Every Fab City made one promise. This is how you tell who is keeping it.
In 2014 Barcelona pledged to make, by 2054, most of what it consumes, and 60 more cities and regions have signed since. A promise with a date needs a measure. The Index is that measure: what a city buys from far away and throws away nearby, what it makes and shares close to home, and how fast it turns what it learns into something done.
A city takes things in and puts things out. The Index reads both.
Products in, trash out
The old way runs in one direction. A city buys what it needs from far away, uses it, and throws it away nearby. Fab City calls that PITO: products in, trash out. It is how almost every city on Earth works today.
Data in, data out
A Fab City runs the other way. It senses what is happening on its own ground, shares designs and know-how openly with other cities, and makes more of what it needs in workshops nearby. Fab City calls that DIDO: data in, data out.
The Index scores both, across four pillars of city life and five scales, from a neighbourhood to the region a city sits in. Then it adds the part no city index has ever scored: how much of what a city learns gets acted on, and how fast. We call that ρ. A reading nobody responds to changes nothing.
The full method, with what is still missing, is on the methodology page.
Nobody can measure a city from one place. The Index is built from three kinds of reading, carried by one network.
The first kind is data that already exists. Cities publish open data. Global providers publish more: air quality networks, trade statistics, satellite imagery, planetary boundaries. Adapters pull from these on a schedule and fill the cells they can. This is how Paris and Hamburg were scored, and it is still where most of the numbers come from.
The second kind is read from the ground. Sensors on a wall, a drone over a river, a soil test, a survey a neighbourhood runs itself. These readings fill the cells no platform holds: what the air is like on this street, what this district actually makes. They come from the people who live and work in the place.
The third thing is not a kind of reading but what carries all of them. PLANETAI is a distributed computer built for this. A hyperlocal node is a small machine in a home, a workshop or a lab that reads its own square kilometre and keeps everything on its own disk. Nodes will hand their summaries up to a city node, a regional node, a bioregional node, and from there to the Index; today they report to the Index directly. The same machines that carry the data also read it: a node knows what changed nearby before any report does, says so to the people who can act, and counts whether anything was done. That is the intelligence the Index adds, and it is what makes ρ a measured number instead of a guess.
Two hyperlocal nodes run today. Bali is the first pledged place with one. City and regional nodes are the next releases. The Index is built by whoever fills a cell, and the members of the network hold the first responsibility for their own place.
Read it. Fill it. Count what nobody counts.
If you want to read
The pledge, the cities, the numbers so far, and where they come from. Most people start here.
The mapIf you run a lab or hold a city's data
You connect the sources that fill the Index for your place: a sensor network, the city's open data, a study you already ran.
The workbenchIf your community wants to count something nobody counts
Some things no platform holds: what the air is like on your street, what a neighbourhood decides matters. A campaign creates that data and puts it on the Index on the community's own terms.
Making Sense BaliSixty-one cities and regions have pledged. Here is how much is known about each.
Loading the network from the Coverage Tracker…
On the full list, two numbers sit beside each place: how many of its cells have a registered source, and how many anyone has checked at all. Most are low. That is the point of publishing them.
The Index, in four parts.
The twenty cells
Four pillars across five scales, and how many cities have a source for each.
Open →How it is worked out
The formula, the weights, and what is still unsettled.
Open →What has been scored
Two published scores, and why no city has a full reading yet.
Open →Where it comes from
Paris 2018, Hamburg 2024, and what this version adds.
Open →