Imported from ollieread/archdoc (plugin/skills/archdoc-backfill/SKILL.md). Install upstream with npx skills add ollieread/archdoc --skill archdoc-backfill. Copyright stays with the author.

Backfilling

Writing up decisions that were taken elsewhere, before this repository existed. (PROCESS.md, Backfilling)

The rule that matters most

Do not invent what was not recorded.

An alternative nobody weighed, or a rationale reconstructed because it sounds convincing, is worse than an admission of ignorance, because a later reader cannot tell it from the real thing. Where the record does not say, write that it does not say.

This is the one rule in the whole process that no lint rule enforces and that an agent will break by default, because producing fluent plausible prose is effortless and the result looks exactly like a real recollection. Treat every sentence as needing a source you could point at.

Acceptable:

## Alternatives considered

Not recorded. The pull request discussion references a comparison against Redis but does not say what was measured or why Postgres was chosen.

Not acceptable:

## Alternatives considered

Redis was considered but rejected because the operational burden of a second datastore outweighed the latency benefit.

The second may even be true. It is still not permitted, because nothing in the record says it and a later reader cannot tell that.

How it differs from an ordinary document

A backfilled document is created directly in a terminal status. It does not pass through draft and proposed, because it was never proposed. Sending it round the lifecycle would fabricate three events that did not happen.

archdoc new adr "Timestamps are stored in UTC" \
  --backfill --status=accepted --created 2024-03-11 --decided 2024-04-02

--status takes a terminal status: accepted, rejected or withdrawn. --created and --decided take the historical dates; omit them and you will be prompted.

Front matter gains one key no other document carries:

created: 2024-03-11      when the work began
decided: 2024-04-02      when the decision was taken
backfilled: 2026-09-13   when this document was written

The historical dates go in created and decided; backfilled is today. That states plainly that the document was written on one date about a decision taken on another, rather than claiming to have existed all along.

Sources are required

Every backfilled document carries a Sources section naming what it was reconstructed from, for the same reason a ref does: the claim needs something it can be checked against. It must be the document's last H2.

Name specific, findable things. A pull request number, a commit hash, an issue thread, a changelog entry, a dated conversation. "Team knowledge" is not a source.

Numbering and order

Numbers are assigned in creation order, not decision order, so a decision from three years ago may carry a higher number than one from last week. When backfilling in bulk at the outset, write the documents in historical order so the two roughly agree. When backfilling later, do not renumber anything.

Before the push

A backfilled document is frozen by the same push as any other. Forty of them in one commit freezes forty documents at once, and a mistake in any of them is then permanent.

Read them before pushing. If you wrote them, you are the worst reviewer of whether you invented anything, so re-read each one asking only: what is my source for this sentence?