changelog

changelog is a skill for Claude Code from MountainUnicorn/add. It costs 16 tokens per session (1,541 once invoked), scanned A, original, MIT.

A command that creates or updates CHANGELOG.md, a file that records notable project changes for each release or period. It builds entries from git history and uses the Keep a Changelog structure.

In plain words
What is it for?
Use it for incremental updates or full regeneration, with conventional commit types placed into sections such as Added, Fixed, Changed, and Security.
Why use it?
It turns commit history into an organized change record without requiring developers to write every entry manually.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Runs only inside a plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else, and the catalogue could not identify which plugin ships it.

Good fit Use it for incremental updates or full regeneration, with conventional commit types placed into sections such as Added, Fixed, Changed, and Security.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for changelog

README.md
[![agentmods](https://agentmods.dev/badge/skills/mountainunicorn/add/changelog.svg)](https://agentmods.dev/skills/mountainunicorn/add/changelog)
Your own site
<a href="https://agentmods.dev/skills/mountainunicorn/add/changelog"><img src="https://agentmods.dev/badge/skills/mountainunicorn/add/changelog.svg" alt="Measured on agentmods" height="20"></a>
Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,541 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00016 $0.01541
Opus 5 $0.00008 $0.00771
Sonnet 5 $0.00003 $0.00308
Haiku 4.5 $0.00002 $0.00154

Measured 7d ago against content hash c908d9337072, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

changelog scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

core/skills/changelog/SKILL.md · 172 lines

How it starts

The opening of the file, as written. The whole thing — 172 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ADD Changelog Command v{{VERSION}}

Generate or refresh the project's CHANGELOG.md from git history using conventional commit parsing. Follows the Keep a Changelog format.

Pre-Flight Check

  1. Check if CHANGELOG.md exists in the project root
  2. If it does NOT exist, create it from ${CLAUDE_PLUGIN_ROOT}/templates/changelog.md.template
  3. Read .add/config.json for changelog.lastProcessedCommit (may be null)
  4. Determine mode: --from-scratch flag means full regeneration; otherwise incremental

Conventional Commit Mapping

Map conventional commit prefixes to Keep a Changelog sections:

Commit Prefix Changelog Section
feat: Added
fix: Fixed
docs: Documentation
refactor: Changed
perf: Changed
deprecate: Deprecated
remove: Removed
security: Security
revert: Fixed

Excluded Prefixes (not added to changelog)

These are internal/maintenance commits and should be silently skipped:

  • chore:
  • test:
  • ci:
  • style:
  • build:

Non-Conventional Commits

Commits that do not match any conventional prefix are categorized under Changed with the full message as the entry text.

Merge Commits

Skip merge commits entirely — they duplicate the content of the merged commits.

Phase 1: Gather Commits

Incremental Mode (default)

  1. Read CHANGELOG.md to understand current state
  2. Read .add/config.json for changelog.lastProcessedCommit
  3. If lastProcessedCommit is set:
    • Run git log --oneline --no-merges {lastProcessedCommit}..HEAD to get new commits
  4. If lastProcessedCommit is null:
    • Run git log --oneline --no-merges to get all commits
  5. If no new commits found, report "Changelog is up to date" and exit

From-Scratch Mode (--from-scratch)

  1. Run git tag --sort=-version:refname to get all version tags
  2. Run git log --oneline --no-merges to get full commit history
  3. Group commits by version tags:
    • Commits after the latest tag go in [Unreleased]
    • Commits between tags go in [tag] - date sections (use tag date)
    • Commits before the earliest tag go in the earliest version section
  4. Regenerate CHANGELOG.md entirely (preserve the header from template)

Read the full file on GitHub · 172 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 172 lines · 16 tokens per session scan A c908d9337072

Subscribe to this mod's changes

changelog is a skill published in the GitHub repository MountainUnicorn/add (11 stars, last pushed 1mo ago), licensed MIT. It adds 16 tokens to every session and 1,541 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.