hk-changelog

Changelog Creator

Generate a changelog entry from git changes, prepend it to CHANGELOG.md, and optionally commit + raise a PR.

Usage

/hk-changelog              → full flow: write + commit + PR
/hk-changelog --dry-run    → print the entry only (no file changes)
/hk-changelog --commit     → write + commit (no PR)

Arguments are passed via $ARGUMENTS.

Instructions

Step 1: Parse arguments

Check $ARGUMENTS for --dry-run or --commit. Default behavior (no args) is the full flow: write, commit, and open a PR.

Step 2: Gather raw git data

Run these commands to collect the raw material. This is mechanical — just capture the output:

# What branch are we on?
git rev-parse --abbrev-ref HEAD

# Commits on this branch that aren't on main
git log main..HEAD --oneline --no-merges 2>/dev/null

# File-level summary
git diff --stat main...HEAD 2>/dev/null
git diff main...HEAD --name-status 2>/dev/null

# Unstaged/untracked
git diff --stat HEAD
git diff --name-status HEAD
git status --short | grep "^??"

If there are no commits diverging from main AND no staged/unstaged changes, tell the user there's nothing to changelog and stop.

If on main with no diverging commits, fall back to diffing against the previous commit:

git log -1 --oneline
git diff HEAD~1 --stat
git diff HEAD~1 --name-status

Also read the existing CHANGELOG.md so the subagent can match the format.

Step 3: Delegate to haiku subagent

Use the Task tool with subagent_type: "general-purpose" and model: "haiku" to do the heavy lifting. The subagent reads diffs, understands the changes, and generates the changelog entry.

Pass the subagent a prompt containing:

1. All the git output from Step 2
2. The existing CHANGELOG.md content (for format reference)
3. The full generation rules below
4. A clear instruction: "Read the actual diffs by subsystem, then generate a changelog entry. Return ONLY the markdown entry, nothing else."

The subagent prompt must include these instructions: