Files
hq/03-DESIGN
jschoubben 148395ca54 Define the control plane, which was used 79 times and defined nowhere
Nineteen files, seventy-nine mentions, no definition. That is how-we-build §5
failing on this repository's own vocabulary — ubiquitous language is checked,
not assumed.

The definition, and it is not arbitrary: the control plane is everything that
needs to know about MORE THAN ONE NODE. It follows from ADR 0037, which has the
host applying rather than deciding precisely because deciding needs knowledge
the machine does not have. So the line falls exactly there — writing a file is
the host's, choosing which nodes run the store is the control plane's, and
anything a single machine could answer alone does not belong here at all.

That last consequence is worth having: putting a single-machine concern in tier
2 is a mistake the tier rule will NOT catch, because the dependency direction
stays correct.

Also states what it is not — not the thing that changes machines, not a surface,
not the substrate, and not privileged on a node beyond what the declaration
vocabulary allows. And the property that makes tier 2 unlike the others: it is
itself a consumer, with the same requirements as any module, which is the
circularity the bundle exists to resolve rather than hide.

Scoped deliberately: this defines the term and does not design the contexts
inside it. Ten is the skeleton's claim rather than a settled list, and research
006 still asks whether the record belongs here or in the substrate.
2026-08-26 23:33:20 +02:00
..
2026-08-25 01:55:52 +02:00

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.