Place your own limit orders on Coinbase without paying extra fees

coinbase_autotrade.py

# I use this script to place my own limit orders (to purchase) crypto on Coinbase
# This saves me the extra fees that Coinbase charges for limit orders
# Using Coinbase's API also incurs less fees even on normal purchases

import time
from coinbase.rest import RESTClient
from json import dumps
import questionary
from datetime import datetime
import os

# Go to https://www.coinbase.com/settings/api to generate your API key and secret
api_key = os.getenv('COINBASE_API_KEY')
api_secret = os.getenv('COINBASE_API_SECRET')
if not api_key or not api_secret:
    raise ValueError("Coinbase API key and secret must be set in environment variables, as variables COINBASE_API_KEY and COINBASE_API_SECRET respectively.")

client = RESTClient(api_key=api_key, api_secret=api_secret)

def preview_order(product_id, quote_size):
    """
    Preview the order and show estimated fees and details.
    """
    try:
        preview = client.preview_market_order_buy(
            product_id=product_id,
            quote_size=quote_size
        )
        print("============ Order Preview ============")
        print("Here is the Order Preview if it were placed at the current price")
        print("This should give you an idea of the fees")
        print("=======================================")
        print(preview)
        return preview
    except Exception as e:
        print(f"Error during order preview: {e}")
        return None

def place_order(product_id, quote_size):
    """
    Place the market order.
    """
    try:
        order = client.market_order_buy(
            client_order_id="auto-order-001",
            product_id=product_id,
            quote_size=quote_size
        )
        if order['success']:
            print("Order placed successfully!")
            print("Order Details:")
            print(dumps(order['success_response'], indent=2))
            return True
        else:
            print("Failed to place order.")
            print("Error Response:")
            print(dumps(order['error_response'], indent=2))
            return False
    except Exception as e:
        print(f"Error during order placement: {e}")
        return False

def monitor_and_buy(product_id, target_price, quote_size):
    """
    Monitor the price and buy the cryptocurrency when it hits the target price.
    """
    print(f"Monitoring {product_id} for target price: ${target_price}")
    while True:
        try:
            product = client.get_product(product_id)
            current_price = float(product["price"])
            print(f"{datetime.now().strftime('%Y-%m-%d %H:%M:%S')} - Current price of {product_id}: ${current_price}; while the target price is ${target_price}.")

            
            if current_price <= target_price:
                print(f"Target price hit! Current price: ${current_price}. Placing order...")
                if place_order(product_id, quote_size):
                    print("Order fulfilled. Exiting monitor.")
                    break
            time.sleep(10)  # Poll every 10 seconds
        except Exception as e:
            print(f"Error during price monitoring: {e}")
            time.sleep(10)

if __name__ == "__main__":
    # Configuration
    product_ids = ["SOL-USD", "BTC-USD", "ETH-USD", "XRP-USD", "AVAX-USD", "ATOM-USD", "DOGE-USD"]
    product_id = questionary.select(
        "Select a product to monitor:",
        choices=product_ids,
    ).ask()
    print(f"Selected product: {product_id}")

    # First show the current price of the asset
    product = client.get_product(product_id)
    current_price = float(product["price"])
    print(f"Current price of {product_id}: ${current_price}")

    target_price = float(questionary.text("Enter the target price in USD: ").ask())
    quote_size = questionary.text("Enter the amount in USD to spend: ").ask()
    print(f"Target price: ${target_price}")
    print(f"Quote size: ${quote_size}")

    # Step 1: Preview the order
    preview = preview_order(product_id, quote_size)
    if not preview:
        print("Preview failed. Exiting.")
        exit(1)
    
    # Step 2: Ask for user confirmation
    confirm = questionary.confirm("Do you want to proceed with the auto-buy process?").ask()
    if not confirm:
        print("Exiting without starting the auto-buy process.")
        exit(0)

    # Step 3: Verify that the target price is less than the current price
    if target_price >= current_price:
        print("\033[31;47m Target price is not less than the current price. Exiting. \033[0m")  # red on white background
        exit(1)

    # Step 4: Start monitoring and buying
    monitor_and_buy(product_id, target_price, quote_size)