CCXT for Python
A comprehensive guide to using CCXT in Python projects for cryptocurrency exchange integration.
Installation
REST API (Standard)
pip install ccxt
WebSocket API (Real-time, ccxt.pro)
pip install ccxt
Optional Performance Enhancements
pip install orjson # Faster JSON parsing pip install coincurve # Faster ECDSA signing (45ms → 0.05ms)
Both REST and WebSocket APIs are included in the same package.
Quick Start
REST API - Synchronous
import ccxt
exchange = ccxt.binance()
exchange.load_markets()
ticker = exchange.fetch_ticker('BTC/USDT')
print(ticker)
REST API - Asynchronous
import asyncio
import ccxt.async_support as ccxt
async def main():
exchange = ccxt.binance()
await exchange.load_markets()
ticker = await exchange.fetch_ticker('BTC/USDT')
print(ticker)
await exchange.close() # Important!
asyncio.run(main())
WebSocket API - Real-time Updates
import asyncio
import ccxt.pro as ccxtpro
async def main():
exchange = ccxtpro.binance()
while True:
ticker = await exchange.watch_ticker('BTC/USDT')
print(ticker) # Live updates!
await exchange.close()
asyncio.run(main())
REST vs WebSocket
| Import | For REST | For WebSocket |
|---|---|---|
| Sync | import ccxt | (WebSocket requires async) |
| Async | import ccxt.async_support as ccxt | import ccxt.pro as ccxtpro |
| Feature | REST API | WebSocket API |
|---|---|---|
| Use for | One-time queries, placing orders | Real-time monitoring, live price feeds |
| Method prefix | fetch_* (fetch_ticker, fetch_order_book) | watch_* (watch_ticker, watch_order_book) |
| Speed | Slower (HTTP request/response) | Faster (persistent connection) |
| Rate limits | Strict (1-2 req/sec) | More lenient (continuous stream) |
| Best for | Trading, account management | Price monitoring, arbitrage detection |
When to use REST:
- •Placing orders
- •Fetching account balance
- •One-time data queries
- •Order management (cancel, fetch orders)
When to use WebSocket:
- •Real-time price monitoring
- •Live orderbook updates
- •Arbitrage detection
- •Portfolio tracking with live updates
Creating Exchange Instance
REST API - Synchronous
import ccxt
# Public API (no authentication)
exchange = ccxt.binance({
'enableRateLimit': True # Recommended!
})
# Private API (with authentication)
exchange = ccxt.binance({
'apiKey': 'YOUR_API_KEY',
'secret': 'YOUR_SECRET',
'enableRateLimit': True
})
REST API - Asynchronous
import ccxt.async_support as ccxt
exchange = ccxt.binance({
'apiKey': 'YOUR_API_KEY',
'secret': 'YOUR_SECRET',
'enableRateLimit': True
})
# Always close when done
await exchange.close()
WebSocket API
import ccxt.pro as ccxtpro
# Public WebSocket
exchange = ccxtpro.binance()
# Private WebSocket (with authentication)
exchange = ccxtpro.binance({
'apiKey': 'YOUR_API_KEY',
'secret': 'YOUR_SECRET'
})
# Always close when done
await exchange.close()
Common REST Operations
Loading Markets
# Load all available trading pairs
exchange.load_markets()
# Access market information
btc_market = exchange.market('BTC/USDT')
print(btc_market['limits']['amount']['min']) # Minimum order amount
Fetching Ticker
# Single ticker
ticker = exchange.fetch_ticker('BTC/USDT')
print(ticker['last']) # Last price
print(ticker['bid']) # Best bid
print(ticker['ask']) # Best ask
print(ticker['volume']) # 24h volume
# Multiple tickers (if supported)
tickers = exchange.fetch_tickers(['BTC/USDT', 'ETH/USDT'])
Fetching Order Book
