html-canvas

html-canvas is a skill for Claude Code, Codex from bks-lab/open-bridge. It costs 216 tokens per session (1,645 once invoked), scanned A, original, MIT.

A tool for creating offline, single-file HTML documents such as explainers, reference pages, and architecture guides. The documents include light/dark themes and German/English language switching.

In plain words
What is it for?
It helps you produce bilingual explainers, concept pages, architecture visualizations, reference kits, and other multi-section HTML documents.
Why use it?
It avoids rebuilding common document controls and avoids relying on external libraries or an internet connection.

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/bks-lab/open-bridge/html-canvas
Any agent
npx skills add bks-lab/open-bridge --skill html-canvas
Clone the repo
git clone --depth 1 https://github.com/bks-lab/open-bridge

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for html-canvas

README.md
[![agentmods](https://agentmods.dev/badge/skills/bks-lab/open-bridge/html-canvas.svg)](https://agentmods.dev/skills/bks-lab/open-bridge/html-canvas)
Your own site
<a href="https://agentmods.dev/skills/bks-lab/open-bridge/html-canvas"><img src="https://agentmods.dev/badge/skills/bks-lab/open-bridge/html-canvas.svg" alt="Measured on agentmods" height="20"></a>
Per session 216 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,645 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 5.1 $0.00216 $0.01645
Opus 5 $0.00108 $0.00822
Sonnet 5 $0.00043 $0.00329
Haiku 4.5 $0.00022 $0.00164

Measured 5d ago against content hash 933f5c06569b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

html-canvas 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 5d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/design-to-css.py, scripts/repo-scan.py), 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.

skills/html-canvas/SKILL.md · 116 lines

How it starts

The opening of the file, as written. The whole thing — 116 lines — stays where its author put it; the contents beside it link to each section on GitHub.

html-canvas

Generate rich single-file HTML that reads well, themes light/dark, switches DE/EN, and pulls every colour from DESIGN.md — the genre we keep hand-building (explainers, reference kits, concept/architecture pages, use-case boards, multi-section docs). One file, offline, no external dependencies, native UTF-8.

Scope: html-canvas owns content-as-document — bilingual explainers, reference/concept/architecture pages, multi-section docs — with first-class light/dark + DE/EN toggles and a DESIGN.md-token section catalog. Marketing / landing / pitch pages belong to a style-picker design skill, if your Bridge ships one.

The three controls every deliverable ships

These are the point of the skill — they come baked into the shell, don't reinvent them:

  1. Light / Dark — button + key T + localStorage, anti-FOUC pre-paint in <head>, OS preference when unset. Applied via the .dark class on <html> (DESIGN.md convention).
  2. DE / EN — button + key L + localStorage. Every translatable run ships as data-de/data-en siblings; the swap is pure CSS. Default = the conversation language. (Repo/OSS-shipped artifacts stay English regardless.)
  3. Print / PDF — first-class: chrome hidden, reveals forced visible, dark pages forced to a light palette for clean paper.

How to build

One page: copy assets/shell.html → fill the {{placeholders}} → compose <main> from the blocks in references/sections.md → add behaviours from references/interactivity.md and motion from assets/animations.css if wanted. Render light and dark, DE and EN, then file under work/tasks/<slug>/deliverables/.

A kit (many pages/boards): use the parallel-builder workflow in references/build-workflow.md — one convention audit emits a shared shell, N builders run concurrently on it, one adversarial reviewer checks every page, then integrate + write an index launcher. This is how the 12-board sets get built consistently.

Read the full file on GitHub · 116 lines

Files

What ships with it

8 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. 5d ago First seen · 116 lines · 216 tokens per session scan A 933f5c06569b

Subscribe to this mod's changes

html-canvas is a skill published in the GitHub repository bks-lab/open-bridge (8 stars, last pushed yesterday), licensed MIT. It adds 216 tokens to every session and 1,645 once invoked, about $0.0011 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 2026-08-31.

Related

Other skills, from other repositories

mcp-host-styling-integration

Integrates MCP App UI with host theming system. Applies host CSS variables, handles onhostcontextchanged, safe area insets, display mode detection, and fullscreen configuration.

a5c-ai/babysitter · 44 tokens

theme-system

CSS custom properties theme architecture for 4 themes (studio, earth, athlete, gradient) with data-theme attribute switching and theme-aware components. Use when implementing theme switching, defining color schemes, or creating theme-responsive UI elements.

BlackBeltTechnology/pi-agent-dashboard · 48 tokens

accessibility-a11y

Semantic HTML, keyboard navigation, focus states, ARIA labels, skip links, and WCAG contrast requirements. Use when ensuring accessibility compliance, implementing keyboard navigation, or adding screen reader support.

BlackBeltTechnology/pi-agent-dashboard · 44 tokens

responsive-mobile-first

Mobile-first responsive patterns with sticky headers, floating CTAs, accessible navigation, and touch-friendly interactions. Use when implementing responsive layouts, mobile navigation, or ensuring touch-friendly UI.

BlackBeltTechnology/pi-agent-dashboard · 39 tokens

tailwind-shadcn

Tailwind CSS utility patterns with shadcn/ui component usage, theming via CSS variables, and responsive design. Use when styling components, installing shadcn components, implementing dark mode, or creating consistent design systems.

BlackBeltTechnology/pi-agent-dashboard · 50 tokens

anti-slop-frontend

A mechanical, countable anti-slop checklist for AI-generated frontend. Catches the specific signatures an undirected model defaults to: AI-purple glows, Inter-everywhere, em-dashes, div-based fake screenshots, eyebrow-on-every-section, beige+brass "premium" palettes, generic Jane Doe / Acme data. Advisory layer that…

BlackBeltTechnology/pi-agent-dashboard · 147 tokens