OpenPlaza
OpenPlaza
§ OPENPLAZA — A WORKING MODEL FOR CIVIC INFRASTRUCTURE

Open-source civic infrastructure,
owned by the cities that run it.

One server inside the municipal building serves every cultural, sports and community institution the city funds. No licence fees. No vendor lock-in. All data stays in the city.

One server
every institution the city funds
EU-hosted
no citizen data leaving the city
Open source
municipality-owned, long-term
90 days
from signed pilot to live deployment
MUSEUMSLIBRARIESTHEATRESCONCERTHALLSCOMMUNITYCENTRESSPORTSVENUES
OpenPlaza
OpenPlaza
§ 01PRINCIPLE

Cities don't need five vendors for one capability — they need one server, shared.

A museum, a library, a sports centre and a theatre each buying their own platform means five contracts, five subscriptions, five data silos to reconcile later. Pooled onto one municipally-owned server, they get modern, self-hosted infrastructure the day it's switched on — and because they share it, their data already speaks one language. Nothing has to be integrated after the fact, because nothing was separated to begin with.

↳ Bought once. Owned locally. Shared by everyone the city funds.

§ 02ARCHITECTURE
One stack. Plug it in.

All components are open source, hosted on municipal hardware inside the EU. No vendor that could switch the system off.

FIG.03 — SYSTEM ARCHITECTUREOPENPLAZA · V1.0
ONE SERVERopenplaza.localEU-HOSTED · OPEN SOURCEFRONTENDweb uiSERVICESapi · workersDATABASErelational storeOBJECTSTORAGEfiles & mediaSYNCENGINEread modelIDENTITYsso · oidc§01§02§03§04§05§06DCAT-AP · CPSV-APdata.europa.eu
  • §01 · FRONTEND

    TanStack Start powers a static-built public site and a reactive admin UI where staff manage internal operations.

  • §02 · SERVICES

    API gateway, background workers, scheduled jobs. Gotenberg for PDF generation, Meilisearch for full-text search.

  • §03 · DATABASE

    Primary relational store on Postgres, accessed via Drizzle ORM. Daily encrypted backups.

  • §04 · OBJECT STORAGE

    S3-compatible object storage for files and media, erasure-coded across local drives.

  • §05 · SYNC ENGINE

    Zero. Real-time read-model sync between clients and DB.

  • §06 · IDENTITY

    Keycloak. SSO, role-based access, OIDC for staff & residents.

← INTER-SERVICE MESHEU · SELF-HOSTED
§ 03INTEROPERABILITY

Published once. Readable across Europe.

Every event, public service, and report a municipality enters is also emitted as machine-readable RDF — DCAT-AP for catalogues, CPSV-AP for public services — at the API boundary. No triple store, no separate database, no extra step for staff: the standard formats are generated from the same Postgres rows that power the site.

A town's data federates upward on its own — into the national open-data portal, into data.europa.eu, into cross-border search — instead of staying trapped in one HTML page. Compliance with the Interoperable Europe Act direction becomes a byproduct of routine work, not a project nobody has time for.

FIG.04 — EMISSION PATH
POSTGRES ROWsource of truthRDFDCAT-AP / CPSV-APdata.europa.eufederated upward
EMITSDCAT-APCPSV-APCORE VOCABULARIES
§ 04AI

Now that the architecture is modern, the same data lets us go one step further — and have AI draft the work that would otherwise never get done.

AI works with the worker, not in their place.

A civic worker writes once, in the language they think in. AI drafts what would otherwise not exist — translations into the city's other languages, accessibility descriptions, press summaries. The worker reads, edits, approves. Nothing is published without a click.

↳ AI is optional. Each deployment chooses where models run.

LIVE · TRANSLATIONRUNTIME · LIVE
EN · source (human-written)
Kaunas Symphony Orchestra invites you to a performance of Shostakovich's Symphony No. 9 at the Philharmonic.
generate ↓
LT
LITHUANIAN
Kauno simfoninis orkestras kviečia į Šostakovičiaus 9-osios simfonijos atlikimą Filharmonijoje.
PL
POLISH
Kowieńska Orkiestra Symfoniczna zaprasza na wykonanie IX Symfonii Szostakowicza w Filharmonii.
DE
GERMAN
Das Sinfonieorchester Kaunas lädt zur Aufführung von Schostakowitschs 9. Sinfonie in der Philharmonie ein.
ALT · descriptionThree-language translation drafts produced in seconds, waiting for a human to approve.
LIVE · ALT TEXTRUNTIME · LIVE
IMG · uploaded by the worker
Installation view of a light and shadow exhibition: a visitor before a long row of backlit screens with painted brushstrokes and a person's silhouette.
describe ↓
LT
LITHUANIAN
Šviesos ir šešėlių parodos vaizdas: lankytojas tamsioje salėje stovi priešais ilgą pašviestų ekranų eilę – viename tapytas gintarinis potėpis, kitame žmogaus, laikančio raštuotą audinį, siluetas tarp rašalo purslų.
EN
ENGLISH
Installation view of a light and shadow exhibition: a visitor stands in a dark hall before a long row of backlit screens, one with a painted amber brushstroke, another with the silhouette of a person holding a patterned cloth amid ink splashes.
PL
POLISH
Widok ekspozycji światła i cienia: zwiedzający stoi w ciemnej sali przed długim rzędem podświetlonych ekranów – na jednym namalowane bursztynowe pociągnięcie pędzla, na drugim sylwetka osoby trzymającej wzorzystą tkaninę pośród plam tuszu.
DE
GERMAN
Ausstellungsansicht einer Licht-und-Schatten-Schau: ein Gast steht in einer dunklen Halle vor einer langen Reihe hinterleuchteter Leinwände – auf einer ein gemalter bernsteinfarbener Pinselstrich, auf einer anderen die Silhouette einer Person mit einem gemusterten Tuch inmitten von Tintenspritzern.
ALT · descriptionFour-language accessibility descriptions drafted from one image, waiting for a human to approve.
§ 05IN PRACTICE

Already running in Kaunas.

Public events site, operator dashboard, analytics, custom institutional websites — all from the same single deployment, in production today.

PUBLIC

Shared events site

Every event, every institution — one citizen-facing portal. Searchable by date, venue, language. Multilingual and accessible by default.

Screenshot of the public KPR site listing events
OPERATOR

Operator dashboard

One window per institution. One entry, one place. Changes appear everywhere the moment they're saved.

Screenshot of the KPR operator dashboard
ANALYTICS

Analytics & reporting

Attendance, reach, language mix. Measured from the platform itself — no third-party trackers, no extra licences.

Screenshot of the KPR analytics view
CUSTOM

Custom institutional websites

One full website per institution. Bespoke design, shared infrastructure. No separate vendor, no separate stack.

Screenshot of an individual organization's website
§ 06CONTACT

Let's start a pilot.

90 days to a working deployment, shaped to your institutions and handed over to your team. No licence. No lock-in.

OBJECTIVE
Working reference deployment
DURATION
≤ 90 days
STACK
TanStack Start · Postgres · Zero · SeaweedFS · Keycloak · Gotenberg · Meilisearch · Dokploy
HOSTING
Municipality-owned hardware, EU
HANDOVER
Long-term, full source + docs
LICENCE
Open source
Or write directly — [email protected]