json-difference: Skill for Claude Code

Create or Update Pull Request

This skill creates a new PR for the current branch, or updates the existing PR if one is already open. In both cases, it regenerates the title (Conventional Commits) and body (Objective + What was done) from the actual diff and commit history. All output is in English, regardless of the conversation language.

When to use

Invoke this skill whenever the user wants to:

• Open a PR for the current branch
• Update an existing PR's title or description
• Refresh the PR after new commits on the branch

Do not invoke for: merging, reviewing, closing PRs, or operations against a different branch.

Preconditions

Before doing any network action, verify:

1. The repository has a GitHub remote (git remote -v shows github.com). If not, abort and tell the user.
2. The current branch is not the main/master branch. Detect the main branch with gh repo view --json defaultBranchRef -q .defaultBranchRef.name. If the user is on it, abort and ask them to switch.
3. The gh CLI is authenticated (gh auth status). If not, abort with instructions.
4. There are commits on the current branch beyond the merge base with the default branch. If zero commits ahead, abort — nothing to PR.

Steps

1. Gather branch + repo context (parallel)

Run these commands in parallel:

git branch --show-current                                            # current branch
gh repo view --json defaultBranchRef -q .defaultBranchRef.name       # default/base branch
gh pr list --head "<current-branch>" --state open --json number,title,body,url --limit 1
git status --porcelain                                               # uncommitted changes check
git rev-parse --abbrev-ref "<current-branch>@{upstream}" 2>&1        # is branch pushed?

2. Gather change context (parallel)

Using the base branch discovered above:

git log <base>..HEAD --oneline                 # commit list
git diff <base>...HEAD --stat                   # files changed + insertions/deletions
git diff <base>...HEAD                          # full diff (truncate if huge)