The "Spatial Justice Manual," a publication by the Centre for the Just City at TU Delft, contributes to the UP2030 Spatial Planning and Design Ready for 2030 Horizon Project. It is a resource for integrating principles of spatial justice into urban development and planning. This manual, rooted in the latest interdisciplinary research and collaborative insights, aims to guide policymakers, spatial planners, citizens, students, and other stakeholders through the complex terrain of integrating justice into sustainability transitions and creating equitable, inclusive, and sustainable urban environments. At the heart of the manual is the conviction that true spatial justice transcends mere access to resources, encompassing the right of all community members to participate in shaping the spaces they inhabit. Through a comprehensive exploration of theoretical foundations—including key concepts such as the Multiverse by Arturo Escobar and communicative planning as conceived by Patsy Healey—the manual provides practical strategies and tools for operationalising spatial justice. These range from participatory mapping and co-design processes to the innovative use of digital twins and engagement through the metaverse. The manual underscores the critical role of urban space in delivering social justice, advocating for designs that foster social cohesion, environmental resilience, and a sense of belonging. By emphasising the need for a collective reimagining of urban spaces, the "Spatial Justice Manual" equips its diverse audience with the knowledge and skills necessary to navigate and shape the urban challenges of the 21st century, making it an indispensable tool for those committed to the pursuit of a more just and equitable urban future.