Atrium

See the page, not its source.

Click a Markdown file in the Explorer and Atrium opens VS Code's native Markdown Preview. Click an HTML file and Atrium opens VS Code's Integrated Browser. Right-click → Open With → Text Editor when you want the source.

What it opens

• Markdown (.md, .markdown) → VS Code's native Markdown Preview, including its parser, themes, plugins, security controls, links, and live reload.
• Local HTML (.html, .htm) → VS Code's Integrated Browser, with native browser behavior, relative assets, navigation, developer tools, and file-change reload support.
• If a native visual editor is unavailable, Atrium opens the file as source and explains why.

Copilot Chat integration (optional)

Atrium registers a URI handler at vscode://vegadevshop.atrium/open?file=<absolute-path>. Any time Copilot Chat (or anything else that emits vscode:// links) ends a response with a link in that format, clicking uses the same route as Explorer: Markdown Preview or Integrated Browser.

Wire Copilot into this by adding to your .github/copilot-instructions.md:

## File references

Whenever I create or edit an `.md`, `.markdown`, `.html`, or `.htm` file, end the response with:

[label](vscode://vegadevshop.atrium/open?file=<urlencoded-absolute-path>)

<urlencoded-absolute-path> is the file's absolute path through encodeURIComponent.

Settings

None required. Optional: workbench.editorAssociations if you want different defaults for a specific file type. To edit .md as source instead of preview, add:

"workbench.editorAssociations": {
  "*.md": "default"
}

Why Atrium?

VS Code already has excellent visual editors, but files normally open as source. Atrium is the missing default-open behavior: click the file, see the result. It does not parse or render your content itself.

Commands

License

MIT