Codifies the structure ADRs 019-022 converged on, pins an Accepted/Superseded/Deprecated lifecycle with a no-silent-rewrite rule, adds an adr-template.md scaffold, and plans a Status-header backfill of ADRs 001-018. Basis for ADR-023. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
132 lines
6.7 KiB
Markdown
132 lines
6.7 KiB
Markdown
# Design — ADR structure & lifecycle
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- **Date:** 2026-06-10
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- **Status:** Approved design — implementation plan to follow
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- **Resolves:** the absence of a written standard for how ADRs in
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`docs/decisions/` are structured. The newest ADRs (019–022) have converged on a
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clean pattern (`Status` → `Context` → `Decision` → `Consequences` → `Related`),
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but it lives only as imitation; ADRs 001–018 predate it and most lack a `Status`
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section.
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- **Becomes:** ADR-023 (this design is the basis for that ADR).
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- **Reuses:** boma's existing `*-template.md` convention (`service-security-template.md`,
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`service-verify-template.md`, `service-access-template.md`, `service-backup-template.md`);
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ADR-014 (knowledge-sourcing → the optional `Verified facts` section); ADR-019/020/021/022
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(the emergent structure being codified); the `/review-repo` command (enforcement home).
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---
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## Problem
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boma documents architectural decisions as numbered ADRs in `docs/decisions/`, and
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CLAUDE.md treats them as load-bearing ("Before assuming a role, provider, or pipeline
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exists, check STATUS.md"; the entire "Further reading" table points into them). Yet
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there is no ADR that says how an ADR is written. The result:
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- **Structural drift.** ADRs 001–018 are freeform; 019–022 converged on a consistent
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shape but only by imitation. A new ADR's structure depends on which existing one the
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author happened to copy.
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- **No status discipline.** Most early ADRs have no `## Status` section, so there is no
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uniform way to tell an active decision from a superseded or deprecated one — and no
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written rule for how a decision gets reversed without silently rewriting history.
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- **No scaffold.** Every other recurring document type in boma has a template
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(`service-security-template.md`, etc.). ADRs do not.
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This design codifies the structure 019–022 already demonstrate, pins a status
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lifecycle, ships a template, and reconciles the back-catalogue.
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## Scope
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- **In:** the canonical section set (mandatory + optional); title and filename
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convention; the `Accepted / Superseded / Deprecated` status lifecycle and the
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no-silent-rewrite rule; cross-reference convention; an ADR template file; a
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lightweight `/review-repo` structure check; a one-time backfill of `## Status` into
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the ADRs that lack one.
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- **Out (for now):** rewriting the *decisions* in any existing ADR; normalizing the
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body section names of 001–018 beyond adding `Status`; a `make lint` / CI gate for
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ADR structure (explicitly rejected in favour of the `/review-repo` check —
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consistent with boma's other doctrine ADRs, which add no CI gate); a "Proposed"
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draft stage (rejected — boma is single-contributor and trunk-based with no review
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gate, so ADRs are born Accepted).
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## Decision
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### 1. Title & filename
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- Title line: `# ADR-NNN — <Title>: <optional clarifying subtitle>` (em-dash `—`,
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matching every existing ADR).
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- Filename: `NNN-kebab-title.md`, zero-padded 3-digit, monotonic, **never reused**
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(a superseded ADR keeps its number and file).
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- A new ADR is registered as a row in the CLAUDE.md "Further reading" table.
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### 2. Canonical sections
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**Mandatory — every ADR, in this order:**
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| Section | Holds |
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|---|---|
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| `## Status` | `Accepted (YYYY-MM-DD)`, plus an optional one-line note (what it resolves/supersedes, or a doctrine-not-yet-built caveat as ADR-022 uses) |
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| `## Context` | the forces, the problem, what exists today, why now |
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| `## Decision` | what we are doing — numbered sub-decisions for multi-part ADRs, as 020/021/022 do |
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| `## Consequences` | results, trade-offs *explicitly accepted*, follow-on work |
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**Optional — use only where genuinely applicable, never as padding:**
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- `## Related` — links to other ADRs by number.
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- `## Scope` — explicit in/out-of-scope boundaries.
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- `## Guardrails` / `## Enforcement` — how the decision is mechanically enforced
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(lint, CI, hooks).
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- `## What was ruled out` — rejected alternatives, each with its reason.
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- `## Verified facts (ADR-014)` — version-stamped facts per the knowledge-sourcing rule.
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### 3. Status lifecycle
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Three states; no "Proposed" stage.
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- Born **`Accepted (YYYY-MM-DD)`** — the sole author commits to it on writing.
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- Replaced by a later decision → the old ADR's Status becomes
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**`Superseded by ADR-NNN (YYYY-MM-DD)`**; the superseding ADR records
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`Supersedes ADR-MMM` in its own `## Status` and `## Related`. The link is
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**bidirectional** — both files must point at each other.
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- Retired with no replacement → **`Deprecated (YYYY-MM-DD)`** plus a one-line reason.
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**Load-bearing rule — no silent rewrites.** An `Accepted` ADR is not edited to reverse
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its decision. Typo and clarity fixes are fine; a *material reversal* requires a new ADR
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and a `Superseded by` marker on the old one. The history of decisions stays legible.
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### 4. Cross-references
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Reference other ADRs by number inline (`ADR-019`), and collect the relationships in a
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`## Related` section.
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### 5. Template file
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Ship `docs/decisions/adr-template.md` — consistent with boma's existing
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`*-template.md` convention. It contains the mandatory section headers pre-filled with
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short HTML-comment hints, and the optional sections listed as commented stubs to
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uncomment when relevant. It is a skeleton, not a numbered decision, so it does not take
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an ADR number.
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### 6. Retroactive backfill (001–018)
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A **separate follow-up step** after the ADR and template land: add a `## Status`
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section to every ADR that lacks one. Status value is `Accepted (YYYY-MM-DD)` where the
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date is reconstructed from each file's **first git-commit date**. **Only the Status
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header is added — no decision content is touched.** ADRs already carrying a `## Status`
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(019–022) are left alone.
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### 7. Enforcement
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Lightweight, no CI gate. The `/review-repo` command gains an ADR-structure check:
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every file in `docs/decisions/` matching `NNN-*.md` has the four mandatory sections and
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a parseable `## Status` line. The template carries the convention forward for new ADRs.
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## Consequences
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- New ADRs have one obvious shape and a scaffold to start from; structural drift stops.
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- Every ADR declares its lifecycle state uniformly, and reversals are traceable rather
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than silent — the back-catalogue becomes a legible decision history.
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- One-time churn: a backfill commit touching ~18 files (Status header only).
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- `/review-repo` grows a new check; no new CI machinery, matching boma's habit of not
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gating doctrine in CI.
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- This ADR is itself the first conformant example — it must follow its own structure.
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## Open questions
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None outstanding — title/filename, the 3-state lifecycle, template name
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(`adr-template.md`), enforcement (`/review-repo`, no CI gate), and the
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Status-only backfill were all confirmed during brainstorming.
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