changelog-create

name	changelog:create
description	This skill should be used when the user asks to "create a changelog", "initialize CHANGELOG.md", "start a changelog", or when the main changelog skill detects no existing CHANGELOG.md file. Creates a new CHANGELOG.md from scratch by analyzing the full git commit history and organizing changes by date-based version sections.
disable-model-invocation	false

Create Changelog

Create a new CHANGELOG.md from scratch by analyzing the full git history. Follows Keep a Changelog with Semantic Versioning.

Reasoning Discipline

This task involves multi-step reasoning across many commits: read each commit message, infer the user-facing impact, choose a category, and synthesize related commits into a single bullet. Think carefully through each commit before writing — do not fall back to keyword-only classification or verbatim copying of commit messages.

Concision Target

Calibrate output to these exact shapes. Do not exceed them.

• One bullet: ≤15 words, one sentence, past tense, capitalized first word, ends with a period.
• One category: 2–5 bullets. If a category would have >5 bullets, merge related ones until ≤5.
• One version or date section: 2–5 populated category headings. Omit any category with zero bullets.
• Whole output: a reader should scan one version section in under 30 seconds.

Preferred bullet examples

• Added OAuth 2.0 login with Google and GitHub providers.
• Fixed crash when uploading files larger than 2GB.
• Reduced dashboard load time by 40%.
• BREAKING: Removed /api/v1/users. Migrate to /api/v2/users.

Preferred section example

## 2026-03-15

### Added

- OAuth 2.0 login with Google and GitHub providers.
- Dark mode toggle in the settings panel.

### Fixed

- Fixed crash when uploading files larger than 2GB.
- Corrected timezone display in the activity log.

Workflow

Step 1: Gather Git Context

Run these commands in parallel:

git tag --sort=-version:refname          # All tags, newest first
git log --oneline --date=short --format="%h %ad %s"       # Full commit history
git remote get-url origin 2>/dev/null    # Remote URL for version links

Determine:

• Tags present? — If semver tags exist (e.g., v1.2.0, 1.0.0), use them as version boundaries to create one section per tagged release. Commits after the latest tag go under [Unreleased].
• No tags? — Use date-based grouping (see Step 2).
• Remote URL — Extract the GitHub/GitLab base URL for version comparison links.

Step 2: Group Commits into Sections

Always produce date-based sections. Never dump all commits into a single flat [Unreleased] list.

When tags exist

Use tags as primary version boundaries. Within each tagged version, order entries chronologically. Commits after the latest tag go under [Unreleased].

When no tags exist

Group commits by date into meaningful sections. Use the commit dates to find natural boundaries:

1. Scan commit dates — Identify clusters of activity separated by gaps.
2. Choose a grouping granularity based on the project's history span:
   • < 1 month of history — Group by week (e.g., ## Week of 2026-03-24).
   • 1–6 months — Group by week or biweekly, whichever produces 4–12 sections.
   • > 6 months — Group by month (e.g., ## 2026-03).
3. Use ISO date headings — Format sections as ## YYYY-MM-DD (for the start date of each group) rather than invented version numbers.
4. Place commits after the most recent group boundary under [Unreleased].

The goal is 4–12 sections that each tell a coherent story. Adjust granularity to hit that range. A single flat list is never acceptable.

Step 3: Analyze Commits

For each section (tag-based or date-based), classify commits into six categories:

Category	Signals
Added	feat:, "add", "new", "introduce", "implement"
Changed	refactor:, "update", "change", "rename", "migrate", "improve"
Deprecated	deprecate:, "sunset"
Removed	remove:, "drop", "delete", "strip"
Fixed	fix:, "bug", "patch", "resolve", "correct"
Security	security:, "CVE", "vulnerability"

Skip merge commits — Merge commits whose subject starts with Merge branch or Merge pull request duplicate the merged commits. Skip them unconditionally.

Omit these commit types unless the change is visible to end users of the software (not developers):

• CI/CD config: files under .github/, .gitlab-ci.yml, Jenkinsfile, .circleci/, azure-pipelines.yml
• Docs-only: README.md, CONTRIBUTING.md, docs/**, inline comments, docstrings
• Lint/format config: .eslintrc*, .prettierrc*, .editorconfig, .rubocop.yml, pyproject.toml tool sections
• Dependency bumps with no behavior change: dependabot, renovate, package-lock.json-only, Gemfile.lock-only
• Whitespace-only, typo-only, or comment-only edits
• Test-only additions (tests/**, *_test.go, *.spec.ts) with no corresponding source change

Keep commits in the above categories when they ship user-visible behavior — e.g., a CI fix that unblocks a release, a test that fixes a regression users reported, a dependency bump that closes a CVE.

Prefix priority — When a conventional commit prefix is present (feat:, fix:, refactor:, perf:, security:, deprecate:, remove:, with optional scope like feat(auth):), the prefix determines the category. Do not re-infer from the body. Fall back to keyword matching only when no recognized prefix exists.

Synthesize, do not copy — Group related commits into single user-facing bullet points describing the end state, not the chronology. Commits are "related" if any of these apply:

• Same user-visible feature or capability (e.g., three commits all touching the login flow)
• Same file, directory, or module scope
• Shared conventional-commit scope prefix (e.g., feat(auth): then fix(auth): then refactor(auth):)
• Iterative fixes on the same bug: initial fix commit plus one or more follow-up correction commits

Write one short, specific, past-tense sentence per bullet focused on what the user sees or feels.

Step 4: Write the File

Consult ../changelog/references/format-guide.md for the full template and formatting rules.

Build the file with:

1. # Changelog header and standard intro paragraph referencing Keep a Changelog and SemVer
2. ## [Unreleased] section (just the heading, no empty sub-headings)
3. One section per version or date group, in reverse chronological order:
   • Tagged releases: ## [X.Y.Z] - YYYY-MM-DD (use ASCII hyphen, not en-dash)
   • Date-based groups: ## YYYY-MM-DD (start date of the group)
4. Only category headings that have entries (omit empty ones)
5. Reference-style version comparison links at the bottom (for tagged versions; omit for date-based groups)

Use ISO date format (YYYY-MM-DD). Detect the remote URL for version links from git remote get-url origin.

Step 5: Present the Result

Show the full generated changelog content inline.

Key Rules

• Concision target — ≤15 words per bullet, 2–5 bullets per category, 2–5 categories per section.
• Date-based sections are mandatory — Never produce a single flat list. Every changelog must have multiple dated sections that tell the project's story over time.
• For humans, not machines — Write user-facing descriptions (e.g., "Added dark mode toggle"). Do not dump raw git log lines.
• Be specific — Write "Fixed crash when uploading large files" rather than "Bug fixes".
• Canonical category order — Added, Changed, Deprecated, Removed, Fixed, Security.
• Omit empty categories — Only include headings that have entries.
• Past tense consistently — "Added", "Fixed", "Removed".
• Call out breaking changes — Prefix with **BREAKING:**, describe impact, provide migration path.
• Deprecate before removing — Mention the target major version when deprecating.
• ASCII hyphen in version headings — ## [X.Y.Z] - YYYY-MM-DD. Never en-dash (–) or em-dash (—).

Reference Files

• ../changelog/references/format-guide.md — Complete format spec, template, style rules, antipatterns, breaking change handling