Where can I get the exchange rate of the main currencies + ruble via API, 2-3 times a day?

Question

API

You need to take the exchange rate of the main currencies such as USD, EUR, GBP... about 5 pieces and the ruble. Through the API. To be safe.
In total there will be 2-3 requests per day, so you need it for free.
Where do you advise? You can use several sources to be even more reliable.

Answer 1

The Central Bank provides data, incl. in XML ( documentation ). For example, quotes of all currencies for today, June 27, 2019:
Courses are updated once a day.
The exchange rate is a free, market thing. Any bank or exchanger can set its own rate and change it at least every second. Look for banks that provide open APIs for their currency quotes.

Answer 2

https://fixer.io/ - in the free plan 1000 requests per month.