You are the mayor of a new city on a 500×500 grid. Every building you place — a household, a store, a mine, a bank — is an independent economic actor with its own cash balance, and the city runs as a live simulation: each day, every company buys labor and materials, produces whatever its recipe calls for, and sells what it makes, while every household sells its residents' labor and spends on food, water, electricity, consumer goods, fuel, and education and administrative services. Nothing is scripted — prices, wages, and growth all emerge from the trades that actually clear.

Production runs in real supply chains: a mine turns labor into iron ore, aluminum, and rare earths; a steel mill turns iron ore and methane into steel; a factory assembles steel, lumber, aluminum, rare earths, and plastic into consumer goods, which travel from a warehouse to a store to a household. Every trade is priced by what a buyer is willing to pay and what a seller needs to charge, delivered — the shipping cost depends on the road network connecting them, and a higher road level moves goods more cheaply. A company that can't afford everything it needs simply produces less, or nothing at all, until conditions change.

Every business pays its own way out of its own cash: wages, materials, and city taxes are all real money leaving its account. A business that runs short can sell bonds to a Bank — up to its own founding cost in debt — and pay them back on a fixed schedule; miss that ceiling while still cash-poor, though, and the bank forecloses, taking the whole business onto its own books, permanently. The city itself earns nothing but taxes: a property tax on every building's value, an income tax on realized profit, and a flat daily fee, all set by you in Tax Policy — a heavier hand raises revenue but slows the growth you're taxing.

As mayor, you paint roads and place buildings from the Build dock, set tax policy, and otherwise let the simulation run — your job is choosing what gets built, where, and how it's taxed, not micromanaging every trade. Households grow, or shrink, based on how well their needs are actually being met, so a thriving city needs its whole supply chain working, not just housing. Check City Books for full GAAP-style financial statements, Companies for any single business's own books and transaction ledger, Market for live prices and trade history, and Analytics for the long view — then decide what your city needs next.