plannotator-visual-explainer

A tool for creating self-contained HTML visual explanations, including plans, code-change walkthroughs, diagrams, tables, and slide decks, using Plannotator’s review interface.

In plain words
What is it for?
Explaining implementation plans, pull requests, system designs, data, presentations, and other technical topics.
Why use it?
It turns technical information into visual material that people can review and annotate in a browser.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/backnotprop/plannotator/plannotator-visual-explainer
Any agent
npx skills add backnotprop/plannotator --skill plannotator-visual-explainer
Clone the repo
git clone --depth 1 https://github.com/backnotprop/plannotator

Made for: Claude Code, Codex.

Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,467 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00078 $0.01467
Opus 5 $0.00039 $0.00733
Sonnet 5 $0.00016 $0.00293
Haiku 4.5 $0.00008 $0.00147

Measured yesterday against content hash 915b90901bce, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plannotator-visual-explainer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

The scan reads SKILL.md. This mod also ships 1 executable file (SKILL.test.ts), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

apps/skills/extra/plannotator-visual-explainer/SKILL.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plannotator Visual Explainer

Three paths depending on content type. Each has its own references and structure.

Route by content type

Implementation plan, design doc, or proposal → Follow the Plan path. Read references/design-system.md and references/svg-patterns.md. Prescriptive structure.

PR explainer, diff review, or code change walkthrough → Follow the PR path. Read references/design-system.md and references/pr-components.md. Prescriptive structure.

Everything else (architecture diagrams, data tables, slide decks, project recaps, general visual explanations) → Follow the Visual explainer path. Delegates to nicobailon/visual-explainer with Plannotator theme tokens.

Delivery

Always deliver via Plannotator's annotation UI. Do NOT use open or xdg-open.

For any deliverable that uses Mermaid, render every diagram with Mermaid 11 in both the light and dark palettes before opening the annotation UI. Rendering is a hard gate: an exception, empty SVG, or error output such as aria-roledescription="error" or Syntax error in text means the explainer is not deliverable. Fix the diagram or theme configuration and rerun both palettes until every SVG passes.

Plans/proposals (user should approve/deny):

plannotator annotate <file> --gate

Everything else (informational):

plannotator annotate <file>

Plan path

For implementation plans, design docs, feature specs, migration guides, and proposals.

Before generating, read:

  1. references/design-system.md — Plannotator theme tokens, typography, component patterns
  2. references/svg-patterns.md — inline SVG building blocks for architecture diagrams, flowcharts, data flow

Document structure (in order, pick what fits):

  1. Header — eyebrow label (mono, uppercase), title (serif, large), prompt box (the original brief)
  2. Summary strip — 3-5 stat cards showing key numbers at a glance (components, endpoints, tables, etc.)
  3. Milestones / timeline — vertical timeline showing phases without time estimates. Phases show sequence and dependencies, not duration.
  4. Architecture / data flow — inline SVG diagram. Use for 3+ interacting components. Highlighted boxes for new components, dashed arrows for async paths.
  5. Mockups — build UI mockups in HTML/CSS directly, not as descriptions
  6. Key code — dark-theme code blocks with syntax highlighting. Only architecturally significant interfaces/schemas — not every function.
  7. Risks & mitigations — table with severity badges (HIGH/MED/LOW)
  8. Open questions — callout cards with decision owner ("Decide with: backend team")

Read the full file on GitHub · 118 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 118 lines · 78 tokens per session scan A 915b90901bce

Subscribe to this mod's changes

plannotator-visual-explainer is a skill published in the GitHub repository backnotprop/plannotator (8,256 stars, last pushed 2d ago), licensed Apache-2.0. It adds 78 tokens to every session and 1,467 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.