Cronos X402 Facilitator SDK for Python

The Cronos Facilitator Python SDK provides a lightweight, strongly typed client for interacting with the Cronos X402 Facilitator API.

It enables Python applications to:

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

This SDK supports fully automated off-chain authorization / on-chain execution payment flows on Cronos Mainnet and Cronos Testnet.

Features

• Facilitator API Client

  • /supported
  • /verify
  • /settle

• EIP-3009 Payment Header Generator

  • Produces Base64-encoded X402 headers

• Typed X402 Payment Requirements

  • JSON-serializable and schema-aware

• Minimal dependencies

  • Uses requests and eth-account only when required

• Cronos-native

  • Supports Cronos Mainnet and Cronos Testnet

Installation

pip install crypto_com_facilitator_client

Note EIP-3009 signing requires optional dependencies:

pip install eth-account hexbytes

Usage

1. Create a Facilitator Client

The Facilitator base URL is fixed internally and cannot be overridden.

from crypto_com_facilitator_client import Facilitator
from crypto_com_facilitator_client.integrations.facilitator_interface import CronosNetwork

facilitator = Facilitator(
    network=CronosNetwork.CronosTestnet  # or CronosMainnet
)

2. Generate Payment Requirements

requirements = facilitator.generate_payment_requirements(
    pay_to="0xRecipientAddress",
    description="Payment for Order #123",
    max_amount_required="1000000",  # base units
)

print(requirements)

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

import os
from eth_account import Account

signer = Account.from_key(os.environ["PRIVATE_KEY"])

header = await facilitator.generate_payment_header(
    to="0xRecipientAddress",
    value="1000000",  # 1 USDCe (6 decimals)
    signer=signer,
    valid_before=int(time.time()) + 600,  # 10 min expiry
)

print("header:", header)

4. Verify a Payment Request

body = facilitator.build_verify_request(header, requirements)

verify_response = await facilitator.verify_payment(body)
print("verify:", verify_response)

5. Settle a Verified Payment

settle_response = await facilitator.settle_payment(body)
print("settled:", settle_response)

6. Discover Supported Networks & Capabilities

capabilities = await facilitator.get_supported()
print(capabilities)

End-to-End Example (Full Flow)

from crypto_com_facilitator_client import Facilitator
from crypto_com_facilitator_client.integrations.facilitator_interface import CronosNetwork
from eth_account import Account
import os
import time

facilitator = Facilitator(network=CronosNetwork.CronosTestnet)

signer = Account.from_key(os.environ["PRIVATE_KEY"])
receiver = "0xRecipientAddress"

header = await facilitator.generate_payment_header(
    to=receiver,
    value="1000000",
    signer=signer,
)

requirements = facilitator.generate_payment_requirements(
    pay_to=receiver,
    description="Premium API access",
    max_amount_required="1000000",
)

body = facilitator.build_verify_request(header, requirements)

verify = await facilitator.verify_payment(body)

if verify.get("isValid"):
    settle = await facilitator.settle_payment(body)
    print("Transaction hash:", settle.get("txHash"))

API Overview

Facilitator Client

Utilities

Supported Networks

• Cronos Mainnet
• Cronos Testnet

License

MIT © 2025 Crypto.com