create-adr

# Creating Architectural Decision Records ## Quick Reference ```bash # 1. Generate the filename prefix date -u +"%Y%m%d%H%M%S" # e.g. 20241115093012 # 2. Choose the ADR collection by decision scope # Repository-wide, multi-package, and inter-package: docs/adrs/ # Package-owned and extractable: packages/<package>/docs/adrs/ # 3. Create the ADR file # Format: YYYYMMDDHHMMSS_snake_case_title.md # Root ADR: touch docs/adrs/20241115093012_your_decision_title.md # Package-local ADR: touch packages/<package>/docs/adrs/20241115093012_your_decision_title.md # 4. Update the owning collection's index # Add a root ADR to docs/adrs/index.md; add a local ADR only to its local index # 5. Validate and commit linter markdown linter cspell git commit -S -m "docs(adrs): add ADR for {short description}" ``` ## When to Create an ADR Create an ADR when making a decision that: - Affects the project's architecture or design patterns - Chooses one approach over alternatives that were considered - Has consequences worth documenting for future contributors - Answers "why was this done this way?" Do **not** create an ADR for trivial implementation choices or style preferences covered by linting. ## File Naming Convention **Format**: `YYYYMMDDHHMMSS_snake_case_title.md` Generate the timestamp prefix: ```bash date -u +"%Y%m%d%H%M%S" ``` **Examples**: - `20240227164834_use_plural_for_modules_containing_collections.md` - `20241115093012_adopt_axum_for_http_server.md` ## ADR Placement Choose the collection according to the scope of the decision, not the paths changed by the implementation: | Decision scope | Location | | --------------------------------------------------------- | ------------------------------- | | Repository-wide, multi-package, or inter-package contract | `docs/adrs/` | | Solely owned by an extractable package | `packages/<package>/docs/adrs/` | Shared configuration, protocol behavior, dependency policy, workspace conventions, and other cross-package contracts require a root ADR even if one package contains all immediate code changes. Every package-local collection needs a `README.md` and an `index.md`. Register an ADR only in the index for its owning collection; root indexes do not duplicate local entries. When a package-local decision becomes repository-wide, create a root ADR that links to and supersedes the local ADR, then retain the local ADR and its local index entry as historical context. The tracker-client CLI I/O ADR and the later root global CLI output ADR demonstrate this local-placement and root-supersession pattern. ## ADR Structure There is no rigid template — derive structure from context. Use [docs/templates/ADR.md](../../../../../docs/templates/ADR.md) as a starting point. Optional sections to add when relevant: - **Alternatives Considered**: other options explored and why they were rejected - **Consequences**: positive and negative effects of the decision ### ADR Status Do **not** add a `- Status:` header by default. An ADR merged into `develop` or `main` is implicitly accepted — the PR review process is the acceptance gate. Only add a `- Status:` header for special terminal states: - `- Status: Superseded by [ADR link]` — this decision has been replaced by a newer ADR. - Additional states (e.g. `Deprecated`) may be introduced as needed. ## Step-by-Step Process ### Step 1: Generate Filename ```bash PREFIX=$(date -u +"%Y%m%d%H%M%S") TITLE="your_decision_title" # snake_case echo "docs/adrs/${PREFIX}_${TITLE}.md" # Or packages/<package>/docs/adrs/ for a local decision. ``` ### Step 2: Write the ADR - **Scope**: State whether the decision is root or package-local and why - **Description**: Explain the problem thoroughly — enough context for future contributors - **Agreement**: State clearly what was decided and why - **Date**: Today's date (`date -u +"%Y-%m-%d"`) - **References**: Issues, PRs, external docs ### Step 3: Update the Index Add a row to the selected collection's `index.md` table: ```markdown | [YYYYMMDDHHMMSS](YYYYMMDDHHMMSS_your_title.md) | YYYY-MM-DD | Short Title | One-sentence description. | ``` - The first column links to the ADR file using the timestamp as display text. - The short description should allow a reader to understand the decision without opening the file. ### Step 3.5: Cross-link ADR and Affected Code When an ADR affects a specific area of code, keep discovery bidirectional: - Add a short "Affected Code" section in the ADR with links to key files (module entry points, traits, setup/wiring files). - Add concise module-level doc comments in those code files pointing back to the ADR. This keeps rationale discoverable whether a contributor starts from docs or from code. ### Step 4: Validate and Commit ```bash linter markdown linter cspell linter all # full check git add docs/adrs/ # Include a package-local ADR path instead when applicable. git commit -S -m "docs(adrs): add ADR for {short description}" git push {your-fork-remote} {branch} ``` If code comments were added to establish ADR links, include those files in the same commit when practical. ## Example ADR For a real example, see [20240227164834_use_plural_for_modules_containing_collections.md](../../../../../docs/adrs/20240227164834_use_plural_for_modules_containing_collections.md).