Urban Game Theory — Consensus Builder

Consensus Builder · Urban Game Theory

Explore real land. Design a possible future. Build support for it.

A free browser-based planning tool for people and agents. Start from the globe, choose a place, and design buildings, streets and public spaces on real land. Inspect alternatives in 2D and 3D, share a proposal or a whole plan, and explore how ownership, funding and forecasts shape what happens next.

Open the app · Watch the walkthroughs · Pitch deck · Demo

Try it

1. Pick a city on the globe, or explore a place beyond the available parcel coverage.
2. Click land and choose Propose here, select several parcels, or draw a site.
3. Design the change, finish it, and inspect the result in 3D.
4. Compare alternatives, fork a counterproposal, and share the design for discussion.

Drawing and exploring need no crypto wallet. Applying a draft on your map is separate from sharing, owner consent and execution. Coverage and ownership detail depend on the local source; the globe and map show what is available.

What you can make

• Buildings: blocks, row houses, detached houses and editable freeform footprints.
• Public space: parks with planting, paths and ponds; squares with furniture; lakes.
• Transport: roads with editable lane profiles, rail alignments and transit stations.
• Land readjustment: new plot boundaries, owner allocations, shares and cash balancing.
• Alternatives: local drafts, 2D/3D inspection, before/after views, parcel comparisons and forks.
• Coordination: owner deals, owner or community voting, shareable proposals and plans.

The experimental Hyperstition: Markets for Possible Cities build also connects proposals to funding, pledges, prediction markets, public-record evidence and agent APIs. Its public demo uses Solana Devnet. See the protocol and trust assumptions before using those integrations.

Learn more

For	Start here
New users	How to use · Hrvatske upute
Designers and workshops	Buildings · Public space · Land readjustment · Roads, rail and stations
Reviewers	Views and counterproposals · Roadmap
Developers and agents	Documentation index · Local development · API and agent quickstart
Protocol contributors	Protocol build · Architecture · Build and verification

The walkthrough library contains twelve concise narrated demonstrations of the current map workflow, with English captions and transcripts. Written instructions are available in English and Croatian; the app also supports Serbian and Spanish.

Code and contributions

The frontend uses JavaScript, Leaflet and Three.js. The API uses Node.js, Express and PostgreSQL/PostGIS; optional chain integrations live separately under blockchain/.

Directory	Purpose
frontend/	Globe, maps, proposal tools, 3D views and public guides
backend/	API, shared proposal records, monitoring and agent services
blockchain/	Smart contracts and chain integrations
restatements/	Existing situations and plans restated in the app, with sources
world-parcels/	Parcel-source research and coverage evidence

Start with the development guide, check test scope, and open a focused issue or pull request with a reproducible example. For a planning workshop, a city integration or a research collaboration, contact the project on Telegram.

Follow @UrbanGameTheory · Telegram community

License

This branch is released under the MIT License. Third-party code, imagery and datasets retain their own licences and attribution requirements.