Analyzing the anarchist commons in Montreal, Canada using participatory action research interviews with 127 participants, we find that anti-authoritarian groups and networks addressing disparate but connected struggles are building an anarchist commons, constructing a loose grouping of spaces, networks and collectives united by a shared political culture. Key debates are explored, centering on: intentional development of the commons; mixed labour models; and anti-oppression practices of calling in vs. calling out. Participants indicate an understanding of the anarchist commons through theories and practices beyond capitalism, including feminist, queer, trans and anti-racist commitments. Finally we argue that the shared anti-authoritarian political culture provides a certain resistance to enclosure of the anarchist commons through the processes and practices used to construct it.