The Stop Secret Spending Act of 2024 requires the federal government to publicly report "other transaction agreements" on USAspending.gov, a government website that tracks federal spending. Other transaction agreements are a type of contract often used by federal agencies for research and development that currently bypass standard spending transparency requirements. The bill mandates that the Secretary of the Treasury create a unique identifier for these agreements within 90 days and establish data standards for reporting them. Additionally, the legislation requires an annual public report detailing the total amount of federal spending that remains unreported, along with explanations for why certain spending has not been disclosed, such as national security reasons or classified information. Federal agency inspectors general must also submit compliance reports to Congress at least every two years, with the first report due within one year of the bill's enactment.