Hi, I read your project brief. I have experience in OAuth 2.0 protocol and have implemented several RESTful APIs which uses it to authenticate users in PHP, Python, and JavaScript. The OAuth 2.0 based APIs which I've implemented include Google Sheets API v4, QuickBooks, FreshBooks, Walmart, and eBay APIs among others.
I can implement the Open Bank API you've mentioned in your brief. I require its documentation, then API credentials among other things. I'd also like to know how do you want this monitoring system to work. I mean how do you want to get alerted.
If you'd like to discuss your project with me then feel free to send me a message even when I'm offline. I usually reply within a few minutes when online and within a few hours when offline.
Thank you!