=== Umay AI Markdown ===
Contributors: umayajans
Tags: markdown, ai-agents, llm, content-negotiation, geo
Requires at least: 6.0
Tested up to: 6.9
Requires PHP: 7.4
Stable tag: 1.1.1
License: GPLv2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html

Serves clean Markdown to AI agents (ChatGPT, Claude, Perplexity) on Accept: text/markdown. HTML stays default for browsers. Zero-config.

== Description ==

Modern AI agents (ChatGPT, Claude, Perplexity, Gemini, etc.) work much better with Markdown than HTML. Umay AI Markdown inspects the incoming `Accept` header and, only when `text/markdown` is requested, intercepts the response and serves a clean, agent-friendly Markdown representation of the page.

Browsers, search engines, and any client that does not explicitly ask for Markdown receive the unchanged HTML response. There is no settings page, no cron job, and no external service call.

**Key features**

* Zero configuration — install, activate, done.
* Only triggers when `Accept: text/markdown` is present. Regular visitors and search engines are never affected.
* Hybrid content extraction: uses `the_content` for posts/pages, falls back to a DOM-based extractor for archives, taxonomies, and the homepage.
* Powered by the industry-standard [league/html-to-markdown](https://github.com/thephpleague/html-to-markdown) library.
* Transient-cached for 12 hours per URL (sha256-keyed). Auto-invalidated on `save_post`, term edits, theme switches, and menu updates.
* Built-in IP rate limiter (30 requests / minute by default) to mitigate abuse.
* Strict input sanitization, header injection protection, libxml entity hardening (XXE-safe), and full WordPress Coding Standards compliance.
* PSR-4 autoloaded, namespaced OOP code. No globals.
* Sends `Vary: Accept`, `X-Robots-Tag: noindex`, and `X-Content-Type-Options: nosniff` on every Markdown response.

**What gets sent to AI agents**

Each Markdown response includes a YAML front-matter block with the page title, site name, canonical URL, and ISO-8601 generation timestamp, followed by the page body converted to Markdown. Navigation, footer, sidebars, scripts, styles, comment forms, related posts, and other page chrome are stripped before conversion.

**Filters**

Two filters are available for advanced customization:

* `umay_mdn_bypass` — Return `true` to skip Markdown handling for the current request.
* `umay_mdn_cache_ttl` — Override the default 12-hour cache lifetime (in seconds, minimum 60).
* `umay_mdn_rate_limit` — Override the default 30-requests-per-minute rate limit.
* `umay_mdn_converter_options` — Modify the league/html-to-markdown converter options array.

== Installation ==

1. Upload the `markdown-negotiator` folder (or the ZIP) via **Plugins > Add New > Upload Plugin**.
2. Activate the plugin.
3. There is no settings page. The plugin starts working immediately.

To verify:

`curl -H "Accept: text/markdown" https://your-site.com/`

You should get back a `Content-Type: text/markdown; charset=utf-8` response with a YAML front-matter and a Markdown body.

== Frequently Asked Questions ==

= Does it slow down my normal site? =

No. The plugin returns immediately on `template_redirect` priority 1 if the request does not include `Accept: text/markdown`. The cost is roughly a single `if` check per request.

= Does this plugin contact any external services? =

No. The plugin does not call any external service, does not send analytics, does not check for updates against a remote server, and does not load any remote assets. All HTML-to-Markdown conversion happens locally using the bundled `league/html-to-markdown` library.

= How is the cache invalidated? =

Per-URL cache keys are deleted on `save_post` and `transition_post_status` for the affected post. Term edits, theme switches, and menu updates flush the entire Markdown cache.

= Is logged-in personalization supported? =

No. Logged-in requests always fall back to HTML to avoid leaking nonces, admin bars, or per-user content into a shared Markdown cache. This is by design.

= How do I clear the cache manually? =

Deactivate and re-activate the plugin. Deactivation calls `Cache::flush_all()`.

