Writing Plans Skill

Purpose: Transform an approved design into a detailed, bite-sized implementation plan.

Announce at start: "I'm using the writing-plans skill to create the implementation plan."

Plan File Location

Save to docs/superpowers/plans/YYYY-MM-DD-<feature-name>.md (User preferences for plan location override this default.)

Step 1: Scope Check

If the spec covers multiple independent subsystems, they should have been broken into sub-project specs during brainstorming. If not, suggest breaking into separate plans — one per subsystem. Each plan should produce working, testable software on its own.

Step 2: File Structure Mapping

Before defining tasks, map which files will be created or modified:

• Design units with clear boundaries and well-defined interfaces
• Each file has one clear responsibility
• Files that change together should live together
• Follow established patterns in existing codebases
• Prefer smaller, focused files over large ones

This structure informs task decomposition.

Step 3: Plan Document Header

Every plan MUST start with this header.

Also reference any existing {phase}-CONTEXT.md from the project for implementation constraints already captured.

# [Feature Name] Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** [One sentence describing what this builds]

**Architecture:** [2-3 sentences about approach]

**Tech Stack:** [Key technologies/libraries]

---

Step 4: Task Structure

Each step is one action (2-5 minutes):

### Task N: [Component Name]

**Files:**
- Create: `exact/path/to/file.py`
- Modify: `exact/path/to/existing.py:123-145`
- Test: `tests/exact/path/to/test.py`

- [ ] **Step 1: Write the failing test**

```python
def test_specific_behavior():
    result = function(input)
    assert result == expected

• Step 2: Run test to verify it fails

Run: pytest tests/path/test.py::test_name -v Expected: FAIL with "function not defined"

• Step 3: Write minimal implementation

def function(input):
    return expected

• Step 4: Run test to verify it passes

Run: pytest tests/path/test.py::test_name -v Expected: PASS

• Step 5: Commit

git add tests/path/test.py src/path/file.py
git commit -m "feat: add specific feature"

## Step 5: Plan Review Loop

After writing the complete plan:

1. Dispatch a single `plan-document-reviewer` subagent with precisely crafted review context — never your session history
2. Provide: path to the plan document, path to spec document
3. If issues found: fix the issues, re-dispatch reviewer for the whole plan
4. If approved: proceed to execution handoff
5. If loop exceeds 3 iterations: surface to human for guidance

Reviewers are advisory — explain disagreements if you believe feedback is incorrect.

## Step 6: Execution Handoff

After saving the plan, offer execution choice:

**"Plan complete and saved. Two execution options:**

**1. Subagent-Driven (recommended)** - Fresh subagent per task, review between tasks, fast iteration

**2. Inline Execution** - Execute tasks in this session using executing-plans, batch execution with checkpoints

**Which approach?**

## Key Principles

- Exact file paths always
- Complete code in plan (not "add validation")
- Exact commands with expected output
- Reference relevant skills with @ syntax
- DRY, YAGNI, TDD, frequent commits
- One action per step (2-5 minutes)

## Integration

- **Required sub-skill:** `superpowers-subagent-driven-development` or `superpowers-executing-plans`
- **Called by:** `superpowers-brainstorming`
- **Creates:** plan document at `docs/superpowers/plans/`
- **Prerequisite:** approved design spec from brainstorming