The Spectra


  1. We designed the first version of a buildable city and we’re releasing the geometry to everyone for free.
  2. If you make any changes to it, we can add your designs to the open-source Toolkit and to the Source City, our virtual reality repository.
  3. If you join the community, you will be able to initiate projects with other members, start blocks, vote and receive technical support.

Join our community on Discord

City Modders

Members who actively contribute to Spectra’s growth, design, and functionality are called city modders. They modify the city across physical, digital, and social dimensions. City modders are free to choose how they contribute according to their own skills and interests.


Spectra Blocks are the fundamental social unit of the city empowered to make decisions over their common space and connections to neighboring spaces. A block’s decisions directly impact the design and function of its courtyard, the ground level below, and the size and shape of the surrounding residential spaces. Within Spectra Cities’ online community, Block Groups represent self-organizing social sub-groups focused on shared interests, goals, identity, or other elements.


Projects are medium and long-term expeditionary ventures proposed and voted on by the Spectra community. When a project reaches enough votes, it is launched by a project team and the results are submitted for inclusion in the Source City if they meet the maintainers criteria. projects can involve both Spectra community members as well as outside guests and partner institutions.

Projects don’t have to have specific deliverables, they can be open-ended, project-based, or inquiry-based.

Guild System

You don’t have to have technical expertise or a professional background to be a City Modder. Through the guild system, you can learn alongside other Spectrans and specialize in a virtual citymaking skillset. City modders can propose new guilds for subjects that interest them, whether it’s architecture, games, AR/VR, economics, governance, sustainability or anything you can dream up with other Spectrans.

Source City Contributors

Source City Contributors are Spectrans who are cleared to contribute changes to the Source City and toolkit. Anyone can become a contributor by participating in the community and completing the application process.

Source City Toolkit

The Source City Toolkit is a living repository of collaborative tools and assets that we’re making available for free use under a CC0 license. As the community grows, the Source City is updated to reflect a snapshot of the virtual city. City modders and teams working on projects in Spectra have regular opportunities to submit them for inclusion in the Source City toolkit. Once Spectra maintainers validate and optimize your submission, it will be added to the next release.

Spectra Cities Forum

Join our community on Discord