Mixity is a collaborative platform for users to interact with the cityscape in mixed reality (MR). It strives to inject open-ended design into the immutable urban context, while boosting its dynamic and ever-changing quality. The Mixity platform implements the notion of remixing culture by providing open-source Kitbash and AI-generated libraries as design tools. These aim to challenge traditional crafting and creation methods, and exist at the intersection of traditional design and MR. To investigate the potential of architecture in the digital age, Mixity invites the crowds to play, create and interact as creative users. The project aims to combat digital totalitarianism by promoting a commons-based collaborative community.