I aim to provide a cognitive semiotic explanation of the role of artefacts in relation to human agency. The contribution of this research is relevant for the current debate on extended/distributed cognition and material agency. In addition to cognitive semiotics, the research is also relevant for understanding the cognitive processes of design. My research deals with the following questions: What is agency? Are artefacts endowed with agency? If artefacts have agency, what kind of agents are they? The discussion around the notion of agency keeps being an unfinished matter with fruitful implications for semiotics of design.