Construct and sign Quantum transactions from Python.

mkdir quantum-python-demo
cd quantum-python-demo
python3 -m venv .venv
. .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install \
  --index-url "https://SDK_USERNAME:SDK_TOKEN@sdk.quantumapi.io/simple/" \
  py-quantum==0.3.0

mkdir quantum-python-demo
cd quantum-python-demo
py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip
python -m pip install `
  --index-url "https://SDK_USERNAME:SDK_TOKEN@sdk.quantumapi.io/simple/" `
  py-quantum==0.3.0

import json
import time
from urllib.request import Request, urlopen

from py_quantum import (
    LegacyTransactionRequest,
    Signer,
    build_and_sign_transaction,
    parse_quantum,
)

RPC = "https://rpc.sandbox.qustody.io"
FAUCET = "https://faucet.sandbox.qustody.io/fund"
CHAIN_ID = 20804
GENESIS = "0x3d9c6813ee3edd227abb5345aff55d6e2e76bc9db3a031d92d0e2bd54c8997e7"


def post_json(url, payload):
    request = Request(
        url,
        data=json.dumps(payload).encode("utf-8"),
        headers={"content-type": "application/json"},
        method="POST",
    )
    with urlopen(request, timeout=30) as response:
        return json.loads(response.read())


def rpc(method, params):
    response = post_json(RPC, {
        "jsonrpc": "2.0", "id": 1, "method": method, "params": params,
    })
    if "error" in response:
        raise RuntimeError(f"{method} failed: {response['error']}")
    return response["result"]


with Signer.generate() as sender, Signer.generate() as recipient:
    chain_id = int(rpc("qc_chainId", []), 16)
    genesis = rpc("qc_getBlockByNumber", ["0x0", False])["hash"].lower()
    if chain_id != CHAIN_ID or genesis != GENESIS:
        raise RuntimeError("refusing to sign for an unexpected network")

    funding = post_json(FAUCET, {"address": sender.address_hex})
    print("sender", sender.address_hex)
    print("faucet", funding)

    deadline = time.monotonic() + 120
    while int(rpc("qc_getBalance", [sender.address_hex, "latest"]), 16) == 0:
        if time.monotonic() > deadline:
            raise TimeoutError("faucet balance did not arrive")
        time.sleep(1)

    value = parse_quantum("0.01")
    call = {
        "from": sender.address_hex,
        "to": recipient.address_hex,
        "value": hex(value),
        "data": "0x",
    }
    nonce = int(rpc("qc_getTransactionCount", [sender.address_hex, "pending"]), 16)
    gas_limit = int(rpc("qc_estimateGas", [call]), 16)
    gas_price = int(rpc("qc_gasPrice", []), 16)

    result = build_and_sign_transaction(
        LegacyTransactionRequest(
            chain_id=CHAIN_ID,
            nonce=nonce,
            gas_limit=gas_limit,
            gas_price=gas_price,
            to=recipient.address_hex,
            value=value,
        ),
        sender,
    )

    node_hash = rpc("qc_sendRawTransaction", [result.raw_transaction]).lower()
    if node_hash != result.transaction_hash.lower():
        raise RuntimeError("node returned a different transaction hash")

    deadline = time.monotonic() + 120
    receipt = None
    while receipt is None:
        receipt = rpc("qc_getTransactionReceipt", [result.transaction_hash])
        if receipt is None and time.monotonic() > deadline:
            raise TimeoutError("transaction receipt did not arrive")
        if receipt is None:
            time.sleep(1)

    if int(receipt["status"], 16) != 1:
        raise RuntimeError("transaction execution failed")

    print("transaction", result.transaction_hash)
    print("block", int(receipt["blockNumber"], 16))
    print("status", int(receipt["status"], 16))
    print("explorer", f"https://explorer.sandbox.qustody.io/tx/{result.transaction_hash}")

from py_quantum import Signer, verify_digest

digest = bytes.fromhex(
    "5b336411c12d54f162ef83653f01897ffb8b0987c666d34bed2920641832a4ef"
)

with Signer.generate() as signer:
    signature = signer.sign_digest(digest)
    assert verify_digest(signer.public_key, digest, signature)
    print(signer.address_hex)