Forex.base_currency_rate/0 is not documented. Looks like it’s used by other functions. Should it be defp instead or maybe @doc false (in case you use it in other modules too)?

I would rather suggest to return structs instead of maps in case you already know what keys and values you have to expect. This would save lots of time on debugging for trivial typos.

You should consider using typespecs now. I’ve got that’s not supposed to be a 1.0.0 release and it does not need to be a top #1 priority, but it would definitely affect the documentation. For example let’s take a look at Forex.options/1.

With a spec like:

@spec options(Keyword.t()) :: options
# or even
@spec options(input_options) :: options

You can define options type, move all options documentation there and finally use options type in spec for other functions. This way you don’t have to copy-paste same documentation as developers interested what options are supported would simply hover or click on the options type link in the function spec.

@spec current_rates(input_options | options) :: map

In this example both options types are just Keyword.t(), but with different @typedoc. The input_options only have to mention that options/1 function would be used to get validated options. This way documentation would be much easier to read.

Please do not use spaces before header syntax in markdown, see: Forex — forex v0.1.1

You should change this line:

to:

    source_ref: "v" <> @version,

This is because your tags have v before version (which is not bad at all) and you don’t have a branch with this version. I guess you have copy-pasted a “working” configuration, but forgot to work in the branch. Because of that tiny mistake all links to the source code does not work.

You may be interested in adding badges to your README.md file, see:

It would be amazing to have a function like Forex.exchange_historic_rate(historic_date). This way people can create an example sites (like shop template) with a real prices. In many cases there would be no need to update the prices because of inflation which may be especially useful if in such template are used base products like food.

Please keep in mind that’s a public post. You may already know what I wrote, but it may be helpful for others.

That’s actually quite nice. Usually that stuff comes with all of those limits. Also daily updates is actually fine for a lot of stuff.

Hmm weird. I’m releasing a new version soon with the changes I highlighted above. So keep tuned for that.

There is no configuration needed. That’s an SSL issue. By default I’m using Req as the client. The error is an issue I had but it’s already fixed in the next version. Dunno why there might be a certificate error with the request tho.

Thanks for reporting.

Thanks for your suggestions! This was just a first release, I actually forgot to delete the application mod, the library is supposed to be started in the supervision tree, of course.
So already doing some changes.

This is exactly what this library does, but with pluggable Cache and client and some extra utilities.

Still rewriting some stuff, adding more tests and some extra utilities. Will release a new version soon.