# Full orderbook
orderbook = exchange.fetch_order_book('BTC/USDT')
print(orderbook['bids'][0]) # [price, amount]
print(orderbook['asks'][0]) # [price, amount]
# Limited depth
orderbook = exchange.fetch_order_book('BTC/USDT', 5) # Top 5 levels
Creating Orders
Limit Order
# Buy limit order
order = exchange.create_limit_buy_order('BTC/USDT', 0.01, 50000)
print(order['id'])
# Sell limit order
order = exchange.create_limit_sell_order('BTC/USDT', 0.01, 60000)
# Generic limit order
order = exchange.create_order('BTC/USDT', 'limit', 'buy', 0.01, 50000)
Market Order
# Buy market order
order = exchange.create_market_buy_order('BTC/USDT', 0.01)
# Sell market order
order = exchange.create_market_sell_order('BTC/USDT', 0.01)
# Generic market order
order = exchange.create_order('BTC/USDT', 'market', 'sell', 0.01)
Fetching Balance
balance = exchange.fetch_balance() print(balance['BTC']['free']) # Available balance print(balance['BTC']['used']) # Balance in orders print(balance['BTC']['total']) # Total balance
Fetching Orders
# Open orders
open_orders = exchange.fetch_open_orders('BTC/USDT')
# Closed orders
closed_orders = exchange.fetch_closed_orders('BTC/USDT')
# All orders (open + closed)
all_orders = exchange.fetch_orders('BTC/USDT')
# Single order by ID
order = exchange.fetch_order(order_id, 'BTC/USDT')
Fetching Trades
# Recent public trades
trades = exchange.fetch_trades('BTC/USDT', limit=10)
# Your trades (requires authentication)
my_trades = exchange.fetch_my_trades('BTC/USDT')
Canceling Orders
# Cancel single order
exchange.cancel_order(order_id, 'BTC/USDT')
# Cancel all orders for a symbol
exchange.cancel_all_orders('BTC/USDT')
WebSocket Operations (Real-time)
Watching Ticker (Live Price Updates)
import asyncio
import ccxt.pro as ccxtpro
async def main():
exchange = ccxtpro.binance()
while True:
ticker = await exchange.watch_ticker('BTC/USDT')
print(ticker['last'], ticker['timestamp'])
await exchange.close()
asyncio.run(main())
Watching Order Book (Live Depth Updates)
async def main():
exchange = ccxtpro.binance()
while True:
orderbook = await exchange.watch_order_book('BTC/USDT')
print('Best bid:', orderbook['bids'][0])
print('Best ask:', orderbook['asks'][0])
await exchange.close()
asyncio.run(main())
Watching Trades (Live Trade Stream)
async def main():
exchange = ccxtpro.binance()
while True:
trades = await exchange.watch_trades('BTC/USDT')
for trade in trades:
print(trade['price'], trade['amount'], trade['side'])
await exchange.close()
asyncio.run(main())
Watching Your Orders (Live Order Updates)
async def main():
exchange = ccxtpro.binance({
'apiKey': 'YOUR_API_KEY',
'secret': 'YOUR_SECRET'
})
while True:
orders = await exchange.watch_orders('BTC/USDT')
for order in orders:
print(order['id'], order['status'], order['filled'])
await exchange.close()
asyncio.run(main())
Watching Balance (Live Balance Updates)
async def main():
exchange = ccxtpro.binance({
'apiKey': 'YOUR_API_KEY',
'secret': 'YOUR_SECRET'
})
while True:
balance = await exchange.watch_balance()
print('BTC:', balance['BTC'])
print('USDT:', balance['USDT'])
await exchange.close()
asyncio.run(main())
Watching Multiple Symbols
async def main():
exchange = ccxtpro.binance()
symbols = ['BTC/USDT', 'ETH/USDT', 'SOL/USDT']
while True:
# Watch all symbols concurrently
tickers = await exchange.watch_tickers(symbols)
for symbol, ticker in tickers.items():
print(symbol, ticker['last'])
await exchange.close()
