[docs](alarm): record the four alert endings

Document the wire contract as implemented: single-origin access through Maestro, no auto-stop, the owner-set persistence cap, the durable delivery ledger and its 409 check-in, explicit acks, hashed device ids, one anonymised event log, and the four ways an alert ends (delivered, expired, disarmed, deleted). Also corrects the heading to match the table it introduces.
This commit is contained in:
2026-10-19 02:28:59 +01:00
parent 6873b1a3f1
commit 3cd04105bb
+385 -80
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@@ -15,6 +15,47 @@ Everything — the API, the auth proxy and the WebSocket — rides that **single
port**. There is no second listener and no TLS on the service itself (an edge
proxy terminates TLS).
### How a client reaches this service
An instance exposes **one** port. Apps and phones do not address a service
directly — not this one, not any other: they address the instance, and Maestro's
data plane relays the request. There is no per-service hostname, and direct
service access is not a supported deployment.
So a client's base URL is `http(s)://<instance>`, and exactly three namespaces
are reachable (`Maestro/src/handlers/dataplane/`, one allowlist, one dispatcher,
HTTP or WebSocket by upgrade presence):
| Public URL | Service path | Purpose |
| --- | --- | --- |
| `{base}/api/alarm/action/{actionName}` | `/action/{actionName}` | the action API documented below |
| `{base}/api/alarm/auth/{path...}` | `/auth/{path...}` | shared-auth proxy (`login`, `register`, `refresh`, `me`, …) |
| `{base}/api/alarm/ws/alarm` | `/ws/alarm` | the live alarm socket (WebSocket upgrade) |
- The data plane is **not** behind Maestro's owner gate: `Maestro/src/main.go`
registers it deliberately outside `RequireSession`, because its callers are
apps and phones that hold no Maestro session and must never be handed the
instance operator's cookie. **The service is the gate** — Alarm validates the
access token and the alert token itself and answers `401`/`403` on its own.
History for the next reader: the action surface shipped ungated, was wrapped
in the owner gate by commit `2ffdf77`, and that gate was a regression for
phone traffic — not a design.
- The query string is forwarded **verbatim** (tokens live there) and
`X-Access-Token` is forwarded untouched. `Authorization` and `Cookie` are
**not** forwarded, so Alarm never sees them; `Sec-WebSocket-*` is rebuilt by
the relay.
- The service's answer is the answer: status, body, `Content-Type` and
end-to-end headers are mirrored byte-for-byte, redirects included. Maestro
envelopes **only its own** failures — `404 ERR_NOT_FOUND` (unknown
service/namespace), `409 ERR_NOT_RUNNING` (stopped container),
`502 ERR_UPSTREAM_UNREACHABLE`, `500 ERR_INTERNAL` (its own plumbing) — with
`{"error":{"code","message"}}`. Hop-by-hop headers and `Set-Cookie` are
stripped by the relay; Alarm sets no cookies, so that changes nothing here.
- `/config` and `/_manifest` are deliberately **unreachable** through the data
plane: `/config` is Maestro's own ES256-signed edge and exposing it would let
a caller skip the mint; `/_manifest` is consumed by Maestro, not by clients.
The manifest is documented below for completeness.
## Routes
| Route | Purpose |
@@ -67,8 +108,9 @@ Two further credentials exist, both **in the payload** (never in a header):
- `adminToken` — the alert's admin secret. Minted once by `createAlert`,
stored only as a SHA-256 hash server-side, and required by the destructive
actions.
- `subscribeToken` — the shareable secret rendered as the QR code. It is
*rotatable* and is the only thing a joining client needs.
- `subscribeToken` — the shareable secret rendered as the QR code. It is minted
once per alert and never rotates (subscribers are permanent for the alert's
lifetime); it is the only thing a joining client needs.
Errors are **not uniform across the request pipeline**. Clients must know
where the boundary is.
@@ -117,6 +159,7 @@ Consequences worth internalising:
| `ERR_ALERT_NOT_SUBSCRIBED` | 404 | caller is neither the admin nor a subscriber of this alert |
| `ERR_ALERT_ALREADY_JOINED` | 409 | unique-constraint race on `(alertId, user, deviceId)`; the normal re-scan path is idempotent and returns `200` |
| `ERR_ALERT_STATE` | 409 | the action is illegal in the alert's current state (e.g. disarming a non-triggered alert, deleting a live one) |
| `ERR_ALARM_TRIGGERED_OFFLINE` | 409 | **not an error**: `alarmStatus` is telling this device it missed a trigger while offline and must ring now (the body carries the frame) |
| `ERR_INTERNAL` | 500 | unexpected server/database failure |
`ERR_METHOD_NOT_ALLOWED` (405) and `ERR_UNAVAILABLE` (503) also exist on the
@@ -124,6 +167,14 @@ WebSocket endpoint — see below. These codes only ever appear in a JSON
envelope; the dispatch-level `405` described above is plain text and carries no
code.
