How to use the CCXT library: connect, fetch and trade
CCXT is the library that makes building a crypto trading bot realistic for a solo developer. Instead of learning the quirks of every exchange’s REST API, you learn one unified interface that speaks to 100+ exchanges with the same method names: fetch candles, read your balance, place an order. Swap Binance for Bybit by changing a single line. This guide walks through installing ccxt, connecting safely, fetching market data, checking balances and placing your first order — all with copy-ready Python.
What ccxt is
CCXT (CryptoCurrency eXchange Trading) is an open-source library, available in Python, JavaScript and PHP, that normalises the APIs of 100+ exchanges behind one consistent interface. It is the backbone of most retail crypto bots, including the examples throughout this site and the crypto bot guide. Learn it once and every major exchange is available with the same code.
Install and connect
bashpip install ccxt
python · connect.pyimport ccxt
ex = ccxt.binance({
'apiKey': KEY,
'secret': SECRET,
'enableRateLimit': True, # ccxt throttles for you — keep this on
})
ex.load_markets()
print(ex.id, len(ex.markets), 'markets')
To switch exchanges, change ccxt.binance to ccxt.bybit or ccxt.kraken — the rest of your code is unchanged. That portability is the whole point.
Fetch market data
python · fetch.pyimport pandas as pd
ohlcv = ex.fetch_ohlcv('BTC/USDT', '1h', limit=200)
df = pd.DataFrame(ohlcv, columns=['ts','open','high','low','close','volume'])
df['ts'] = pd.to_datetime(df['ts'], unit='ms')
ticker = ex.fetch_ticker('BTC/USDT')
print('last price', ticker['last'])
This OHLCV frame is exactly the input your algorithm needs and what you feed into a backtest data pipeline.
Read your balance
python · balance.pybal = ex.fetch_balance()
print('USDT free:', bal['USDT']['free'])
print('BTC total:', bal['BTC']['total'])
Place an order
python · order.py# market buy a tiny test size
ex.create_market_buy_order('BTC/USDT', 0.0001)
# or a limit order with a price
ex.create_limit_sell_order('BTC/USDT', 0.0001, 75000)
Pick the right order type for the job — market for certainty of fill, limit for certainty of price.
Using ccxt safely
Exchanges throttle, time out and reject orders. Keep enableRateLimit on, wrap calls in try/except for ccxt.NetworkError and ccxt.ExchangeError (see error handling), and never enable withdrawal permission on the key — only trade and read, as in API key security. Test on the testnet or with 0.0001-size orders before scaling.
Frequently asked questions
What is the ccxt library?
CCXT (CryptoCurrency eXchange Trading) is an open-source library for Python, JavaScript and PHP that normalises the APIs of more than 100 crypto exchanges behind one consistent interface. Instead of learning each exchange’s individual REST API, you use the same method names — fetch_ohlcv, fetch_balance, create_order — and can switch exchanges by changing a single line.
How do I fetch price data with ccxt?
Call fetch_ohlcv with a symbol, timeframe and limit, for example ex.fetch_ohlcv("BTC/USDT", "1h", limit=200), which returns a list of timestamp, open, high, low, close and volume rows. Load it into a pandas DataFrame and you have exactly the input a trading algorithm needs. Use fetch_ticker for the latest price.
How do I place an order with ccxt?
Use the order helpers: create_market_buy_order(symbol, amount) for an immediate market buy, or create_limit_sell_order(symbol, amount, price) for a limit order at a set price. Always start with the smallest size the exchange allows (often 0.0001) and pick market for certainty of fill or limit for certainty of price.
Is ccxt safe to use for live trading?
It is safe if you use it carefully. Keep enableRateLimit on so ccxt throttles requests, wrap every call in try/except for NetworkError and ExchangeError, and use an API key scoped to trade and read only — never enable withdrawals. Test on the exchange testnet or with tiny order sizes before running real capital.