parking_solution/wiki/entities/subscription.md

---
type: entity
tags: [parking, domain, business, subscriptions, identity, pricing]
sources: []
updated: 2026-06-18
status: open
---

# Subscription

A **subscriber**: a known holder who parks on a **recurring plan** (e.g. **10,000 ALL / month**)
instead of paying per stay. The second of the "two populations" ([[entry-exit-readers]]); a valid
subscription **short-circuits the payment step** of a [[parking-session]] ([[session-model]]).
Transient is built first; subscriptions layer on top.

> **Renamed 2026-06-18 (was "Permit").** The operator term is **subscription / abonim**, not
> "permit / lejet". The master-data **tables/routes/UI/types were renamed** permit→subscription
> (migration `0004`). The **signed ledger keeps its `permitId` payload field** — that is immutable,
> hash-chained history, so renaming it would break verification of past events. So: *code & data =
> "subscription"; the on-chain field name stays `permitId`.* See the schema note in `schema.ts`.

## Pricing — recurring monthly plan (built 2026-06-18)

Each subscription records its **own price**, so an individual and a company fleet can differ:

- `priceMinor` — the recurring price in **minor units** (integer; e.g. `1000000` = 10,000.00).
  `null` = no price set (a comp / legacy subscription).
- `period` — the billing period. **`"monthly"` only** today (the enum is widened later if a site
  ever needs weekly/annual).
- `currency` — ISO-4217 of `priceMinor` (e.g. `"ALL"`); required when a price is set.

A **site default monthly price** lives in `site_config.subscription_monthly_price_minor` — it
merely **pre-fills** the new-subscription form; each subscription still stores its own value and may
override.

### Collecting the fee is a SHIFT transaction (decided 2026-06-18, deferred build)

Selling/renewing a subscription is a **financial transaction a common operator makes during their
[[shift]]** — the subscriber pays the monthly fee at the booth like any other customer. So it is
**not** an admin-only master-data edit; the money must land in **that operator's shift**: their
drawer (if cash) and their [[shift|Z-report]].

The clean way (the model already supports it): collection writes a signed **`payment`** ledger event
— same shape the transient pay-station uses (`{ amountMinor, currency, tender }`) — at collection
time, tagged with `{ subscriptionId }` so it's identifiable as subscription revenue.

- It folds into the shift automatically: the Z-report sums `payment` events in `[start, end]` **by
  payment time**, and the drawer fold adds **cash** tenders (card settles to the bank) — no new
  summing logic needed. The fee lands in **whichever shift was open when it was taken**, attributed
  to that operator. (See [[shift]] "drawer balance".)
- **Admin** still edits the subscription master data (price, window, credentials); the **operator**
  takes the money. Two different acts.
- A subscription's own [[parking-session|entry/exit]] events stay **free** (no per-stay `payment`) —
  only the *plan fee* is a payment, decoupled from any individual stay.

> **Deferred build.** Today we only *record* the agreed price + coverage window
> (`validFrom`/`validTo`); no collection event is written yet, so subscription revenue does not flow
> into the drawer/Z-report or [[reconciliation]]. Open detail when built: whether to model it as a
> plain `payment` (simplest, folds today) or a distinct `subscription_payment` type (clearer in
> reports, but the shift/drawer fold would need to count it too). Leaning **plain `payment` +
> `subscriptionId` tag**. (Decision 2026-06-18: store price now, collect-in-shift later.)

## Credentials (how a subscription is presented) — confirmed 2026-06-15

Recognized by a credential read at the barrier. Two kinds, mapping to the two identity paths, and
**either can be combined with LPR/ANPR plate identity** (the plate binding below):

- **RF tag / chip / card.** An RFID/proximity credential, read **host-side** (reader → host →
  `pulseOpen`). A Wiegand-out reader keeps a future autonomous path open ([[entry-exit-readers]]) but
  isn't required (the [[dingtian-relay]] has no onboard card list).
- **QR code.** Read by the optical reader — inherently **host-side** ([[entry-exit-readers]]). Host
  decodes the QR → looks up the subscription → decides. A subscription's QR can be **printed**.
- **Plate (LPR/ANPR) — NOT YET IMPLEMENTED.** When plate-bound (below), a matching plate read is an
  accepted identity too. The vision/ANPR service that produces plate reads is future work
  ([[opencv-anpr-service]] / [[lpr-camera]]); until it exists, plate binding has no live source.

Both feed the host as a reader event whose `source` is `wiegand` / `qr` (the `IdentitySource`
already in the model) and whose value is the credential id.

## Two optional, independent bindings — confirmed 2026-06-15

A subscription has **two constraints the admin may or may not apply**, orthogonally. Either, both, or
neither.

### 1. Car-count binding (default: 1)

- **Optional.** By default bound to **1 car at a time**. The admin may raise the limit (a household, a
  company fleet) or **unbind it entirely** (no cap).
- The limit is on **cars inside at once** (`maxConcurrent`), enforced over the [[parking-session]]
  projection: at entry, count the subscription's currently-open sessions; if `< maxConcurrent` (or
  unbound) allow, else reject. A fold over the signed ledger, **not a counter someone can edit**.

### 2. Plate binding (default: off)

- **Optional.** By default not plate-bound — any car may use it (identity is the card/QR). The admin
  may bind it to a set of specific plates; a matching plate then **is an accepted identity**
  (card/QR **OR** plate, not a second factor).
- **Accepted tradeoff:** card-OR-plate doesn't prevent card-sharing; the signed
  [[append-only-event-chain]] records exactly which credential/plate entered, so abuse is visible to
  [[reconciliation]]. Plate-spoofing (a printed plate on a different car) is caught by the
  [[opencv-anpr-service]]'s vehicle-attribute verification, not here.

