@crypto.com/facilitator-client

$3

The Crypto.com Facilitator SDK provides a lightweight, strongly typed Node.js/TypeScript client for interacting with the Cronos X402 Facilitator API.
It allows developers to easily:

- Generate EIP-3009 signed payment headers
- Build X402 Payment Requirements
- Submit payments for verification and settlement
- Discover supported networks and capabilities

This SDK enables fully automated off-chain authorization / on-chain execution payments on Cronos Mainnet and Cronos Testnet.

!npm
!License

Features

- Facilitator API Client
/verify, /settle, /supported

- EIP-3009 Header Generator
Produces Base64-encoded X402 payment headers

- Typed X402 Payment Requirements
Fully typed and schema-driven

- Zero unnecessary dependencies
Built around ethers and native Node features

- Cronos-native
Supports Cronos Mainnet and Cronos Testnet

Installation

``bash npm install @crypto.com/facilitator-client

`or`


yarn add @crypto.com/facilitator-client


Usage
1. Create a Facilitator Client
> The Facilitator base URL is fixed internally and cannot be overridden.

`ts import { Facilitator } from '@crypto.com/facilitator-client'; import { CronosNetwork } from '@crypto.com/facilitator-client';

const facilitator = new Facilitator({ network: CronosNetwork.CronosTestnet, // or CronosMainnet });`

`2. Generate Payment Requirements`

`ts const requirements = facilitator.generatePaymentRequirements({ payTo: '0xRecipientAddress', description: 'Payment for Order #123', maxAmountRequired: '1000000', // base units });

console.log(requirements);`

`3. Generate a Base64 Payment Header (EIP-3009)`

`ts import { ethers } from 'ethers';

const signer = new ethers.Wallet(process.env.PRIVATE_KEY!, new ethers.JsonRpcProvider('https://evm-t3.cronos.org'));

const header = await facilitator.generatePaymentHeader({ to: '0xRecipientAddress', value: '1000000', // 1 USDCe (6 decimals) signer, validBefore: Math.floor(Date.now() / 1000) + 600, // 10 min expiry });

console.log('header:', header);`

`4. Verify a Payment Request`

`ts const body = facilitator.buildVerifyRequest(header, requirements);

const verifyResponse = await facilitator.verifyPayment(body); console.log('verify:', verifyResponse);`

`5. Settle a Verified Payment`

`ts const settleResponse = await facilitator.settlePayment(body); console.log('settled:', settleResponse);`

`6. Discover Supported Networks & Schemes`

`ts const capabilities = await facilitator.getSupported(); console.log(capabilities);`

`End-to-End Example (Full Flow)`

`ts const facilitator = new Facilitator({ network: CronosNetwork.CronosTestnet });

const signer = new ethers.Wallet(PRIVATE_KEY, new ethers.JsonRpcProvider('https://evm-t3.cronos.org'));

const header = await facilitator.generatePaymentHeader({ to: RECEIVER, value: '1000000', signer, });

const requirements = facilitator.generatePaymentRequirements({ payTo: RECEIVER, description: 'Premium API access', maxAmountRequired: '1000000', });

const body = facilitator.buildVerifyRequest(header, requirements);

const verify = await facilitator.verifyPayment(body);

if (verify.isValid) { const settle = await facilitator.settlePayment(body); console.log('Transaction:', settle.txHash); }`

`API Overview`

`$3`

| Method | Description | | ------------------------------------------ | ----------------------------------------------------- | |getSupported()| Returns supported networks, schemes, and capabilities | |verifyPayment(request)| Validates the Base64 header + requirements | |settlePayment(request)| Executes the authorized transfer on-chain | |buildVerifyRequest(header, requirements) | Helper to produce valid X402 bodies |