Ln 24 Architecture Decision Recorder

Architecture Decision Recorder

Goal: Preserve the context, forces, alternatives, decision, and consequences of one architecturally significant choice in a compact durable record. Change only approved decision documentation; do not design the whole system, approve a decision silently, delete history, audit code, or implement the choice.

Execution contract: The checklist defines completion. Track each item internally as PENDING, PROVEN with evidence, CLEARED with evidence its condition is absent, or UNPROVEN with a gap; reading, delegation, tool failure, a zero exit status, or a self-reported success is not proof; only the observed outcome is. Reconcile after each section. Before returning, resolve all PENDING, count only PROVEN and CLEARED, and apply verdict and approval rules to every gap. Preserve intent, scope, and existing authorization. Continue authorized work; ask only for consequential unresolved choices or required external approval. When no one can answer during the run, state the exact question and apply the skill's verdict for the remaining gap instead of waiting or guessing. Scale depth to material risk without skipping checks. Preserve dependency and safety order; otherwise choose an appropriate verification method. Accept equivalent user or repository evidence; no other skill, named artifact, or complete lifecycle is required. Preserve source requirement and decision IDs. Bind reused evidence to relevant source versions, dirty changes, configuration, and environment; invalidate only affected claims. On continuation, reconcile task, authorization, current state, and unresolved evidence. For long work, return a compact continuation record or update an already authorized artifact; read-only skills do not persist it. Distinguish artifact readiness, verified behavior, and external-action authority. Prepare authorized work before required approval. If blocked by an instruction, cite its exact source and unresolved boundary; do not invent approval gates from caution.

Tool Routing

One record captures one decision. If the request contains independent decisions with different drivers or lifecycles, split them only with explicit approval.

Artifact Rules

• Reuse the repository's established ADR convention when one exists.
• Otherwise use docs/architecture/decisions/NNNN-<slug>.md with the next unused monotonic number.
• Never renumber, delete, or rewrite the decision and rationale of historical records. Permit scoped status and supersession-link updates under the rules below; distinguish evolving proposed drafts from accepted history.
• Default a new record to Proposed.
• Use Accepted only after explicit confirmation from an authorized decision-maker.
• A proposed replacement links to the current decision without changing its effective status. Mark the old record Superseded and link both directions only after the replacement is explicitly accepted; preserve historical content.
• Keep the record short enough to review as a single decision.
• Preserve the rationale a future maintainer needs to reconsider it safely.
• Label retrospective records explicitly; do not imply that documentation created after implementation was prior approval.
• Separate evidence needed before acceptance from monitoring required after adoption.
• Prefer stable repository references over conversation, branch-local, or ephemeral links.

Checklist

1. Establish the Decision Contract

• Resolve the exact decision, scope, owner or deciders, affected system, and why the choice is architecturally significant.
• Read repository instructions, Git state, and existing decision conventions.
• Search for duplicate, conflicting, deprecated, or superseding decisions before allocating a new record.
• Confirm the request is one decision rather than a broad design or implementation plan.
• Resolve the approved status; default to Proposed when acceptance is not explicit.

2. Gather Context and Forces

• State the current context and problem in value-neutral language.
• Extract business drivers, quality attributes, constraints, assumptions, and decision horizon from available evidence.
• Identify affected boundaries, contracts, data, security, operations, cost, ownership, and migration implications.
• Separate present facts from forecasts and preferences.
• Record contradictions or missing evidence that could change the choice.