Stack Splitter

Automatically split a monolithic branch with many changes into a logical, reviewable stack of PRs using semantic analysis and Graphite.

Note: This skill requires Graphite CLI (gt) as PR stacking is a Graphite-specific concept. For standard Git workflows without stacking, consider creating separate branches and PRs manually or using the standard PR creator.

When to Activate

• User has a large branch with many commits
• User wants to break changes into reviewable pieces
• User asks to "split" or "stack" their changes
• User needs help creating a PR stack
• User mentions Graphite stack management

Prerequisites

• Graphite CLI installed: npm install -g @withgraphite/graphite-cli@latest (required - this is a Graphite-only feature)
• Repository initialized with Graphite: gt repo init
• Clean working directory: No uncommitted changes
• Feature branch with 3+ commits to split

Why Graphite-only? PR stacking (having multiple dependent PRs that automatically rebase when lower PRs are merged) is a core Graphite feature. Standard Git doesn't support this workflow natively.

Quick Process

1. Analyze Changes: Examine all commits and file changes since branch diverged
2. Semantic Grouping: Group related changes by functionality
3. Dependency Analysis: Use Nx project graph to understand dependencies
4. Plan Generation: Create logical split plan optimized for reviewability
5. User Approval: Present plan and wait for approval/modifications
6. Execute Splits: Use gt split to create the stack

Semantic Analysis Principles

Logical Boundaries

Group changes that:

• Implement the same feature or fix the same bug
• Share the same domain/context (auth, payments, UI)
• Have natural dependencies (types → implementation → tests)

Dependency Awareness

• Use Nx project graph for package dependencies
• Foundational changes go at bottom of stack
• Integration/glue code goes at top
• Each PR reviewable independently

Reviewability Optimization

Each PR should:

• Tell a coherent story with clear purpose
• Be small enough to review in 15-30 minutes
• Include relevant tests
• Have descriptive title and description

Output Format

## 📋 Proposed Stack Split Plan

**Current Branch:** `feature/big-changes`
**Base Branch:** `main`
**Total Commits:** 15

### Stack Structure (bottom to top)

#### PR #1: `feat: add authentication types`

**Commits:** 3 commits
**Files:** 5 files (+123 -12)
**Rationale:** Foundational types that other changes depend on
**Reviewability Score:** 9/10

#### PR #2: `feat: implement JWT service`

**Commits:** 5 commits
**Files:** 12 files (+456 -89)
**Dependencies:** PR #1
**Reviewability Score:** 7/10

[... continues for each PR ...]

Examples

"Split this branch into PRs"
"Break up my changes into a reviewable stack"
"Create a PR stack from my feature branch"
"Help me split these 15 commits into logical PRs"

Delegation

Invokes the stack-splitter-agent with:

• Current branch name and base branch
• All commits since divergence
• File changes with diff
• Nx project structure (if available)