<p>This study examines how smallholder farmers in South Africa innovate the digital through user-led, grassroots appropriation of existing platforms. Drawing on multiple qualitative case studies of a Facebook group, a WhatsApp group, and two purpose-built agricultural applications, and informed by user innovation and grassroots innovation theory, the study develops four core insights. First, digital innovation emerges through use-based reconfiguration rather than technological invention, as farmers recombine and repurpose existing tools into multifunctional entrepreneurial infrastructures. Second, digital platforms function as grassroots entrepreneurial infrastructure assembled from below through intentional appropriation, not provisioned from above. Third, user innovation in this context is not diffusion-oriented; it is internally directed toward improving users’ own entrepreneurial positioning, challenging linear models that privilege scaling or commercialisation. Finally, scaling occurs through collective appropriation and entrepreneurial layering, where innovations accumulate relationally rather than spread through standardisation or market replication. The study shows that digital innovation can be use-based, self-directed, and scaled through cumulative, layered appropriation rather than invention or diffusion. For policy and practice, this implies supporting user-led digital innovation by prioritising platform affordances that enable adaptation, experimentation, and visibility, thereby strengthening users’ capacity to assemble grassroots entrepreneurial infrastructures from below.</p>