Search open US federal government job postings from the official USAJOBS API. Filter by keyword (title/skills), location (e.g. "Austin, Texas" or a state), and/or hiring organization; at least one is required. Returns the total matching count plus current openings with title, agency and department, location(s), salary range (USD) and pay interval, GS pay grade, work schedule, posting/close dates, and the official apply link. Keyless to the caller, public-domain (OPM). Live federal hiring data an LLM cannot recall — for job search, labor-market and workforce research.