**Every error response carries a human-readable message; there is no
bare-status form on the wire.** A JSON error always has a non-empty `code`
**and** `message` (the emitter substitutes the code's canonical message if a
handler ever supplies an empty one, so this holds by construction rather than by
convention), and a plain-text dispatch error always has a non-empty body. No
documented case exists where an error message is legitimately empty — if one is
ever needed, it must be added here first.
## Action summary
The dispatcher routes by HTTP method (`GET`, `POST`, `PUT`, `DELETE`); in every
@@ -145,10 +196,10 @@ GET-only** (`POST /action/me` is a `501`). `DELETE` accepts the two removals.
| `removeSubscription` | DELETE, POST | — | admin (any row) or the subscriber (own row) |
| `triggerAlert` | POST | required | admin |
| `disarmAlert` | POST | required | admin |
| `alarmStatus` | GET, POST | — | admin **or** subscriber |
| `ackAlarm` | POST | — | admin **or** subscriber; subscribers must send `deviceId` |
| `alarmStatus` | GET, POST | — | admin **or** subscriber; read-only (reports debt, clears nothing) |
| `deleteAlert` | DELETE, POST | required | admin |
| `qrImage` | GET, POST | — | admin **or** subscriber |
| `rotateSubscribeToken` | POST | required | admin |
### Shared-auth actions (`/auth/*` proxies)
@@ -182,8 +233,7 @@ Creates an alert and makes the caller its admin.
```json
{ "payload": {
"name": "Fire drill",
"message": "Leave the building now",
"autoStopSeconds": 300
"message": "Leave the building now"
} }
```
@@ -191,7 +241,6 @@ Creates an alert and makes the caller its admin.
| --- | --- | --- |
| `name` | string | required, 1–255 characters after trimming |
| `message` | string | optional, ≤ 2000 bytes, the default text pushed with a trigger |
| `autoStopSeconds` | int | optional, `0`–`86400`; `0` (default) means "ring until disarmed" |
Response `200`:
@@ -205,8 +254,6 @@ Response `200`:
"adminToken": "…", // shown ONCE, store it
"subscribeToken": "…",
"qrPayload": "https://alarm.dcntrlized.org/a/0f8f…e#…",
"autoStopSeconds": 300,
"tokenVersion": 1,
"created": "2026-10-18T17:00:00Z"
}
```
@@ -214,6 +261,19 @@ Response `200`:
`adminToken` is returned **only here** (and nowhere else, ever). The server
keeps a hash. Losing it means losing admin rights over that alert.
There is **no auto-stop and no ringing duration**: an alert created here rings
from the moment it is triggered until its owner disarms it (see `triggerAlert`).
An old client that still sends `autoStopSeconds` is accepted — unknown payload
fields are ignored — but the value has no effect.
There *is* an owner-set **persistence** window, and it is a different clock:
[`expiresInSeconds`](#validation-and-the-persistence-cap) sets how long the alert
itself lives (default 24 h, minimum 60 s, hard maximum 14 days = 1 209 600 s).
Above the cap is `ERR_VALIDATION`, not a silent clamp. The response carries
`expiresAt` (RFC 3339), as does every `alertView`. After that instant the alert
is destroyed with everything about it, and clients see `ERR_ALERT_NOT_FOUND` —
stragglers are ignored by design.
Errors: `ERR_VALIDATION`, `ERR_UNAUTHORIZED`.
## `getAlert`
@@ -231,8 +291,6 @@ Response `200`:
"message": "Leave the building now",
"status": "triggered", // "armed" | "triggered" | "disarmed"
"active": true, // derived, see alarmStatus
"autoStopSeconds": 300,
"tokenVersion": 1,
"created": "2026-10-18T17:00:00Z",
"modified": "2026-10-18T17:05:00Z",
"triggeredAt": "2026-10-18T17:05:00Z",
@@ -284,11 +342,17 @@ Subscribes the caller's device. This is what the QR scan calls.
