commit-style

Git Commit Style

Conventions for writing git commit messages and pull request descriptions. Project-specific conventions always take priority.

Subject Line

• Try to keep under 50 characters total
• No trailing period
• Lowercase imperative verbs: fix, add, remove, use, avoid, ensure, adjust, allow, enable, extract, introduce, show, move, roll
• Capital letter only when starting with a proper noun or class name — never capitalize verbs
• Embed the "why" directly when possible: avoid enlarging small images, avoid double-save on withdraw
• Technical identifiers kept verbatim: config.x.asset_file_uploadable, event_submission_open?
• Arrow notation for renames: ops-lb: rknw -> rknet

Keeping Under 50 Characters

Techniques when the subject runs long:

• Drop add when the subject already names the primary new thing: site-sessions: SiteSession model not … add SiteSession model — keep add when supplementing existing code (specs, logging)
• Omit secondary artifacts when the primary deliverable is clear: site-sessions: SiteSessionIssuance service not … service and background jobs — mention omitted parts in the body
• & over and: PrimarySession & User changes
• Drop qualifiers the prefix already provides: site-sessions: PrimarySession & User changes not … for site sessions

Contextful Verbs

Prefer specific verbs over generic ones:

• avoid or address over fix for preventive changes
• extract over refactor when pulling out a concern/class
• introduce over add when creating a new concept/abstraction
• reflect over update when syncing with external state
• gains for new capabilities (component as subject): SponsorEvent: gains hero image upload
• learns for new options/parameters: TitoApi: learns v3.1 pagination
• no longer for behavioral removals: event_submission_open? no longer gates asset uploads
• roll for dependency updates and referenced image/git tag updates, releng for release engineering, trigger for CI/build triggers

Prefix Pattern

Format: prefix: rest of subject — use when the commit targets a specific component.

Prefix types vary by what is being changed:

• Class/module name (PascalCase, matching actual name; short, greppable, consistent — prefer over lowercase descriptive forms): SponsorEventAssetFilesController: fix set_asset_file authorization, SiteSessionRenewal: just propagate errors
• Method reference (Class#method): SponsorEventsController#destroy: avoid double-save on withdraw
• View/route path: broadcasts/show: sort recipients alphabetically
• Feature/epic name (hyphenated, no spaces — consistent across a series): event-assets: begin validation, site-sessions: SiteSession model
• File or directory: Dockerfile: build minimal libvips, CI: install libvips-tools
• Subsystem/infra name: tf/k8s: ..., radius: ..., grafana: ...

Omit prefix when:

• The subject already names the target: Extract GithubInstallation from GenerateSponsorsYamlFileJob
• Whole-project or obvious-context changes: roll latest dependencies, trigger build for 3.2.10
• Terse commits: typo, wip, oops

Body

The most important role of the body is to explain background and context that is NOT obvious from the diff. The diff shows what changed; the body explains why it was changed, what problem it solves, or what non-obvious behavior motivated the change.

• Do not repeat what the diff already says — focus on what a reader cannot infer from code alone
• Opening sentence or paragraph: the background, rationale, or problem
• Bullet list with - when enumerating multiple specifics
• Wrap lines at ~72 characters
• Issue references: Closes #N
• Skip body entirely when the subject + diff are self-explanatory

Examples:

sponsor_events: wrap asset file update in transaction

Prevent data loss when replacing a hero image and the subsequent
update fails validation. The old asset file destroy is now rolled
back if the event update doesn't succeed.

SponsorEventsController#destroy: avoid double-save on withdraw

withdrawn! saves immediately, creating one editing history record,
then save! creates a second one with no meaningful diff. The job
was enqueued with the second history, missing the status change
and skipping YAML regeneration.

Pull Request Titles and Descriptions

Apply the same subject line conventions to PR titles (under 70 chars).

• Single-commit branch: use the commit subject as title and commit body as description
• Multi-commit branch: write a concise summary title, then explain individual commits under headings or bullet points using Markdown

Never include test procedures, test plans, QA checklists, task lists, or TODO checkboxes in PR descriptions.

Git Command Usage

• Never use git -C <path> — it invalidates pre-approved permissions in Claude Code. Always cd to the target directory first, then run git commands.