Q: How can I make sure my currency exchange rates are regularly updated?
A: In PrestaShop, all currencies is associated with the exchange rate for Euro.
These exchange rates are updated every day (at 2:00AM) by authorities in charge of these currencies. The API used to get those rates is https://fixer.io/
The PrestaShop company gathers these rates and expose them through API endpoint https://api.prestashop.com/xml/currencies.xml (URL available in the code through constant _PS_CURRENCY_FEED_URL_).
Function Currency::refreshCurrencies() is able to fetch these rates and update a shop currency data. In order to update currency exchange rates regularly, you need to setup an automatic task that execute Currency::refreshCurrencies() regularly.
To help you do so, a script cron_currency_rates.php exists in your admin directory.
This script can be triggered by a webserver if you hit the right URL. The admin directory is different for every shop so you need to use your own admin folder name.
You also need to provide an authentication secure_key.
In order to obtain this secure key, you need 2 items:
_COOKIE_KEY_ of your shop that you can find in app/config/parameters.phpThe secure key is computed like this:
$secureKey = md5(_COOKIE_KEY_ . Configuration::get('PS_SHOP_NAME'));
Assuming your admin directory is, for example, admin_9282, the URL you need to call will then be myshop.com/admin_9282/cron_currency_rates.php?secure_key={my_secure_key}
By sending an HTTP request to the URL computed above, if received by a webserver, you will trigger the currency rate exchange. You now need to setup an automatic task that send HTTP requests regularly.
A popular way to do it is to rely on a crontab. Most hosting providers allow you to configure one.
Provided your hosting provider allows you to configure cron jobs, you need to add an entry for a cron job to regularly call the needed URL. This tool can help you to write the statement you want.
Example of such a cronjob:
0 6 * * * curl "https://myshop.com/admin_9282/cron_currency_rates.php?secure_key={my_secure_key}"