Documenting urban food supply systems is essential for understanding their functioning, impacts, and future evolution. While this task is a critical step in implementing urban food policies, it faces significant challenges— particularly in low‑ and middle‑income countries. Through a case study of Hanoi, Vietnam, we use diverse empiri‑ cal data sources to tackle the issue. We quantify the urban food supply system of Hanoi for one key product: fresh vegetables. By combining multiple investigative methods, we employ social network analysis to map the interme‑ diary networks connecting production and consumption. Volume of food flows moving through different supply channels and the spatial expansion of the entire system have been determined. Our findings reveal that Hanoi currently sources vegetables from a vast area, encompassing all of northern Vietnam and parts of China. While local production (within Hanoi) still accounts for 46% of the supply, most locally grown vegetables pass through intermediaries—such as wholesalers, retailers, and street vendors. These intermediaries play a crucial role by bringing fresh produce closer to consumers, thereby enhancing the overall efficiency of the supply chain. The re‑ sults align with predictions from previous research, indicating that food supply systems in Southern cities are in‑creasingly following trends observed in Northern cities as urbanization progresses. We recommends that future food policies should explicitly address the role of middlemen, particularly street vendors. The roles and contribu‑ tions of these informal operators to the urban food systems of the Global South should be formally recognized. Keywords: Urban Food Supply; Food Flows; Intermediaries; Informal Economy; Food‑Sheds