Plan Visualization

Render planned changes as structured ASCII visualizations with risk analysis, execution order, and impact metrics. Every section answers a specific reviewer question.

Core principle: Encode judgment into visualization, not decoration.

bash

/plan-viz                          # Auto-detect from current branch
/plan-viz billing module redesign  # Describe the plan
/plan-viz #234                     # Pull from GitHub issue

STEP 0: Detect or Clarify Plan Context

First, attempt auto-detection by running

scripts/detect-plan-context.sh

bash

bash "$SKILL_DIR/scripts/detect-plan-context.sh"

This outputs branch name, issue number (if any), commit count, and file change summary.

If auto-detection finds a clear plan (branch with commits diverging from main, or issue number in args), proceed to Step 1.

If ambiguous, clarify with AskUserQuestion:

python

AskUserQuestion(
  questions=[{
    "question": "What should I visualize?",
    "header": "Source",
    "options": [
      {"label": "Current branch changes (Recommended)", "description": "Auto-detect from git diff against main"},
      {"label": "Describe the plan", "description": "I'll explain what I'm planning to change"},
      {"label": "GitHub issue", "description": "Pull plan from a specific issue number"},
      {"label": "Quick file diff only", "description": "Just show the change manifest, skip analysis"}
    ],
    "multiSelect": false
  }]
)

STEP 1: Gather Data

Run

scripts/analyze-impact.sh

for precise counts:

bash

bash "$SKILL_DIR/scripts/analyze-impact.sh"

This produces: files by action (add/modify/delete), line counts, test files affected, and dependency changes.

For architecture-level understanding, spawn an Explore agent on the affected directories:

python

Task(
  subagent_type="Explore",
  prompt="Explore the architecture of {affected_directories}. Return: component diagram, key data flows, health scores per module. Use the ascii-visualizer skill for diagrams.",
  model="haiku"
)

STEP 2: Render Tier 1 Header (Always)

Use

assets/tier1-header.md

template. Fill in from gathered data. This is always shown first.

PLAN: {plan_name} ({issue_ref})  |  {phase_count} phases  |  {file_count} files  |  +{added} -{removed} lines
Risk: {risk_level}  |  Confidence: {confidence}  |  Reversible until {last_safe_phase}
Branch: {branch} -> {base_branch}

[1] Changes  [2] Execution  [3] Risks  [4] Decisions  [5] Impact  [all]

Risk level = highest risk across all phases (LOW/MEDIUM/HIGH/CRITICAL). Confidence = LOW if >50% of changes are in untested code, MEDIUM if mixed, HIGH if well-tested paths. Reversible until = last phase before an irreversible operation (DROP, DELETE data, breaking API change).

STEP 3: Ask Which Sections to Expand

python

AskUserQuestion(
  questions=[{
    "question": "Which sections to render?",
    "header": "Sections",
    "options": [
      {"label": "All sections", "description": "Full visualization with all 5 core sections"},
      {"label": "Changes + Execution", "description": "File diff tree and execution swimlane"},
      {"label": "Risks + Decisions", "description": "Risk dashboard and decision log"},
      {"label": "Impact only", "description": "Just the numbers: files, lines, tests, API surface"}
    ],
    "multiSelect": false
  }]
)

STEP 4: Render Requested Sections

Section [1]: Change Manifest

Use

references/change-manifest-patterns.md

. Render a Terraform-style annotated file tree:

src/
├── api/
│   ├── routes.py          [M] +45 -12    !! high-traffic path
│   └── schemas.py         [M] +20 -5
├── services/
│   └── billing.py         [A] +180       ** new file
├── models/
│   └── invoice.py         [A] +95        ** new file
└── tests/
    └── test_billing.py    [A] +120       ** new file

Legend: [A]dd [M]odify [D]elete  !! Risk  ** New
Summary: +460 -17  |  3 new  |  2 modified  |  0 deleted

Rules:

Use
```
[A]
```
/
```
[M]
```
/
```
[D]
```
prefix symbols (Terraform convention)
Show
```
+N -N
```
line counts per file
Flag high-risk files with
```
!!
```
and annotation
Mark new files with
```
**
```
Always end with a summary line

Section [2]: Execution Swimlane

Use

references/execution-swimlane-patterns.md

. Show phases as horizontal lanes with dependency lines:

Backend  ===[Schema]======[API]===========================[Deploy]====>
                |            |                                ^
                |            +------blocks------+             |
                |                               |             |
Frontend ------[Wait]--------[Components]=======[Integration]=+
                                                      |
Tests    ------[Wait]--------[Wait]-----------[E2E Tests]========>

=== Active work   --- Blocked/waiting   | Dependency
Critical path: Schema -> API -> Deploy (estimated: 4-6 hours)

Rules:

```
===
```
for active work,
```
---
```
for blocked/waiting
Vertical
```
|
```
for dependencies with
```
blocks
```
annotations
Identify and label the critical path
Show parallel opportunities explicitly

Section [3]: Risk Dashboard

Use

references/risk-dashboard-patterns.md

. Two parts: reversibility timeline + pre-mortem.

Part A: Reversibility Timeline

REVERSIBILITY TIMELINE
Phase 1  [================]  FULLY REVERSIBLE    (add column, nullable)
Phase 2  [================]  FULLY REVERSIBLE    (new endpoint, additive)
Phase 3  [============....] PARTIALLY           (backfill data)
              --- POINT OF NO RETURN ---
Phase 4  [........????????]  IRREVERSIBLE        (drop old column)
Phase 5  [================]  FULLY REVERSIBLE    (frontend toggle)

Part B: Pre-Mortem (3 scenarios)

PRE-MORTEM: This plan failed because...

