Human intellectual development is grounded in dialogue and collaboration. This study examined how students' collaborative epistemic actions and activities evolve and expand in interactive online learning meetings and how digital technology affords coordinated epistemic actions, enhancing students' agency in learning in an institutional massive open online course (MOOC). As data, recordings of students' online video meetings were analyzed using interaction analysis and interpreted using the cultural-historical theory of learning. The findings revealed that students engaged in four epistemic actions and several epistemic activities: (a) co-orientation (epistemic positioning and planning rules of engagement), (b) presentation (sharing ideas explicitly), (c) assessment (questioning, clarifying, and feedback giving), and (d) reflection (concluding and outlining further actions). These collaborative epistemic actions evolved when the students presented, explained, claimed, and vetted their epistemic claims related to creating the examination assignment in the online collaborative learning meetings. Digital technology can effectively mediate students' coordinated epistemic activities. Online interactive sessions will establish the relational zone of belonging, and foster students' emotional, cognitive, or intellectual becoming, enhancing their agency in online learning.