CCXT cryptocurrency exchange library for PHP developers. Covers both REST API (standard) and WebSocket API (real-time). Helps install CCXT, connect to exchanges, fetch market data, place orders, stream live tickers/orderbooks, handle authentication, and manage errors in PHP 8.1+. Use when working with crypto exchanges in PHP projects, trading bots, or web applications. Supports both sync and async (ReactPHP) usage.
A comprehensive guide to using CCXT in PHP projects for cryptocurrency exchange integration.
composer require ccxt/ccxt
<?php
date_default_timezone_set('UTC'); // Required!
require_once 'vendor/autoload.php';
$exchange = new \ccxt\binance();
$exchange->load_markets();
$ticker = $exchange->fetch_ticker('BTC/USDT');
print_r($ticker);
<?php
use function React\Async\await;
date_default_timezone_set('UTC');
require_once 'vendor/autoload.php';
$exchange = new \ccxt\async\binance();
$ticker = await($exchange->fetch_ticker('BTC/USDT'));
print_r($ticker);
<?php
use function React\Async\await;
use function React\Async\async;
date_default_timezone_set('UTC');
require_once 'vendor/autoload.php';
$exchange = new \ccxt\pro\binance();
while (true) {
$ticker = await($exchange->watch_ticker('BTC/USDT'));
print_r($ticker); // Live updates!
}
await($exchange->close());
| Mode | REST | WebSocket |
|---|---|---|
| Sync | \ccxt\binance() | (WebSocket requires async) |
| Async | \ccxt\async\binance() | \ccxt\pro\binance() |
| 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 |
<?php
date_default_timezone_set('UTC');
require_once 'vendor/autoload.php';
// Public API (no authentication)
$exchange = new \ccxt\binance([
'enableRateLimit' => true // Recommended!
]);
// Private API (with authentication)
$exchange = new \ccxt\binance([
'apiKey' => 'YOUR_API_KEY',
'secret' => 'YOUR_SECRET',
'enableRateLimit' => true
]);
<?php
use function React\Async\await;
$exchange = new \ccxt\async\binance([
'enableRateLimit' => true
]);
$ticker = await($exchange->fetch_ticker('BTC/USDT'));
<?php
use function React\Async\await;
// Public WebSocket
$exchange = new \ccxt\pro\binance();
// Private WebSocket (with authentication)
$exchange = new \ccxt\pro\binance([
'apiKey' => 'YOUR_API_KEY',
'secret' => 'YOUR_SECRET'
]);
// Always close when done
await($exchange->close());
// Load all available trading pairs
$exchange->load_markets();
// Access market information
$btc_market = $exchange->market('BTC/USDT');
print_r($btc_market['limits']['amount']['min']); // Minimum order amount
// Single ticker
$ticker = $exchange->fetch_ticker('BTC/USDT');
print_r($ticker['last']); // Last price
print_r($ticker['bid']); // Best bid
print_r($ticker['ask']); // Best ask
print_r($ticker['volume']); // 24h volume
// Multiple tickers (if supported)
$tickers = $exchange->fetch_tickers(['BTC/USDT', 'ETH/USDT']);
// Full orderbook
$orderbook = $exchange->fetch_order_book('BTC/USDT');
print_r($orderbook['bids'][0]); // [price, amount]
print_r($orderbook['asks'][0]); // [price, amount]
// Limited depth
$orderbook = $exchange->fetch_order_book('BTC/USDT', 5); // Top 5 levels
// Buy limit order
$order = $exchange->create_limit_buy_order('BTC/USDT', 0.01, 50000);
print_r($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);
// 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);
$balance = $exchange->fetch_balance();
print_r($balance['BTC']['free']); // Available balance
print_r($balance['BTC']['used']); // Balance in orders
print_r($balance['BTC']['total']); // Total balance
// 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');
// Recent public trades
$trades = $exchange->fetch_trades('BTC/USDT', null, 10);
// Your trades (requires authentication)
$my_trades = $exchange->fetch_my_trades('BTC/USDT');
// Cancel single order
$exchange->cancel_order($order_id, 'BTC/USDT');
// Cancel all orders for a symbol
$exchange->cancel_all_orders('BTC/USDT');
<?php
use function React\Async\await;
$exchange = new \ccxt\pro\binance();
while (true) {
$ticker = await($exchange->watch_ticker('BTC/USDT'));
print_r($ticker['last']);
}
await($exchange->close());
