Changelog Generator Skill

Changelog Generator Skill

Converts raw git commits, a diff summary, or developer release notes into a polished changelog entry — categorised, user-facing, and following Keep a Changelog conventions.

Required Inputs

Ask for these if not provided:

• Commits or release notes (paste git log --oneline, raw commit messages, or a description of what changed)
• Version number (e.g. 2.4.0, v1.0.0-beta.2)
• Release date (or "today")
• Audience (developers using an API / end users of a product / internal team — affects language)
• Any breaking changes (flag these explicitly if known)
• Previous version behaviour (optional — paste the previous changelog entry or describe what is changing; needed for accurate "Changed" entries)
• Scope (whole product / specific package or module — e.g. "payments SDK only", "iOS app", "all services")

Output Format

Follow Keep a Changelog format:

---

[X.Y.Z] — YYYY-MM-DD

Breaking Changes ⚠️

[Only include if there are breaking changes]

• [Breaking change]: [What changed and what it breaks]
• Migration required: [Specific action the user must take]

Added

• [New feature or capability, written from the user's perspective]
• [Another addition]

Changed

• [Changed behaviour — what it did before vs. what it does now]
• [Performance improvement with measurable impact if known]

Fixed

• [Bug fixed — describe what was broken, not the fix implementation]
• [Another fix]

Deprecated

• [Deprecated thing] — use [replacement] instead. Will be removed in [version].

Removed

• [Removed thing] — was deprecated in [version]

Security

• [Security fix — describe the vulnerability class, not exploit details]

---

---

Skill guidance — do not include the following section in the delivered changelog:

Formatting Rules Applied

Language: Write for the reader, not the committer. "Add dark mode support" not "implement ThemeProvider with dark palette variant".

Breaking changes: Always call these out first with ⚠️. Include a migration path.

Bug fixes: Describe what was broken, not what was changed. "Fix crash when user has no profile picture" not "null-check avatar URL before rendering".

Granularity: Group related commits into one line. Don't list every micro-commit separately.

Tone: Active voice, imperative mood. "Add", "Fix", "Remove" — not "Added", "Fixed", "Removed".

Empty sections: Omit any section with no entries. Don't include empty ### Fixed blocks.

Deeper Materials

This skill ships with support files — use them when they are available:

• references/user-translation.md — Commit-to-Changelog Translation: Writing for the People Affected. Apply it while producing the output; it carries the calibration and judgment calls the method summary above compresses.
• templates/release-entry.md — a fill-in version of the deliverable with the quality gates inline. Offer it when the user wants to work the document themselves rather than have it generated.

Scoring Rubric (0–40)

Score any output of this skill before handing it over; 32+ is ship-quality.

Dimension	0	5	10
Reader-facing translation	Entries restate commit messages, with internal identifiers and implementation details	Mostly user-facing, but a few entries leak internals or describe the patch rather than what was broken	Every entry describes the change from the reader's perspective — what changed for them, never how the code was refactored
Breaking-change handling	Breaking changes buried mid-list or missing a migration path	Flagged at the top, but migration guidance is vague ("update your code")	At the top with ⚠️, each with a specific migration action the user can execute
Curation & grouping	Every micro-commit listed; internal-only commits included	Some grouping, but related commits still appear as separate entries or noise slips through	Related commits grouped into single entries; internal-only commits excluded; nothing a user can't observe
Format discipline	Wrong or missing version/date header; past-tense verbs; empty sections left in	Header correct but tense or empty-section slips remain	Keep a Changelog conventions throughout — correct header, imperative mood, only populated sections

Quality Checks

• Breaking changes are at the top with migration instructions
• All entries are user-facing language (no internal variable names or implementation details)
• Related commits are grouped into single entries (not listed individually)
• Version and date header is correct
• Empty sections are omitted
• No entries start with past-tense verbs (no "Added", "Fixed", "Removed" — use "Add", "Fix", "Remove")
• Every breaking change entry includes a specific migration action (not just "update your code")

Anti-Patterns

• Do not include implementation details in changelog entries — users need to know what changed for them, not how the code was refactored internally
• Do not list every micro-commit as a separate entry — related commits should be grouped into one user-facing change
• Do not omit the migration path for breaking changes — a breaking change entry without a specific migration action forces users to read the source code
• Do not include empty sections — a "### Fixed" section with no entries signals the template was filled in carelessly
• Do not write breaking changes in the same casual tone as minor additions — breaking changes must be visually prominent and call out migration requirements explicitly

Usage Examples

• "Write a changelog for version [X]" + [paste commits]
• "Generate release notes from these commits"
• "Turn this git log into a CHANGELOG entry"
• "Write the CHANGELOG.md update for this release"
• "What changed in this release?" + [paste commit list]