Getting started

Ferrolink checks the HTML your static site generator has already written. Build the site first, then check its output directory. Links, assets and anchors are checked locally; external URLs are counted without being fetched.

Start with the command line

Install the Rust CLI, then point it at your finished build:

cargo install --locked ferrolink
ferrolink check dist

Replace dist with your generator’s output directory. If your site is served under a project path, include it in the check:

ferrolink check dist --site-url https://example.org/docs/

The URL supplies the /docs/ base path and identifies absolute links to your own host. A link to /guide/ that forgets /docs/ is an issue.

An exit code of 0 means the check passed, 1 means it found issues, and 2 means it could not run. Put the command after the build in CI to stop a broken artifact before deployment.

Read the full CLI reference, including archived versions, assumed targets and JSON output.

Add a Vite build check

The npm package includes prebuilt native binaries, so Node.js users do not need a Rust toolchain:

npm install --save-dev ferrolink

Add the plugin to your Vite configuration:

import { defineConfig } from "vite";
import ferrolink from "ferrolink/vite";

export default defineConfig({
  plugins: [ferrolink({ siteUrl: "https://example.org/" })],
});

The plugin checks the client output after the build and fails it when issues are found. Its base path defaults to Vite’s base. Frameworks that render pages in Vite’s buildApp phase, including Ardo, are checked after those hooks have completed.

Node.js 20.19+ or 22.12+ and Vite 7 or 8 are supported. The Node.js and Vite reference lists options, native platforms and the programmatic API.

Read the result

Every issue identifies its source file, line, reference and resolved target. A missing file is a broken_link; an absent element on an existing page is a missing_anchor; a URL leaving the configured project path is outside_base.

The homepage example shows the same small build before and after fixing all three. Its results are generated by the real Rust CLI and checked again in CI.

Know the boundary

Ferrolink checks the build on disk. It does not test external availability, run JavaScript or validate the full HTML standard. Its scanner is tuned for generator output. Known differences on malformed markup and limited named character-reference decoding are recorded in the parser decision.

The JavaScript API is the supported integration contract. Before version 1.0, breaking changes arrive in minor releases; Rust library internals can also change in any minor release. See the stability policy before integrating.