`deviceId` is part of the subscription's identity, so it is **not optional**:
missing or empty is `400 ERR_VALIDATION` (`deviceId is required`). Generate it
once per install (a random UUID persisted in app storage is enough) and never
rotate it — a new value makes the same user a separate subscription, which is
once per install (a random value persisted in app storage is enough) and never
change it — a new value makes the same user a separate subscription, which is
exactly the "second device" behaviour. Reuse the same value as `?deviceId=` on
`/ws/alarm` so the right subscription's `last_seen_at` is refreshed.
**The server never stores the raw value: it stores `sha256:<64 lowercase hex>`**
(`crypto/sha256`, 71 bytes, inside `VARCHAR(128)`). Every comparison hashes the
caller's input first — this join, the unique key, and the `?deviceId=` lookup on
the socket — so behaviour is unchanged and the client neither learns nor needs
the hash. It keeps sending the raw value.
Response `200` — the subscription view (see `listSubscriptions`).
**Idempotent per `(alertId, user, deviceId)`**: re-scanning the same QR on the
@@ -310,7 +374,7 @@ is *not* required for this read).
```json
{ "items": [
{ "id": "…", "userId": "…", "deviceId": "android-8f2c…",
{ "id": "…", "userId": "…",
"deviceLabel": "Pixel 7", "platform": "android",
"enabled": true, "lastSeenAt": "2026-10-18T17:04:00Z",
"created": "2026-10-18T16:00:00Z" }
@@ -322,6 +386,19 @@ schema and Alarm does not read another service's tables. The field is omitted
rather than sent empty. `lastSeenAt` is refreshed whenever that subscription's
socket connects or heartbeats.
`deviceId` is intentionally **not** in this view. Note who "admin" means here:
the **alert owner** — the user who created this particular alert and holds its
admin token. It is *not* the Maestro instance operator; no instance-level
operator ever reads this view. The value is a stable pseudonymous idempotency
key (see `joinAlert`), not a credential, and the alert owner has no need to read
every subscriber's device identifier. The subscription `id` is the revocation
handle (`removeSubscription` takes it). To tell several identical-looking
devices apart — labels are roles now, so three Android phones share one label —
use `created` (the join time), `lastSeenAt`, `deviceLabel` and `platform`; none
of those identifies a device. The digest is still stored server-side and is
still part of the `(alertId, subscriber, device digest)` unique key that makes a
re-join idempotent; only the read exposure is removed.
Errors: `ERR_VALIDATION`, `ERR_ALERT_NOT_FOUND`, `ERR_ALERT_NOT_ADMIN`,
`ERR_UNAUTHORIZED`.
@@ -367,7 +444,6 @@ Response `200`:
"eventId": "…",
"action": "trigger",
"serverTime": "2026-10-18T17:05:00.123Z",
"autoStopSeconds": 300,
"delivered": 2
}
```
@@ -377,8 +453,45 @@ Response `200`:
not connected (or are on another instance) are reached by the reconnect
catch-up and by the `alarmStatus` fallback instead.
- Re-triggering an already-triggered alert is allowed and always produces a
**new `eventId`**, restarting the auto-stop window. Clients must treat each
`eventId` as a new alarm.
**new `eventId`**. Clients must treat each `eventId` as a new alarm.
### Two clocks, four endings
Keep these apart; conflating them is how the next reader gets it wrong.
**Clock 1 — ringing.** There is no auto-stop and no ringing timer. An alert is
active from the moment it is triggered until it ends. A subscriber's *ringing*
ends when that subscriber dismisses it locally; that is a client action which by
itself changes no server state until the client sends `ackAlarm` (or the socket
`ack`), and the server never depends on a client's cooperation to stop an event.
**Clock 2 — alert lifetime.** `expires_at`, chosen by the owner at creation
(cap 14 days), bounds how long the alert exists at all. It is not a ringing
timer: it is the persistence cap that stops a device that never returns from
pinning an alert forever.
