@erudite-intelligence/x402-hbar

x402 exact payment scheme implementation for Hedera HBAR.

Part of the EruditePay x402 multi-chain payment infrastructure by Erudite Intelligence LLC.

Overview

This package implements the x402 protocol's exact payment scheme for the Hedera network. It enables HTTP 402-based micropayments using native HBAR transfers.

• CAIP-2 Network ID: hedera:mainnet
• Unit: tinybars (1 HBAR = 100,000,000 tinybars)
• Signing: Ed25519 / ECDSA via Hedera SDK
• Verification: Mirror Node REST API + on-chain receipt

Installation

npm install @erudite-intelligence/x402-hbar

Usage

Client — Create a Payment

import { createPayment } from "@erudite-intelligence/x402-hbar";

const paymentHeader = await createPayment({
  senderAccountId: "0.0.12345",
  senderPrivateKey: "302e020100300506032b657004220420...",
  recipientAccountId: "0.0.67890",
  amount: "1.5",          // 1.5 HBAR
  validForSeconds: 120,
  network: "mainnet",
  memo: "x402 payment for API access",
});

// Use paymentHeader as the X-PAYMENT header value

Server — Verify & Settle

import { verifyAndSettle } from "@erudite-intelligence/x402-hbar";

const result = await verifyAndSettle({
  paymentHeader: req.headers["x-payment"],
  expectedRecipient: "0.0.67890",
  expectedAmountTinybars: "150000000",  // 1.5 HBAR
  network: "mainnet",
  operatorAccountId: "0.0.99999",
  operatorPrivateKey: "302e020100...",
});

if (result.success) {
  console.log("Settled:", result.txId);
} else {
  console.error("Payment failed:", result.error);
}

Security

• Replay protection: In-memory Map with 1-hour TTL. Multi-instance deployments MUST use Redis/DB.
• Fail-closed: If balance verification or any API call fails, the payment is REJECTED.
• Expiry enforcement: Transactions with expired validStart windows are rejected.

License

MIT — Erudite Intelligence LLC