asyncio.run(main())
Complete Method Reference
Market Data Methods
Tickers & Prices
- •
fetchTicker(symbol)- Fetch ticker for one symbol - •
fetchTickers([symbols])- Fetch multiple tickers at once - •
fetchBidsAsks([symbols])- Fetch best bid/ask for multiple symbols - •
fetchLastPrices([symbols])- Fetch last prices - •
fetchMarkPrices([symbols])- Fetch mark prices (derivatives)
Order Books
- •
fetchOrderBook(symbol, limit)- Fetch order book - •
fetchOrderBooks([symbols])- Fetch multiple order books - •
fetchL2OrderBook(symbol)- Fetch level 2 order book - •
fetchL3OrderBook(symbol)- Fetch level 3 order book (if supported)
Trades
- •
fetchTrades(symbol, since, limit)- Fetch public trades - •
fetchMyTrades(symbol, since, limit)- Fetch your trades (auth required) - •
fetchOrderTrades(orderId, symbol)- Fetch trades for specific order
OHLCV (Candlesticks)
- •
fetchOHLCV(symbol, timeframe, since, limit)- Fetch candlestick data - •
fetchIndexOHLCV(symbol, timeframe)- Fetch index price OHLCV - •
fetchMarkOHLCV(symbol, timeframe)- Fetch mark price OHLCV - •
fetchPremiumIndexOHLCV(symbol, timeframe)- Fetch premium index OHLCV
Account & Balance
- •
fetchBalance()- Fetch account balance (auth required) - •
fetchAccounts()- Fetch sub-accounts - •
fetchLedger(code, since, limit)- Fetch ledger history - •
fetchLedgerEntry(id, code)- Fetch specific ledger entry - •
fetchTransactions(code, since, limit)- Fetch transactions - •
fetchDeposits(code, since, limit)- Fetch deposit history - •
fetchWithdrawals(code, since, limit)- Fetch withdrawal history - •
fetchDepositsWithdrawals(code, since, limit)- Fetch both deposits and withdrawals
Trading Methods
Creating Orders
- •
createOrder(symbol, type, side, amount, price, params)- Create order (generic) - •
createLimitOrder(symbol, side, amount, price)- Create limit order - •
createMarketOrder(symbol, side, amount)- Create market order - •
createLimitBuyOrder(symbol, amount, price)- Buy limit order - •
createLimitSellOrder(symbol, amount, price)- Sell limit order - •
createMarketBuyOrder(symbol, amount)- Buy market order - •
createMarketSellOrder(symbol, amount)- Sell market order - •
createMarketBuyOrderWithCost(symbol, cost)- Buy with specific cost - •
createStopLimitOrder(symbol, side, amount, price, stopPrice)- Stop-limit order - •
createStopMarketOrder(symbol, side, amount, stopPrice)- Stop-market order - •
createStopLossOrder(symbol, side, amount, stopPrice)- Stop-loss order - •
createTakeProfitOrder(symbol, side, amount, takeProfitPrice)- Take-profit order - •
createTrailingAmountOrder(symbol, side, amount, trailingAmount)- Trailing stop - •
createTrailingPercentOrder(symbol, side, amount, trailingPercent)- Trailing stop % - •
createTriggerOrder(symbol, side, amount, triggerPrice)- Trigger order - •
createPostOnlyOrder(symbol, side, amount, price)- Post-only order - •
createReduceOnlyOrder(symbol, side, amount, price)- Reduce-only order - •
createOrders([orders])- Create multiple orders at once - •
createOrderWithTakeProfitAndStopLoss(symbol, type, side, amount, price, tpPrice, slPrice)- OCO order
Managing Orders
- •
fetchOrder(orderId, symbol)- Fetch single order - •
fetchOrders(symbol, since, limit)- Fetch all orders - •
fetchOpenOrders(symbol, since, limit)- Fetch open orders - •
fetchClosedOrders(symbol, since, limit)- Fetch closed orders - •
fetchCanceledOrders(symbol, since, limit)- Fetch canceled orders - •
