BAI2 is the cash-management file format US business banks offer for accounting imports. The reader in ai-bookkeeper was written from the layout alone, with hand-made test files. This run fed it the four sample files in the MIT-licensed ministryofjustice/bai2 test data (Citi, NatWest, SVB-shaped and a blank-trailer file), reading them and copying nothing.
Amounts, dates, 88 continuation lines and the closing ledger balance all came out right. One thing did not: the SVB-shaped file lists the same account in two daily groups, and the reader called that "2 accounts", warned the user to export one at a time, and threw away the closing balance. Accounts are now counted by distinct number, and the latest group's balance is kept. One new test covers it.
Still true: these are sample files, not a real bank download. The reader has not met one yet, and the README says so.