Racing the sirens

The worst part of a siren is not the sound. It is the three seconds after, where you do not know if it is you.

There are apps for this. I have used them. They hand you a list of place names, and under stress a list of place names is a puzzle: read it, parse it, try to remember whether that neighborhood is near you. Three seconds becomes ten.

I wanted to look, not read.

The wall

The real source is the Home Front Command feed. Reading it should be the easy part. It was not. The path between me and a clean, low-latency subscription ran into an IP-level block: data meant for the people standing here, gated in a way a naive client could not hold onto.

So azaka has a piece most alert apps do not. An egress relay: a small always-on node that sits on the correct side of the block, keeps the subscription alive, normalizes the alerts, and re-publishes them over a WebSocket that anything can subscribe to.

It is the unglamorous half, and it is the reason the visible half works at all. That is usually how it goes. The thing you would demo is downstream of the thing nobody sees.

Look, do not read

The client is React and MapLibre. An alert lands on the socket and the region lights up on a map. “Is this me?” gets answered by your eyes, in the time it takes to glance.

MapLibre because it is real vector rendering with no toll booth on every tile. Bun because it is fast and gets out of the way. Neither choice is interesting. Both were right.

What earned its place

Two things.

The relay-first shape. The moment I stopped fighting the block request by request and accepted that a node has to live over there, the whole design collapsed into something simple.

And the map as the primary object, not a feature. A civic-safety tool has exactly one job: lower the cognitive load at the worst possible moment. A map does that. A feed of strings makes you work.

It runs at azaka.orellius.ai. I hope you never need it.