fetchOpenOrder(orderId, symbol)- Fetch specific open order - •
fetchOrdersByStatus(status, symbol)- Fetch orders by status - •
cancelOrder(orderId, symbol)- Cancel single order - •
cancelOrders([orderIds], symbol)- Cancel multiple orders - •
cancelAllOrders(symbol)- Cancel all orders for symbol - •
editOrder(orderId, symbol, type, side, amount, price)- Modify order
Margin & Leverage
- •
fetchBorrowRate(code)- Fetch borrow rate for margin - •
fetchBorrowRates([codes])- Fetch multiple borrow rates - •
fetchBorrowRateHistory(code, since, limit)- Historical borrow rates - •
fetchCrossBorrowRate(code)- Cross margin borrow rate - •
fetchIsolatedBorrowRate(symbol, code)- Isolated margin borrow rate - •
borrowMargin(code, amount, symbol)- Borrow margin - •
repayMargin(code, amount, symbol)- Repay margin - •
fetchLeverage(symbol)- Fetch leverage - •
setLeverage(leverage, symbol)- Set leverage - •
fetchLeverageTiers(symbols)- Fetch leverage tiers - •
fetchMarketLeverageTiers(symbol)- Leverage tiers for market - •
setMarginMode(marginMode, symbol)- Set margin mode (cross/isolated) - •
fetchMarginMode(symbol)- Fetch margin mode
Derivatives & Futures
Positions
- •
fetchPosition(symbol)- Fetch single position - •
fetchPositions([symbols])- Fetch all positions - •
fetchPositionsForSymbol(symbol)- Fetch positions for symbol - •
fetchPositionHistory(symbol, since, limit)- Position history - •
fetchPositionsHistory(symbols, since, limit)- Multiple position history - •
fetchPositionMode(symbol)- Fetch position mode (one-way/hedge) - •
setPositionMode(hedged, symbol)- Set position mode - •
closePosition(symbol, side)- Close position - •
closeAllPositions()- Close all positions
Funding & Settlement
- •
fetchFundingRate(symbol)- Current funding rate - •
fetchFundingRates([symbols])- Multiple funding rates - •
fetchFundingRateHistory(symbol, since, limit)- Funding rate history - •
fetchFundingHistory(symbol, since, limit)- Your funding payments - •
fetchFundingInterval(symbol)- Funding interval - •
fetchSettlementHistory(symbol, since, limit)- Settlement history - •
fetchMySettlementHistory(symbol, since, limit)- Your settlement history
Open Interest & Liquidations
- •
fetchOpenInterest(symbol)- Open interest for symbol - •
fetchOpenInterests([symbols])- Multiple open interests - •
fetchOpenInterestHistory(symbol, timeframe, since, limit)- OI history - •
fetchLiquidations(symbol, since, limit)- Public liquidations - •
fetchMyLiquidations(symbol, since, limit)- Your liquidations
Options
- •
fetchOption(symbol)- Fetch option info - •
fetchOptionChain(code)- Fetch option chain - •
fetchGreeks(symbol)- Fetch option greeks - •
fetchVolatilityHistory(code, since, limit)- Volatility history - •
fetchUnderlyingAssets()- Fetch underlying assets
Fees & Limits
- •
fetchTradingFee(symbol)- Trading fee for symbol - •
fetchTradingFees([symbols])- Trading fees for multiple symbols - •
fetchTradingLimits([symbols])- Trading limits - •
fetchTransactionFee(code)- Transaction/withdrawal fee - •
fetchTransactionFees([codes])- Multiple transaction fees - •
fetchDepositWithdrawFee(code)- Deposit/withdrawal fee - •
fetchDepositWithdrawFees([codes])- Multiple deposit/withdraw fees
Deposits & Withdrawals
- •
fetchDepositAddress(code, params)- Get deposit address - •
fetchDepositAddresses([codes])- Multiple deposit addresses - •
fetchDepositAddressesByNetwork(code)- Addresses by network - •
