beancount is a plaintext accounting/personal finance system: https://bitbucket.org/blais/beancount/overview

This is an importer between YNAB4 -- https://www.youneedabudget.com. YNAB4 is the previous, desktop based version, of the software.

This is designed to be run on a recurring basis: you enter data in YNAB and then sync it into beancount. However, it also will work perfectly fine is you just want to do a one-time migration from YNAB to beancount.

Running the import is straightforward, you just point it at your YNAB file and your beancount file.

./import.py ynab bean

It will output the beancount statements to stdout and a summary to stderr

2016-12-31 * "Uber"
    ynab-id: "60C90246-EEF9-FB6F-8FC6-57663DF068C1"
    Assets:VN:Citibank-Visa    -25,000 VND
    Expenses:Everyday:Spending-Money

2016-12-31 * "Uber"
    ynab-id: "F266AE25-BDFA-3C59-3A79-57665331CF0A"
    Assets:VN:Citibank-Visa    -36,000 VND
    Expenses:Everyday:Spending-Money

0 errors during import
30 warnings during import.
	Check and fix income statements.
	Search for Category/__ImmediateIncome__ and Category/__DeferredIncome__.
1165 imported.
0 already imported; skipped.
Don't forget to run bean-check on the result!

This allows you to redirect the output, appending it to your beancount file.

./import.py ynab-file bean-file >> bean-file
0 errors during import
30 warnings during import.
	Check and fix income statements.
	Search for Category/__ImmediateIncome__ and Category/__DeferredIncome__.
1165 imported.
0 already imported; skipped.
Don't forget to run bean-check on the result!

Buried somewhere deep inside your YNAB folder there is a file named Budget.yfull which contains all of your transactions. That's the file the importer relies on. On my machine the full path is:

./YNAB/My Budget Test~CAB5B90E.ynab4/data1~E6B943B1/9133AEC3-2369-8AFB-52EB-CC52E6BE8478/Budget.yfull

but it will be slightly different for you.

In order for the importer to map between YNAB and beancount, it relies on metadata in the beancount file. The ynab-name metadata on an account tells the importer how to match up accounts. YNAB has a two-level hierarchy of accounts. Use a colon (:) to separate the two levels.

2016-01-01 open Expenses:Vacation
    ynab-name: "Savings Goals:Vacation"

All income from YNAB will come from one of two accounts: Categories/__DeferredIncome__ and Categories/__ImmediateIncome__. You can either map those to an account

2016-01-01 open Income:Salary
    ynab-name: "Categories/__DeferredIncome__"

Or you can leave them unmapped. If you leave them unmapped then the importer will generate statements that look like

2016-01-01 * "My Company"
    Assets:VN:Cash    1,000,000 VND
    Category/__DeferredIncome__

This is not valid syntax in beancount, so bean-check will complain. But it makes it easy to search through your beanfile and add the correct accounts.

YNAB has the concept of hidden categories. These are budget categories that you are no longer using. Creating the mapping for them is a little tricky since YNAB effectively renames them.

Imagine you had a master category called Monthly Spending. And inside of that you had a subcategory called Yoga Classes. You've quit yoga, so you've made it a hidden category, so that it doesn't clutter up YNAB. Normally you'd use a mapping key of Monthly Spending:Yoga Classes. But since it is now a hidden category you have to use

Hidden Categories:Monthly Spending ` Yoga ` A4

There are three things to note:

1. The master category is now Hidden Categories
2. YNAB uses the backtick (`) as a separator between the old master category and the subcategory.
3. There's a magic number. This is an internal category id that YNAB uses. There's really no way to know what this is other than to run the import once and see if there are any errors about hidden categories.

The importer will infer the currency of the transaction from the account in beancount.

2016-01-01 open Assets:US:Cash  USD

YNAB only supports a single currency so this seems like a better approach than specifying the currency in some other way. It does, however, require you to specify the currency on the account in beancount.

The importer will generate a ynab-id metadata statement for each transaction. This allows you to re-run the importer multiple times and only import new transactions. This is what makes it possible to use YNAB every day for data entry and then sync new data over to beancount whenever you like.

2016-12-31 * "Uber"
    ynab-id: "F266AE25-BDFA-3C59-3A79-57665331CF0A"
    Assets:VN:Citibank-Visa    -36,000 VND
    Expenses:Everyday:Spending-Money

Those aren't imported into beancount. Not yet, at least.

YNAB has flags, that track whether a given transaction has been reconciled or not. Those are currently not imported.