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

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)
• *Ws suffix - 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)

Prediction Markets

CCXT supports prediction-market exchanges (Polymarket, Kalshi, Limitless, Myriad, Hyperliquid) under a dedicated ccxt.prediction namespace (async-only in Python — ccxt.prediction.<id> IS the async class). They use the same unified API, but prices are quoted 0–1 (USDC per outcome share) and the tradeable unit is an outcome (e.g. a market's YES/NO token), not a regular market symbol.

import asyncio
import ccxt.prediction  # async-only

async def main():
    exchange = ccxt.prediction.polymarket()
    await exchange.load_markets()
    # discover events -> markets -> outcomes
    events = await exchange.fetch_events({'query': 'Trump'})
    outcome = events[0]['markets'][0]['outcomes'][0]
    # each outcome has: outcome (handle, e.g. 'TRUMP_OUT_PRESIDENT_2027:YES'),
    # outcomeId, market, label ('YES'/'NO')
    handle = outcome['outcome']
    ticker = await exchange.fetch_ticker(handle)
    book = await exchange.fetch_order_book(handle)
    # limit buy 5 YES shares @ 0.40 USDC (price is 0..1 per share)
    order = await exchange.create_order(handle, 'limit', 'buy', 5, 0.40)
    await exchange.cancel_order(order['id'], handle)
    await exchange.close()

asyncio.run(main())

• Price/trade methods (fetch_ticker, fetch_order_book, fetch_ohlcv, fetch_trades, create_order, cancel_order, …) take an outcome handle or outcomeId (the outcome / outcomes parameter), not symbol.
• Check support with exchange.has['prediction']; discover markets via fetch_events / fetch_event (or load_markets).

Order Router

Two things, either usable without the other. A client for the CCXT order-router service — a separate process holding live books across many venues, which answers "what is the cheapest way to turn asset A into asset B right now?", including bridges (SOL -> USDT -> BTC when no SOL/BTC market exists). And an execution engine for plans you build yourself, which needs no router service and no API key. It is not an exchange: it does not subclass Exchange, has no unified methods, and is constructed directly.

import os, ccxt

router = ccxt.OrderRouter()

# exactly one of amountIn / amountOut
route = router.fetch_route('USDT', 'BTC', {'amountIn': 1000})
print(route['effectiveRate'], route['impactBps'], route['fillRatio'])

# execute takes the route directly: it builds the plan, loads each venue's markets and
# runs the safety check itself, refusing to place anything on a blocking violation
report = router.execute(route, {'binance': binance, 'kraken': kraken}, {
    'strategy': 'sequential',
    'usdRates': {'USDT': 1},
})
# want to see or change the plan first? the steps in between are public and PURE (no I/O):
# build_execution_plan(route, {}) then check_execution_plan_safety(plan, markets, {})

execute defaults to dry_run, and anything other than an explicit live flag forces dry_run regardless of the strategy requested — a call that looks live but forgot the flag places nothing.

The service, and what it costs

https://docs.ccxt.com/router/api. Every endpoint is public: there is no API key, no signup and no login. The service rate-limits by client IP address instead.

The client still accepts an apiKey and still sends it as x-api-key when you pass one, so a deployment that fronts the service with its own authentication keeps working. With no key the header is omitted entirely rather than sent empty.

The full contract is published as OpenAPI 3.1 at https://docs.ccxt.com/router/openapi.yaml. curl -O https://docs.ccxt.com/router/openapi.yaml and point codegen at it, import it into Postman/Insomnia, or diff it between deploys. It is the authority on every field this client reads; where the two disagree, the spec is right. Rendered prose version: /router/docs and /router/docs/api.

Free to use for now, up to the published rate limit — not a permanent commitment, so expect a paid tier eventually. Your existing key is how that would be billed; nothing in the client changes. Read the limit off the response headers (x-ratelimit-limit, x-ratelimit-remaining, x-ratelimit-reset) rather than hardcoding a number. A 429 raises RateLimitExceeded with the retry interval folded into the message.

