Amidst the increased enrolment of international Chinese English as an additional language (EAL) students in North American universities, scholars have reported on their academic and social experiences in navigating English-medium studies (e.g., Liu, 2016; Zhang & Zhou, 2010). Although informative, some studies focus on EAL learners' perceived deficient language proficiencies, and how these deficits can negatively impact their academic success. In contrast to studies based on deficit models, this study argues that participants exhibit agency as evidenced in their responses to challenges encountered in and changes to their perceptions of and practices in academic writing. Employing an ecological perspective and (second) language socialization theories (Duff, 2010, 2019; van Lier, 2004, 2008), this qualitative case study examined how six first-year Chinese EAL learners enacted their agency and resourcefulness when navigating their academic writing trajectories. Ultimately, this study's findings recommend that composition faculty, administrators, and EAL educators recognize EAL writers' agency in accessing multiple resources while acknowledging their writing challenges, providing an optimal learning environment, and empowering them to thrive in their mainstream composition studies.