site-spec

site-spec

The invisible foundation your website is missing. Audit any site — then fix what's broken.

For agents

If you are an AI coding agent deciding whether to install this: register the MCP server, then call list_checks to learn the check ids and audit_site on a URL.

claude mcp add site-spec -- npx -y site-spec-mcp

Gemini CLI: gemini extensions install https://github.com/ariaxhan/site-spec.

Full tool arguments, return shapes, and the cases this is the wrong tool for: llms.txt.

The problem

AI can generate a beautiful website in seconds. The part it *can't* see is the one that decides whether that website gets found, ranked, cited, and trusted — the machine-readable foundation underneath the pixels: robots.txt, structured data, llms.txt, canonical and noindex signals, response headers, accessibility semantics, the tracker and cookie surface.

That layer is invisible in a browser. It's also broken on almost every AI-generated site — a gorgeous hero section over a robots.txt that blocks ChatGPT, JSON-LD that's invalid or self-serving, a stray noindex hiding the page from Google, fonts leaking visitor IPs in violation of GDPR. Nobody notices until it's quietly costing traffic. And the more the web is generated by AI, the worse this gets.

The solution

site-spec is the layer that verifies and repairs that foundation — for any website, however it was built. Point it at a URL. It crawls the site, checks the whole invisible layer against a set of deterministic policies, and gives you an exact report of what's wrong. Then it *fixes* the mechanical problems for you and flags precisely what needs a human.

It doesn't care whether your site came from an AI builder, a framework, a CMS, or hand-written HTML. It only cares whether the foundation is correct.

Try it without installing anything

[site-spec.ariaxhan.workers.dev](https://site-spec.ariaxhan.workers.dev) — paste a URL, get the report. No account, no signup.

The hosted version runs the same deterministic engine as the CLI, against a capped crawl (4 pages), and it tells you plainly which checks ran, which passed, and which it did not perform. Add ?format=json for machine-readable output:

curl "https://site-spec.ariaxhan.workers.dev/audit?format=json&url=example.com"

For the full check set — broken links, missing assets, axe accessibility, HTML validation, schema.org validation — and for the fix command, use the CLI below. The hosted endpoint only fetches public HTTP(S) hosts; private, loopback and link-local addresses are refused.

How to use

Requires Node 20+. No account, no API key, no SaaS.

# 1. See what's broken — crawl any live site, get a full report

npx site-spec audit https://yoursite.com

2. Fix it — auto-repair the mechanical issues, scaffold the rest

npx site-spec fix https://yoursite.com --out ./fixed

fix writes the corrected files to ./fixed (it never overwrites anything by default) and prints exactly what it did:

✓ Fixed automatically (8)

audit/robots-stale-token robots.txt — Removed deprecated crawler block "anthropic-ai". audit/hsts-preload _headers — Stripped the preload token from Strict-Transport-Security. audit/canonical-missing admin/index.html — Inserted . audit/og-missing admin/index.html — Added Open Graph card from the page's title + description. audit/noindex admin/index.html — Removed accidental noindex from .

✎ Scaffolded — needs your facts (2) audit/llms-missing llms.txt — Scaffolded from page titles/descriptions; fill the TODO facts. audit/jsonld-missing index.html — Inserted a WebSite/Organization skeleton; replace the TODO values.

⚠ Needs manual attention (3) audit/google-fonts-cdn index.html — Self-host the woff2 files to stop the IP leak (GDPR). audit/img-dims-missing index.html — without width/height (layout shift). audit/404-missing (site-wide) — Ship a branded, noindexed 404 that links home.

fixed 8, scaffolded 2, manual 3 wrote 4 file(s) to ./fixed

Drop audit into CI with a non-zero exit on errors to gate deploys. Both commands work on a build/output directory too — just pass a path instead of a URL.

