---
name: stack-branch
description: Create a new branch stacked on another PR. Use when you want to start work that depends on an existing PR that hasn't been merged yet.
allowed-tools: "Read,Bash(git:*),Bash(~/.claude/skills/stack-branch/scripts/gh-pr-create.sh:*),Bash(gh pr create:*),Skill,AskUserQuestion,mcp__jira__*"
version: "1.0.0"
author: "flurdy"
---

# Create Stacked Branch

Create a new branch based on an existing PR branch (not main) for dependent work.

## Usage

```
/stack-branch AB-456
/stack-branch AB-456 feature/parent-branch    # Explicit parent
```

## Instructions

### 1. Get the Jira Ticket

The first argument is the Jira ticket number for the new work.

Use the `/jira-ticket` skill or the Jira MCP tools directly to get ticket details:

```
mcp__jira__jira_get with:
  path: /rest/api/3/issue/{ticketNumber}
  jq: "{key: key, summary: fields.summary, issuetype: fields.issuetype.name}"
```

### 2. Identify Parent Branch

If parent branch not specified:

```bash
# Check if currently on a feature branch
git branch --show-current
```

If on a feature branch (not main), offer to use it as the parent.
Otherwise, ask the user which branch to stack on.

### 3. Ensure Parent is Up to Date

```bash
# Fetch the parent branch
git fetch origin {parent-branch}

# Check out and update local copy
git checkout {parent-branch}
git pull origin {parent-branch}
```

### 4. Create Branch Name

Map the Jira issue type to conventional commit prefix:

| Issue Type | Prefix |
|------------|--------|
| Story | `feat` |
| Task | `feat` |
| Bug | `fix` |
| Improvement | `feat` |
| Spike | `chore` |
| Sub-task | inherit from parent |

Create branch name:
```
{prefix}/{TICKET}-{summary-in-kebab-case}
```

Example: `feat/AB-456-add-caching-layer`

### 5. Create the Branch

```bash
git checkout -b {new-branch-name}
```

### 6. Push and Set Upstream

```bash
git push -u origin {new-branch-name}
```

### 7. Inform User

Tell the user:
- Created branch `{new-branch-name}` based on `{parent-branch}`
- When creating a PR, target `{parent-branch}` not `main`
- When `{parent-branch}` is merged, use `/rebase-merged-parent` to rebase onto main

### 8. Optional: Create Draft PR

Ask if the user wants to create a draft PR now:

Check for a repo-specific PR template at `.github/pull-request-template.md` or `.github/pull_request_template.md`. If found, use that format. If not, ask user for confirmation on generating the body ourselves.

#### Create the PR targeting parent branch

```bash
~/.claude/skills/stack-branch/scripts/gh-pr-create.sh --draft --base {parent-branch} --title "{type}({scope}): {description}" --body "$(cat <<'EOF'
{body}
EOF
)"
```

If the script is unavailable, fall back to:

```bash
gh pr create --draft --base {parent-branch} --title "{type}({scope}): {description}" --body "$(cat <<'EOF'
{body}
EOF
)"
```