# FAQ

> Stub — frequently asked questions.

## Does ETM PowerSync send my data to the cloud?

No. The optimisation logic runs locally, on your hardware. That is an architectural
decision, not an option.

## Is the project open source?

The foundation (`powersync-core`) and the plugins are under GPL-3.0. So is the connector
to the optimiser (`optimizer-plugin`) — everything linked against nymea is. The
optimisation **business logic**, however (`powersync-optimizer`: tariff arbitration,
Predict AI), is proprietary: it runs in a separate process, reached over a Unix socket.
That IPC boundary is the heart of the Open Core model — the plugin stays free, the
business logic stays proprietary.

## What is the difference between Community and Pro?

Two editions, not three — the prediction layer has not been sold separately since
2026-10-14; it is part of Pro.

- **Community** — the GPL-3.0 foundation, self-hostable: deterministic rule-based
  control, solar surplus, load shedding, REST/MQTT API. No subscription.
- **Pro** — installed by ETM-Schurig: adds tariff arbitration and the prediction layer
  (*Predict AI*: PV and consumption forecasting, heat-pump thermal inertia). **No
  subscription either**, and everything stays local.

Tariff arbitration and prediction are on the **roadmap**: the Open Core boundary already
exists, the functions it separates are not all shipped. See
[etm-powersync.fr](https://etm-powersync.fr/en/hems.html).