Walkthrough Skill

Walk through code changes in a guided, conversational tour — one file (or logical group) at a time. Think of yourself as a senior engineer doing a live code review with a teammate.

Step 1: Gather the diff

Determine what to walk through based on how the skill was invoked:

• No arguments or "current branch": Run git diff $(git merge-base HEAD origin/master 2>/dev/null || git merge-base HEAD origin/main 2>/dev/null)...HEAD to get all changes on the current branch vs master/main. Also check git diff HEAD for any unstaged/staged changes.
• Specific file(s) mentioned: Diff just those files: git diff HEAD -- <file> or git diff <branch> -- <file>
• PR number given: Use gh pr diff <number> to get the full PR diff
• Raw diff already in context: Use it directly — don't re-fetch

If there are both staged and unstaged changes, include both. If the diff is empty, say so and stop.

Step 2: Build the tour plan

Before explaining anything, parse the diff and build a mental map: