phx:brief

# Plan Briefing

Interactive walkthrough of a plan's reasoning, decisions, and solution
shape. Designed for developers who need to understand a plan in 1-2
minutes instead of reading the full document.

## Why This Exists

Plans answer "what to do" but bury "why." This skill bridges that
gap with an interactive walkthrough.

## Usage

```
/phx:brief                                    # Latest plan
/phx:brief .claude/plans/user-auth/plan.md    # Specific plan
```

## Arguments

- `$ARGUMENTS` = Path to plan file (optional, auto-detects latest)

## Mode Detection

Read the plan file and determine mode from phase statuses:

- **All phases `[PENDING]`** = Pre-work briefing (what WILL happen)
- **Any phase `[COMPLETED]` or `[IN_PROGRESS]`** = Post-work briefing
  (what WAS done and why)

## Execution Flow

### Step 1: Locate and Load Plan

1. If `$ARGUMENTS` has a path, use it
2. Otherwise, find latest plan:

   Use Glob to find `.claude/plans/*/plan.md` and pick the most recent.

3. If no plan found, tell user and suggest `/phx:plan`
4. Read the plan file

### Step 2: Load Supporting Artifacts

Read what's available (don't fail if missing):

- `.claude/plans/{slug}/summaries/consolidated.md` (research summary)
- `.claude/plans/{slug}/scratchpad.md` (decisions, dead-ends)
- `.claude/plans/{slug}/progress.md` (work log, post-work only)

### Step 3: Present Briefing Sections

Present ONE section at a time, wrapped in the visual briefing block
(see `${CLAUDE_SKILL_DIR}/references/briefing-guide.md` Visual Formatting). After each
section, use `AskUserQuestion` with options:

- If sections remain: **"Next: {title}"**, **"Ask me a question
  about this"**, **"Stop here"**
- If final section: no question needed, show closing message

### Section Flow (Pre-Work Mode)

| # | Title | Source |
|---|-------|--------|
| 1 | What We're Building | Summary + Scope |
| 2 | Key Decisions | Technical Decisions + scratchpad rationale |
| 3 | Solution Shape | Phases overview + Data Model |
| 4 | Risks & Confidence | Risks table + unknowns/spikes |

### Section Flow (Post-Work Mode)

| # | Title | Source |
|---|-------|--------|
| 1 | What Was Built | Summary + completion status |
| 2 | Key Decisions & Why | Technical Decisions + scratchpad |
| 3 | How It Was Built | Phases with implementation notes |
| 4 | Lessons & Patterns | Risks encountered + patterns used |

See `${CLAUDE_SKILL_DIR}/references/briefing-guide.md` for section content templates.

## Iron Laws

1. **ONE section at a time** — never dump all content
2. **User controls pace** — always offer to stop
3. **Explain WHY, not just WHAT** — rationale over listing
4. **Ground in artifacts** — focus on insights specific to this
   plan's research, decisions, and scratchpad entries, not general
   programming concepts
5. **Keep each section under 20 lines** — this is a briefing,
   not a lecture
6. **NEVER skip sections or auto-start work** — briefing is read-only; do not execute plan tasks or launch `/phx:work` without explicit user request

## Closing Message

After final section (or when user stops):

```
That's the briefing! For full details, see:
{plan_path}

Ready to proceed? Try `/phx:work {plan_path}` to start execution.
```

Post-work variant:

```
That's what was built! For full details, see:
{plan_path}

Consider `/phx:compound` to capture key learnings for future reference.
```

## Integration

```text
/phx:plan  -->  /phx:brief (optional)  -->  /phx:work  -->  /phx:brief (optional)
  create       understand before            execute        understand after
```

## Complex Plan Enhancement

For plans with 5+ phases or 4+ key decisions, consider suggesting
visual rendering after Section 3. See
`${CLAUDE_SKILL_DIR}/references/visual-explainer.md` for thresholds and commands.

## Notes

- Runs in main conversation context (not a subagent)
- Model: no special requirement — uses default session model
- No artifacts written — briefing is ephemeral, plan IS the artifact
- Reference file readable since skill runs in user's session