## Time-of-day access windows — DESIGN NOTE, NOT YET IMPLEMENTED (2026-06-18)

A subscription may be valid **only during certain hours of the day**, behaving as a normal transient
customer outside them. The motivating case: an **overnight subscriber** allowed in on their
subscription **19:00 → 07:00**, but charged the normal [[tariff]] if they park during the day.

Intended behaviour (to design + build later):

- The subscription carries one or more **recurring daily time windows** (e.g. `[{ from: "19:00",
  to: "07:00", days: [...] }]`). Windows may **wrap past midnight** (19:00→07:00 spans two calendar
  days) — the check must handle the wrap.
- **At ENTRY**, evaluate the window against the host clock ([[clock-integrity]]):
  - **inside the window** → subscription entry (no ticket, no fee), exactly as today;
  - **outside the window** → the car is treated as a **normal transient**: it takes a ticket and
    pays the [[tariff]] on the way out. The subscription is simply *not used* for this stay.
- **The boundary cases need a decision** (flagged, not resolved):
  - *Enters inside the window, exits outside it* (parks past 07:00): is the whole stay free
    (entry-time decides), or is the over-window time charged transient (like
    [[tariff|lapsed-mid-stay]])? Leaning **entry-time decides** for simplicity, but confirm.
  - *Day-of-week scope* (weekdays vs. weekends), holidays.
  - Interaction with `maxConcurrent` and plate binding (orthogonal — should still apply).
- **Data:** a child table (e.g. `subscription_windows`) or a JSON column on `subscriptions`; TBD with
  the implementation. Legacy precedent exists — the ParkSQL2017 schema had
  `MembershipPlansTime` / `ActiveDays` ([[parksql2017-legacy-schema]] §"time-/day-restricted
  memberships"), confirming this is a real market need.

> **Explicitly postponed.** For now this is documentation only — no schema, no enforcement. A
> subscription is valid whenever it is active and within `validFrom`/`validTo`, all day.

## Data model (as-built 2026-06-18)

Tables (mutable master data; every *use* still produces a signed `vehicle_entry`/`vehicle_exit`):

| Table / field | Notes |
| --- | --- |
| `subscriptions.id`, `holderName`, `contact` | the subscriber |
| `subscriptions.priceMinor` / `period` / `currency` | recurring plan (monthly); null price = unset |
| `subscriptions.maxConcurrent` | car-count binding; **default 1**, raise for fleets, `null` = unbound |
| `subscriptions.validFrom` / `validTo` / `status` | coverage window; active / suspended / revoked |
| `subscription_credentials[]` | `{ kind: 'rf' \| 'qr', value }` |
| `subscription_plates[]` | bound plates (accepted identities when set) |

## Interaction with the session model

- **Entry:** credential read → subscription lookup → valid (active, in window, plate allowed **if
  plate-bound**, concurrent cars `< maxConcurrent` **if car-bound**) → signed `vehicle_entry`
  (`source = wiegand/qr/lpr`), open barrier. No ticket, no fee.
- **Exit:** credential/plate read → matching open subscription session → signed `vehicle_exit`, open.
- **Lapsed mid-stay:** subscription expires while parked → uncovered time falls back to the transient
  [[tariff]] (edge case to design — and the same question the time-window boundary raises above).
- **Revoked:** a revoked subscription fails the entry check → treated as transient or refused (OPEN).

## As-built (2026-06-15, renamed + priced 2026-06-18)

`apps/server/src/subscription-flow.ts` (was `permit-flow.ts`), reached via the **read dispatcher**
(`read-dispatch.ts`): a credential read routes to the subscription flow if it **matches a
subscription** (card/QR credential, or a bound plate) — otherwise to the transient exit flow.

- **Direction inferred from session state for that car** — no open session → ENTRY (check
  `maxConcurrent`, sign `vehicle_entry`, open); an open session → EXIT (sign `vehicle_exit`, open,
  close). A fleet has one session per car; anti-passback falls out.
- **`maxConcurrent`** enforced as a fold over the signed ledger (the on-chain `permitId` payload is
  the match key). Refusals (revoked / out-of-window / at-capacity) are signed `anomaly` events.
- **Admin CRUD** (`apps/server/src/routes/subscriptions.ts` + `apps/web/src/SubscriptionManager.tsx`):
  a subscription is an **aggregate** (row + credentials + bound plates + price). `GET
  /api/subscriptions` (any signed-in role — for lookup), `POST/PUT/DELETE /api/subscriptions[/:id]` +
  `POST /api/subscriptions/:id/revoke` (**admin only**). Validation: `maxConcurrent` positive int or
  `null`; `priceMinor` non-negative int (currency required when set); at least one credential or one
  bound plate.
- **Pricing** stored on each subscription (`priceMinor`/`period`/`currency`), pre-filled from
  `site_config.subscription_monthly_price_minor`; **fee collection into the ledger is deferred**
  (see Pricing above).

## Open questions

1. **Reader hardware** — confirm the RF reader and QR/optical reader models (procurement; [[bom]],
   [[open-questions]]).
2. **Lapsed-mid-stay & revoked** policy (fall back to transient [[tariff]] vs. refuse) — confirm.
3. **Subscription-fee collection** — a **shift transaction** (operator takes the monthly fee at the
   booth → signed `payment` → folds into their drawer/Z-report). Deferred build; see Pricing.
4. **Time-of-day access windows** (overnight subscribers) — design + build; boundary-case policy
   above (see the design note).