
    "status": "authorized",
    "amount": 9999,
    "currency": "USD",
    "card_brand": "visa",
    "card_last4": "4242",
    "created_at": "2026-01-24T10:00:00Z"
  }
}

Verifying Webhook Signatures

Always verify webhook signatures to ensure requests are from Payment Gateway.

const crypto = require('crypto');

function verifyWebhook(payload, signature, secret) {
  const expectedSignature = crypto
    .createHmac('sha256', secret)
    .update(payload)
    .digest('hex');
  
  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(expectedSignature)
  );
}

// In your webhook handler
app.post('/webhooks/payment', (req, res) => {
  const signature = req.headers['x-webhook-signature'];
  const payload = JSON.stringify(req.body);
  
  if (!verifyWebhook(payload, signature, process.env.WEBHOOK_SECRET)) {
    return res.status(401).send('Invalid signature');
  }
  
  // Process webhook
  const event = req.body;
  
  switch(event.event) {
    case 'payment.authorized':
      // Handle authorization
      break;
    case 'payment.captured':
      // Handle capture
      break;
  }
  
  res.status(200).send('OK');
});

Webhook Retry Logic

Initial Delivery

Webhook sent immediately after event

Retry Schedule

If delivery fails (non-200 response):

1st retry: After 5 minutes
2nd retry: After 15 minutes
3rd retry: After 1 hour
4th retry: After 6 hours

Maximum Attempts

After 5 failed attempts, webhook is marked as failed

Expiration

Webhooks expire after 24 hours

Next Steps

Quick Start

Create your first payment intent in 5 minutes

Merchant API

Manage merchant accounts and team members

Checkout Integration

Build a custom checkout flow

CLI Tool

Test payments from the command line

Questions? Contact support at [email protected]

​Payment API Service

​Authentication

​Rate Limits

Payment Operations

Transaction Queries

Public Endpoints

Idempotency Cache

​Payment Flow Overview

​Payment Operations

​Authorize Payment

​Sale Payment

​Capture Payment

​Void Payment

​Refund Payment

​Get Payment

​Payment Intents

​Create Payment Intent

​Get Payment Intent (Public)

​Confirm Payment Intent

​Cancel Payment Intent

​Transaction Endpoints

​Get Transaction

​List Transactions

​Test Cards

✅ Visa - Approved

✅ Mastercard - Approved

❌ Generic Decline

❌ Insufficient Funds

❌ Expired Card

❌ CVV Mismatch

❌ Processing Error

⚠️ High Fraud Risk

​Payment Status Lifecycle

​Status Descriptions

​Error Codes

​Idempotency

​How It Works

​Best Practices

Use Unique Keys

Consistent Keys

24-Hour Expiry

Test Retries

​Webhooks

​Webhook Events

payment.authorized

payment.captured

payment.voided

payment.refunded

payment.failed

payment_intent.created

payment_intent.succeeded

payment_intent.canceled

​Webhook Payload

​Verifying Webhook Signatures

​Webhook Retry Logic

​Next Steps

Quick Start

Merchant API

Checkout Integration

CLI Tool

Payment API Service

Authentication

Rate Limits

Payment Flow Overview

Payment Operations

Authorize Payment

Sale Payment

Capture Payment

Void Payment

Refund Payment

Get Payment

Payment Intents

Create Payment Intent

Get Payment Intent (Public)

Confirm Payment Intent

Cancel Payment Intent

Transaction Endpoints

Get Transaction

List Transactions

Test Cards

Payment Status Lifecycle

Status Descriptions

Error Codes

Idempotency

How It Works

Best Practices

Webhooks

Webhook Events

Webhook Payload

Verifying Webhook Signatures

Webhook Retry Logic

Next Steps