 for personal budgeting and I love it, it's a great tool. On a weekly basis, I will manually reconcile my YNAB transactions with each of my banking providers. This is pretty straightforward as I enter transactions as and when I spend money. In addition, I schedule repeating transactions such as rent.

YNAB is great for one-off purchases and regular payments. However, entering a public transport ticket can be tedious as it's always the same payee, amount and category. The only variable is the date which is irregular. I have no idea how many times I'll take public transport in a given week. 

 has an endpoint where you can add a transaction to your budget. Once I got my personal Access Token I could successfully hit the CRUD endpoints in 

. I then set up an API route in NextJS to hit the YNAB endpoint and integrated the API route with the client.

I wanted the UX to be simple to the point where I didn't have to type. If there was any data entry required then I may as well use the YNAB mobile app. I hid the trigger on my website and now, whenever I get on the tube, I hit the trigger and a transaction is entered in my budget.

This is the most basic of hacks, it's just hitting an API from a front end, and likely only a relevant problem for me. However, it's now turned a tedious task of entering 5 data points into a form field into a fun secret for me. 

Building a custom functionality for irregular transactions

Node

APIs

Irregular budgeting with YNAB API

When I started working with lambda functions I struggled to find a simple solution to check if the correct values were present either in a JSON body or as a query parameter.

I stumbled upon a useful package on npm - 

 - and this was a big step in the right direction. Here is a simple example:

This only checks that there is a value for uuid in the query parameter. A more complex situation could have completely custom validation of the value as well as a custom error message: 

When making a mistake in calling your API, you would now get a specific error message:

Whilst it isn't perfect, it covered my use case pretty well and has saved me time multiple times.

How I return helpful error messages in Node

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Irregular budgeting with YNAB API

Validating API bodies and query params