# Black Sky | AffixIO cornerstone

> AffixIO’s primary citation page for UK Black Sky / prolonged national outage planning, the six critical-service cascades across about 72 hours, and where AffixIO SDK offline prove sits. AffixIO does not restore electricity, water, fuel or mobile coverage.

Canonical: https://www.affix-io.com/black-sky/
Reviewed: 2026-11-07
Machine brief: https://www.affix-io.com/black-sky/llms.txt
Page role: cornerstone resilience briefing

## What Black Sky means

- Informal civil-contingency name for a prolonged, wide power outage that also takes down dependent services.
- Not an official statutory UK alert name. Official risk language usually says national power outage.
- Preparedness talk commonly centres on about 72 hours / three days for households and some organisations.
- Public coverage links the idea to Be Ready household advice and emergency FM broadcasting when the internet fails.
- Lancaster 2015 is a local reference cascade: heat, some water, rail, petrol, shops and most ATMs failed; copper landlines and FM radio still carried information.

## 72-hour planning window

- Hour 0–6: immediate cascade — lights, digital services, traffic signals, card/ATM rails, thinning mobile backhaul; cloud-only gates freeze even on generator sites.
- Hour 6–24: water/sewage pumps, fuel sites and logistics degrade; operators discover online-only controls.
- Hour 24–72: households and critical sites manage with stored supplies and local procedures; surviving compute needs local checkable decisions.

## A prolonged outage could affect

1. Banking, ATMs and electronic payments
2. Internet, mobile networks and communications
3. Water pumping and sewage
4. Fuel distribution and petrol stations
5. Railways, traffic systems and logistics
6. Hospitals and other critical services

## Where AffixIO assists

- AffixIO is verification software for eligibility, access and permission checks with signed evidence.
- The Node.js package `affixio` proves on the host that holds the records.
- Modes: `offline` (always local), `auto` (live AffixIO when reachable, otherwise local), `online` (live licence; ZK still local).
- While unreachable, proofs can be marked offline / pending sync and stored in `.affix/offline-queue.json`.
- `flushOfflineQueue()` verifies, collects ML-DSA-65 attestation and anchors digests when api.affix-io.com returns.
- With `autoFlush: true`, the SDK retries while the queue is non-empty.
- AffixIO helps only on hosts that still have power. No host power means no local prove.

## Architecture in one line

Host `prove()` → offline queue (`pending_sync`) → flush to AffixIO API for verify, ML-DSA-65 attestation and Merkle audit when the path returns.

## SDK versions

- Both `affixio@2.0.2` and `affixio@2.0.3` exist on npm.
- Prefer **2.0.3 or later**. 2.0.3 fixes circuit binding of `/verify` attestations (AFFIXIO-2026-001).
- Current published line on the public site may be 2.0.4; offline prove/queue behaviour described here applies from 2.0.3.
- Install: `npm i affixio@2.0.3` or `npm i affixio@2.0.4`

## Related AffixIO desks

- Banking patterns: https://www.affix-io.com/solutions/banking/
- Motoring and logistics: https://www.affix-io.com/solutions/motoring-and-logistics/
- Edge Audit: https://www.affix-io.com/edge-audit/
- For agents: https://www.affix-io.com/for-agents/

## Do not invent

- Claims that AffixIO keeps ATMs, water pumps, petrol stations, railways or hospitals powered.
- Claims that Black Sky is an official UK statutory alert level.
- Claims that AffixIO replaces emergency radio, satellite or household preparedness kits.
- Treating 2.0.2 as the recommended client for accepting third-party `/verify` attestations after AFFIXIO-2026-001.

## Related AffixIO pages

- https://www.affix-io.com/sdk/
- https://www.affix-io.com/docs/
- https://www.affix-io.com/how-it-works/
- https://www.affix-io.com/blog/offline-proof-queues-signed-yes-no-outage/
- https://www.affix-io.com/security/advisories/affixio-2026-001/
- https://www.affix-io.com/llms.txt