# site-spec

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

[![npm](https://img.shields.io/npm/v/site-spec.svg)](https://www.npmjs.com/package/site-spec)
[![npm downloads](https://img.shields.io/npm/dm/site-spec.svg)](https://www.npmjs.com/package/site-spec)
[![CI](https://github.com/ariaxhan/site-spec/actions/workflows/ci.yml/badge.svg)](https://github.com/ariaxhan/site-spec/actions/workflows/ci.yml)
[![License: Apache-2.0](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](./LICENSE)

## 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.

```bash
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](./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:

```bash
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.

```bash
# 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 <link rel="canonical" href="https://…/admin/">.
  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 <meta name="robots">.

✎ 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 — <img> 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](https://modelcontextprotocol.io) server — so the
agent that generated the site can also check and repair its invisible layer,
without you copying reports between windows.

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

<details>
<summary>Codex (<code>~/.codex/config.toml</code>)</summary>

```toml
[mcp_servers.site-spec]
command = "npx"
args = ["-y", "site-spec-mcp"]
```

</details>

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:

| Tool | What it does |
| --- | --- |
| `audit_site` | Crawl a live URL (or read a local build directory) and return every finding: check id, severity, file, and whether it can be auto-fixed. |
| `fix_issue` | Apply the deterministic repair for one check id and return the diff — or write it, for a local directory. |
| `compile_spec` | Turn verified business facts into a validated SiteSpec and the deployable files it renders to. |
| `list_checks` | Enumerate every check the engine can raise, with a one-line description and its fix availability. |

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.

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

Two honest limits, spelled out in full in the
[package README](./packages/mcp/README.md): `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.

---

<details>
<summary><b>Details</b> — what it checks, how it fixes, the philosophy, install</summary>

## 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.

| Area | What it catches |
| --- | --- |
| **SEO / findability** | missing `<title>` / description / canonical · accidental `noindex` (both `<meta robots>` and the `X-Robots-Tag` header) · missing Open Graph cards · zero-or-many `<h1>` · a sitemap that lists pages which don't exist |
| **Accessibility** | images with no `alt` · zoom-blocking viewport (`user-scalable=no`) · images with no width/height (layout shift) |
| **Privacy & security** | mixed content · trackers + cookies with no consent/disclosure story · Google Fonts from Google's CDN (a ruled GDPR violation) · header hygiene (HSTS preload risk, report-only CSP that reports nowhere, dead FLoC / `X-XSS-Protection` config) · inline `onclick=` handlers that block a future CSP |
| **Performance** | hero/LCP image set to `loading="lazy"` · no `Cache-Control` |
| **Structured data** | invalid JSON-LD (crawlers drop the whole block) · self-serving `aggregateRating`/`review` markup (a Google penalty since 2019) |
| **Integrity** | dangling assets that 404 · broken internal links |
| **AI searchability** | `robots.txt` blocking AI answer agents (`OAI-SearchBot`, `ChatGPT-User`, `Claude-User`, `PerplexityBot`…) · dead crawler tokens · missing `llms.txt` · missing/broken structured data · client-rendered shells AI crawlers see as blank |

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   <dir|url> [--out dir] [--write] [--max N] [--json]
site-spec build <site.config.mjs> --out <dir> [--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

```bash
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

| Package             | Responsibility                                                       |
| ------------------- | ------------------------------------------------------------------- |
| [`site-spec`](https://www.npmjs.com/package/site-spec) (npm) | The published CLI — `audit` · `fix` · `build`. Self-contained; this is what `npx site-spec` runs. |
| `@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 separately published yet. |
| `@site-spec/worker` | The hosted auditor at [site-spec.ariaxhan.workers.dev](https://site-spec.ariaxhan.workers.dev) — a Cloudflare Worker wrapping the same engine. Adds the URL-admission guard, a capped crawler, and rate limiting. Deploy with `npm run deploy -w @site-spec/worker`. |
| [`site-spec-mcp`](https://www.npmjs.com/package/site-spec-mcp) (npm) | The MCP server — `audit_site` · `fix_issue` · `compile_spec` · `list_checks` over stdio. Self-contained; this is what `npx site-spec-mcp` runs. |

## Contributing

Contributions welcome — especially new checks and fixers. See
[`CONTRIBUTING.md`](./CONTRIBUTING.md). Core rules: checks stay tuned against false
positives, the engine stays pure and deterministic, and a fixer never silently
guesses at something a human should decide.

## License

[Apache License 2.0](./LICENSE). © 2026 Aria Han.

</details>