Building an Arbitrage Bot Using Mila-ex in 10 Minutes

What Is Crypto Arbitrage?

Crypto arbitrage involves exploiting small price differences for the same asset across multiple exchanges. You buy low on one exchange, sell high on another, and capture profit from the spread. Traditionally, this process required multiple API integrations, inconsistent response structures, and constant maintenance. Mila-ex changes that completely.

Why Use Mila-ex?

Mila-ex provides a unified cryptocurrency market data API that aggregates data from multiple exchanges into one consistent RESTful interface. You get standardized tickers, OHLCV data, and order books—all using the same request and response structure. That means no more juggling multiple API keys, endpoints, or response formats.

Benefits of Using Mila-ex for Arbitrage

Single Unified API: Fetch market data from 10+ exchanges with one endpoint.
Consistent JSON Format: No more custom parsing for each exchange.
Fast & Reliable: Aggregated endpoints optimized for low-latency trading bots.
Free Tier Available: Get started instantly with your API key.

Prerequisites

Basic knowledge of Python (or JavaScript)
A free Mila-ex account
Your API key from the Mila-ex dashboard

Step 1: Set Up Your Environment

Install the required dependency using pip:

pip install requests

Step 2: Fetch Market Data from Multiple Exchanges

Here’s a complete Python example showing how to use the Mila-ex unified API to fetch BTC prices across multiple exchanges and detect arbitrage opportunities.

import requests
import time

# Mila-ex API config
API_KEY = "your_api_key_here"
BASE_URL = "https://api.milaex.com/api/v1/exchange"

# Exchanges that support FetchTicker and BTC trading
EXCHANGES = [
    {"key": "binance", "base": "BTC", "quote": "USDT"},
    {"key": "bitfinex", "base": "BTC", "quote": "USD"},
    {"key": "valr", "base": "BTC", "quote": "USDT"},
    {"key": "bitstamp", "base": "BTC", "quote": "USDT"},
    {"key": "coinbase", "base": "BTC", "quote": "USDT"},
    {"key": "coinex", "base": "BTC", "quote": "USDT"},
    {"key": "cryptocom", "base": "BTC", "quote": "USDT"},
    {"key": "gateio", "base": "BTC", "quote": "USDT"},
    {"key": "luno", "base": "BTC", "quote": "USDC"},
    {"key": "poloniex", "base": "BTC", "quote": "USDT"},
]

ARBITRAGE_THRESHOLD = 0.5 # Minimum profit % to flag an opportunity

# Fetch ticker price from a specific exchange
def get_price(exchange_key, base, quote):
    try:
        url = f"{BASE_URL}/ticker"
        headers = {"x-api-key": API_KEY}
        params = {"exchange": exchange_key, "base_name": base, "quote_name": quote}
        response = requests.get(url, headers=headers, params=params)
        response.raise_for_status()
        data = response.json()
        return float(data["Data"]["lastPrice"])
    except Exception as e:
        print(f"[ERROR] {exchange_key}: {e}")
        return None

# Compare prices and detect arbitrage opportunities
def check_arbitrage(prices):
    opportunities = []
    for buy in prices:
        for sell in prices:
            if buy["key"] == sell["key"] or buy["price"] is None or sell["price"] is None:
                continue

            diff = ((sell["price"] \- buy["price"]) / buy["price"]) * 100
            if diff \>= ARBITRAGE_THRESHOLD:
                opportunities.append({
                    "buy_from": buy["key"],
                    "sell_to": sell["key"],
                    "buy_price": buy["price"],
                    "sell_price": sell["price"],
                    "profit_percent": round(diff, 2)
                })
    return opportunities

# Main bot loop
def run_bot():
    while True:
        print("🔍 Checking BTC prices...")
        prices = []

        for ex in EXCHANGES:
            price = get_price(ex["key"], ex["base"], ex["quote"])
            prices.append({"key": ex["key"], "price": price})
            print(f"{ex['key']}: {price} {ex['quote']}")

        print("\n💡 Arbitrage Opportunities:")
        opps = check_arbitrage(prices)

        if opps:
            for opp in opps:
                print(f"💰 Buy from {opp['buy_from']} at {opp['buy_price']}, "
                      f"sell to {opp['sell_to']} at {opp['sell_price']} → "
                      f"Profit: {opp['profit_percent']}%")
        else:
            print("No arbitrage opportunities found.")

        print("\n⏳ Waiting 15 seconds...\n")
        time.sleep(15)

if __name__ == "__main__":
    run_bot()

Step 3: View the Full API Reference

You can find detailed endpoint documentation (including OHLCV, tickers, and order books) in the official Mila-ex API Docs.

Step 4: Explore More Examples

Check out more ready-to-run examples and helper scripts in the open-source Mila-ex Arbitrage Bot repository on GitHub.

Step 5: Factor in Real-World Conditions

Before going live, always consider:

Exchange trading fees (typically 0.1–0.25%)
Withdrawal and deposit times
Network transaction fees
Slippage on high-volume trades

Advanced Enhancements

Add order book depth analysis to improve accuracy
Integrate automatic trade execution via exchange APIs
Implement risk management and position sizing
Use historical data for backtesting strategies

Conclusion

In less than 10 minutes, you’ve built a fully functional crypto arbitrage monitor powered by the Mila-ex Unified API. With one consistent schema across all supported exchanges, scaling from one pair to hundreds becomes effortless. Start experimenting today with your free account at dashboard.milaex.com.