| name | html-coder |
| description | Expert HTML development skill for building web pages, forms, and interactive content. Use when creating HTML documents, structuring web content, implementing semantic markup, adding forms and media, working with HTML5 APIs, or needing HTML templates, best practices, and accessibility guidance. Supports modern HTML5 standards and responsive design patterns. |
| description_zh | 用于构建网页、表单和交互内容的专业HTML开发技能。当创建HTML文档、组织网页内容、实现语义化标记、添加表单和媒体、使用HTML5 API，或需要HTML模板、最佳实践和无障碍指引时使用。支持现代HTML5标准和响应式设计模式。 |
| homepage | https://clawhub.ai/jhauga/html-coder |
| collaborators | ["make-skill-template","finalize-agent-prompt"] |
| provenance | {"origin":"clawhub-mit0","license":"MIT-0","upstream_url":"https://clawhub.ai/jhauga/html-coder","maintained_by":"OpenSquilla"} |
HTML Coder Skill
Expert skill for professional HTML development with focus on semantic markup, accessibility, HTML5 features, and standards-compliant web content.
When to Use This Skill
- Creating HTML documents with semantic structure
- Building accessible forms with HTML5 validation
- Implementing responsive markup and multimedia
- Using HTML5 APIs (Canvas, SVG, Storage, Geolocation)
- Troubleshooting validation or accessibility issues
OpenSquilla Webpage Delivery
For a new runnable webpage when workspace file-authoring tools are available:
- Create a filesystem-safe, dedicated project subdirectory such as
webpage-<topic-slug>/; never place a generated site directly in the
workspace root.
- Keep
index.html, local CSS/JavaScript, and every local asset inside that
project root, using browser-relative references.
- Validate the finished project, then call
publish_artifact exactly once
with the entry file and the complete dedicated root:
{
"path": "webpage-<topic-slug>/index.html",
"mime": "text/html",
"bundle": "directory",
"bundle_root": "webpage-<topic-slug>"
}
Do not bundle the entire workspace. When a caller explicitly requests
source-only output, forbids tool calls, or supplies its own deterministic
writer—as AwesomeWebpageMetaSkill does—follow that narrower caller contract
instead. When file authoring or publish_artifact is unavailable, return only
the requested guidance or source and do not claim that a runnable project was
published.
Core Capabilities
- Semantic HTML: Document structure, content sections, accessibility-first markup
- Forms: All input types, validation attributes, fieldsets, labels
- Media: Responsive images, audio/video, Canvas, SVG
- HTML5 APIs: Web Storage, Geolocation, Drag & Drop, Web Workers
- Accessibility: ARIA, screen reader support, WCAG compliance
Essential References
Core documentation for HTML experts:
Best Practices
Semantic HTML - Use elements that convey meaning: <article>, <nav>, <header>, <section>, <footer>, not div soup.
Accessibility First - Proper heading hierarchy, alt text, labels with inputs, keyboard navigation, ARIA when needed.
HTML5 Validation - Leverage built-in validation (required, pattern, type="email") before JavaScript.
Responsive Images - Use <picture>, srcset, and loading="lazy" for performance.
Performance - Minimize DOM depth, optimize images, defer non-critical scripts, use semantic elements.
Quick Patterns
Semantic Page Structure
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Page Title</title>
</head>
<body>
<header><nav></nav></header>
<main><article></article></main>
<aside></aside>
<footer></footer>
</body>
</html>
Accessible Form
<form method="post" action="/submit">
<fieldset>
<legend>Contact</legend>
<label for="email">Email:</label>
<input type="email" id="email" name="email" required
pattern="[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$">
<button type="submit">Send</button>
</fieldset>
</form>
Responsive Image
<picture>
<source media="(min-width: 1200px)" srcset="large.webp">
<source media="(min-width: 768px)" srcset="medium.webp">
<img src="small.jpg" alt="Description" loading="lazy">
</picture>
Troubleshooting
- Validation: W3C Validator (validator.w3.org), check unclosed tags, verify nesting
- Accessibility: Lighthouse audit, screen reader testing, keyboard nav, color contrast
- Compatibility: Can I Use (caniuse.com), feature detection, provide fallbacks
Key Standards
