How to use bean-price and extend it

[francocalvo]

Hi! I'm new to beancount, and I'm trying to load the ARS-USD 'real' conversion rate (CR). Yahoo Finance and other sources inform the official CR, which is inaccessible. For example, right now we got:

Yahoo Finance ARS=X => 1 USD = 260.97 ARS

DolarHoy source 'DolarBlue' => 1 USD = 492 ARS

For this I'll need a custom source for the bean-price. I read in an issue that the supported bean-price is this repo. As of now, I'm using NixOS as my OS, and I've installed the latest v2 Beancount version, which comes with a bean-price bundled.

 I've installed in a flake and venv the git package for bean-price, but I'm not sure if it's that the version I'm using. Currently, for example, I can't access the ratesapi source, so I guess not. Any hand on this?

On the other hand, I'd like to write this custom source, but I'd love a quick example on how configure it to use it from the CLI. I read that a normal module would do it, so I made a little module using Poetry, but I'm not sure how it has to look as a stand-alone module. Would anyone be able to help me with an example?