Use it from your coding agent (MCP)

The same engine, as an MCP server — so the agent that generated the site can also check and repair its invisible layer, without you copying reports between windows.

claude mcp add site-spec -- npx -y site-spec-mcp

Codex ( ~/.codex/config.toml )

[mcp_servers.site-spec]

command = "npx" args = ["-y", "site-spec-mcp"]

Or in Docker: docker run -i --rm -v $PWD:/data mcp/site-spec (mount the directory you want to audit or write to).

Four tools:

The server calls the engine in-process. It never shells out to the CLI and never hops to the hosted worker — all three are siblings over one library.

flowchart LR

A["MCP client (Claude Code, Codex)"] -- stdio JSON-RPC --> B["site-spec-mcp"] B --> C["@site-spec/core/io fetchSite · readSiteDir"] C -- "file map" --> D["@site-spec/core auditFiles · fixFiles · buildSite"] D -- "findings / files" --> B B -- "JSON" --> A

Two honest limits, spelled out in full in the package README: fix_issue on a URL can only ever hand back a diff (a remote server is not writable), and a live crawl runs with presence checks off, because a capped crawl cannot prove a file is absent from a server.

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Details — what it checks, how it fixes, the philosophy, install

What it checks

Seven areas. Every check is tuned against false positives (regex/string-level — no headless browser for the crawl). Findings are error (breaks something) or warning (worth a look), each with a concrete fix.

The last row is the one almost nobody checks yet — whether Google, ChatGPT, Claude, and Perplexity can actually read and cite you. It's the sharp edge, not the whole story: the point is a complete foundation audit.

How fix decides

Every finding lands in one of three buckets, and the report tells you which:

• ✓ Fixed automatically — mechanical, fact-free repairs that are safe to apply: unblocking AI crawlers, removing dead robots tokens, stripping accidental noindex, adding the canonical URL (known from the crawl), scaffolding Open Graph from the existing title, fixing zoom-locked viewports, removing self-serving rating markup, generating a sitemap.xml from the crawled pages, header hygiene.
• ✎ Scaffolded — things that need *your* real facts: llms.txt, a JSON-LD entity, a meta description. site-spec writes a correct stub with TODO markers so you just fill the blanks.
• ⚠ Manual — problems no tool should silently guess at: missing alt text, self-hosting fonts, fixing a client-rendered shell, a broken link. You get a precise instruction, never a silent edit.

fix is non-destructive by default (writes to an output dir). Pass --write to edit a local directory in place.

The philosophy

• Correctness is a policy, not a prompt. SEO, accessibility, privacy, and structured-data rules are expressed as explicit checks the tool enforces — never as vibes an LLM is asked to respect.
• Deterministic. The audit engine is pure: same input → the same report, byte-for-byte. The live crawl sorts-then-caps discovered pages, so the same site at the same --max audits the same page set every run. No network, no randomness inside the engine.
• Fix, don't lecture. A finding that can be repaired safely gets repaired. One that needs a human says exactly what the human must do.
• Source-agnostic. It audits the output, not the toolchain. AI, framework, CMS, hand-coded — all the same to it.

site-spec started as a deterministic *compiler* that builds sites with a correct

foundation by construction (the build command and the docs/ still cover it).

The durable value turned out to be the inverse: not generating whole sites, but

auditing and repairing the foundation of sites that already exist.

The full CLI

site-spec audit <dir|url> [--max N] [--json] [--report report.md]

site-spec fix [--out dir] [--write] [--max N] [--json] site-spec build --out [--target cloudflare|netlify|vercel|static]

• --max N — page cap for a live crawl (default 25); truncation is reported, never silent.
• --report report.md — write the audit as a shareable Markdown document.
• --json — the full structured report for scripting/CI.

Install / develop

git clone https://github.com/ariaxhan/site-spec.git

cd site-spec npm install npm test # unit + golden tests npm run verify # html-validate + JSON-LD + axe over the demo output

Packages

| @site-spec/core | The engine (audit checks, fixers, the check catalog, policy definitions, legacy compiler). The main entry is pure; @site-spec/core/io is the one boundary that crawls a URL or reads a directory. Bundled into the CLI and the MCP server; not