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Asked whether a real setup is coverable — router, modem, access points — the answer splits, and one part was a genuine gap. Most equipment is invisible and the omission is deliberate. The test: does the device change what an IP packet can do? A switch moves frames within a segment. An access point bridges wireless clients onto one — a machine on wifi and a machine on cable are the same machine to IP. A controller configures equipment and has no packets of its own. Modelling any of them adds a fixture with no fault to catch. Two entries in that list do matter. A modem in bridge mode is a media converter and invisible; in router mode it is a second gateway, which is double NAT — expressible as nested segments, but publishing through two gateways still is not, and that is now named as the one real absence. And VLANs are segments, which exposed the gap: inter-segment policy was inexpressible. inbound: is a HOST firewall, per machine. A segmented router enforcing rules between networks is a different thing and blocks traffic regardless of what the destination thinks — a node behind such a rule cannot be reached even by a peer that knows exactly where it is. policy: states it as a fact about a pair rather than a property of either, defaulting to allowed and asymmetric by design, because the useful configuration is almost always one-directional. Segments may also share a gateway: identical gateway declarations mean one gateway machine, not two, because that is what a VLAN-capable router is — and two routers sharing an address would not work anyway.
03-DESIGN
The authoritative specification. Implementation is built against what is written here.
Two layers
| Folder | What it is |
|---|---|
00-as-is/ |
The mesh that exists today. Shipped behaviour, described as it is — including behaviour nobody would choose again. |
01-to-be/ |
The mesh being built toward. Every statement traceable to a record in 02-DECISIONS/. |
They are never mixed. A statement about the future does not belong in an as-is document, and an as-is document is never edited to describe an intention.
When a to-be design ships, it does not move. Its as-is counterpart is written or updated,
the to-be document's status becomes implemented, and both stand — one describing what runs,
the other recording what was intended. Deleting the intention loses the reasoning, which is
the expensive half.
Frontmatter
Every design document (not the READMEs) carries:
---
layer: as-is | to-be
status: designed | in-progress | implemented | abandoned
code: [] # owning code repo(s), from 00-META/repos.md
updated: YYYY-MM-DD # date of the last status change, not of text edits
decisions: [] # 02-DECISIONS/ records this document rests on
---
For an as-is document, status: implemented is the normal state — it describes something that
runs — and code: names where that implementation lives.
Status changes when implementation state changes, never because design text was edited. An
implemented claim must be defensible from the owning repository's main branch, not from
intent. If it cannot be checked, it is in-progress.
Cross-cutting views are generated from this frontmatter by the hq-status skill and never
written to disk.
What belongs here
Functional analysis, architectural description, and specification — prose and diagrams
only, no code. A manifest field may be named; a manifest may not be pasted. A document
enters the to-be layer only after the decision behind it is recorded in 02-DECISIONS/
and the research that produced it is closed.
Subfolders are encouraged where a layer grows enough to need them.