#!/usr/bin/env python3
# Use ScanPay as an OpenAI-compatible, pay-per-call LLM gateway (x402, no API key).
# pip install requests eth-account x402
import base64, json, os, requests
from eth_account import Account
from x402.http.x402_http_client_base import encode_payment_signature_header
from x402.mechanisms.evm.exact.client import ExactEvmScheme
from x402.schemas import PaymentPayload, PaymentRequirements

BASE = "{base}"
URL = BASE + "/v1/chat/completions"
acct = Account.from_key(os.environ["PRIVATE_KEY"])  # any funded Base wallet

body = {{"model": "deepseek-chat", "messages": [{{"role": "user", "content": "Say OK"}}], "max_tokens": 16}}
r = requests.post(URL, json=body, timeout=60)
if r.status_code == 402:
    quote = json.loads(base64.b64decode(r.headers["PAYMENT-REQUIRED"]))
    accept = next(a for a in quote["accepts"] if a["network"] == "eip155:8453")
    req = PaymentRequirements(scheme=accept["scheme"], network=accept["network"], asset=accept["asset"],
                              amount=accept["amount"], pay_to=accept["payTo"],
                              max_timeout_seconds=accept.get("maxTimeoutSeconds", 300),
                              extra=accept.get("extra"))
    inner = ExactEvmScheme(acct).create_payment_payload(req)
    payload = PaymentPayload(x402_version=2, payload=inner, accepted=req)
    r = requests.post(URL, json=body, headers={{"PAYMENT-SIGNATURE": encode_payment_signature_header(payload)}}, timeout=60)

print(r.status_code, r.json())
print("delivery receipt:", r.headers.get("X-Delivery-Receipt"))