An alert ends in exactly three ways, each destroyed through the same path with
its own `event_log` row (`event:"destroyed"`, `reason`):
| Ending | Trigger | Analytics reason | Note |
|---|---|---|---|
| **delivered** | every enabled subscription has acked (`ackAlarm`/WS `ack`) | `delivered` | drain-to-empty; a trigger with **zero** subscribers never counts as drained |
| **expired** | `now() >= expires_at` | `expired` | destroys even with unacked deliveries — stragglers are ignored |
| **disarmed** | owner calls `disarmAlert` (triggered **or** still armed) | `disarmed` | on an armed alert this is "delete it without ever firing" |
| **deleted** | owner calls `deleteAlert` explicitly | `deleted` | converges with disarm for an armed alert; kept as a separate intent |
`disarmAlert` therefore ends an armed alert too — it is not a no-op and not a
re-arm. Deleting or disarming an alert removes its delivery-ledger rows by
cascade, so a device that still had an unacked delivery is **never** later told
"you missed a trigger": replay and the 409 read only that ledger, and a destroyed
alert has no debt left to report. On reconnect the client learns the alert is
gone (`ERR_ALERT_NOT_FOUND`) — that means **ended**, not **triggered**.
Deliberate consequence, so it is not a surprise later: an owner who loses their
phone (or admin token) cannot stop a ringing alert before it expires — but the
persistence cap now guarantees the alert (and its debt) eventually disappears.
That trade — an alarm nobody can miss versus one nobody can stop forever — is
the accepted design.
- The alert state is stored **before** the fan-out, so a client that reconnects
immediately after the call still sees the live event.
@@ -401,29 +514,33 @@ Response `200` — same shape as `triggerAlert` with `"action": "disarm"`:
"eventId": "…",
"action": "disarm",
"serverTime": "2026-10-18T17:09:00.456Z",
"autoStopSeconds": 300,
"delivered": 2
}
```
`autoStopSeconds` echoes the alert's **configured** value (e.g. `300`), not
`0`: disarming does not rewrite the stored column, and the same value rides the
broadcast `disarm` frame. Treat it as informational — "that is how long the
trigger would have rung" — never as a stop signal. **Cancel the ring on
`action: "disarm"`** (or on `active: false` from `alarmStatus`). A client that
waits for `autoStopSeconds === 0` before stopping will keep ringing.
Disarm **ends the alert**, whatever its state:
Disarming an alert that is **not** currently active is `409 ERR_ALERT_STATE`.
- **triggered** — the live alarm ends; outstanding deliveries cascade away
(closed, not acked) and the alert is destroyed with event-log reason
`disarmed`;
- **armed / never triggered** — the alert is destroyed as well. This is the
user's "delete the whole alarm without triggering it": clients learn it ended,
never that it fired.
Errors: as `triggerAlert`, plus `ERR_ALERT_STATE`.
**Cancel the ring on `action: "disarm"`** (or on `active:false`). Disarming an
already-destroyed alert is `ERR_ALERT_NOT_FOUND`; the action is idempotent in
intent and cannot destroy twice or log twice.
Errors: as `triggerAlert`, plus `ERR_ALERT_NOT_FOUND`.
## `alarmStatus`
The cheap, indexed fallback a client polls when its socket is down, or on cold
start when it may have been killed mid-alarm.
**GET** `/action/alarmStatus?alertId=<uuid>` ·
**POST** `{ "payload": { "alertId": "…" } }`
**GET** `/action/alarmStatus?alertId=<uuid>[&deviceId=<raw id>]` ·
**POST** `{ "payload": { "alertId": "…" } }` (a `deviceId` in the payload is not
read; send it in the query if you want to pin the subscription)
```json
{
@@ -431,21 +548,107 @@ start when it may have been killed mid-alarm.
"eventId": "…",
"action": "trigger",
"message": "Leave the building now",
"serverTime": "2026-10-18T17:05:00.123Z",
"autoStopSeconds": 300
"serverTime": "2026-10-18T17:05:00.123Z"
}
```
`active` is **derived**, never a timer: it is true only when the newest event is
a `trigger`, the stored status is `triggered`, and (when `autoStopSeconds > 0`)
`now < triggeredAt + autoStopSeconds`. Nothing sweeps the database, so the
answer stays correct across restarts and across instances. When there is no
event yet the fields are empty and `active` is `false`.
`active` is **derived**, never a ringing timer: it is true only when the newest
event is a `trigger` and the stored status is `triggered`. The answer stays
correct across restarts and instances, and it stays `true` until the owner
disarms or the alert expires. (There *is* a sweeper, but it destroys expired
alerts — it never changes an event's meaning.) An expired or destroyed alert is
`ERR_ALERT_NOT_FOUND` here like everywhere else. When there is no event yet the
fields are empty and `active` is `false`.
`serverTime` is the event's timestamp (or the server's clock when there is no
event) — use it to correct client clock skew rather than comparing with the
device clock.
