jschoubben
5b3d0ebd4f
The blocking question was where a container image comes from, and the version that blocked assumed the machine might have no network. That assumption came from the LAB: a scenario is a closed address space by design, which is what lets two scenarios hold the same addresses without meeting. Production is not sealed — a machine being adopted has a network, and one that does not is a machine where very little works anyway. So substrate.lock carries references, not payload: an image name and a digest, fetched at apply time. A first node pulls from upstream because no mesh registry exists yet; every node after that pulls from the mesh's own. The lab is the exception and places images itself, the way it already places the host binary — a property of a test environment, and letting it dictate the production design would be the tail wagging the dog. Pinned by DIGEST rather than tag. Reproducibility comes from pinning the identity of a thing, not from carrying its bytes, which is what makes fetching acceptable rather than a compromise. ADR 0041 survives untouched, which was the point. "Copy it onto a machine and run it" stays literally true — one binary, a few megabytes, which then fetches what it was told to. Carrying images would have quietly redefined the property that decision rests on. Costs accepted and named: an apply can now fail because something is unreachable, which a self-contained artifact could not, so it must fail legibly — naming what it could not fetch and from where. And the lab needs a way to place images into a machine that also has no container runtime, both of which are lab-installation concerns and neither solved here. Research 012's build-time-versus-apply-time reframing narrows accordingly: it still holds for what a tailored installer contains, and no longer has to hold for images.
02-DECISIONS
Architecture decision records — the "why" trail behind the rules in
00-META and the specifications in 03-DESIGN.
Numbered 02 because a decision precedes the design it authorises. Research concludes,
the decision is recorded here, and only then is the design written. Following the folder
numbers walks the process in the order it happens.
One file per decision, numbered, never deleted. A superseded record has its status: changed
and gains a pointer to what replaced it — its text is never edited. The reasoning that was
rejected is the expensive half to rediscover.
The records run in the order the decisions were taken, oldest first.
Every decision is a record. There is no ledger and no index file — if a decision is worth
recording it is worth a record, and if it is not worth a record it is not recorded
(ADR 0026). A "decision" small enough to be one line is
almost always a rule, and a rule belongs in
00-META/how-we-build.md, where it is enforced and keeps the
incident that earned it.
Frontmatter
---
status: proposed | accepted | superseded
date: YYYY-MM-DD # when the decision was taken, not when it was written down
deciders: name
reconstructed: true|false # true when the record was written after the fact from evidence
superseded-by: # 02-DECISIONS/NNNN-....md, when status is superseded
extends: # 02-DECISIONS/NNNN-....md, when this record widens an earlier one
---
Body
# N. Title in plain language
## Context what was true, with evidence
## Considered Options numbered, each with why it was rejected
## Decision what was decided
## Consequences what follows, including what got harder
## References commits, pull requests, knowledge-base entries, prior art
State evidence, not assertion. "Zero of 124 modules declare brain as a dependency"
outranks "the dependency rule is not followed".
Reconstructed records
Records 0001–0014 were written on 2026-08-23, after the decisions they describe. Records 0015 onward were taken as records. Those
decisions were taken in implementation rather than in a document; the records state what was
decided and the evidence it was decided from, and each carries reconstructed: true and says
so in its first lines.
A reconstructed record is not a transcript. Where the deliberation is not recoverable, the options section states what the alternatives were and why the chosen one won on the evidence available — not a discussion that did not happen. Where a date is not establishable it says so rather than guessing.
Index
The index is generated, not maintained — run the hq-status skill, which reads the
frontmatter of every record. A hand-written index drifts from the folder it describes, and
this one had already done so after a single addition.