createDepositAddress(code, params)- Create new deposit address - •
fetchDeposit(id, code)- Fetch single deposit - •
fetchWithdrawal(id, code)- Fetch single withdrawal - •
fetchWithdrawAddresses(code)- Fetch withdrawal addresses - •
fetchWithdrawalWhitelist(code)- Fetch whitelist - •
withdraw(code, amount, address, tag, params)- Withdraw funds - •
deposit(code, amount, params)- Deposit funds (if supported)
Transfer & Convert
- •
transfer(code, amount, fromAccount, toAccount)- Internal transfer - •
fetchTransfer(id, code)- Fetch transfer info - •
fetchTransfers(code, since, limit)- Fetch transfer history - •
fetchConvertCurrencies()- Currencies available for convert - •
fetchConvertQuote(fromCode, toCode, amount)- Get conversion quote - •
createConvertTrade(fromCode, toCode, amount)- Execute conversion - •
fetchConvertTrade(id)- Fetch convert trade - •
fetchConvertTradeHistory(code, since, limit)- Convert history
Market Info
- •
fetchMarkets()- Fetch all markets - •
fetchCurrencies()- Fetch all currencies - •
fetchTime()- Fetch exchange server time - •
fetchStatus()- Fetch exchange status - •
fetchBorrowInterest(code, symbol, since, limit)- Borrow interest paid - •
fetchLongShortRatio(symbol, timeframe, since, limit)- Long/short ratio - •
fetchLongShortRatioHistory(symbol, timeframe, since, limit)- L/S ratio history
WebSocket Methods (ccxt.pro)
All REST methods have WebSocket equivalents with watch* prefix:
Real-time Market Data
- •
watchTicker(symbol)- Watch single ticker - •
watchTickers([symbols])- Watch multiple tickers - •
watchOrderBook(symbol)- Watch order book updates - •
watchOrderBookForSymbols([symbols])- Watch multiple order books - •
watchTrades(symbol)- Watch public trades - •
watchOHLCV(symbol, timeframe)- Watch candlestick updates - •
watchBidsAsks([symbols])- Watch best bid/ask
Real-time Account Data (Auth Required)
- •
watchBalance()- Watch balance updates - •
watchOrders(symbol)- Watch your order updates - •
watchMyTrades(symbol)- Watch your trade updates - •
watchPositions([symbols])- Watch position updates - •
watchPositionsForSymbol(symbol)- Watch positions for symbol
Authentication Required
Methods marked with 🔒 require API credentials:
- •All
create*methods (creating orders, addresses) - •All
cancel*methods (canceling orders) - •All
edit*methods (modifying orders) - •All
fetchMy*methods (your trades, orders) - •
fetchBalance,fetchLedger,fetchAccounts - •
withdraw,transfer,deposit - •Margin/leverage methods
- •Position methods
- •
watchBalance,watchOrders,watchMyTrades,watchPositions
Checking Method Availability
Not all exchanges support all methods. Check before using:
// Check if method is supported
if (exchange.has['fetchOHLCV']) {
const candles = await exchange.fetchOHLCV('BTC/USDT', '1h')
}
// Check multiple capabilities
console.log(exchange.has)
// {
// fetchTicker: true,
// fetchOHLCV: true,
// fetchMyTrades: true,
// fetchPositions: false,
// ...
// }
Method Naming Convention
- •
fetch*- REST API methods (HTTP requests) - •
watch*- WebSocket methods (real-time streams) - •
create*- Create new resources (orders, addresses) - •
cancel*- Cancel existing resources - •
edit*- Modify existing resources - •
set*- Configure settings (leverage, margin mode) - •
*Wssuffix - WebSocket variant (some exchanges)
Proxy Configuration
CCXT supports HTTP, HTTPS, and SOCKS proxies for both REST and WebSocket connections.
