Files
root d523f0f600 Fix code quality violations and exclude Manifest from checks
Document application modes (development/debug/production)
Add global file drop handler, order column normalization, SPA hash fix
Serve CDN assets via /_vendor/ URLs instead of merging into bundles
Add production minification with license preservation
Improve JSON formatting for debugging and production optimization
Add CDN asset caching with CSS URL inlining for production builds
Add three-mode system (development, debug, production)
Update Manifest CLAUDE.md to reflect helper class architecture
Refactor Manifest.php into helper classes for better organization
Pre-manifest-refactor checkpoint: Add app_mode documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2026-01-14 10:38:22 +00:00
..

Welcome to MDN data

Note

We are in the process of deprecating the mdn/data package in favor of w3c/webref. If you depend on this project, let us know in our community GitHub discussions. Thank you.

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This repository contains general data for Web technologies and is maintained by the MDN team at Mozilla.

Repository contents

The data in this repository is used in MDN Web Docs to build information boxes and sidebar navigation. External tools make use of this data as well, for example, the CSSTree CSS parser.

There's a top-level directory for each broad area covered: for example, api and css. Inside each of these directories is one or more JSON files containing the data.

api

Contains data about Web APIs:

  • API inheritance (interface inheritance and mixin implementations)

css

Contains data about:

  • CSS at-rules
  • CSS functions
  • CSS properties
  • CSS selectors
  • CSS syntaxes
  • CSS types
  • CSS units

For more information, see the CSS data documentation and the Updating CSS JSON DB guide.

l10n

The l10n folder contains localization strings that are used in the various json files throughout this repository.

Problems?

If you find a problem, please file an issue.

Contributing

We're very happy to accept contributions to this data. Please familiarize yourself with the schema for the data you're editing, and send us a pull request. See the CONTRIBUTING.md document for more information.

See also