### Offline check-in — `409 ERR_ALARM_TRIGGERED_OFFLINE`
The same call is the offline check-in. A trigger writes a **durable delivery
ledger row** for every enabled subscription
(`alarm.alarm_deliveries`), so a device that was offline at trigger time has a
record owing it an alarm even though `pg_notify` and the in-memory catch-up
never reached it. When that device calls `alarmStatus`, it gets:
```
HTTP/1.1 409 Conflict
```
```json
{
"error": { "code": "ERR_ALARM_TRIGGERED_OFFLINE", "message": "…" },
"alarm": {
"type": "alarm",
"alertId": "0f8fad5b-…",
"eventId": "…",
"action": "trigger",
"message": "Leave the building now",
"serverTime": "2026-10-18T17:05:00.123Z"
}
}
```
**This is a success-shaped alarm signal — the HTTP status is `409` but the
response means "ring", never "the request failed".** `error` is the platform
envelope verbatim (do not expect frame fields inside it, and there is no third
top-level key): the frame lives in the sibling `alarm` object, shaped exactly
like the WebSocket frame, so one parser serves both paths. A client that renders
this as an error has failed to deliver the alarm. Handle `alarm` exactly like a
live `trigger` frame: max volume, wake the screen, `ack`, and stop on a disarm.
The socket is the primary path now: the same ledger is replayed on WebSocket
connect (see "Reconnect catch-up"), which reaches the native service even when
the JS layer is not running. The 409 is the secondary path for a client that is
running and polling but has no socket — both settle the same rows.
- The rows are marked acknowledged by the act of returning this response, so the
same uninterrupted alarm cannot produce a second `409`.
- On the live path the WebSocket `ack` frame marks them too, so an online client
that actually received the frame is never told again.
- Everything is idempotent: an ack for an event the device never owed, or a
repeated ack, updates nothing and is not an error.
- A trigger that was already disarmed before the device checked back in is not
news: the ledger entries are cleared and the normal body (`active: false`) is
returned instead of a stale ring.
- `?deviceId=` selects the subscription (raw value, as sent to `joinAlert`);
without it the caller's oldest subscription on the alert is used, mirroring the
socket. The service hashes it before comparing.
- If several triggers were missed, all pending entries are retired at once and
the newest missed event is the one returned — a device is not made to ring once
per missed event.
Errors: `ERR_VALIDATION`, `ERR_ALERT_NOT_FOUND`, `ERR_ALERT_NOT_SUBSCRIBED`,
`ERR_UNAUTHORIZED`.
## `ackAlarm`
**POST** `/action/ackAlarm` — the explicit dismissal of a ringing alarm. The
device rides the payload (or the query string), exactly like `joinAlert`:
```json
{ "payload": { "alertId": "…", "eventId": "…", "deviceId": "pixel-7" } }
```
Response `200`:
```json
{ "alertId": "…", "eventId": "…", "acked": 1, "destroyed": false }
```
- Clearing is **ack-driven**, never response-driven: `alarmStatus` only *reports*
debt (409 + frame) and clears nothing, so a 409 lost in transit does not
forfeit the alarm — the next check-in finds the same row.
- Idempotent: a repeat ack (or an ack for an event the device never owed) returns
`acked: 0`, never an error. The WebSocket `ack` frame settles the same rows.
- `acked` counts the ledger rows cleared for this device. When the ack clears the
last unacked row of the alert, the alert drains and is destroyed (reason
`delivered`) — `destroyed: true` reports that intended outcome.
- The alert owner has no delivery row, so an owner ack is a well-formed no-op.
- Subscribers must pass `deviceId` (raw; the server hashes it). A device can only
clear its own row.
Errors: `ERR_VALIDATION`, `ERR_ALERT_NOT_FOUND`, `ERR_ALERT_NOT_SUBSCRIBED`,
`ERR_UNAUTHORIZED`.
@@ -457,7 +660,8 @@ Errors: `ERR_VALIDATION`, `ERR_ALERT_NOT_FOUND`, `ERR_ALERT_NOT_SUBSCRIBED`,
{ "payload": { "alertId": "…", "adminToken": "…" } }
```
Deletes the alert, its subscriptions and its event history (cascade). Response
Deletes the alert, its subscriptions, its event history and its delivery-ledger
rows (all `ON DELETE CASCADE` in the schema). Response
`200`:
```json
@@ -496,30 +700,6 @@ Keep the quiet zone at ≥ 4 modules; scanners reject codes without it.
