There are few importers available which have been opensourced (look at the Actual's github org), I have only tried one during migration from greedy YNAB.

There is also an API which works quite well. I am using it to import transactions from Revolut. So no Open Banking yet, but afaik it's painful to get in the UK anyways

> You could even hook up your own bank syncing -- Plaid support a free development plan that covers an individual user. In fact, you'll see Plaid support in the syncing server because I already started building this out.

Not yet, but it sounds like a top priority.