Look up or search US Congressional bills via the Library of Congress Congress.gov API. Pass congress + type + number to fetch a specific bill (title, sponsors, latest action, action/amendment/committee counts, policy area, congress.gov URL). Or omit number to list bills filtered by congress, bill type (hr | s | hjres | sjres | hconres | sconres | hres | sres), date range, with pagination + sort. Bill type semantics: hr=House Bill, s=Senate Bill, hjres/sjres=joint resolution, hconres/sconres=concurrent resolution, hres/sres=simple resolution.