If you're based in Europe or UK, Nordigen has a completely free API do exactly what you described (I'm one of the cofounders).
We're connected to 1,500 EU/UK banks and you can connect your bank account to your script/app without any license, certificates or any fees. We don't charge for accessing banking data, we only charge for complimentary data enrichment services like transaction categorisation.
We were considering using Nordingen but our main concern is that it seems that Nordingen is essentially able to MITM all calls on PSD2 endpoints, right? How do you establish trust, and how can you keep the service free?
We're connected to 1,500 EU/UK banks and you can connect your bank account to your script/app without any license, certificates or any fees. We don't charge for accessing banking data, we only charge for complimentary data enrichment services like transaction categorisation.
https://nordigen.com/