Limen — Open Civic Data Platform

Italian open data, made visible.

Limen is an open-source civic data platform that makes Italian public data explorable through maps and visualizations. Boundaries, demographics, transit, vehicles, emissions — all in an interactive browser-based workbench.

Quick Start

npm install
npm run dev

Open http://localhost:3000.

Architecture

• No backend — all data is static files served from /public/data/
• Client-side processing — CSV/GeoJSON/SHP parsed in the browser
• MapLibre GL JS — vector-based map rendering
• Zustand — lightweight state management for the workbench
• Three-tier data: API-fed (auto-updated) → Curated static (expiry alerts) → Computed/derived

Data Pipeline

Processed data in public/data/ is committed to the repo — you don't need to run any scripts to develop locally. Scripts in scripts/ are used to refresh or add data.

Script categories

Fetch — download from public APIs (anyone can run these):

npx tsx scripts/fetch-boundaries.ts        # ISTAT WFS → GeoJSON boundaries
npx tsx scripts/fetch-population.ts        # ISTAT SDMX → population CSV
npx tsx scripts/fetch-demographics.ts      # ISTAT demographic structure

Process — transform raw source files into public/data/. These require raw data files (GTFS ZIPs, ACI CSVs, etc.) that are not included in the repo. See Adding a new dataset below.

npx tsx scripts/process-gtfs-stops.ts      # GTFS feeds → stops GeoJSON
npx tsx scripts/process-vehicles.ts        # ACI vehicle fleet (Sardinia)
npx tsx scripts/process-vehicles-national.ts # ACI vehicle fleet (national)
npx tsx scripts/process-population.ts      # Population by comune
npx tsx scripts/process-pendolarismo.ts    # ISTAT commuter matrix
npx tsx scripts/process-income.ts          # MEF income data

Compute — derive indicators from already-processed data in public/data/ (anyone can run these):

npx tsx scripts/compute-population-density.ts    # Pop ÷ area
npx tsx scripts/compute-motorization.ts          # Vehicles ÷ population
npx tsx scripts/compute-income-per-capita.ts     # Income ÷ population
npx tsx scripts/compute-emissions.ts             # ISPRA emission factors
npx tsx scripts/compute-demographic-indicators.ts # Age indices
npx tsx scripts/compute-commuter-balance.ts      # Net commuter flows

Utility:

npx tsx scripts/check-freshness.ts         # Check all dataset statuses

Adding a new dataset

1. Download the raw data from the official source (link it in your PR description)
2. Write a script in scripts/ — either a fetch-* (if the source has a public API) or process-* (if manual download)
3. Output goes to the appropriate folder in public/data/ (e.g. public/data/boundaries/, public/data/population/)
4. Add metadata to the dataset catalog in lib/datasets/catalog.ts
5. Commit the processed output — raw source files stay out of the repo, processed data goes in
6. Open a PR with the script + processed data + catalog entry

See CONTRIBUTING.md for code conventions and PR workflow.

Pages

Route	Purpose
/	Landing page
/workbench	Split-panel map workbench
/dati	Data catalog with freshness badges
/dati/[id]	Dataset detail page
/info	About the project

Tech Stack

Next.js · React · TypeScript · Tailwind CSS v4 · MapLibre GL JS · Zustand · Papa Parse

License

Code: MIT. Derived data: CC BY 4.0.