1. {scenario_description}
   Probability: {level} | Impact: {level}
   Mitigation: {action}
   Rollback: {steps} ({time_estimate})

2. ...
3. ...

Rules:

Always identify the point of no return
Generate exactly 3 pre-mortem scenarios (most likely, most severe, most subtle)
Each scenario needs a concrete mitigation, not generic advice

Section [4]: Decision Log

Use

references/decision-log-patterns.md

. ADR-lite format for each non-obvious choice:

DECISION LOG

#1: {decision_title}
    Context:      {why this decision exists}
    Decision:     {what was chosen}
    Alternatives: {what was rejected and why}
    Tradeoff:     + {gain}  - {cost}

#2: ...

Rules:

Only document non-obvious decisions (skip "we need a database table for invoices")
Always show at least one rejected alternative
Tradeoffs must be honest — show the cost, not just the benefit

Section [5]: Impact Summary

Use

assets/impact-dashboard.md

template:

IMPACT SUMMARY
+=========+==========+===========+
| Category | Files   | Lines     |
+=========+==========+===========+
| Added    |    3    |    +395   |
| Modified |    2    |  +65 -17  |
| Deleted  |    0    |      0    |
+---------+----------+-----------+
| NET      |    5    |    +443   |
+---------+----------+-----------+

Tests:    2 new  |  1 modified  |  Coverage: 73% -> 68% (needs +4 tests)
API:      2 new endpoints  |  0 breaking changes
Deps:     +1 (stripe-python)  |  0 removed

STEP 5: Offer Actions

After rendering, offer next steps:

python

AskUserQuestion(
  questions=[{
    "question": "What next?",
    "header": "Actions",
    "options": [
      {"label": "Write to designs/", "description": "Save as designs/{branch}.md for PR review"},
      {"label": "Generate GitHub issues", "description": "Create issues from execution phases with labels and milestones"},
      {"label": "Drill deeper", "description": "Expand blast radius, cross-layer check, or migration checklist"},
      {"label": "Done", "description": "Plan visualization complete"}
    ],
    "multiSelect": false
  }]
)

Write to file: Save full report to

designs/{branch-name}.md

using the

assets/plan-report.md

template.

Generate issues: For each execution phase, create a GitHub issue with:

Title:
```
[{component}] {phase_description}
```
Labels: component label +
```
risk:{level}
```
Milestone: current milestone if set
Body: relevant plan sections
Blocked-by references to dependency issues

DEEP DIVES (Tier 3, on request)

[6] Blast Radius

Use

references/blast-radius-patterns.md

. Show concentric rings of impact:

                    Ring 3: Tests (8 files)
               +-------------------------------+
               |    Ring 2: Transitive (5)      |
               |   +------------------------+   |
               |   |  Ring 1: Direct (3)     |   |
               |   |   +--------------+      |   |
               |   |   | CHANGED FILE |      |   |
               |   |   +--------------+      |   |
               |   +------------------------+   |
               +-------------------------------+

Direct dependents:   auth.py, routes.py, middleware.py
Transitive:          app.py, config.py, utils.py, cli.py, server.py
Test files:          test_auth.py, test_routes.py, ... (+6 more)

[7] Cross-Layer Consistency

Verify frontend/backend alignment:

CROSS-LAYER CONSISTENCY
Backend Endpoint          Frontend Consumer     Status
POST /invoices            createInvoice()       PLANNED
GET  /invoices/:id        useInvoice(id)        PLANNED
GET  /invoices            InvoiceList.tsx        MISSING  !!

[8] Migration Checklist

Generate ordered runbook with constraints:

MIGRATION CHECKLIST

Sequential Block A (database):
  1. [ ] Backup production database                    [~5 min]
  2. [ ] Run migration: 001_add_invoices.sql           [~30s]   <- blocks #4

Parallel Block B (after #2):
  3. [ ] Deploy API v2.1.0                             [~3 min]
  4. [ ] Update frontend bundle                        [~2 min]

Sequential Block C (verification):
  5. [ ] Smoke test                                    [~2 min]
  6. [ ] Monitor error rate 15 min                     [~15 min]

Key Principles

Principle	Application
Progressive disclosure	Tier 1 header always, sections on request
Judgment over decoration	Every section answers a reviewer question
Precise over estimated	Use scripts for file/line counts
Honest uncertainty	Confidence levels, pre-mortems, tradeoff costs
Actionable output	Write to file, generate issues, drill deeper
Anti-slop	No generic transitions, no fake precision, no unused sections

Rules Quick Reference

Rule	Impact	What It Covers
ascii-diagrams	MEDIUM	Box-drawing characters, file trees, progress bars, workflow diagrams
ascii-architecture	MEDIUM	Layered architecture, blast radius, reversibility timelines, comparisons

References

Change Manifest Patterns
Execution Swimlane Patterns
Risk Dashboard Patterns
Decision Log Patterns
Blast Radius Patterns

Assets

Plan Report Template — Full mustache-style report
Impact Dashboard Template — Impact table
Tier 1 Header Template — 5-line summary

plan-viz

NPX Install

Tags

SKILL.md Content

Plan Visualization

STEP 0: Detect or Clarify Plan Context

STEP 1: Gather Data

STEP 2: Render Tier 1 Header (Always)

STEP 3: Ask Which Sections to Expand

STEP 4: Render Requested Sections

Section [1]: Change Manifest

Section [2]: Execution Swimlane

Section [3]: Risk Dashboard

Section [4]: Decision Log

Section [5]: Impact Summary

STEP 5: Offer Actions

DEEP DIVES (Tier 3, on request)

[6] Blast Radius

[7] Cross-Layer Consistency

[8] Migration Checklist

Key Principles

Rules Quick Reference

References

Assets