containment.ai — Brief 02: OT deployment and fail-closed behaviour. Status of record: www.containment.ai/trust.html
BRIEF 02 — FOR AN OT OR PLANT SECURITY ENGINEER
Where the Gateway sits, and what happens when it cannot decide.
A deterministic ruling on AI-originated commands before they reach the control network. This brief states the fail-closed contract, separates what we will put in writing today from what only your pilot can establish, and names the numbers we have not measured.
Where it sits
IEC 62443 puts a conduit between zones. The Gateway sits in that conduit as a governed crossing: an AI-originated flow on the IT side — a copilot suggestion, an agent action, an operator prompt touching OT data — is ruled on before it reaches the control network. Only ALLOW-ruled commands cross. Denied or ambiguous commands do not.
Your existing safety logic stays authoritative. The plant’s SIS, PLCs and site-certified safety functions define the process response. Containment decides whether an AI-originated command is authorized to reach them; it does not replace, arbitrate, or sit inside a safety instrumented function.
The fail-closed contract
ambiguityResolves to DENY. An input the policy cannot evaluate is not permitted through on the assumption that it is probably fine.
policy coreDeterministic. The same canonical command, policy version and context produce the same ruling — which is what makes a pilot report reproducible.
loss of linkThe decision path is local by design, for DDIL, segmented and air-gap-capable environments. A lost uplink does not turn enforcement off.
response contractSite-defined. What the control system does after a DENY is agreed with your engineers, in writing, before a pilot starts.
STATED IN WRITING TODAY
— Deterministic, fail-closed rulings before a command reaches the control network
— Ambiguity resolves to DENY
— Local decision path; architecture designed for DDIL and air-gapped postures
— A decision record per governed outcome, exportable for your pilot report
— Designed to map to the 62443 zone-and-conduit model
VALIDATED PER PILOT — NOT CLAIMED IN ADVANCE
— Protocol integration (Modbus, OPC-UA, vendor stacks) — scoped with your team
— Decision-path latency on your hardware — measured, not brochure-quoted
— The fail-closed response contract — defined with your site
— Handoff to existing safety controls — validated with your engineers
Numbers we have not measured
We do not publish a latency figure, a throughput figure, or a protocol-coverage matrix for your environment, because we have not run in it. There are no production OT deployments today and the Gateway is pre-ATO. Any number that matters to your safety case should come out of your pilot on your hardware — and should go in your pilot report, not in our marketing.
Three questions worth asking us
1 What exactly happens on our line after a DENY, and who signs off on that contract?
2 Which of our protocols are in scope for the pilot, and which are not?
3 What has to be true about our network for the mediated set to be complete?
Containment.ai is pre-ATO and holds no completed certification or authorization. No independent audit report exists. Current product and assurance status is stated in full on
the Trust record — versioned, dated, and it outranks this brief.
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