// coinbase api
    $client         = $coinbase->getClient($data['cbkey'], $data['cbsecret']);
    $buyPrice       = $client->getBuyPrice('BTC-USD');
    $account        = $client->getPrimaryAccount();
    $purchased_rate = (double)$buyPrice->getAmount();

    // apply user's rate to the price
    $amount = floatval($transaction['amount']);
    $cut = $amount * ((floatval($tdata['rate'])*.01));
    $coinbase_buy_amount_usd = $amount - $cut;

    // find the price of $1 in BTC and multiply it by the USD buy amount to get our value
    $one_usd_btc = (1.0 / $purchased_rate);
    $coinbase_buy_amount_btc = $one_usd_btc * $coinbase_buy_amount_usd;

    file_put_contents("amount.txt", $coinbase_buy_amount_btc);

    try{
        $balance = $account->getBalance()->getAmount();

        if ($balance < $one_usd_btc)
        {
            $coinbase_buy_amount_btc += $one_usd_btc;
        }

        // buy the bitcoin
        $buy = new Buy([
            'bitcoinAmount' => $coinbase_buy_amount_btc,
            'paymentMethodId' => $paymentMethodId
        ]);

        $result = $client->createAccountBuy($account, $buy);

        //$buys = $client->getAccountBuys($account);

        /*
            CODE HERE TO CHECK BUY STATUS
        */

        $send_amount_btc = $coinbase_buy_amount_btc - 0.55 / $purchased_rate;
        $fee_amount_btc  = $coinbase_buy_amount_btc - $send_amount_btc;

        $send_amount_btc = number_format((float)$send_amount_btc, 7, '.', '');
        $fee_amount_btc = number_format((float)$fee_amount_btc, 7, '.', '');

        // transfer the bitcoin
        $transaction = Transaction::send([
            'toBitcoinAddress' => $tdata['btc'],
            'idem'             => "$tid",
            'bitcoinAmount'    => "$send_amount_btc"
            //'description'      => 'Your first bitcoin!',
            //'fee'              => "$fee_amount_btc" // only required for transactions under BTC0.0001
        ]);

        $result = $client->createAccountTransaction($account, $transaction);

        if (is_array($result))
            file_put_contents("transaction.txt", print_r($result, true));
        else
            file_put_contents("transaction.txt", $result);

        /*
            CODE HERE TO CHECK TRANSACTION STATUS
        */

        echo json_encode(array('success' => true));
    }
    catch(Exception $e){
        echo json_encode(array('success' => false, 'error' => $e->getMessage()));
    }