["Global Networks, Volume 26, Issue 3, July 2026. ", "\nABSTRACT\nThis article reconceptualizes migrant smuggling along the Balkan Route through the lens of the smuggling assemblage, which captures the fluid, relational and context‐dependent nature of clandestine mobility. Based on multi‐sited ethnographic fieldwork between 2020 and 2023 across six countries, including 85 semi‐structured interviews and observation, the study challenges dominant portrayals of smuggling as the work of hierarchical, centralized networks. Instead, it reveals shifting and sometimes contradictory roles: migrants act as guides, brokers or ‘self‐smugglers’; locals, state agents and legitimate businesses facilitate crossings; and alliances emerge and dissolve in response to volatile border conditions shaped by EU externalization policies. Applying the lens of relational agency, the analysis shows how mobility is co‐produced through transient trust networks, shared knowledge and material resources within dynamic borderscapes. Moving beyond victim–perpetrator binaries, the study centres migrant agency and highlights the permeability of roles, contributing to critical migration scholarship and extending assemblage thinking in border and mobility studies.\n"]