Errors: `ERR_VALIDATION`, `ERR_ALERT_NOT_FOUND`, `ERR_ALERT_NOT_SUBSCRIBED`,
`ERR_UNAUTHORIZED`, `ERR_INTERNAL` (encoder failure — never expected).
## `rotateSubscribeToken`
Invalidates the current QR and mints a new subscribe token. Existing
subscriptions keep working; only *joining* with the old token stops working.
Use it when the QR leaked.
**POST** `/action/rotateSubscribeToken`
```json
{ "payload": { "alertId": "…", "adminToken": "…" } }
```
Response `200`:
```json
{ "alertId": "…", "subscribeToken": "…",
"qrPayload": "https://alarm.dcntrlized.org/a/…#…",
"tokenVersion": 2 }
```
Errors: as `triggerAlert`.
---
## QR payload format
The QR encodes exactly the `qrPayload` field:
@@ -543,10 +723,18 @@ to a server by a browser — the token stays client-side until the app posts it
## Live protocol — `GET /ws/alarm`
The service path is:
```
ws://<host>:8088/ws/alarm?alertId=<uuid>&token=<adminToken|subscribeToken>&accessToken=<token>[&deviceId=<id>]
/ws/alarm?alertId=<uuid>&token=<adminToken|subscribeToken>&accessToken=<token>[&deviceId=<id>]
```
Through an instance (the supported path) that is
`wss://<instance>/api/alarm/ws/alarm?…`; on the dev host the raw service port is
`ws://localhost:8088/ws/alarm?…`. The data plane relays control frames end to
end, so the 20s ping / 60s pong accounting below is measured between client and
service, not against the proxy.
The socket is **authenticated, not anonymous**: the access token identifies the
user and the second token proves the relationship to the alert.
@@ -586,16 +774,13 @@ from one fan-out:
"eventId": "…",
"action": "trigger", // "trigger" | "disarm"
"message": "Leave the building now",
"serverTime": "2026-10-18T17:05:00.123Z",
"autoStopSeconds": 300
"serverTime": "2026-10-18T17:05:00.123Z"
}
```
`ack` — the server's acknowledgement of a client ack:
```json
{ "type": "ack", "eventId": "…" }
```
There is **no** server → client `ack` frame: `ack` is client → server only (it
counts the acknowledgement and clears the durable delivery-ledger row). A client
must not wait for one.
### Client → server frames
@@ -633,11 +818,43 @@ candidate; the same applies to sending non-JSON frames.
### Reconnect catch-up
The service keeps the **last event per alert** in memory. On connect, if that
event is still active (a `trigger` whose auto-stop window has not expired), the
server sends it immediately — so a client that reconnects mid-alarm fires
without polling, and a client that reconnects *after* the alarm is over is never
re-alarmed.
Two replays happen on a successful upgrade, both before anything else is sent:
1. **Durable ledger replay (the authoritative one).** Every trigger writes a
delivery-ledger row per enabled subscription. When a socket connects, the
service sends **every trigger frame this exact `(alert, subscription)` still
owes**, oldest first — up to a bounded handful. This is what makes delivery
survive being offline even when the client's JS layer is dead: the Android
foreground service holds the socket, receives the frame, and schedules the
alarm clock without any app-level check-in. Nothing is marked by the replay
itself: the debt clears only when the client `ack`s (or the `alarmStatus`
check-in settles it), so a frame the client never processed stays owed and is
sent again on the next connect.
2. **In-memory last-event catch-up (the fast path).** The service also keeps the
last event per alert in memory and replays it if it is still live (a
`trigger` not superseded by a disarm). This is belt-and-braces: it covers the
window before/while the ledger row is visible, and it is what the duplicate
suppression below is about — if the ledger replay already sent that exact
`eventId`, the catch-up is skipped.
A trigger that was already **disarmed** before the device reconnects is not
replayed — ringing a stale alarm would be worse than silence; the check-in
clears that debt instead.
Honest limits: the in-memory catch-up is per-instance, so on an instance that
never saw the trigger it does nothing; the ledger is what crosses instances and
restarts. And replay and a live `NOTIFY` can race, so a client may legitimately
see the same `eventId` twice — acks are keyed by `eventId` and ledger clearing is
idempotent, so it is a duplicate, not a fault.
### Deployment constraint — `DEV_MODE_STATIC_SERVICES`
The Maestro data plane (`/api/<service>/…`) resolves the target through
`serviceproxy.Resolve`, which always goes through the Docker client. Under
Maestro's `DEV_MODE_STATIC_SERVICES` there are no containers to resolve, so the
data plane cannot work in that mode; a real instance always has Docker. This is a
platform constraint, not an Alarm limitation — direct service addressing is not a
supported deployment.
