Geomann1: If you are talking about campaign contributions, for the US House that is widely transparent and monitored by the FEC and all contributions and expenditures by campaigns are available online, (I know because I ran for Congress in 2016 and we dealt with FEC filings. The auditors at the FEC were super helpful).

Presidential contributions are also online. But the Senate needs to be dragged into the 21st century. They do NOT process their campaign finances electronically but instead have allowed themselves to submit PAPER filings via the secretary of the Senate and thus are hardly transparent at all.