Audit a shipped web surface across all six invisible-correctness axes (perceivable, operable, off-happy-path, key-private, findable, fast-and-stable) with the MISSING conformance auditor. Pass a url to fetch and audit the served HTML, or pass html directly. Returns a per-axis report that declares the axes a static check cannot judge rather than reporting them clean.

Generate the findability head tags (title, description, canonical, Open Graph, Twitter card) for a page from a flat metadata object, as an SSR/build-time string. Also returns the html lang attribute.

Serialize one or several schema.org objects into a JSON-LD script tag, with the sequence escaped. Pass a schema object or an array of them.

Serialize a sitemap.xml from a list of canonical URLs (strings, or objects with loc, lastmod, changefreq, priority).

Serialize a robots.txt for crawl control. Pass allow/disallow (string or array) and one or more sitemap URLs. Index control belongs in the head robots directive, not here.

Audit a page HTML string for findability in depth (BEACON): head essentials, Open Graph, Twitter, JSON-LD validity, and the canonical-versus-og:url agreement invariant.

Generate responsive or markup with reserved dimensions and correct scheduling. Mark the LCP image priority (eager, high fetchpriority); mark offscreen images lazy. Pass avif/webp for format negotiation to get a .

Generate cache-header config for a named host (netlify, vercel, nginx): revalidate HTML, cache content-hashed assets for a year as immutable.

Audit a page HTML string for delivery in depth (FLEET): unsized images, a lazy-loaded first image, render-blocking head scripts, and inline @font-face without font-display.

Solve a full TEMPER palette to verified contrast floors for a mode. mode is light, soft-light, soft-dark, or dark; notch is 0 (brighter), 1 (middle), or 2 (deeper); family is a color family key (for example iron, oxblood, moss); vision constrains for a color-vision deficiency (default, rg, by, mono). Returns the semantic token set.

Check the WCAG 2.1 contrast ratio between two hex colors and whether it clears the AA thresholds (4.5:1 for normal text, 3:1 for large text or non-text).