### Multiple instances
@@ -651,15 +868,16 @@ subscribers of instance B as well. Duplicate deliveries are suppressed by
### Minimal client
```js
// Through an instance: wss://<instance>/api/alarm/ws/alarm?…
const ws = new WebSocket(
`ws://alarm:8088/ws/alarm?alertId=${alertId}&token=${subscribeToken}` +
`&accessToken=${accessToken}&deviceId=${deviceId}`);
`wss://${instance}/api/alarm/ws/alarm?alertId=${alertId}` +
`&token=${subscribeToken}&accessToken=${accessToken}&deviceId=${deviceId}`);
ws.onmessage = (ev) => {
const f = JSON.parse(ev.data);
if (f.type === "alarm" && f.action === "trigger") {
// autoStopSeconds: 0 = ring until a disarm arrives; >0 = self-stop after N
ring(f.message, f.eventId, f.autoStopSeconds); // max volume, wake screen
// No auto-stop: ring until a disarm frame (or a local dismissal) arrives.
ring(f.message, f.eventId); // max volume, wake screen
ws.send(JSON.stringify({ type: "ack", eventId: f.eventId }));
}
if (f.type === "alarm" && f.action === "disarm") stopRinging(f.eventId);
@@ -675,6 +893,19 @@ like a live `trigger` frame, and `active: false` (or `action: "disarm"`) as the
stop signal. Always prefer the socket: it is the < 1s path, and polling only
bounds the worst case.
Polling rides the same instance path as everything else:
`GET {base}/api/alarm/action/alarmStatus?alertId=…` with the same access token —
the data plane forwards the query string verbatim, so the exact same URL the
socket uses for its identity works here. There is no separate "mode": the socket
and the poll are two transports over one address.
The honest failure story is therefore **"the socket is not listening"**, not
"the wrong mode": the phone cannot reach the instance at all (no network, wrong
instance URL, service stopped — the relay answers `409 ERR_NOT_RUNNING` while
the instance itself is up), or the socket keeps dropping. Polling bounds the
worst case in every one of those; it never turns a reachable instance into an
unreachable one.
---
## `GET /_manifest`
@@ -699,6 +930,8 @@ mount the shared-auth proxy.
## Worked example
```bash
# Through an instance (the supported path) the base is https://<instance>/api/alarm.
# On the dev host you can talk to the service directly for debugging:
BASE=http://localhost:8088
# 1. access token (shared auth)
@@ -709,7 +942,7 @@ TOKEN=$(curl -s -X POST "$BASE/auth/login" \
# 2. create the alert (keep adminToken!)
curl -s -X POST "$BASE/action/createAlert" -H "X-Access-Token: $TOKEN" \
-H 'Content-Type: application/json' \
-d '{"payload":{"name":"Fire drill","message":"Leave the building","autoStopSeconds":300}}' | jq
-d '{"payload":{"name":"Fire drill","message":"Leave the building"}}' | jq
# 3. a second user scans the QR payload and joins
curl -s -X POST "$BASE/action/joinAlert" -H "X-Access-Token: $BOB" \
@@ -728,6 +961,12 @@ curl -s -X POST "$BASE/action/triggerAlert" -H "X-Access-Token: $TOKEN" \