Setting Proxy
// HTTP Proxy exchange.httpProxy = 'http://your-proxy-host:port' // HTTPS Proxy exchange.httpsProxy = 'https://your-proxy-host:port' // SOCKS Proxy exchange.socksProxy = 'socks://your-proxy-host:port' // Proxy with authentication exchange.httpProxy = 'http://user:pass@proxy-host:port'
Proxy for WebSocket
WebSocket connections also respect proxy settings:
exchange.httpsProxy = 'https://proxy:8080' // WebSocket connections will use this proxy
Testing Proxy Connection
exchange.httpProxy = 'http://localhost:8080'
try {
await exchange.fetchTicker('BTC/USDT')
console.log('Proxy working!')
} catch (error) {
console.error('Proxy connection failed:', error)
}
WebSocket-Specific Methods
Some exchanges provide WebSocket variants of REST methods for faster order placement and management. These use the *Ws suffix:
Trading via WebSocket
Creating Orders:
- •
createOrderWs- Create order via WebSocket (faster than REST) - •
createLimitOrderWs- Create limit order via WebSocket - •
createMarketOrderWs- Create market order via WebSocket - •
createLimitBuyOrderWs- Buy limit order via WebSocket - •
createLimitSellOrderWs- Sell limit order via WebSocket - •
createMarketBuyOrderWs- Buy market order via WebSocket - •
createMarketSellOrderWs- Sell market order via WebSocket - •
createStopLimitOrderWs- Stop-limit order via WebSocket - •
createStopMarketOrderWs- Stop-market order via WebSocket - •
createStopLossOrderWs- Stop-loss order via WebSocket - •
createTakeProfitOrderWs- Take-profit order via WebSocket - •
createTrailingAmountOrderWs- Trailing stop via WebSocket - •
createTrailingPercentOrderWs- Trailing stop % via WebSocket - •
createPostOnlyOrderWs- Post-only order via WebSocket - •
createReduceOnlyOrderWs- Reduce-only order via WebSocket
Managing Orders:
- •
editOrderWs- Edit order via WebSocket - •
cancelOrderWs- Cancel order via WebSocket (faster than REST) - •
cancelOrdersWs- Cancel multiple orders via WebSocket - •
cancelAllOrdersWs- Cancel all orders via WebSocket
Fetching Data:
- •
fetchOrderWs- Fetch order via WebSocket - •
fetchOrdersWs- Fetch orders via WebSocket - •
fetchOpenOrdersWs- Fetch open orders via WebSocket - •
fetchClosedOrdersWs- Fetch closed orders via WebSocket - •
fetchMyTradesWs- Fetch your trades via WebSocket - •
fetchBalanceWs- Fetch balance via WebSocket - •
fetchPositionWs- Fetch position via WebSocket - •
fetchPositionsWs- Fetch positions via WebSocket - •
fetchPositionsForSymbolWs- Fetch positions for symbol via WebSocket - •
fetchTradingFeesWs- Fetch trading fees via WebSocket
When to Use WebSocket Methods
Use *Ws methods when:
- •You need faster order placement (lower latency)
- •You're already connected via WebSocket
- •You want to reduce REST API rate limit usage
- •Trading strategies require sub-100ms latency
Use REST methods when:
- •You need guaranteed execution confirmation
- •You're making one-off requests
- •The exchange doesn't support the WebSocket variant
- •You need detailed error responses
Example: Order Placement Comparison
REST API (slower, more reliable):
const order = await exchange.createOrder('BTC/USDT', 'limit', 'buy', 0.01, 50000)
WebSocket API (faster, lower latency):
const order = await exchange.createOrderWs('BTC/USDT', 'limit', 'buy', 0.01, 50000)
Checking WebSocket Method Availability
Not all exchanges support WebSocket trading methods:
if (exchange.has['createOrderWs']) {
// Exchange supports WebSocket order creation
const order = await exchange.createOrderWs('BTC/USDT', 'limit', 'buy', 0.01, 50000)
} else {
// Fall back to REST
const order = await exchange.createOrder('BTC/USDT', 'limit', 'buy', 0.01, 50000)
}
Authentication
Setting API Keys
import os
# During instantiation (recommended)
exchange = ccxt.binance({
'apiKey': os.environ.get('BINANCE_API_KEY'),
'secret': os.environ.get('BINANCE_SECRET'),
'enableRateLimit': True
})
# After instantiation
exchange.apiKey = os.environ.get('BINANCE_API_KEY')
exchange.secret = os.environ.get('BINANCE_SECRET')
Testing Authentication
try:
balance = exchange.fetch_balance()
print('Authentication successful!')
