Even though the importance of corrective feedback (CF) is widely recognized, there is no agreement on the most effective type of CF for promoting self-regulation. Thus, this study adopts a sociocultural perspective on learning and employs dynamic assessment (DA) as a CF form. DA is considered a theoretically promising approach to CF as it focuses on the learning process rather than the end product. Instead of the common teacher-learner interaction, this study initiates a teacher-learner group interaction with the support of text chat. Text chat helps teachers to cater to all students in the class simultaneously through several chat groups. This longitudinal study was part of an ongoing, university-level three-month English-as-a-second-language course. The findings demonstrate that this collaborative approach facilitates self-regulation through teacher mediation and peer scaffolding, and that the text chat supports implementing DA in the classroom while its features support mediational and reciprocity moves of the DA process.