Code Week @ School is a grassroots initiative aimed at promoting computational thinking and coding activities in schools. It encourages schools to join the initiative, with the goal of having 50% of European schools participate by 2020. The document provides information for teachers on how to get involved, such as organizing coding activities and registering them on the Code Week map. Teachers are encouraged to mobilize other schools and use provided toolkits and resources to spread knowledge of coding and computational thinking to students. The initiative also includes challenges like Code Week for All to engage students across multiple schools and countries.