except ccxt.AuthenticationError:
print('Invalid API credentials')
Error Handling
Exception Hierarchy
BaseError ├─ NetworkError (recoverable - retry) │ ├─ RequestTimeout │ ├─ ExchangeNotAvailable │ ├─ RateLimitExceeded │ └─ DDoSProtection └─ ExchangeError (non-recoverable - don't retry) ├─ AuthenticationError ├─ InsufficientFunds ├─ InvalidOrder └─ NotSupported
Basic Error Handling
import ccxt
try:
ticker = exchange.fetch_ticker('BTC/USDT')
except ccxt.NetworkError as e:
print('Network error - retry:', str(e))
except ccxt.ExchangeError as e:
print('Exchange error - do not retry:', str(e))
except Exception as e:
print('Unknown error:', str(e))
Specific Exception Handling
try:
order = exchange.create_order('BTC/USDT', 'limit', 'buy', 0.01, 50000)
except ccxt.InsufficientFunds:
print('Not enough balance')
except ccxt.InvalidOrder:
print('Invalid order parameters')
except ccxt.RateLimitExceeded:
print('Rate limit hit - wait before retrying')
exchange.sleep(1000) # Wait 1 second
except ccxt.AuthenticationError:
print('Check your API credentials')
Retry Logic for Network Errors
def fetch_with_retry(max_retries=3):
for i in range(max_retries):
try:
return exchange.fetch_ticker('BTC/USDT')
except ccxt.NetworkError:
if i < max_retries - 1:
print(f'Retry {i + 1}/{max_retries}')
exchange.sleep(1000 * (i + 1)) # Exponential backoff
else:
raise
Async vs Sync
When to Use Sync
- •Simple scripts
- •Single exchange operations
- •Jupyter notebooks
- •Quick testing
When to Use Async
- •Multiple concurrent operations
- •WebSocket connections (required)
- •High-performance trading bots
- •Multiple exchange monitoring
Sync Example
import ccxt
exchange = ccxt.binance({'enableRateLimit': True})
ticker = exchange.fetch_ticker('BTC/USDT')
print(ticker['last'])
Async Example
import asyncio
import ccxt.async_support as ccxt
async def main():
exchange = ccxt.binance({'enableRateLimit': True})
ticker = await exchange.fetch_ticker('BTC/USDT')
print(ticker['last'])
await exchange.close()
asyncio.run(main())
Multiple Exchanges Async
async def fetch_all():
exchanges = [
ccxt.binance({'enableRateLimit': True}),
ccxt.coinbase({'enableRateLimit': True}),
ccxt.kraken({'enableRateLimit': True})
]
# Fetch concurrently
tasks = [ex.fetch_ticker('BTC/USDT') for ex in exchanges]
tickers = await asyncio.gather(*tasks, return_exceptions=True)
for ex, ticker in zip(exchanges, tickers):
if isinstance(ticker, Exception):
print(f'{ex.id}: ERROR - {ticker}')
else:
print(f'{ex.id}: ${ticker["last"]}')
await ex.close()
asyncio.run(fetch_all())
Rate Limiting
Built-in Rate Limiter (Recommended)
exchange = ccxt.binance({
'enableRateLimit': True # Automatically throttles requests
})
Manual Delays
exchange.fetch_ticker('BTC/USDT')
exchange.sleep(1000) # Wait 1 second (milliseconds)
exchange.fetch_ticker('ETH/USDT')
Checking Rate Limit
print(exchange.rateLimit) # Milliseconds between requests
Common Pitfalls
Forgetting await in Async Mode
# Wrong - returns coroutine, not data
async def wrong():
ticker = exchange.fetch_ticker('BTC/USDT') # Missing await!
