This chapter summarizes a multiyear investigation of task design and instructional practices for teaching coding with tangible screen-free coding toys in kindergarten classrooms (ages 5 and 6 years in the United States). Through multiple cycles of design-based research in classrooms, we iteratively designed instructional tasks, operationalized early childhood computational thinking (CT) and developed assessment items for CT competencies involving what we call “grid-agent” robot coding toys. In this chapter we summarize some of the design elements for tasks and instruction that support coding in kindergarten. Design elements included considerations for introductory lessons, attention to skills and strategies within engaging challenges and leveraging robot toys’ design features for specific CT and mathematics skills. We also introduce a competency model for the grid-agent robot coding toy genre that synthesizes our findings related to CT concepts for task and assessment design, which also emphasizes spatial concepts, symbolization of space, sequencing, iteration of units and other mathematics concepts and skills.