Usfiscaldata

This gives Claude direct access to the U.S. Treasury's free REST API with 54 datasets covering national debt, daily treasury statements, interest rates, exchange rates, and securities auctions. No API key needed, which is rare for government data. The skill documentation is unusually thorough with actual endpoint paths, parameter tables, and working Python examples for common patterns like fetching Debt to the Penny or paging through large result sets. The API returns everything as strings including nulls, so you'll need to cast types yourself. Best for economic analysis, tracking federal finances, or building dashboards around Treasury data without the usual authentication headaches.