You are here REST API - Source Code us a United States Treasury information provider that makes the data reported by the treasury on a daily basis readily available. The API provides users with access to the treasury's Operating Cash Balance , Deposits and Withdrawals, Public Debt Transactions, Adjustment of Public Dept Transactions to Cash Basis, Debt Subject to Limit, Federal Tax Deposits, Short-term Cash Investment, and Income Tax Refunds Issued. The API uses REST calls and returns JSON.