One API to look up U.S. federal GSA per-diem (travel lodging + M&IE) and HUD Fair Market Rent / Small Area FMR (rent by bedroom, with voucher payment-standard bands) for any ZIP code — joined in a single call. FY2026, public-domain data, clean JSON. Built for travel-nurse stipend, relocation/HR, and real-estate/Section-8 tools. Unofficial; not affiliated with GSA or HUD.
