Architecture Decision Records

Architecture decision records

Source: https://github.com/dirnbauer/webconsulting-skills

Write ADRs as a durable record of why one architecturally significant choice was made. Prefer a small factual record over a broad design guide.

Workflow

1. Read repository instructions, existing ADRs, documentation tooling, and the implementation affected by the decision.
2. Decide whether the record is prospective or retrospective. Never present a reconstructed decision as if it had been written when the choice was made.
3. Identify one significant decision. Split independent, phased, or separately reversible choices into separate records.
4. Use the repository's established template. Without one, use Nygard's minimal anatomy: status, context, decision, and consequences. Add alternatives when they explain the choice; use MADR when option comparison needs more detail.
5. For a retrospective ADR, inspect Git history first. Record relevant commit hashes and dates, then verify every claim against current code, tests, configuration, and authoritative platform documentation.
6. Write context as forces and constraints, not a disguised solution. State the decision assertively. Include material benefits, costs, risks, and limits.
7. Use Proposed, Accepted, Rejected, Deprecated, or Superseded by ADR-NNN. Preserve accepted and rejected records; supersede them with a new ADR instead of rewriting history.
8. Update the decision-log index and reciprocal supersession links. Render or lint the documentation using the repository's native toolchain.
9. Run the bundled validator and report unresolved evidence gaps honestly.

Quality rules

• Use monotonic identifiers and never reuse a removed number.
• Keep one decision per record and make the title describe that decision.
• Separate observed facts, the selected decision, and expected consequences.
• Include credible alternatives; do not create straw-man options.
• Do not assign net scores or weights unless the ADR defines a scoring model and cites the measurements behind it.
• Distinguish verified history from inference and current policy from past fact.
• Keep secrets, personal data, and internal credentials out of evidence.
• Keep the record concise, standalone, linkable, and reviewable in a code diff.

Validation

python3 skills/architecture-decision-records/scripts/validate_adrs.py docs/adr \
  --git-repo . --require-history

Omit --require-history for prospective records. Add the repository's own renderer, link checker, or Markdown/ReST linter after this structural check.

Decisions taken inside a running process

Some skills record decisions while work is in progress rather than in a project's permanent docs/adr. typo3-upgrade-run is the case to know: it writes ADRs into .typo3-update/decisions/ for the run scope, degraded sampling, and any URL it had to exclude from its invariance claim.

Two rules apply there and are worth carrying to any similar process:

• An ADR that weakens a guarantee must say so explicitly, and the weakening must also appear in whatever certificate or report states the guarantee. A documented limitation is honest; an implied one is not.

• Validate before the loop closes, not at the end of the project:

  python3 skills/architecture-decision-records/scripts/validate_adrs.py \
    .typo3-update/decisions
  

Run-scoped ADRs stay with their run. Promote one into the project's permanent decision log only when it outlives the process that produced it.

Resources

• Read references/best-practices.md for the standards landscape, lifecycle, evidence method, and review rubric.
• Copy assets/adr-template.md for Markdown projects.
• Copy assets/AdrTemplate.rst for TYPO3 or other ReST documentation projects.