curl -s -X POST "$BASE/action/disarmAlert" -H "X-Access-Token: $TOKEN" \
-H 'Content-Type: application/json' \
-d '{"payload":{"alertId":"'$ALERT'","adminToken":"'$ADMIN'"}}' | jq
# 7. what a device that was offline during the trigger sees when it checks in.
# First call: 409 ERR_ALARM_TRIGGERED_OFFLINE + the alarm frame. Second call:
# a normal 200 with active:false — the ledger row was cleared by the first.
curl -si -H "X-Access-Token: $BOB" \
"$BASE/action/alarmStatus?alertId=$ALERT&deviceId=pixel-7" | head -20
```
## Storage
@@ -736,9 +975,75 @@ All state lives in the shared PostgreSQL database, schema `alarm`:
| Table | Contents |
| --- | --- |
| `alarm.alerts` | one row per alert: name, message, admin user id, admin-token hash, subscribe token + version, status, timestamps, `auto_stop_seconds` |
| `alarm.subscriptions` | `(alert, user, device)` unique, label/platform, `enabled`, `last_seen_at` |
| `alarm.alerts` | one row per alert: name, message, admin user id, admin-token hash, subscribe token, status, timestamps, `expires_at` (owner-set persistence cap, hard maximum 14 days). No auto-stop/ringing-duration column exists. |
| `alarm.subscriptions` | `(alert, user, sha256(device id))` unique, label/platform, `enabled`, `last_seen_at`. `device_id` stores `sha256:<64 lowercase hex>`, never the raw client value. |
| `alarm.alarm_events` | append-only trigger/disarm history; its `AFTER INSERT` trigger issues the `pg_notify` that fans out to other instances |
| `alarm.alarm_deliveries` | the durable per-device delivery ledger: `(alert, subscription, event)` primary key, `created_at`, nullable `acked_at`. Written in the trigger transaction, one row per enabled subscription; cascades with its alert and subscription. It is what makes an offline device's missed alarm recoverable and what makes "no auto-stop" safe. |
Migrations live in `database/migrations/` and are applied by the compose
`migrate` one-shot; they are idempotent and safe to re-apply.
### What the device-id hash does and does not buy
`sha256:<hex>` makes a database dump useless as a list of device identifiers and
it means the raw value never sits at rest. It is **not** a credential (it never
authenticates anything — identity comes from the access token) and it is **not**
an unlinkability guarantee: the same raw id on the same alert always maps to the
same digest, and that correlation is the whole point, because it is what makes a
re-join idempotent. If two people share one device, they are one device for this
purpose by design.
## Validation and the persistence cap
`createAlert` accepts an optional `expiresInSeconds` (integer, seconds):
| Bound | Value | Why |
| --- | --- | --- |
| default (field omitted) | **24 h** (`86400`) | an alert is a transient safety mechanism; a day covers "created tonight, triggered tomorrow morning" without leaving debris for a week |
| minimum | **60 s** | the sweeper ticks every ~60 s; anything shorter could expire before a device can join |
| maximum | **14 days** (`1209600`) | the user's hard cap; values above are `ERR_VALIDATION`, never silently clamped, because a silent clamp changes what the owner asked for |
`expiresAt` (RFC 3339) is returned by `createAlert` and by every `alertView`.
An alert past its instant reads as `ERR_ALERT_NOT_FOUND` on every action —
including `alarmStatus` — even before the sweeper reaches it, so a client cannot
observe a zombie.
## The event log
Exactly one durable, anonymised lifecycle table: **`alarm.event_log`**.
| Column | Type | Meaning |
| --- | --- | --- |
| `id` | `BIGSERIAL` | primary key |
| `occurred_at` | `TIMESTAMPTZ NOT NULL DEFAULT now()` | when |
| `event` | `TEXT NOT NULL` | `created`, `joined`, `triggered`, `delivered`, `destroyed` |
| `alert_hash` | `TEXT NOT NULL` | SHA-256 hex of the alert UUID |
| `user_hash` | `TEXT` | SHA-256 hex of the actor/subscriber UUID |
| `reason` | `TEXT` | `destroyed` rows only: `delivered`, `expired`, `disarmed`, `deleted` |
It records **important lifecycle events only**. It is **not** a mirror of stdout:
the per-request access log stays on stdout. It has deliberately **no** column for
an IP, a user agent, a token, a request body, a query string or a request
identifier of any kind, and adding one later would be a privacy regression.
Anonymisation, two schemes on purpose:
- `alert_hash` / `user_hash`: **plain SHA-256** over the canonical UUID string. A
UUID carries ~122 random bits, so a plain digest is genuinely one-way.
- The stdout request line hashes the client IP and user agent with the same plain
SHA-256. Honest limitation: an IPv4 address is a 2^32 space, so a plain digest
is enumerable — that is anonymisation of *records* (a log dump does not
directly name a client), **not** cryptographic protection. Do not add a pepper,
a salt or a work factor; the user rejected that as overengineering, and the
network identifier never reaches durable storage anyway.
No foreign keys: rows survive the alert they describe by construction.
### Retention
- `event_log`: **age-based only — 7 days**, swept by the same ~60 s goroutine as
expiry (`DELETE … WHERE occurred_at < now() - interval '7 days'`). This is the
fastest-growing table in the schema; it must never grow without bound.
- Alerts: destroyed at `expires_at` (or by drain/disarm/delete), never by age
alone without the owner having chosen `expiresInSeconds`.
- Delivery ledger rows: removed only with their alert/subscription cascade.