src/services/Anticaptcha.php
public function getBalance()
    {
        $this->setParam(static::ACTION_FIELD_ACTION, static::ACTION_BALANCE);
        $response = $this->getResponse(static::ACTION_BALANCE);
        $result = $this->decodeResponse(static::DECODE_ACTION_BALANCE, $response);
        if ($result[static::DECODE_PARAM_RESPONSE] != 0) {
            return 0;
        }

        return (float) $result[static::DECODE_PARAM_BALANCE];
    }
public function getBalance()
    {
        $this->setParam(static::ACTION_FIELD_ACTION, static::ACTION_BALANCE);
        $response = $this->getResponse(static::ACTION_BALANCE);
        $result = $this->decodeResponse(static::DECODE_ACTION_BALANCE, $response);
        if ($result[static::DECODE_PARAM_RESPONSE] != 0) {
            return 0;
        }

        return (float) $result[static::DECODE_PARAM_BALANCE];
    }
Баланс

@return float