Simplifying my finances is one of those things that’s been on the list forever and just never got looked at. It sat there, neglected, while everything else got attention instead.
Part of the reason is that I spread certain banking functions across different banks. If you follow personal finance blogs, you already know that’s not the recommended move. I try to follow the You Need A Budget methodology, which is the app I use to manage my budget, and the whole philosophy there is keep things as simple as possible. One account, one clear picture.
But my problem is I don’t want all of my money for the month just sitting in a current account. I don’t want that to be where irregular spending, or spending in general, comes out of. Some banks solve this with what people call pots or envelopes, virtual ways to segregate money inside one account. This bill comes from here, that bill comes from there, savings live somewhere else, all under one umbrella. I’m not going to say which bank I use for this, but not many banks in the US or the UK actually offer it, so if you go looking you’ll probably figure it out. The bank I use also has a developer API, which is both potentially dangerous and potentially powerful.
What I wanted was something that could handle the bills coming out of one pot (mortgage, electric, the recurring stuff), set aside money for the credit card bill so it’s always covered when it lands, round up spending a bit each week and stash the extra somewhere, and keep the actual monthly savings separate from all of that. Then whatever’s left sits in the current account for general spending.
The catch is that thing needs constant care and feeding. Bills are fixed, so you pad them a little and move the money over. Paycheck comes in, and you have to decide how much sits where, because I want money sitting somewhere earning interest until I actually need to spend it. It’s a lot of small administrative decisions that need to happen on a schedule, and none of it is hard, it’s just tedious.
So naturally, when you’re a tech person with an API, and a private server sitting at home that you’ve locked down tight, my answer was to build something.
I got access to the developer API and dictated all of it into my notes app first, walking through every use case. Then I fed that into Codex, since that’s what I’m building with these days, and told it what I wanted. It came back and said, yes, absolutely doable, confirming the one thing I already knew I’d need. Everything had to live in one bank, using pots instead of separate current accounts, because the API can only do things within that bank itself, not across open banking connections. That part wasn’t news, it’s why I’d spent the past month or so slowly relocating everything into one place beforehand, betting the API work would do what I thought it could. I was playing the long game on it.
I know at least one or two friends who’ve played with this same API before and had good things to say about it. Someone else at work has built something much bigger with it too, which I’ll get into another time once I’ve actually built my own version of that.
What I ended up with is a website with a UI that tracks the different use cases and, more importantly, the logic rules, because there have to be very specific rules in place so it never moves money it doesn’t have or shouldn’t touch. I built it with a few maturity levels. At the bottom, it’s purely informative, just telling me what’s going on and what it suggests. Above that, semi-manual, where it recommends a move and I go execute the transfer myself. That’s roughly where I am right now, moving from just getting notified to getting a recommendation I still have to act on.
After that, the plan is a warning stage, a day or two heads up before it makes a move on its own, and eventually full automation, where it just tells me after the fact that it moved money, on top of whatever notification I’d get from the bank itself anyway.
The whole point is that if I’m not around to do it, my wife doesn’t have to think about it, and it saves me from manually shuffling money around every week or month. The only thing I’ll still need to do is reconcile it in You Need A Budget, since it’ll pull the transactions in through open banking like anything else. Because the moves are predictable, I’ll know what I’m looking at when they show up.
The logic itself is actually pretty simple. It’s the fact that it touches money that makes me cautious, which is why there are four or five approval levels instead of just flipping it on. The plan is to ratchet it up gradually over a few months, and if it’s consistently accurate after five or six months, I’ll trust it with full automation.
That’s where the AI part gets more interesting, past the point of just building the thing. Once it’s built, I don’t really need AI for it anymore beyond patching bugs or tweaking the UI. The real question becomes whether what I built for manual human intervention is actually the smart way to do it. Is the amount of headroom I gave the bills pot right? Are the intervals right? What actually makes sense here? I’ve asked it to help me look back at a couple months of data eventually and suggest improvements, which feels like the more useful use of AI in this than the building itself.
There’s a part of my brain that’s irrationally nervous about handing this over, even though it can’t make trades and can’t send money anywhere outside my own accounts, and I’ll see everything it does. It’s managed risk, I’d say. But if it works the way I think it will, it saves real time every month, so it’s worth the caution.
Next up, I want to see if there’s a US equivalent I could set up something similar with. My early research says no, but we’ll see.
