Payra Node SDK

Official Node SDK for integrating Payra's on-chain payment system into your backend applications.

This SDK provides:

• Secure generation of ECDSA signatures compatible with the Payra smart contract — used for order payment verification.
• Simple methods for checking the on-chain details of orders to confirm completed payments.

How It Works

The typical flow for signing and verifying a Payra transaction:

1. The frontend prepares all required payment parameters:
   • Network – blockchain name (e.g. Polygon, Linea)
   • Token address – ERC-20 token contract address
   • Order ID – unique order identifier
   • Amount WEI – already converted to the smallest unit (e.g. wei, 10⁶)
   • Timestamp – Unix timestamp of the order
   • Payer wallet address – the wallet address from which the user will make the on-chain payment
2. The frontend sends these parameters to your backend.
3. The backend uses this SDK to generate a cryptographic ECDSA signature with its signature key (performed offline).
4. The backend returns the generated signature to the frontend.
5. The frontend calls the Payra smart contract (payOrder) with all parameters plus the signature.

This process ensures full compatibility between your backend and Payra’s on-chain verification logic.

Features

• Generates Ethereum ECDSA signatures using the secp256k1 curve.
• Fully compatible with Payra's Solidity smart contracts (ERC-1155 payment verification).
• Supports .env and config/payra.php configuration for multiple blockchain networks.
• Laravel IoC container integration (easy dependency injection)
• Verifies order payment details directly on-chain via RPC or blockchain explorer API.
• Provides secure backend integration for signing and verifying transactions.
• Includes optional utility helpers for:
• Currency conversion (via ExchangeRate API)
• USD ⇄ WEI conversion for token precision handling.

Setup

Before installing this package, make sure you have an active Payra account:

https://payra.cash/products/on-chain-payments/registration

Before installing this package, make sure you have a MerchantID

• Your Merchant ID (unique for each blockchain network)
• Your Signature Key (used to sign Payra transactions securely)

Additionally: To obtain your RPC URLs which are required for reading on-chain order statuses directly from the blockchain, you can use the public free endpoints provided with this package or create an account on one of the following services for better performance and reliability:

• QuickNode – Extremely fast and excellent for Polygon/Mainnet. (quicknode.com)

• Alchemy – Offers a great developer dashboard and high reliability. (alchemy.com)

• DRPC – Decentralized RPC with a generous free tier and a strict no-log policy. (drpc.org)

• Infura – The industry standard; very stable, especially for Ethereum. (infura.io)

Optional (recommended):

• Create a free API key at ExchangeRate API to enable automatic fiat → USD conversions using the built-in utility helpers.

Installation

From NPM

Install the latest stable version from NPM:

npm  install  payra-sdk-node

Environment Configuration

Create a .env file in your project root (you can copy from example):

cp  .env.example  .env

This file stores your private configuration and connection settings for all supported networks. Never commit .env to version control.

Required Variables

Exchange Rate (optional)

Used for automatic fiat → USD conversions via the built-in Payra utilities.

# Optional — only needed if you want to use the built-in currency conversion helper
PAYRA_EXCHANGE_RATE_API_KEY= # Your ExchangeRate API key (from exchangerate-api.com)
PAYRA_EXCHANGE_RATE_CACHE_TIME=720  # Cache duration in minutes (default: 720 = 12h)

# Polygon Network Configuration
PAYRA_POLYGON_OCP_GATEWAY_CONTRACT_ADDRESS=0xc56c55D9cF0FF05c85A2DF5BFB9a65b34804063b
PAYRA_POLYGON_SIGNATURE_KEY=
PAYRA_POLYGON_MERCHANT_ID=
PAYRA_POLYGON_RPC_URL_1=https://polygon-rpc.com
PAYRA_POLYGON_RPC_URL_2=

# Ethereum Network Configuration
PAYRA_ETHEREUM_OCP_GATEWAY_CONTRACT_ADDRESS=
PAYRA_ETHEREUM_SIGNATURE_KEY=
PAYRA_ETHEREUM_MERCHANT_ID=
PAYRA_ETHEREUM_RPC_URL_1=
PAYRA_ETHEREUM_RPC_URL_2=

# Linea Network Configuration
PAYRA_LINEA_OCP_GATEWAY_CONTRACT_ADDRESS=
PAYRA_LINEA_SIGNATURE_KEY=
PAYRA_LINEA_MERCHANT_ID=
PAYRA_LINEA_RPC_URL_1=
PAYRA_LINEA_RPC_URL_2=

Important Notes

• The cache automatically refreshes when it expires.
• You can adjust the cache duration by setting PAYRA_EXCHANGE_RATE_CACHE_TIME:
  • 5 → cache for 5 minutes
  • 60 → cache for 1 hour
  • 720 → cache for 12 hours (default)
• Each network (Polygon, Ethereum, Linea) has its own merchant ID, signature key, and RPC URLs.
• The SDK automatically detects which chain configuration to use based on the selected network.
• You can use multiple RPC URLs for redundancy (the SDK will automatically fall back if one fails).
• Contract addresses correspond to the deployed Payra Core Forward contracts per network.