<?php
use function React\Async\await;
$exchange = new \ccxt\pro\binance();
while (true) {
$orderbook = await($exchange->watch_order_book('BTC/USDT'));
print_r('Best bid: ' . $orderbook['bids'][0][0]);
print_r('Best ask: ' . $orderbook['asks'][0][0]);
}
await($exchange->close());
<?php
use function React\Async\await;
$exchange = new \ccxt\pro\binance();
while (true) {
$trades = await($exchange->watch_trades('BTC/USDT'));
foreach ($trades as $trade) {
print_r($trade['price'] . ' ' . $trade['amount'] . ' ' . $trade['side']);
}
}
await($exchange->close());
<?php
use function React\Async\await;
$exchange = new \ccxt\pro\binance([
'apiKey' => 'YOUR_API_KEY',
'secret' => 'YOUR_SECRET'
]);
while (true) {
$orders = await($exchange->watch_orders('BTC/USDT'));
foreach ($orders as $order) {
print_r($order['id'] . ' ' . $order['status'] . ' ' . $order['filled']);
}
}
await($exchange->close());
<?php
use function React\Async\await;
$exchange = new \ccxt\pro\binance([
'apiKey' => 'YOUR_API_KEY',
'secret' => 'YOUR_SECRET'
]);
while (true) {
$balance = await($exchange->watch_balance());
print_r('BTC: ' . $balance['BTC']['total']);
}
await($exchange->close());
fetchTicker(symbol) - Fetch ticker for one symbolfetchTickers([symbols]) - Fetch multiple tickers at oncefetchBidsAsks([symbols]) - Fetch best bid/ask for multiple symbolsfetchLastPrices([symbols]) - Fetch last pricesfetchMarkPrices([symbols]) - Fetch mark prices (derivatives)fetchOrderBook(symbol, limit) - Fetch order bookfetchOrderBooks([symbols]) - Fetch multiple order booksfetchL2OrderBook(symbol) - Fetch level 2 order bookfetchL3OrderBook(symbol) - Fetch level 3 order book (if supported)fetchTrades(symbol, since, limit) - Fetch public tradesfetchMyTrades(symbol, since, limit) - Fetch your trades (auth required)fetchOrderTrades(orderId, symbol) - Fetch trades for specific orderfetchOHLCV(symbol, timeframe, since, limit) - Fetch candlestick datafetchIndexOHLCV(symbol, timeframe) - Fetch index price OHLCVfetchMarkOHLCV(symbol, timeframe) - Fetch mark price OHLCVfetchPremiumIndexOHLCV(symbol, timeframe) - Fetch premium index OHLCVfetchBalance() - Fetch account balance (auth required)fetchAccounts() - Fetch sub-accountsfetchLedger(code, since, limit) - Fetch ledger historyfetchLedgerEntry(id, code) - Fetch specific ledger entryfetchTransactions(code, since, limit) - Fetch transactionsfetchDeposits(code, since, limit) - Fetch deposit historyfetchWithdrawals(code, since, limit) - Fetch withdrawal historyfetchDepositsWithdrawals(code, since, limit) - Fetch both deposits and withdrawalscreateOrder(symbol, type, side, amount, price, params) - Create order (generic)createLimitOrder(symbol, side, amount, price) - Create limit ordercreateMarketOrder(symbol, side, amount) - Create market ordercreateLimitBuyOrder(symbol, amount, price) - Buy limit ordercreateLimitSellOrder(symbol, amount, price) - Sell limit ordercreateMarketBuyOrder(symbol, amount) - Buy market ordercreateMarketSellOrder(symbol, amount) - Sell market ordercreateMarketBuyOrderWithCost(symbol, cost) - Buy with specific costcreateStopLimitOrder(symbol, side, amount, price, stopPrice) - Stop-limit ordercreateStopMarketOrder(symbol, side, amount, stopPrice) - Stop-market ordercreateStopLossOrder(symbol, side, amount, stopPrice) - Stop-loss ordercreateTakeProfitOrder(symbol, side, amount, takeProfitPrice) - Take-profit ordercreateTrailingAmountOrder(symbol, side, amount, trailingAmount) - Trailing stopcreateTrailingPercentOrder(symbol, side, amount, trailingPercent) - Trailing stop %createTriggerOrder(symbol, side, amount, triggerPrice) - Trigger ordercreatePostOnlyOrder(symbol, side, amount, price) - Post-only ordercreateReduceOnlyOrder(symbol, side, amount, price) - Reduce-only ordercreateOrders([orders]) - Create multiple orders at oncecreateOrderWithTakeProfitAndStopLoss(symbol, type, side, amount, price, tpPrice, slPrice) - OCO orderfetchOrder(orderId, symbol) - Fetch single orderfetchOrders(symbol, since, limit) - Fetch all ordersfetchOpenOrders(symbol, since, limit) - Fetch