The terminal shipped with three names and three PINs compiled into it. Same
three on every install, readable by anyone with the APK, and permanent —
nothing anywhere could replace them.
`/pos/staff` answers with the people the back office says may ring a bill at an
outlet, and the same list rides down with the session so a till is ready to
trade the moment it signs in. The terminal writes them over its own and
deactivates whatever it had, which is what actually kills the seeded logins.
Two sources are unioned because the schema has two and neither is complete.
`tenantstaffs` is the table built for this and holds 12 rows on the entire
platform; `app_users.locationid` is where staff actually ended up. Either alone
returns nothing for almost every shop.
The endpoint takes no location parameter. The answer carries PINs, so the
outlet comes from the caller's token and a request without one is refused
whatever POS_AUTH_REQUIRED says — a till must not be able to ask who works at
the shop next door.
Rows with no PIN are dropped rather than sent: a name on screen nobody can sign
in as reads as a broken terminal rather than as an unfinished setup. Duplicate
PINs are dropped too, keeping the first — live data has 1234 on eleven accounts
and 1111 on nine, and two people sharing one would make the till attribute a
bill to whichever row it checked first.
The PIN travels in the clear over TLS, deliberately. Four digits are
brute-forceable in microseconds however they are wrapped, so hashing here would
buy the appearance of strength and not the substance — while costing something
real, since the terminal salts every PIN with its own salt before storing it
and could never verify a hash computed here. A PIN is shift attribution, not a
security boundary; the boundary is the session token.
Verified against live data, and it says the fallback still matters: outlet 1135
— the one the POS actually uses — has zero staff, and the only staff row found
anywhere is a delivery rider on PIN 1111.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The POS surface was open. A till named its own outlet — `store_id` in a query
or in an ingest batch — and was believed, so one number changed in Settings
read another tenant's catalogue or posted bills into their books. There was no
middleware in the codebase at all, and the `JWT_SECRET_KEY` in the config was
read and never used.
Products were never mis-scoped: `resolvePosStore` already derived the tenant
from the location and the catalogue query already filtered on both. The tenant
was never taken from the wire. What was missing was any check that the caller
was entitled to the location they named.
So the outlet now comes *out* of a sign-in rather than going *in* from the
till. `POST /pos/login` authenticates against the same `app_users` rows the web
console uses — one account store, so deactivating a leaver closes both doors —
and answers with the outlets that account may reach, sealed in an HMAC-SHA256
token the terminal cannot edit.
Two checks then guard everything else, in order: the token verifies, and the
outlet named in the request belongs to the token's tenant. The second is the
one that matters — a valid token is a licence to name *your* outlets, not any.
Notes on the awkward parts:
- The guard reads the outlet from the body as well as the query. The two routes
that write carry `store_id` in a JSON batch and never in the URL, so a
query-only check would have left exactly the dangerous call unguarded.
- Three spellings of one thing survive — `store_id`, `locationid`,
`location_id`. All three are read rather than normalised, because renaming
them breaks terminals already in the field.
- `POS_AUTH_REQUIRED` defaults to false. Tills are billing real customers
against the open endpoints right now and enforcing at deploy would stop every
one mid-trade. A token is still verified when sent, and a wrong-tenant token
still refused; the flag only governs requests carrying none.
- `POS_TOKEN_SECRET` has no baked-in fallback and fails loudly. A development
secret in source is the same as no signature at all.
- `configid` is inferred when the till does not send it, because a person at a
counter has no way to know theirs. `authname` is not unique in this schema —
live data has one address twice under one configid — so an ambiguous match is
refused rather than resolved by LIMIT 1, which could bill into the wrong
tenant's books.
Verified against live data: 58 accounts across 34 tenants can open a till, an
account pinned to a location resolves to it alone, a tenant-level account gets
all six of its outlets, and a cross-tenant outlet request is refused.
