---
type: overview
tags: [parking, overview, synthesis]
sources: [parking-system-architecture]
updated: 2026-06-21
---

# Parking System — Overview

The synthesis / entry point for this wiki. Start here, then follow links. Catalog of every page:
[[index]]. Source summaries: [[parking-system-architecture]].

## What it is

A **parking-management web application** running on a **dedicated, hardened Linux appliance**
deployed on-site at a parking facility. Two forces shape nearly every decision:

1. **[[offline-first]]** — a park may be air-gapped; nothing core may depend on a network.
2. **[[threat-model]]** — the primary adversary is the **legitimate operator at the booth**, not
   an outsider. The classic fraud is *take the cash, delete the record.*

## The architecture in one pass

- **Stack** ([[technology-stack]] / [[standing-decisions]]): [[turborepo]] · [[fastify]] ·
  [[react-vite-spa]] · [[sqlite]] + [[drizzle-orm]] · [[local-jwt-auth]] — all open-licensed to
  avoid lock-in (cf. rejected [[payload-cms]], [[refine]], [[logto-zitadel-oidc]]). The operator UI
  ships as a thin **[[desktop-shell-tauri|Tauri v2]]** kiosk shell (chosen over Electron).
- **Integrity** is the heart of it: an [[append-only-event-chain]] (hash-chained, signed) plus
  external [[reconciliation]] — *that's* what remote sync really is. Signing is **software today**
  (key on-disk → forgeable by a host owner); a non-extractable **hardware signer** (TPM / USB-HSM;
  the [[atecc608]] is upcoming) is the pending fix — [[hardware-signer-options]]. Encryption at rest
  ([[disk-os-hardening]]) defends a secondary threat.
- **Devices** sit behind a [[device-adapter-pattern]] (swap hardware → new adapter only), with
  the [[barrier-not-a-door]] safety principle keeping physical safety in barrier-operator firmware.
- **Access control** today is the **[[dingtian-relay]]** relay+input controller behind
  [[network-isolation]] — chosen because its inputs are **decoupled from its relays**, enabling
  host-in-the-loop ticket-first entry (resolving [[access-controller-button-flow]]). The
  [[uhppote-controller]] and [[zkteco-controller]] were evaluated and **rejected** (historical).
  The deeper fork is still the [[trust-boundary]] ([[uhppote-vs-esp32|detection vs. prevention]]);
  the [[esp32-custom-controller]] remains the prevention-grade alternative.
- **Readers** split two ways ([[entry-exit-readers]]): permit holders via [[wiegand]]
  (autonomous), casual/transient via host-side [[lpr-camera]] / QR; both can share a relay.
- A reference [[bom]] lists recommended devices.

## Where it stands

6 [[open-questions]] still drive procurement — most critically **lane topology**, **failure
modes (fail-open on exit)**, the **reconciliation channel**, and **backup/durability**.

## Reading paths

- *Security-first:* [[threat-model]] → [[append-only-event-chain]] → [[reconciliation]] →
  [[uhppote-vs-esp32]].
- *Hardware-first:* [[bom]] → [[dingtian-relay]] → [[access-controller-button-flow]] →
  [[entry-exit-readers]].
- *Stack-first:* [[technology-stack]] → [[offline-first]] → [[device-adapter-pattern]].