Validate

blume validate checks every link in your content — pages, anchors, assets, and optionally external URLs — and fails CI when one is broken.

blume validate reads your content the way a build does and checks every link it finds. It doesn’t generate or build anything, so it’s the fast gate to put in front of blume build:

blume validate

Internal page links (/guides/intro, ./sibling) must resolve to a real page — broken ones are reported as errors. A component’s string href (<Card href="./install">) is checked the same way; an href={…} expression isn’t.
Anchor links (#section, /guides/intro#setup) must match an anchor on the target page — a heading’s id (generated or pinned) or a raw HTML element’s id attribute — with misses reported as warnings. Ids inside code blocks, inline code, HTML comments, and <Prompt> blocks don’t count.
Asset links are checked where the file lives: an absolute path (/logo.png) against the public/ directory, a relative image embed (![](./diagram.png)) against the page’s own folder. A plain link to a relative path still resolves as a site route — only image embeds go through the image pipeline.
External links are only checked with --external (off by default since it requires the network); dead links (404/410/unreachable) are errors, while rate-limited or transient responses (403/429/5xx/timeout) are warnings.

What counts as a page

Links resolve against everything the built site serves, not just Markdown pages: custom .astro pages, the generated changelog index, every configured redirect, and, on a multi-language site, an untranslated page’s fallback URL under each locale. A page that fails to parse is reported alongside the link findings, because a page that never loads is a link-validation blind spot rather than a clean result.

Flags

--external — also check external http(s) links over the network.
--strict — exit non-zero on warnings too. Info-level notes stay advisory.
--json — emit the diagnostics as JSON on stdout instead of the terminal report.

Diagnostics

Code	Severity	Meaning
`BLUME_BROKEN_LINK`	error	An internal link points at a route no page serves.
`BLUME_BROKEN_ANCHOR`	warning	The page exists but has no anchor matching the fragment.
`BLUME_BROKEN_ASSET`	warning	An absolute path isn’t in `public/`, or a relative image embed isn’t beside the page.
`BLUME_ASSETS_UNCHECKED`	info	There is no `public/` directory, so absolute asset paths weren’t checked.
`BLUME_DEAD_LINK`	error or warning	An external link (with `--external`) returned 404/410 or was unreachable (error), or a transient 403/429/5xx/timeout (warning).

The exit code is the contract: errors exit non-zero, and --strict makes warnings do the same.

JSON output

With --json, blume validate (and blume doctor) write one object to stdout: a diagnostics list, each entry carrying its code, severity, message, the file relative to the project root with line and column when the finding has a location, a suggestion, and a docsUrl pointing at the page that explains the code, plus a summary of counts per severity. The exit code is unchanged, so the same invocation gates CI and feeds an editor integration.