Empower
Your Business to
Accept Crypto Payments

Your Business. Your Keys. The Non-Custodial Standard. Eliminate Chargebacks. Save 90% on fees, To democratize global commerce by providing a trustless, non-custodial payment infrastructure that returns full financial control to the merchant.

0.8%

Fixed On-Chain Split

0%

Custodial Risk

~$9.00/mo

Self-Hosted VPS Overhead

Live Invoice #1024 Merchant: Apex Store

99.2% Direct Route

Total Amount: $100.00 USDT

Merchant Wallet (99.2%): $99.20 USDT

KayPay Gateway (0.8%): $0.80 USDT

Derived Addr #0: bc1q9v8k7y...3a2u

Supported Cryptocurrencies & Low-Fee Blockchain Rails

₿

Bitcoin

BTC Mainnet & BIP21 Split

UTXO

⚡

Lightning Network

Sub-Second Payments

Instant

Ethereum & L2s

Arbitrum, Base, Optimism

EVM

₮

Tether (USDT)

TRC-20, ERC-20, Solana

Stablecoin

USD Coin (USDC)

Solana, Arbitrum, Base

Stablecoin

◎

Solana

High-Speed Web3 Multi-Call

Ultra-Low Fee

Interactive Demo

See How On-The-Fly Fee Splitting Works

Enter any transaction amount to simulate how KayPay routes 99.2% directly into your merchant wallet while automatically sending 0.8% to the platform gateway in a single transaction.

Invoice Payment Amount:

Select Asset / Chain:

Deterministic xpub Sub-Address Derivation:

bc1q9v8k7y3m2x4p6l0w5n1t8r9e7c3a2u

Address Index: #0

Transaction Fee Split Breakdown

Merchant Share (99.2%): $248.00 USDT

KayPay Gateway Fee (0.8%): $2.00 USDT

🔒 Zero Pre-Paid Gas Tanks Required: Unlike legacy crypto gateways, KayPay executes fee splitting during customer checkout so merchants never need to pre-fund account fuel tanks.

Value Creation

What Makes KayPay the Best Crypto Payment Processor?

Architected for complete merchant sovereignty, operational privacy, and zero maintenance overhead.

100% Non-Custodial

Your funds go directly from the buyer to your personal wallet. Server database stores zero private keys—only public derivation paths (`xpub`).

On-The-Fly Fee Split

Natively routes 99.2% to your wallet and 0.8% to the gateway platform operator within a single transaction. No billing balances needed.

Sequential xpub Privacy

BIP32/BIP44 derivation generates unique, isolated sub-addresses for every invoice, preventing third parties from mapping your total wallet balance.

Ultra-Lightweight VPS

Runs on minimal infrastructure (1 vCPU, 1GB RAM) using free third-party public API & RPC nodes. Total hosting cost is ~$9.00/month.

Competitive Edge

Why Merchants Choose KayPay Over Legacy Gateways

Compare KayPay against custodial payment gateways and legacy merchant solutions.

Feature / Metric	🚀 KayPay	Coinbase Commerce	BitPay	Crypto.com
Processing Fee	0.8% Fixed Split	1.0%	1.0%	0.5% - 1.0%
Custody Standard	High, 100% Non-Custodial	Medium, Custodial	Medium, Custodial	Custodial
Pre-Paid Merchant Fuel Balance	NO (On-the-Fly Split)	N/A	Required	Required
Address Privacy (BIP44)	Unique Address per Invoice	Reused / Shared	Reused / Shared	Reused / Shared
Minimum Payout Amount	No Limit (Instant Direct)	No Limit	No Limit	Limited
Server Requirement & Cost	Self-Hosted (~$9/mo VPS)	SaaS Lock-in	SaaS Lock-in	SaaS Lock-in

Integrations

Integration Plugins & Developer Tools

Easily integrate KayPay into your online store or custom tech stack in under 1 minute.

Shopify Hosted Checkout

WooCommerce WordPress Plugin

Ecwid Storefront Module

BigCommerce App Extension

PrestaShop Payment Module

PaidMembership Pro Subscription Module

EasyDigitalDownloads Digital Downloads

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REST API & Webhooks Custom Integration

Under The Hood

System Architecture & Code Logic

Explore how KayPay derives addresses, routes multi-output split transactions, and maintains maximum security posture.

When a customer clicks checkout, KayPay derives a sequential address using the merchant's stored Extended Public Key (xpub). Private keys are never touched.

// Address Derivation Routine (Node.js / Python)
function generateInvoiceAddress(merchantXpub, addressIndex) {
  // m/44'/0'/0'/0/index
  const node = bip32.fromBase58(merchantXpub);
  const child = node.derive(0).derive(addressIndex);
  const { address } = bitcoin.payments.p2pkh({ pubkey: child.pubkey });
  
  // Increment database counter for next order
  return { address, index: addressIndex + 1 };
}

For UTXO networks like Bitcoin, KayPay constructs BIP21 payment URIs that broadcast a single transaction with two distinct outputs.

// UTXO BIP21 Multi-Output Split Request
const paymentUri = `bitcoin:${merchantDerivedAddress}?amount=${merchantAmount}`
  + `&req-output2=${operatorWalletAddress}&amount2=${operatorFeeAmount}`;

// Customer wallet broadcasts single tx with 2 outputs:
// Output 1: 99.2% -> Merchant Derived Address
// Output 2: 0.8%  -> KayPay Platform Wallet

On smart contract networks (Solana, Arbitrum, Tron), client checkout wrappers execute atomic token transfer calls in a single batch.

// Smart Contract Token Split Routine
async function executeWeb3Checkout(usdtContract, merchantAddress, operatorWallet, totalAmount) {
  const merchantAmount = totalAmount.mul(9920).div(10000); // 99.2%
  const operatorAmount = totalAmount.mul(80).div(10000);   // 0.8%

  // Synchronous web3 multi-call execution
  await usdtContract.transfer(merchantAddress, merchantAmount);
  await usdtContract.transfer(operatorWallet, operatorAmount);
}

FAQ

Frequently Asked Questions

Everything you need to know about setting up and running your self-hosted KayPay gateway.

Is KayPay really 100% non-custodial?

Yes, absolutely. KayPay never generates or stores private keys on the server. Merchants input their Extended Public Key (xpub), and KayPay acts solely as an address derivation and passive payment monitoring engine. Funds land directly in your wallet.

How does the 0.8% fee split work without pre-paid fuel balances?

KayPay splits transaction fees natively during transaction broadcast. On Bitcoin, it uses BIP21 multi-output instructions (99.2% to merchant, 0.8% to gateway). On EVM/Solana, it uses inline token transfer instructions. This eliminates the need to deposit fuel balances.

What are the server hosting requirements?

KayPay is designed to run on minimal hardware specs (1 vCPU, 1GB RAM) with < 25GB SSD. By querying free public RPC/API nodes, you avoid running heavy full nodes. Total running cost is roughly $8-$9/month.

What happens if my server gets hacked?

Because private keys are never stored on the server, a database compromise only exposes public derivation keys (xpub) and public invoice metadata. Attackers cannot freeze, drain, or steal any merchant or customer funds.

Empower Your Business to Accept Crypto Payments