Link Check

VMark verifies that local link and image targets in your markdown actually exist on disk. Runs alongside the markdown lint engine on Cmd-Shift-L or Tools → Check Markdown.

What it checks

For every local link and image in the document:

• [text](./other.md) — the file ./other.md resolves and exists
• ![alt](./image.png) — the image file exists
• [text](./other.md#section) — the file exists (anchor checking is handled by the linkFragments rule)

When a target is missing, the link's text is underlined with a red squiggle and an entry appears in the lint badge / F2 navigation.

What it skips

• Fragment-only links (#anchor) — handled by the linkFragments rule which checks against the current document's headings
• External URLs — http://, https://, ftp://, mailto:, tel:, data:, file:
• Untitled documents — without a saved file path, relative URLs can't be resolved against any directory

How resolution works

Link Check resolves paths relative to the source file's directory:

Link in /repo/docs/intro.md	Resolves to
[a](./other.md)	/repo/docs/other.md
[a](../shared.md)	/repo/shared.md
[a](images/logo.png)	/repo/docs/images/logo.png
[a](/docs/intro.md)	/repo/docs/docs/intro.md (rooted as relative within the file's dir)

Fragments are stripped before file lookup — [a](./other.md#section) checks ./other.md only.

Performance

• Async — runs in parallel with the sync rules; results merge in when ready
• Deduped — each unique resolved path is checked once per run, even if linked multiple times
• No keystroke triggering — fs.exists on every keystroke would thrash; runs only on the explicit lint trigger
• Operational error tolerance — if fs.exists throws (permission denied, capability scope issue), the result is error (skipped), not missing. Better silent than wrong.

Diagnostic codes

Code	Severity	Trigger
M001	Error	Image file not found at resolved local path
M002	Error	Linked file not found at resolved local path

See also

• Markdown Lint — full rule reference
• Settings → Markdown → Lint