open ordersfetchClosedOrders(symbol, since, limit) - Fetch closed ordersfetchCanceledOrders(symbol, since, limit) - Fetch canceled ordersfetchOpenOrder(orderId, symbol) - Fetch specific open orderfetchOrdersByStatus(status, symbol) - Fetch orders by statuscancelOrder(orderId, symbol) - Cancel single ordercancelOrders([orderIds], symbol) - Cancel multiple orderscancelAllOrders(symbol) - Cancel all orders for symboleditOrder(orderId, symbol, type, side, amount, price) - Modify orderfetchBorrowRate(code) - Fetch borrow rate for marginfetchBorrowRates([codes]) - Fetch multiple borrow ratesfetchBorrowRateHistory(code, since, limit) - Historical borrow ratesfetchCrossBorrowRate(code) - Cross margin borrow ratefetchIsolatedBorrowRate(symbol, code) - Isolated margin borrow rateborrowMargin(code, amount, symbol) - Borrow marginrepayMargin(code, amount, symbol) - Repay marginfetchLeverage(symbol) - Fetch leveragesetLeverage(leverage, symbol) - Set leveragefetchLeverageTiers(symbols) - Fetch leverage tiersfetchMarketLeverageTiers(symbol) - Leverage tiers for marketsetMarginMode(marginMode, symbol) - Set margin mode (cross/isolated)fetchMarginMode(symbol) - Fetch margin modefetchPosition(symbol) - Fetch single positionfetchPositions([symbols]) - Fetch all positionsfetchPositionsForSymbol(symbol) - Fetch positions for symbolfetchPositionHistory(symbol, since, limit) - Position historyfetchPositionsHistory(symbols, since, limit) - Multiple position historyfetchPositionMode(symbol) - Fetch position mode (one-way/hedge)setPositionMode(hedged, symbol) - Set position modeclosePosition(symbol, side) - Close positioncloseAllPositions() - Close all positionsfetchFundingRate(symbol) - Current funding ratefetchFundingRates([symbols]) - Multiple funding ratesfetchFundingRateHistory(symbol, since, limit) - Funding rate historyfetchFundingHistory(symbol, since, limit) - Your funding paymentsfetchFundingInterval(symbol) - Funding intervalfetchSettlementHistory(symbol, since, limit) - Settlement historyfetchMySettlementHistory(symbol, since, limit) - Your settlement historyfetchOpenInterest(symbol) - Open interest for symbolfetchOpenInterests([symbols]) - Multiple open interestsfetchOpenInterestHistory(symbol, timeframe, since, limit) - OI historyfetchLiquidations(symbol, since, limit) - Public liquidationsfetchMyLiquidations(symbol, since, limit) - Your liquidationsfetchOption(symbol) - Fetch option infofetchOptionChain(code) - Fetch option chainfetchGreeks(symbol) - Fetch option greeksfetchVolatilityHistory(code, since, limit) - Volatility historyfetchUnderlyingAssets() - Fetch underlying assetsfetchTradingFee(symbol) - Trading fee for symbolfetchTradingFees([symbols]) - Trading fees for multiple symbolsfetchTradingLimits([symbols]) - Trading limitsfetchTransactionFee(code) - Transaction/withdrawal feefetchTransactionFees([codes]) - Multiple transaction feesfetchDepositWithdrawFee(code) - Deposit/withdrawal feefetchDepositWithdrawFees([codes]) - Multiple deposit/withdraw feesfetchDepositAddress(code, params) - Get deposit addressfetchDepositAddresses([codes]) - Multiple deposit addressesfetchDepositAddressesByNetwork(code) - Addresses by networkcreateDepositAddress(code, params) - Create new deposit addressfetchDeposit(id, code) - Fetch single depositfetchWithdrawal(id, code) - Fetch single withdrawalfetchWithdrawAddresses(code) - Fetch withdrawal addressesfetchWithdrawalWhitelist(code) - Fetch whitelistwithdraw(code, amount, address, tag, params) - Withdraw fundsdeposit(code, amount, params) - Deposit funds (if supported)transfer(code, amount, fromAccount, toAccount) - Internal transferfetchTransfer(id, code) - Fetch transfer infofetchTransfers(code, since, limit) - Fetch transfer historyfetchConvertCurrencies() - Currencies available for convertfetchConvertQuote(fromCode, toCode, amount) - Get conversion quotecreateConvertTrade(fromCode, toCode, amount) - Execute conversionfetchConvertTrade(id) - Fetch convert tradefetchConvertTradeHistory(code, since, limit) - Convert historyfetchMarkets() - Fetch all marketsfetchCurrencies() - Fetch all currenciesfetchTime() - Fetch exchange server timefetchStatus() - Fetch exchange statusfetchBorrowInterest(code, symbol, since, limit) - Borrow interest paidfetchLongShortRatio(symbol, timeframe, since, limit) - Long/short ratiofetchLongShortRatioHistory(symbol, timeframe, since, limit) - L/S ratio historyAll REST methods have WebSocket equivalents with watch* prefix:
watchTicker(symbol) - Watch single tickerwatchTickers([symbols]) - Watch multiple tickerswatchOrderBook(symbol) - Watch order book updateswatchOrderBookForSymbols([symbols]) - Watch multiple order bookswatchTrades(symbol) - Watch public tradeswatchOHLCV(symbol, timeframe) - Watch candlestick updateswatchBidsAsks([symbols]) - Watch best bid/askwatchBalance() - Watch balance updateswatchOrders(symbol) - Watch your order updateswatchMyTrades(symbol) - Watch your trade updateswatchPositions([symbols]) - Watch position updateswatchPositionsForSymbol(symbol) - Watch positions for symbolMethods marked with 🔒 require API credentials:
create* methods (creating orders, addresses)cancel* methods (canceling orders)edit* methods (modifying orders)fetchMy* methods (your trades, orders)fetchBalance, fetchLedger, fetchAccountswithdraw, transfer, depositwatchBalance, watchOrders, watchMyTrades, watchPositionsNot 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,
// ...
// }
fetch* - REST API methods (HTTP requests)watch* - WebSocket methods (real-time streams)create* - Create new resources (orders, addresses)cancel* - Cancel existing resourcesedit* - Modify existing resourcesset* - Configure settings (leverage, margin mode)*Ws suffix - WebSocket variant (some exchanges)CCXT supports HTTP, HTTPS, and SOCKS proxies for both REST and WebSocket connections.
// 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'
WebSocket connections also respect proxy settings:
exchange.httpsProxy = 'https://proxy:8080'
// WebSocket connections will use this proxy
exchange.httpProxy = 'http://localhost:8080'
try {
await exchange.fetchTicker('BTC/USDT')
console.log('Proxy working!')
} catch (error) {
console.error('Proxy connection failed:', error)
}
Some exchanges provide WebSocket variants of REST methods for faster order placement and management. These use the *Ws suffix:
Creating Orders:
createOrderWs - Create order via WebSocket (faster than REST)createLimitOrderWs - Create limit order via WebSocketcreateMarketOrderWs - Create market order via WebSocketcreateLimitBuyOrderWs - Buy limit order via WebSocketcreateLimitSellOrderWs - Sell limit order via WebSocketcreateMarketBuyOrderWs - Buy market order via WebSocketcreateMarketSellOrderWs - Sell market order via WebSocketcreateStopLimitOrderWs - Stop-limit order via WebSocketcreateStopMarketOrderWs - Stop-market order via WebSocketcreateStopLossOrderWs - Stop-loss order via WebSocketcreateTakeProfitOrderWs - Take-profit order via WebSocketcreateTrailingAmountOrderWs - Trailing stop via WebSocketcreateTrailingPercentOrderWs - Trailing stop % via WebSocketcreatePostOnlyOrderWs - Post-only order via WebSocketcreateReduceOnlyOrderWs - Reduce-only order via WebSocketManaging Orders:
editOrderWs - Edit order via WebSocketcancelOrderWs - Cancel order via WebSocket (faster than REST)cancelOrdersWs - Cancel multiple orders via WebSocketcancelAllOrdersWs - Cancel all orders via WebSocketFetching Data:
fetchOrderWs - Fetch order via WebSocketfetchOrdersWs - Fetch orders via WebSocketfetchOpenOrdersWs - Fetch open orders via WebSocketfetchClosedOrdersWs - Fetch closed orders via WebSocketfetchMyTradesWs - Fetch your trades via WebSocketfetchBalanceWs - Fetch balance via WebSocketfetchPositionWs - Fetch position via WebSocketfetchPositionsWs - Fetch positions via WebSocketfetchPositionsForSymbolWs - Fetch positions for symbol via WebSocketfetchTradingFeesWs - Fetch trading fees via WebSocketUse *Ws methods when:
Use REST methods when:
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)
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)
}
<?php
// During instantiation (recommended)
