We revisit the urban margins by recasting service hubsconspicuous clusters of helping agencies in inner-city locales, designed to serve vulnerable populationsas both spaces of survival but potentially transformative, emerging as so-called 'cracks' in the city. We undertake this recasting using the concept of the commons. Using case studies in London, Miami and Osaka, we focus on the everyday practices of commoning and the role service hubs play in the city as spaces of sustenance, care and solidarity. The results are mixedservice hubs enabled unfettered survival and operated largely outside of capitalism, ensuring that some spaces in the city remain de-commodified and 'at the margins'. However, the service hubs were also limited in their transformational capacity. These results contribute to a sense of commons at the margins, rethinking them more as an edge between capitalism and an existence separate from it, rather than presenting them as exclusively marginal in the sense of subordinated, excluded and bordered.