<![CDATA[The low critical thinking skills of elementary school students in Indonesian language learning, exacerbated by the lack of adaptive teaching tools for technological disruption, poses a pressing pedagogical challenge in developing regions. This research aims to develop valid, practical, and effective teaching modules through the integration of a collaborative approach. Lesson Study and technology Generative Artificial Intelligence (GenAI). The research method used is Research and Development (R&D) by adopting the 4D model (Define, Design, Develop, Disseminate). The trial subjects involved 34 fifth-grade students at SD Negeri 1 Muara Bungo, Bungo Regency, Jambi. Data collection was carried out through expert validation sheets, response questionnaires, and observations. Lesson Study, and critical thinking essay test. The results of the study showed: (1) The teaching module obtained very good validity scores from material experts (93.2%), media (88.5%), and language (91.0%) with an Aiken's V value of > 0.85; (2) The level of practicality based on teacher and student responses reached 89.4% (very practical category); (3) The effectiveness test showed a significant increase in students' critical thinking skills with a value ofN-Gainof 0.66 (medium-high category), where the analysis and evaluation indicators experienced the sharpest increase. GenAI integration in the cycle Plan-Do-See on Lesson Study It has been proven to facilitate teachers' pedagogical reflection and challenge students to go beyond simply accepting machine-generated information to logically critique technological output. This module is worthy of adoption as a supplement to Indonesian language learning in elementary schools, particularly in areas transitioning to digital literacy.]]>