= Is the Markdown response indexable by search engines? =

No. Every Markdown response includes `X-Robots-Tag: noindex` to prevent duplicate-content issues. The HTML version remains the canonical, indexable representation.

= Does this work with caching plugins like LiteSpeed Cache, WP Rocket, or W3 Total Cache? =

The plugin sets `Vary: Accept` so any well-behaved cache layer will store the Markdown and HTML variants separately. If your cache layer ignores the Vary header, exclude the URLs from the cache when the `Accept: text/markdown` header is present.

== Screenshots ==

1. Markdown response served when an AI agent requests `Accept: text/markdown` — full HTTP headers (Content-Type, Vary, X-Cache, X-Robots-Tag, X-Content-Type-Options, X-Markdown-Generator), followed by a YAML frontmatter block (title, site, URL, generated timestamp) and the converted Markdown body.
2. Built-in transient cache in action: the first request to a URL returns `X-Cache: MISS` (Markdown generated on the fly), the next request to the same URL returns `X-Cache: HIT` (served from cache, no rendering work).
3. Transparent content negotiation: same WordPress URL, two different responses based on the `Accept` request header — browsers receive `text/html` (the normal theme output), AI agents receive `text/markdown` (clean, machine-readable content) with the plugin's enriched header set.

== Changelog ==

= 1.1.1 =
* Aligned text domain with WordPress.org plugin slug: changed from `umay-ai-markdown` to `markdown-negotiator` across plugin header, gettext calls, and POT file (per WP.org review feedback).
* Hardened Markdown response output: replaced raw `echo $markdown` with `wp_kses( $markdown, array() )` to satisfy Plugin Check's late-escape rule while preserving Markdown syntax.
* Removed bundled tr_TR translation files; only the English POT template ships in the WordPress.org distribution. Translations now flow through translate.wordpress.org.

= 1.1.0 =
* Renamed plugin: "Markdown Negotiator" → "Umay AI Markdown"; slug and text domain changed to `markdown-negotiator` (per WordPress.org review feedback to ensure the name is distinctive).
* Removed deprecated `libxml_disable_entity_loader()` calls in `ContentExtractor` and `Converter`. XXE protection unchanged: libxml 2.9+ disables external entities by default, and `LIBXML_NONET` is still passed to `loadHTML()`.
* Refactored Tier 2 (non-singular) request pipeline: replaced the open `ob_start( $callback )` on `template_redirect` with a `template_include` filter that opens and closes its buffer (`ob_start` paired with `ob_get_clean`) inside a single function scope, satisfying Plugin Check's buffer-pairing requirement.
* Added `try/catch` around the template render so a fatal in a theme/plugin returns a clean 500 instead of a half-buffered response.

= 1.0.1 =
* HTML sanitization hardening: strip `<style>`, `<script>`, `<noscript>` blocks via regex (defense in depth on top of league/html-to-markdown's `remove_nodes`).
* Lazy-load image normalization: promotes `data-lazy-src` / `data-src` / `data-original` and the first `srcset` URL into the real `src`. Drops empty/placeholder images.
* Page-builder anchor cleanup: anchors with `href="#elementor-action:..."`, `javascript:`, or bare `#` are unwrapped to plain text.
* Internationalization: text domain is now loaded on `init` and a base POT file ships in `/languages/`.

= 1.0.0 =
* Initial release.

== Upgrade Notice ==

= 1.1.1 =
Aligned text domain with plugin slug (`markdown-negotiator`), hardened Markdown output escaping for Plugin Check compliance, and switched distribution language files to English POT-only.

= 1.1.0 =
Plugin renamed to "Umay AI Markdown" (slug `markdown-negotiator`). Removes deprecated libxml calls and refactors the output buffer pipeline for WordPress.org compliance. After upgrading, deactivate and re-activate to flush the cache.

= 1.0.1 =
Cleaner Markdown output: strips inline page-builder CSS, fixes lazy-loaded images, removes JavaScript pop-up links, and adds translation support.

= 1.0.0 =
First public release.