Passwords are still plaintext platform-wide. Flagged at the comparison site;
fixing it is a migration touching every login path, not this endpoint.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Two faults found while checking whether today's live bills had landed. They
had — 17 of them, complete — but both of these were sitting in the same data.
**Health existed only over MQTT.** The consumer subscribes to the health topic
and has done since startup, but a terminal on the HTTP route has no way to
reach it. Today's terminal was on HTTP, so it reported nothing and the board
showed "online 0 of 1" while the till was demonstrably alive and selling.
POST /pos/health now takes the same payload the broker carries, into the same
Redis record, so the board cannot tell the two routes apart and does not need
to. It answers 202 and swallows failures: a till that cannot say how it is must
still sell.
**terminalid was empty on 16 of 17 bills.** The consumer backfills a missing
terminal code from the topic, but onto the batch, while the row was built from
the order — the two never met, and importPosOrder was not handed the batch's
value at all. Over HTTP there was no topic to fall back on either. So the
invoice numbers read INV-2608-T5EDD-000NN while the column they should have
matched was blank, and `byterminal` on the sales summary grouped almost
everything under "". The bill's own terminal now wins with the batch's as the
fallback, trimmed, so whitespace is not mistaken for a code.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The ingest only ever wrote. A bill that reached pos_orders was safe and
completely unreachable — no screen in the product could show it, and the
only way to see a day's counter takings was to query the database by
hand.
Three endpoints: a paged bill list, one bill with its lines, and a
summary split the three ways somebody actually asks for — by tender for
reconciling a drawer, by day for a chart, by till for an outlet running
several counters.
locationid is required on all of them and is the authorisation boundary,
so a caller cannot page through another shop's takings by omitting a
parameter. Fetching a bill under the wrong outlet returns 404 even when
the reference is a real one.
Dates match businessdate rather than arrival, because a till that was
offline overnight uploads yesterday's bills this morning and they belong
to yesterday. The list is ordered by billedat for the same reason —
sorting by arrival would interleave a recovered backlog through today.
Unlike the ingest handlers these answer in the usual envelope: they are
read by the web app, not by a terminal, and nothing about them is bound
to the till's contract.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A till holds every bill in its own SQLite database and keeps it for
seven days after we acknowledge it, marking one synced only when its id
comes back in an ack. Everything here follows from that.
Silence is not acceptance, so a failing ingest publishes nothing at all
and the terminal simply sends again. A duplicate is a success, because
at-least-once delivery means a lost ack legitimately re-delivers bills
we already hold, and calling those failures would strand a day of
takings on the till. Deduplication is a unique index on the terminal's
UUID plus an advisory lock held for the transaction.
Bills land in pos_orders / pos_order_items rather than orders: a counter
bill carries a cashier, a terminal, a rounding adjustment, promos,
loyalty movement and a payment split that orders has nowhere to put, and
forcing one into the other loses whatever does not fit. Stock is *not*
split — a counter sale writes the same productstocks rows an app order
does, through helpers extracted from createOrderTx so the rule that
prevents overselling has one implementation rather than two.
GetRevenueSummary and GetSalesSummary were extended to union the new
table in; any new report has to remember the same.
Terminal health goes to Redis under a 90-second TTL, sharing the
instance the express backend uses. A heartbeat is a fact with an expiry
date: a till that loses power stops refreshing and ages off the board by
itself, where a Postgres row would need ~288k writes a day and a reaper.
Proven end to end against the live estate before commit: a bill over
HTTP and one over the real Mosquitto broker, the same bill three times
producing one row and one stock movement, and a heartbeat arriving on
the health endpoint. All probe data was removed afterwards.
Four things that only surfaced against real data. An unset jsonb column
failed the very first bill. Product SKUs are unusable as barcodes — 6,245
products share 93 SKUs and "1" covers 5,794 of them — against the till's
unique index, so barcodes fall back to the product id. A taxpercent of
-1 exists and would have put negative GST in a filed slab. And a product
with id 0 exists, which can never be billed and is now skipped.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
