livecodes/configuration

A guide to configuring LiveCodes, an in-browser playground for running HTML, CSS, JavaScript, and other supported code. It covers project content, editor settings, processors, external resources, and URL options.

In plain words
What is it for?
Use it to set markup, styles, scripts, languages, editors, query parameters, preprocessors, and linked resources when embedding or setting up LiveCodes.
Why use it?
It helps developers control what the playground displays and how it runs code instead of relying on default settings.

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/live-codes/livecodes/configuration
Any agent
npx skills add live-codes/livecodes --skill configuration
Clone the repo
git clone --depth 1 https://github.com/live-codes/livecodes

Made for: Claude Code, Codex.

Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,828 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 $0.00047 $0.03828
Opus 5 $0.00023 $0.01914
Sonnet 5 $0.00009 $0.00766
Haiku 4.5 $0.00005 $0.00383

Measured yesterday against content hash 8df2145b5ab6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

livecodes/configuration 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.

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.

.agents/skills/livecodes/configuration/SKILL.md · 412 lines

How it starts

The opening of the file, as written. The whole thing — 412 lines — stays where its author put it; the contents beside it link to each section on GitHub.

LiveCodes — Configure Playground

LiveCodes uses configuration objects to define project content and behavior. Config can be passed to createPlayground or set via URL parameters.

Setup

import { createPlayground } from 'livecodes';

// Full config object
createPlayground('#container', {
  config: {
    title: 'My Project',
    markup: { language: 'html', content: '<h1>Hello</h1>' },
    style: { language: 'css', content: 'h1 { color: blue; }' },
    script: { language: 'javascript', content: 'console.log("hi")' },
    activeEditor: 'script',
  },
});

// Query params (simpler syntax)
createPlayground('#container', {
  params: {
    html: '<h1>Hello</h1>',
    css: 'h1 { color: blue; }',
    js: 'console.log("hi")',
    console: 'open',
  },
});

Core Patterns

Configure each editor

const config = {
  markup: {
    language: 'markdown',
    content: '# Title\n\nParagraph',
    contentUrl: 'https://example.com/content.md', // Alternative to content
  },
  style: {
    language: 'scss',
    content: '$color: blue; h1 { color: $color; }',
  },
  script: {
    language: 'typescript',
    content: 'const x: number = 1;',
    hiddenContent: 'export function helper() {}', // Hidden but evaluated
  },
};

Enable CSS processors

const config = {
  style: { language: 'css', content: '...' },
  processors: ['tailwindcss', 'autoprefixer'], // Processors run in order
};

Add external resources

const config = {
  stylesheets: ['https://cdn.jsdelivr.net/npm/tailwindcss@3/dist/tailwind.min.css'],
  scripts: ['https://cdn.jsdelivr.net/npm/lodash@4/lodash.min.js'],
};

Configure tests

const config = {
  tests: {
    language: 'typescript',
    content: `
      import { sum } from './script';
      test('sums numbers', () => {
        expect(sum(1, 2)).toBe(3);
      });
    `,
  },
};

Set display mode

const config = {
  mode: 'simple', // 'full' | 'focus' | 'simple' | 'lite' | 'editor' | 'codeblock' | 'result'
  view: 'result', // 'split' | 'editor' | 'result'
  readonly: true, // Read-only mode
};

Read the full file on GitHub · 412 lines

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 · 412 lines · 47 tokens per session scan A 8df2145b5ab6

Subscribe to this mod's changes

livecodes/configuration is a skill published in the GitHub repository live-codes/livecodes (1,488 stars, last pushed 4d ago), licensed MIT. It adds 47 tokens to every session and 3,828 once invoked, about $0.0002 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.