Build with HENKERR

Integrate our payment infrastructure with a clean RESTful API. Go from sandbox to live in hours, not weeks.

Quick Start

Process your first transaction in four steps.

1. Authenticate

Obtain your API keys from the merchant dashboard. Use your secret key for server-to-server requests with HMAC-SHA256 signatures.

2. Process

Submit payment requests to our /api/process endpoint. We handle routing, 3DS, and fraud scoring transparently.

3. Handle 3DS

If 3DS is required, redirect the cardholder to the authentication URL. We handle the callback and complete the transaction.

4. Receive Webhooks

Get real-time notifications for transaction outcomes. Retry logic and dead letter queue ensure you never miss an event.

API Examples

Real request and response formats from our payment API.

Process Payment Request

curl -X POST https://app.henkerrpay.com/api/process \
  -H "Content-Type: application/json" \
  -H "X-API-Key: sk_live_your_api_key" \
  -H "X-Signature: hmac_sha256_signature" \
  -d '{
    "amount": 10000,
    "currency": "USD",
    "card": {
      "number": "4111111111111111",
      "exp_month": "12",
      "exp_year": "2027",
      "cvv": "123"
    },
    "customer": {
      "email": "[email protected]",
      "ip": "203.0.113.42"
    },
    "metadata": {
      "order_id": "ORD-12345"
    }
  }'

Success Response

{
  "id": "txn_8f3a2b1c4d5e6f7g",
  "status": "approved",
  "amount": 10000,
  "currency": "USD",
  "approval_code": "A12345",
  "fraud_score": 120,
  "acquirer": "acq_primary",
  "created_at": "2026-04-03T12:00:00Z"
}

Webhook Payload

{
  "event": "transaction.completed",
  "data": {
    "id": "txn_8f3a2b1c4d5e6f7g",
    "status": "approved",
    "amount": 10000,
    "currency": "USD"
  },
  "timestamp": "2026-04-03T12:00:01Z",
  "signature": "hmac_sha256_webhook_signature"
}

Sandbox Environment

Our sandbox provides a full-featured test environment with simulated acquirer responses. Test approvals, declines, 3DS flows, and webhook delivery before going live. Use test card numbers to simulate any scenario.

Ready to integrate?

Get API Keys