Defining currencies

Now you have multiple accounts and they may have varied currencies in them. The commodities.bean already has definitions for a few:

1970-01-01 commodity GBP
  price: "USD:yahoo/GBPUSD=X"
  asset_class: "currency"

1970-01-01 commodity USD
  price: "GBP:yahoo/USDGBP=X"
  asset_class: "currency"

1970-01-01 commodity EUR
  price: "USD:yahoo/EURUSD=X"
  asset_class: "currency"

Now, your local currency may not be in there. Fortunately enough, all you need to do is just a copy-pasting one of the statements, replacing the name and adjusting the price field configuration. The data is fetched from Yahoo.Finance by default and it probably has your currency. Providing asset_class is optional but it will make more dashboards work and will be used to distinguish currencies from various investments.

Commodities config

Conversion rates

prices folder contains Beancount files with data about conversion rates and various ticker prices over time.

In order to add a new data point for specific date:

Navigate to the Prices tab in the Lazy Beancount UI. It will allow you to choose the date and will automatically run the bean-price command to download prices for your commodities for that date. If you want to save the fetched values in your ledger (as displayed in the interface), just click on the “Save” button.

Commodities config

Some of the rates are fetched in GBX instead of GBP and this is not handled by bean-price itself. That means they’re off by a 0.01/100x multiplier. Additional config file prices_config.yml allows to fix that automatically if you use the interface. You can edit the file from the Config tab.

To fetch an entry for the specific date, run

  PYTHONPATH=PYTHONPATH:. bean-price data/main.bean -i --date=2023-12-03

from the command line. Then insert the output as a new block in prices.bean or a file under prices/ directory.

More details about how this all works can be found in the original documentation.

Regularity

I fetch these values at a regular frequency (weekly in my case). You may want to do this at the same time as updating your account valuations but you don’t have to. You can always fill these values retroactively.

Make sure the first prices fetched preceed the first transaction or pad directive in your ledger. Otherwise you may see some strange-looking graphs in Fava because the older values could not be converted between each other.

Note that if you add a new commodity to the file the already existing files under prices/* will not be updated automatically. There’s no automation to fix this currently, maybe this repository is worth looking into.

Configuration

main.bean has configuration for your primary currencies.

option "operating_currency" "USD"
option "operating_currency" "GBP"
option "operating_currency" "EUR"

These are the ones that you will be able to select from in the Fava interface (e.g. if you want to convert all the values and see the graphs in specific currency).

Additional plugin is required if you want to do indirect conversions in the interface. For example, a commodity’s (e.g. GOLD) price is in USD but you want to see its value in EUR (and you already have the USD->EUR rate fetched).

plugin "beancount-generate-base-ccy-prices.generate_base_ccy_prices" "EUR"

Result

You are able to see any graphs and reports in the currency of your choice. Most of the time you won’t need to think too much about conversions. For example, for manual cash transactions just specify in the currency it happened.

The information about commodities configuration is also applicable to when you start tracking investments later on. You will just use ticker symbols instead of the currency names.