Usage Example

Generate Signature

import { generateSignature, PayraUtils } from  'payra-sdk-node';

try {
	// convert to wei if need
	// const amountWei = PayraUtils.toWei(3.34, "polygon", "usdt");

	const  network = 'polygon';
	const  tokenAddress = '0xc2132D05D31c914a87C6611C10748AEb04B58e8F'; // example token (USDT)
	const  orderId = 'ord-258';
	const  amountWei = 12340000; // 1 token (in wei)
	const  timestamp = 1760274141;  // Math.floor(Date.now() / 1000)
	const  payerAddress = '0xbCd665bE1393094bfD5013E0e2e21aB6Df1D6078';
	
	const  sig = generateSignature(
		network,
		tokenAddress,
		orderId,
		amountWei,
		timestamp,
		payerAddress
	);

	console.log('Signature generated:', sig);
} catch (err) {
	console.error('Error:', err.message);
}

Input Parameters

| Field | Type | Description | |--------------|----------|----------------------------------------------| | network | string | Selected network name | | tokenAddress | string | ERC20 token contract address | | orderId | string | Unique order reference (e.g. ORDER-123) | | amountWei | string or integer | Token amount in smallest unit (e.g. wei) | | timestamp | number | Unix timestamp of signature creation | | payerAddress | string | Payer Wallet Address

Get Order Details

Retrieve full payment details for a specific order from the Payra smart contract. This method returns the complete on-chain payment data associated with the order, including:

• whether the order has been paid,
• the payment token address,
• the paid amount,
• the fee amount,
• and the payment timestamp.

Use this method when you need detailed information about the payment or want to display full transaction data.

import { getOrderDetails } from  'payra-sdk-node';
const  result = await  getOrderDetails("polygon", "ord-170");
console.log(result);

Example response structure

{
	success: true,
	paid: true,
	error: null,
	token: '0xc2132D05D31c914a87C6611C10748AEb04B58e8F',
	amount: 400000,
	fee: 3600,
	timestamp: 1765138941
}

Check Order Paid Status

Perform a simple payment check for a specific order. This method only verifies whether the order has been paid (true or false) and does not return any additional payment details.

Use this method when you only need a quick boolean confirmation of the payment status.

import { isOrderPaid } from  'payra-sdk-node';
const  result = await  isOrderPaid("polygon", "ord-170");
console.log(result);

Example response structure

{
	success: true,
	paid: true,
	error: null
}

Note: Network identifiers should always be lowercase (e.g., "polygon", "ethereum", "linea", "flare").

Utilities / Conversion Helpers

The SDK includes helper functions for working with token amounts and currency conversion.

1. Get Token Decimals

import { PayraUtils } from  'payra-sdk-node';
const  tokenDecimals = PayraUtils.getTokenDecimals("polygon", "usdt");
console.log("Token decimals polygon usdt:", tokenDecimals);

Returns the number of decimal places for a given token on a specific network.

2. Convert USD/Token Amounts to Wei

import { PayraUtils } from  'payra-sdk-node';
const  amountWei = PayraUtils.toWei(3.34, "polygon", "usdt");
console.log("To Wei:", amountWei);

3. Convert Wei to USD/Token

import { PayraUtils } from  'payra-sdk-node';
const  amount = PayraUtils.fromWei(amountWei, "polygon", "usdt");
console.log("From Wei:", amount);

4. Currency Conversion (Optional)

Payra processes all payments in USD. If your store uses another currency (like EUR, AUD, or GBP), you can:

• Convert the amount to USD on your backend manually, or
• Use the built-in helper provided in the SDK.

import { PayraUtils } from 'payra-sdk-node';
// Convert 100 EUR to USD
const usdValue = await  PayraUtils.convertToUSD(100, "EUR");
console.log("100 EUR =",nusdValue, "USD");

Setup for Currency Conversion

To use the conversion helper, you need a free API key from exchangerate-api.com.

1. Register a free account and get your API key.
2. Add the key to your .env file:

PAYRA_EXCHANGE_RATE_API_KEY=your_api_key_here

4. That’s it — Payra will automatically fetch the exchange rate and calculate the USD amount.

Note: The free plan allows 1,500 requests per month, which is sufficient for most stores. Exchange rates on this plan are updated every 24 hours, so with caching, it’s more than enough. Paid plans offer faster update intervals.

Security Notice

Never expose your signature key in frontend or client-side code.
This SDK is server-side only and must be used securely on your backend. Never use it in frontend or browser environments. Also, never commit your .env file to version control.

Project

• https://payra.cash
• https://payra.tech
• https://payra.xyz
• https://payra.eth - suporrted by Brave and Opera Browser or .limo

Social Media

• Telegram Payra Group
• Telegram Announcements
• Twix (X)
• Dev.to

License

MIT © Payra