A router that has restarted is alive long before it can price anything. Asked to route in that window it refuses with 503 cache_cold, and the client raises ExchangeNotAvailable — a retry, distinct from the ExchangeError that means something is actually wrong.

Holdings are POSTed, never put in a URL. fetch_route normally sends a GET, but when you pass balances the client switches to POST /route and puts every parameter in the body: the service scrubs holdings from its own logs, but a reverse proxy, an ALB, a CDN, browser history and a Referer all see the full request line, and no in-process redaction reaches them. fetch_route_with_balances does this for you.

Two flags the client verifies for you, because one silently lost in transit looks identical to one never sent. balances: the service ignores them entirely if it predates the feature and answers byte-identically, so fetch_route throws unless the router echoes balancesApplied (or balanceEntryCount, which is how an empty wallet is confirmed) — pass requireBalancesApplied: false to opt out. requireFullFill: the one flag that fails open, so the client stamps what you asked for and the safety check makes partial_fill blocking when you asked for a full fill and did not get one.

An empty value is not an omitted one. Omit bridges and you get the default bridge set; send bridges= and you have asked for no bridging at all. Same for exchanges= (no venues) and balances= (you hold nothing). The client forwards an empty value rather than dropping it.

requestId is sent as the x-request-id header, so your log and the router's decision log can be joined; the service mints one when absent.

Asking the service about itself

Gate deploys on readiness, not health — /health is 200 before a single websocket has connected. fetch_readiness() does not raise when the answer is no: the service replies 503 carrying the same body it returns on 200, and you need those counts to know why.

readiness = router.fetch_readiness()
if readiness['status'] != 'ready':
    print(readiness['freshCount'], 'of', readiness['bookCount'], 'books are fresh')

/metrics (Prometheus) has no client method — it answers text/plain and this class parses every response as JSON.

Watching a route. /stream/route pushes the same RouteResult whenever any market the route depends on moves. watch_route raises NotSupported in Python: this port is synchronous and has no websocket client to drive, and polling fetch_route on a timer is not the same thing, so it is refused rather than silently substituted. streamUrl IS implemented, so the url grammar and the client-side refusals stay verified here. The endpoint refuses balances and balanceMode — a socket outlives the holdings it was opened with — and defaults includeQuotes to false.

Watching a run, and stopping it

execute is not opaque. options.onStep is called after each step completes AND after its reconciliation — never mid-order — and its return value decides whether the route continues.

def on_step(event):
    print(event['stepIndex'], event['status'], event['outAmount'])
    return 'halt' if event['status'] == 'partial' else ''   # 'halt' stops the route

report = router.execute(plan, venues, {
    'strategy': 'sequential', 'live': True, 'usdRates': {'USDT': 1},
    'retryFailedSteps': 2,               # only a DEFINITIVELY REJECTED step is retried
    'onStep': on_step,
})

The event is a plain dictionary: planId, stepIndex, hopIndex, legIndex, exchangeId, symbol, side, status, requestedAmount, filledAmount, outAsset, outAmount, orderId, clientOrderId, errorCode, attempt, reconciliation, ordersPlaced, halted, haltReason, stepsTotal, stepsRemaining.

• It can only narrow. 'halt' stops the route and sets haltReason to halted_by_on_step; nothing it returns resumes a route the reconciliation already halted.
• It is called on the halt paths too, with an empty reconciliation, so it always learns how the route ended.
• Do no network I/O in it — it sits between orders on the money path.
• A hook that throws is recorded in report['errors'] as on_step_hook_failed and the run continues; losing the report would destroy the only account of orders already live.

For decisions that need I/O, slice the plan and call execute per hop with its own idempotencyKey instead.

options.retryFailedSteps (default 0, retryDelayMs default 1000) re-places a step the venue definitively rejected. An outcome_unknown step is never retried at any setting: it may already be a live position, and re-placing it is the double-fill this class exists to prevent. The winning attempt is reported as attempt. The router sets no client order id of its own — venues disagree on length and charset, so whatever you pass in orderParams travels untouched.

