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:

   ls -t .claude/plans/*/plan.md 2>/dev/null | head -1
   

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 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 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

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

/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 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