Everything you care about, in one live channel
A pool is a live channel. You name it — My Workshop, My Car, My Home — and connect whatever should belong together: a board on a USB cable, a weather feed, a camera, a phone's GPS, a machine's own temperature. Every source becomes the same observation, and the pool is one stream you can watch in the browser, subscribe to from an application, or feed into automation.
Not a dashboard
Dashboards are a way of looking at data. Fusion is the data. A source goes in, the pool updates, every subscriber hears it — without polling. The browser view is one subscriber; an application using @leumas/fusion is another; a rule that fires when the temperature passes eighty is a third. Nothing downstream ever learns which cable or which protocol a reading came from.
Three ways in, one way out
The browser connects the sources a browser can reach — a serial board over Web Serial, a camera, a microphone, GPS, a Bluetooth device, the machine's own battery and network. The Fusion Node runs on a computer of yours and connects what a browser cannot: COM ports headless, MQTT brokers, local HTTP and WebSocket services, the machine's telemetry. An HTTP call or a webhook connects anything else. All of it comes out as one observation shape.
Private by default
A camera, a microphone or a GPS trace must never become public because somebody forgot a setting. Every pool starts private. A key you mint is scoped to one pool and to the verbs you chose — read, subscribe, write — and a public pool is a deliberate flip with a warning on it.
What the free tier is
One pool, five sources, a day of history and two keys, on any Leumas account. That is enough to plug in an Arduino, watch the numbers arrive and read them from a script — the whole demonstration. A membership adds pools, sources, a week of history and the right to publish a pool. The Fusion plan is for a fleet.
Questions
What counts as a source?
Anything that produces readings or events. Serial boards (Arduino, ESP32), MQTT topics, WebSocket and HTTP services, webhooks, cameras, microphones, GPS, Bluetooth devices, smart plugs on MQTT, the computer itself — CPU, memory, Wi-Fi state. If it can be turned into a line of text or a JSON object, it can be a source.
Do I need to install anything?
No. The browser at fusion.leumas.tech connects a serial board, a camera, a microphone, GPS and Bluetooth by itself, in Chrome or Edge. The Fusion Node is for sources a browser cannot reach, or for running with the browser closed.
Does it work without the cloud?
The Fusion Node keeps a local outbox and a local stream, so a workshop keeps working through an outage and catches the pool up when the connection returns.