$exchange = new \ccxt\binance([
'apiKey' => getenv('BINANCE_API_KEY'),
'secret' => getenv('BINANCE_SECRET'),
'enableRateLimit' => true
]);
// After instantiation
$exchange->apiKey = getenv('BINANCE_API_KEY');
$exchange->secret = getenv('BINANCE_SECRET');
try {
$balance = $exchange->fetch_balance();
print_r('Authentication successful!');
} catch (\ccxt\AuthenticationError $e) {
print_r('Invalid API credentials');
}
BaseError
├─ NetworkError (recoverable - retry)
│ ├─ RequestTimeout
│ ├─ ExchangeNotAvailable
│ ├─ RateLimitExceeded
│ └─ DDoSProtection
└─ ExchangeError (non-recoverable - don't retry)
├─ AuthenticationError
├─ InsufficientFunds
├─ InvalidOrder
└─ NotSupported
<?php
try {
$ticker = $exchange->fetch_ticker('BTC/USDT');
} catch (\ccxt\NetworkError $e) {
echo 'Network error - retry: ' . $e->getMessage();
} catch (\ccxt\ExchangeError $e) {
echo 'Exchange error - do not retry: ' . $e->getMessage();
} catch (\Exception $e) {
echo 'Unknown error: ' . $e->getMessage();
}
<?php
try {
$order = $exchange->create_order('BTC/USDT', 'limit', 'buy', 0.01, 50000);
} catch (\ccxt\InsufficientFunds $e) {
echo 'Not enough balance';
} catch (\ccxt\InvalidOrder $e) {
echo 'Invalid order parameters';
} catch (\ccxt\RateLimitExceeded $e) {
echo 'Rate limit hit - wait before retrying';
sleep(1); // Wait 1 second
} catch (\ccxt\AuthenticationError $e) {
echo 'Check your API credentials';
}
<?php
function fetch_with_retry($exchange, $max_retries = 3) {
for ($i = 0; $i < $max_retries; $i++) {
try {
return $exchange->fetch_ticker('BTC/USDT');
} catch (\ccxt\NetworkError $e) {
if ($i < $max_retries - 1) {
echo "Retry " . ($i + 1) . "/$max_retries\n";
sleep(1 * ($i + 1)); // Exponential backoff
} else {
throw $e;
}
}
}
}
$exchange = new \ccxt\binance([
'enableRateLimit' => true // Automatically throttles requests
]);
$exchange->fetch_ticker('BTC/USDT');
usleep($exchange->rateLimit * 1000); // Convert ms to microseconds
$exchange->fetch_ticker('ETH/USDT');
print_r($exchange->rateLimit); // Milliseconds between requests
// Wrong - will cause errors
<?php
require_once 'vendor/autoload.php';
$exchange = new \ccxt\binance(); // ERROR!
// Correct
<?php
date_default_timezone_set('UTC'); // Required!
require_once 'vendor/autoload.php';
$exchange = new \ccxt\binance();
// Wrong - missing leading backslash
$exchange = new ccxt\binance(); // May fail!
// Correct
$exchange = new \ccxt\binance(); // Leading backslash!
// Wrong - wastes rate limits
while (true) {
$ticker = $exchange->fetch_ticker('BTC/USDT'); // REST
print_r($ticker['last']);
sleep(1);
}
// Correct - use WebSocket
use function React\Async\await;
$exchange = new \ccxt\pro\binance();
while (true) {
$ticker = await($exchange->watch_ticker('BTC/USDT')); // WebSocket
print_r($ticker['last']);
}
// Wrong - memory leak
$exchange = new \ccxt\pro\binance();
$ticker = await($exchange->watch_ticker('BTC/USDT'));
// Forgot to close!
// Correct
$exchange = new \ccxt\pro\binance();
try {
while (true) {
$ticker = await($exchange->watch_ticker('BTC/USDT'));
}
} finally {
await($exchange->close());
}
// Check required extensions before running
<?php
$required = ['curl', 'mbstring', 'iconv', 'gmp'];
foreach ($required as $ext) {
if (!extension_loaded($ext)) {
die("Error: $ext extension is not loaded\n");
}
}
1. "date_default_timezone_get(): Invalid date.timezone"
date_default_timezone_set('UTC'); at the top2. "Class 'ccxt\binance' not found"
composer require ccxt/ccxt\ccxt\binance with leading backslash3. "RateLimitExceeded"
'enableRateLimit' => true4. "AuthenticationError"
5. "InvalidNonce"
6. Missing PHP extensions
apt-get install php-curl php-mbstring php-gmp// Enable verbose logging
$exchange->verbose = true;
// Check exchange capabilities
print_r($exchange->has);
// Array(
// 'fetchTicker' => true,
// 'fetchOrderBook' => true,
// 'createOrder' => true,
// ...
// )
// Check market information
print_r($exchange->markets['BTC/USDT']);
// Check last request/response
print_r($exchange->last_http_response);
print_r($exchange->last_json_response);