I got this wrong first time. "Head office cannot show live video cheaply"
conflated TRUE VIDEO with SEEING THE CAMERA NOW, and only the first needs
WebRTC and a TURN server.
The shop PC is behind a router with no inbound route, so head office
cannot pull the engine's MJPEG. It can answer the agent's outbound
requests, which is the shape of everything else here: the server holds a
poll open, the agent asks "is anyone watching?", and pushes JPEGs up for
exactly as long as somebody is.
Measured on the office camera: 98 KB full frame, 20.8 KB re-encoded at
640/q60, so one watcher costs ~83 KB/s. 47 frames arrived in 12 seconds -
4 fps, as configured. The UI says "about 4 frames a second" rather than
letting anyone conclude the camera stutters.
Nothing is uploaded when nobody is looking, which is the whole cost
argument: Publish returns false once the last viewer goes, interest lapses
on a timer each viewer refreshes as it reads (so a closed tab stops the
upload within seconds), one push is capped at five minutes, and the UI
streams one camera at a time.
LiveHub is deliberately the opposite of the arrivals Hub. There a doorbell
pushes nothing because nothing may be lost; here a dropped frame is the
correct outcome, so each viewer has a one-slot buffer that is overwritten -
the only frame worth having is the newest, and a queue would show an
ever-growing delay behind the shop instead of dropping back to live.
Ownership is proved once, before anything streams: the relay is keyed on a
camera id, a hub does not know whose camera it holds, and a camera id is
not a secret. Verified: another tenant gets 404, no session gets 401, and
an agent cannot push into another site's camera.
Also fixes a bug I introduced with it - the Live button was gated on
`connected`, which is head office's last report and up to two minutes
stale, so it hid itself during every reconnect. "Is that camera really
down?" is exactly when somebody wants to look, and a hidden control says
"you cannot" where the honest answer is "here is why".
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HViLj9gYNRtSr7YVZmW5sn
Migrations were run by hand and nothing recorded which had run, so
re-running the setup script against an existing database failed on the
first CREATE TABLE, and shipping a new migration gave an operator no way
to know whether an estate had it. A missed migration is not a startup
error - it is a query referencing a column that is not there, surfacing
later on whichever endpoint touches it first.
server/internal/migrate applies pending migrations at boot and refuses to
start against a schema it does not match. One transaction per file
holding both the DDL and the row that records it; an advisory lock so two
servers starting at once cannot both apply 008; checksums so an edited
migration is refused by name rather than silently skipped; numeric
ordering so 010 does not run before 009. `migrate -baseline N` adopts a
database built before any of this existed, because "the clients table
exists" does not say whether 007's index does.
Verified on the live database: adopted 001-007, applied 008.
008 adds two indexes on `purchases`, found by asking the database which
foreign keys had nothing behind them and then checking what queries the
table. The conversion report filters client_id + occurred_at, which is
exactly the estate-wide case with no site to narrow it.
run-local.sh had two bugs, both found by running it rather than reading
it: it reused a broker container whose bind mount pointed at a directory
that no longer existed, and it discarded stderr on the mosquitto_passwd
call, so under `set -e` it exited at step 5 with no output at all.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HViLj9gYNRtSr7YVZmW5sn
Five components that ship as one product:
- behavision/ the recognition engine. RTSP ingest, YuNet detection, IoU
tracking, ArcFace embeddings, a FAISS/SQLite gallery, and a
FastAPI dashboard. Identity is decided once per TRACK from an
average of at least three embeddings, never per frame.
- agent/ the Go edge agent: supervises the engine, holds a durable
spool, and drains it to MQTT. Nothing is acked before the
broker confirms.
- desktop/ the shop PC application (Wails + React + tray).
- server/ the cloud API, MQTT consumer, reports and assistant.
- web/ platform.loyaly.ai, the head-office app, embedded in the
server binary.
The gallery stores 512-float embeddings and timestamps - no images unless
`app.store_faces` is switched on. Those embeddings are biometric personal
data under GDPR and India's DPDP: template inversion reconstructs a
recognisable face from an ArcFace vector, so data/behavision.db is treated
as a biometric database and DELETE /api/visitors/{id} is a real erasure.
CLAUDE.md carries the reasoning behind every non-obvious decision here,
including the ones that were measured and the ones that were wrong first.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HViLj9gYNRtSr7YVZmW5sn
