StreetRx.com is a website that assembles and organizes crowdsourced information about the black-market price of prescription drugs. The street market for prescription medications—such as Vicodin®, Adderall®, and fentanyl—comprises a vast underground economy that is little studied and poorly understood. Launched by public-health researchers at Epidemico, Boston, Massachusetts, StreetRx closes this knowledge gap, providing an extensive, searchable database of the latest street-price data.