> Does this service get historical rates from its sources in real time or does it store those in its own local database?
Historical data are stored and synchronized at regular intervals in the local db.
> How long will this service be free for? What’s the business model that’s being thought about?
I was looking for stable service and i did not find any,
that would have satisfied my needs, so i decidide create myself.
Current features will be as free in the future as they are now.
> What kind of rate limiting, if any, is used so that a developer who uses these APIs doesn’t have their app go down because someone else is hammering the server with a lot of requests?
Yes, there are rate limit, currently 300 per minute, you can see it in the response header.
> Does this service get historical rates from its sources in real time or does it store those in its own local database?
Historical data are stored and synchronized at regular intervals in the local db.
> How long will this service be free for? What’s the business model that’s being thought about?
I was looking for stable service and i did not find any, that would have satisfied my needs, so i decidide create myself. Current features will be as free in the future as they are now.
> What kind of rate limiting, if any, is used so that a developer who uses these APIs doesn’t have their app go down because someone else is hammering the server with a lot of requests?
Yes, there are rate limit, currently 300 per minute, you can see it in the response header.