Executing your own plans

execute takes a plan, not a route, and never checks where the plan came from — so your own strategy can supply its own trades and still get the notional cap, halt-and-reconcile between hops, resting-order cleanup and the unwind plan. A plan that has been through JSON or a database, or a hand-rebuilt tail of a halted route, is equally valid.

A step is one order on one venue. Required: exchangeId, symbol, side, amount, base, quote. Optional: stepIndex (defaults to position), hopIndex/legIndex (steps sharing a hopIndex are one hop — what parallel_within_hop parallelises), expectedPrice, limitPrice, notionalQuote.

plan = {
    'requestId': 'my-strategy-0001',            # identity; a live run refuses without one
    'calculatedAt': exchange.milliseconds(),
    'steps': [
        {'exchangeId': 'binance', 'symbol': 'BTC/USDT', 'side': 'buy', 'amount': 0.01,
         'base': 'BTC', 'quote': 'USDT', 'hopIndex': 0, 'expectedPrice': 64000},
    ],
}
report = router.execute(plan, {'binance': binance}, {
    'strategy': 'sequential', 'live': True, 'usdRates': {'USDT': 1}, 'maxNotionalUsd': 25,
})

A live execute requires an identity and refuses without one: the identity is remembered in-process so a second execute of the same plan is refused before any venue is contacted. Supply it as the plan's requestId or as the options' idempotencyKey. execute never sets a clientOrderId of its own: each exchange's create_order keeps sending whatever identifier it generates internally, and a clientOrderId you put in the options' orderParams travels untouched (to every step alike).

Make it stable and tied to the intent (a strategy name plus the signal's timestamp). A fresh value per call — a wall-clock timestamp and friends — turns the guard off while looking like it is on. To re-run deliberately, pass allowReexecution. The guard does not survive a restart.

checkExecutionPlanSafety is worth running on a hand-written plan first: it checks every step against that venue's real market rules — minimum amount, minimum cost, precision — which is where a hand-picked amount usually goes wrong.

Strategies: dry_run (default), sequential, parallel_within_hop (concurrent across venues, serialised within a venue), limit_protected (rests a limit order and cancels it at orderTimeoutMs, polling every pollIntervalMs), atomic_ish (requires the route pre-funded), best_effort (single-hop, never halts).

Every report carries planAgeMs — how old the plan's prices were when execute was called (-1 when the route carried no calculatedAt, which means unknown, not fresh). Pass options.maxPlanAgeMs to refuse a live execution of a plan older than that; there is no default limit, and under an active limit a plan whose age cannot be determined is refused too.

There is no notional cap by default — trade cents or trade thousands. maxNotionalUsd is an opt-in guardrail: pass it to the constructor, or per call in the options, and it is honoured exactly at whatever value you choose, in either direction; omit it (or pass 0) and no notional check runs. Only a negative value is refused.

A market order cannot be placed under a cap: the cap is checked against the plan's limit price and a market order carries no price at all, so asking for allowMarketOrders together with a cap is refused rather than silently unbounded.

When a cap IS set it is enforced immediately before every order — not just at plan time, because a reconciliation may have resized the plan since — and a step that cannot be valued in USD blocks, so supply a USD rate for every quote asset in the plan. With no cap set there is nothing to evaluate and USD rates are not required either.

In the report, status: 'outcome_unknown' means the request may or may not have reached the venue — execution halts rather than reconciling, because reconciling would read the fill as 0 and report "nothing filled", asserting the one thing nobody knows. Check the open orders and the venue before retrying. placementAttempted is false until an order was actually dispatched.

buildExecutionPlan refuses a route that does not run from the asset you offered to the asset you wanted, or whose hops do not connect — the answer is checked against the client's own record of the question, so a compromised or buggy router response cannot steer orders into another market.

Full reference: Order Router in the CCXT Manual.

Learn More

• CCXT Manual
• CCXT Pro Documentation
• Supported Exchanges
• GitHub Repository