callbase
Every NCUA 5300 filing, as one file per quarter
Available Free data.quartercall.com
The NCUA 5300 Call Report, mirrored from NCUA as Parquet that you can query from a laptop, with one request per cycle and no credentials. Amendments are resolved to the filing that stands, and values keep the precision they were filed with.
Documentation — how to read it, table by table.