Muninn for VS Code

A reading-first Markdown editor for specifications, documentation and notes. Read, follow links and make small changes in one pane while keeping ordinary Markdown files and useful Git diffs.

Help shape the preview

Trying Muninn 1.0.0 Preview? Tell us where reading or editing Markdown feels awkward, or what would make it more useful. Report a bug or suggest an improvement. When a Muninn editor is active, click Muninn: Report issue in VS Code's status bar to open the native issue reporter. You can also use Help: Report Issue… or Muninn for VS Code: Report an Issue from the Command Palette.

Please describe the task you were doing and the result you expected. Include steps to reproduce a bug when possible; remove private content from any sample Markdown or screenshots. Muninn does not collect feedback or usage data automatically.

Start reading

The first release candidate is 1.0.0 Preview, distributed on the pre-release channel. Install the pre-release extension and open a .md or .markdown file. If another editor is already your default, use Reopen Editor With… → Muninn Markdown Editor. Muninn respects your editor preferences.

• Read and navigate: comfortable line width, Unicode heading links, the native Headings picker, relative file links and VS Code Find.
• Edit: a compact toolbar with additional actions under More; standard GFM tasks and strikethrough; editable table cells with raw-source access.
• Capture notes: Muninn for VS Code: New Markdown Note uses the native file dialog. Insert File Link connects existing files with ordinary relative Markdown.
• Review diagrams: local, lazy-loaded Mermaid previews, gated by workspace trust.
• Use Source: open the same file in VS Code's Markdown text editor whenever you need the full source syntax.

Untouched files round-trip byte for byte in the regression corpus. Edits preserve surrounding source syntax; changes that cannot be mapped safely are rejected with a Source fallback. Conflicting external edits are preserved in a separate unsaved recovery document. Save and Source wait for pending rich edits. No proprietary note syntax or database is introduced.

Settings

The old muninn.editorAssociations setting is deprecated and has no effect. Configure defaults with VS Code's editor picker.

Remote images do not load automatically. Imported images are limited to 10 MiB. Markdown HTML stays disabled. The extension makes no telemetry calls. Desktop VS Code 1.85.2+ is supported; browser/vscode.dev support is not advertised.

Development

Use Node 24 and your preferred editor or AI development environment. The contributor documentation contains the shared setup, architecture, development rules, and testing guide.

npm ci
npm run compile
npm run bundle
npm run coverage
npm test
npm run package
npm run test:e2e

F5 runs the checked-in compile/bundle task. Packaging produces a minified pre-release VSIX and third-party notices; the UI suite tests that exact archive.

Security policy · Security posture

License

GNU Affero General Public License v3.0 (AGPL-3.0-only). See LICENSE.

License — plain language

Using Muninn to edit files imposes nothing on those files, your employer's code, or any repository you open. Your markdown, and anything you write with Muninn, is yours. The AGPL governs copying, distributing, or modifying Muninn itself. If you distribute a modified Muninn, share it under the same license and keep required notices. If you serve a modified Muninn through hosted VS Code environments such as code-server, Codespaces, or Gitpod, offer users the source for that modified Muninn. Redistributing unmodified Muninn keeps the LICENSE and notices with the extension. Common-understanding summary, not legal advice; the LICENSE text governs.