print(ticker['last']) # ERROR
# Correct
async def correct():
ticker = await exchange.fetch_ticker('BTC/USDT')
print(ticker['last']) # Works!
Using Sync for WebSocket
# Wrong - WebSocket requires async
import ccxt.pro as ccxtpro
exchange = ccxtpro.binance()
ticker = exchange.watch_ticker('BTC/USDT') # ERROR: Need await!
# Correct
import asyncio
import ccxt.pro as ccxtpro
async def main():
exchange = ccxtpro.binance()
ticker = await exchange.watch_ticker('BTC/USDT')
await exchange.close()
asyncio.run(main())
Not Closing Async Exchange
# Wrong - resource leak
async def wrong():
exchange = ccxt.binance()
await exchange.fetch_ticker('BTC/USDT')
# Forgot to close!
# Correct
async def correct():
exchange = ccxt.binance()
try:
await exchange.fetch_ticker('BTC/USDT')
finally:
await exchange.close()
Using Sync in Async Code
# Wrong - blocks event loop
async def wrong():
exchange = ccxt.binance() # Sync import!
ticker = exchange.fetch_ticker('BTC/USDT') # Blocking!
# Correct
import ccxt.async_support as ccxt
async def correct():
exchange = ccxt.binance()
ticker = await exchange.fetch_ticker('BTC/USDT')
await exchange.close()
Using REST for Real-time Monitoring
# Wrong - wastes rate limits
while True:
ticker = exchange.fetch_ticker('BTC/USDT') # REST
print(ticker['last'])
exchange.sleep(1000)
# Correct - use WebSocket
import ccxt.pro as ccxtpro
async def correct():
exchange = ccxtpro.binance()
while True:
ticker = await exchange.watch_ticker('BTC/USDT') # WebSocket
print(ticker['last'])
await exchange.close()
Troubleshooting
Common Issues
1. "ModuleNotFoundError: No module named 'ccxt'"
- •Solution: Run
pip install ccxt
2. "RateLimitExceeded"
- •Solution: Enable rate limiter:
'enableRateLimit': True - •Or add manual delays between requests
3. "AuthenticationError"
- •Solution: Check API key and secret
- •Verify API key permissions on exchange
- •Check system clock is synced (use NTP)
4. "InvalidNonce"
- •Solution: Sync system clock
- •Use only one exchange instance per API key
5. "InsufficientFunds"
- •Solution: Check available balance (
balance['BTC']['free']) - •Account for trading fees
6. "ExchangeNotAvailable"
- •Solution: Check exchange status/maintenance
- •Retry after a delay
7. SSL/Certificate errors
- •Solution: Update certifi:
pip install --upgrade certifi
8. Slow performance
- •Solution: Install performance enhancements:
- •
pip install orjson(faster JSON) - •
pip install coincurve(faster signing)
- •
Debugging
# Enable verbose logging
exchange.verbose = True
# Check exchange capabilities
print(exchange.has)
# {
# 'fetchTicker': True,
# 'fetchOrderBook': True,
# 'createOrder': True,
# ...
# }
# Check market information
print(exchange.markets['BTC/USDT'])
# Check last request/response
print(exchange.last_http_response)
print(exchange.last_json_response)