limit_order.py

import os
import asyncio
from eth_account import Account
from eth_account.messages import encode_defunct
import httpx
from dotenv import load_dotenv
from predict_sdk import (
    OrderBuilder,
    ChainId,
    Side,
    MarketHelperInput,
    MarketHelperValueInput,
    LimitHelperInput,
    BuildOrderInput
)


def approve():
    # Load environment variables
    load_dotenv()

    # Create a wallet to sign the message (must be the orders' `maker`)
    private_key = os.getenv("WALLET_PRIVATE_KEY")
    signer = Account.from_key(private_key)

    builder = OrderBuilder.make(ChainId.BNB_MAINNET, signer)

    # Calculate order amounts for a LIMIT order
    amounts = builder.get_limit_order_amounts(
        LimitHelperInput(
            side=Side.BUY,
            price_per_share_wei=10000000000000000,  # 0.01 USDT per share
            quantity_wei=100000000000000000000,  # 100 shares
        )
    )

    print(f"Maker Amount: {amounts.maker_amount}")  # 1 USDT # 买方需要支付的USDT in wei
    print(f"Taker Amount: {amounts.taker_amount}") # 买方将获得的份额 in wei
    print(f"Last Price: {amounts.last_price}")  # 0.01 USDT
    print(f"Price Per Share: {amounts.price_per_share}")  # 0.01 USDT
    # - maker_amount: 买方需要支付的USDT（wei）
    # - taker_amount: 买方将获得的份额（wei）
    # - price_per_share: 加权平均价格
    # - last_price: 最后一笔成交的价格

    # Build an order
    order = builder.build_order(
        "LIMIT",
        BuildOrderInput(
            side=Side.BUY,
            # Get from GET /markets endpoint
            token_id="51923869364888026720633707255758662304830403989354809616621058202583057583874",
            maker_amount=str(amounts.maker_amount),
            taker_amount=str(amounts.taker_amount),
            fee_rate_bps=200,  # Get from GET /markets endpoint
        ),
    )

    # Now you can sign orders and interact with contracts
    typed_data = builder.build_typed_data(
        order,
        is_neg_risk=False,  # Get from GET /markets endpoint
        is_yield_bearing=False,  # Get from GET /markets endpoint
    )

    signed_order = builder.sign_typed_data_order(typed_data) # w3w is responsible for this

    # Print all signed_order fields
    print("\n=== Signed Order Fields ===")
    print(f"salt: {signed_order.salt}")
    print(f"maker: {signed_order.maker}")
    print(f"signer: {signed_order.signer}")
    print(f"taker: {signed_order.taker}")
    print(f"token_id: {signed_order.token_id}")
    print(f"maker_amount: {signed_order.maker_amount}")
    print(f"taker_amount: {signed_order.taker_amount}")
    print(f"expiration: {signed_order.expiration}")
    print(f"nonce: {signed_order.nonce}")
    print(f"fee_rate_bps: {signed_order.fee_rate_bps}")
    print(f"side: {signed_order.side}")
    print(f"signature_type: {signed_order.signature_type}")
    print(f"signature: {signed_order.signature}")
    print(f"hash: {signed_order.hash}")


if __name__ == '__main__':
    approve()