This article suggests a theoretical framework for re-examining the complex relationship of language, literacy, and cultural practices, across multiple generations in the context of community-based Indigenous language revitalization. In the scholarship of Indigenous language revitalization and education, researchers have shifted from viewing language policy and planning as a top-down process to suggesting the imperative for engaging local communities in the dialogues and development of language-related programmes. Going beyond taken-for-granted notions of bounded, monolithic community structures, we ask: what are the critical mediating practices between individuals and larger communal structures that create affordances or constrain opportunities for collective efforts? To address this, we employ cultural-historical activity theory (CHAT) to examine the processes of language revitalization in one Truku (Indigenous) village in Taiwan. With its attention to the role of artefacts in an activity system, CHAT helps us to problematize the use of orthographic conventions in language revitalization. Furthermore, we discuss how the incorporation of other semiotic resources mediates the spaces of agency and expands villagers' opportunities to participate. Lastly, CHAT helps community researchers and practitioners to reconceptualize the frustrations that accompany their language revitalization efforts as 'historically accumulated contradictions' across activity systems. We conclude with a reinterpretation of community-based language revitalization as an emerging process in which a shared goal is actively sought and negotiated.