Does Czar need the internet?

No. A Czar does its job, serving perception, decisions, and language models to every robot in the building, over the facility's own network. The robots are inside the building, the rack is inside the building, and the traffic between them never needs to leave. An internet connection is not required to install a Czar, to run it, to update it, or to get support for it. Whether to connect it to anything at all is a choice the site makes.

Two postures, one appliance

Element 31 treats connectivity as a posture chosen per site, not as a different product. The first posture is air-gapped: no path out. The Czar has no route to the internet or to anything beyond the floor it serves. Software updates arrive as signed bundles carried in by media, and the node verifies the signature before it accepts anything.

The second posture is connected, but only to systems the site already secures. That usually means the robot vendors' fleet software, the warehouse system, the PLCs on the line, and whatever else the site has declared. It does not mean the open internet. Local Bridge, the governed connectivity in Substrate, permits only the routes the site declared and denies everything else by default.

Mixed estates run both. A plant might keep its assembly floor air-gapped and connect its receiving dock to the warehouse system. Both are Czar. The difference is in what the site decided, not in what Element 31 shipped.

What people usually mean by the question

The question is often a stand-in for three others: whether the appliance phones home, whether it needs a cloud to think, and whether support needs a way in.

It does not phone home. Camera feeds, captures, task records, adapted model weights, and the record of every decision stay on the operator's hardware inside the operator's network, and that is true in both postures. It does not need a cloud to think; the models run on the Czar, which is the entire reason it sits in the rack rather than somewhere far away. And support does not need a standing way in. Customer appliances never connect to Element 31's portal. A remote session is customer-initiated, and on a sovereign site it requires the customer's attestation before an uplink window is approved, with a hard expiry.

Choosing a posture

An air-gapped posture suits a site whose feeds must not leave, such as a terminal with outdoor cameras covering a large area, or a plant with process knowledge it does not share. A connected posture suits a warehouse whose robots need to take orders from the warehouse system and report back to the vendors' fleet software. Many sites are somewhere in between and declare a short list of routes.

The decision does not have to be made once for the whole estate. It is made per site, it is recorded, and it can be revisited. The technology page describes Local Bridge and Watchman in more depth, and the update question covers how a site with no path out stays current.