Developer

Request flow

The extension adds three PSR-15 middlewares to the frontend stack. No route enhancer is involved: the middlewares answer the text files themselves and remove .md before TYPO3 routes the request.

request
  ├─ woit/si-llms-txt/markdown-suffix   before typo3/cms-frontend/site
  ├─   typo3/cms-frontend/site
  ├─ woit/si-llms-txt/llms-txt          before typo3/cms-frontend/base-redirect-resolver
  ├─   … page-resolver, prepare-tsfe-rendering, shortcut redirect
  ├─ woit/si-llms-txt/markdown-render   after prepare-tsfe-rendering
  └─   rendering

Middleware	Task
`MarkdownSuffixMiddleware`	`/de/page.md` → routes `/de/page` and sets the request attribute `sillmstxt.markdown`. Responses without Markdown become a plain 404; redirects keep the `.md` suffix.
`LlmsTxtMiddleware`	Answers `llms.txt` / `llms-full.txt` for the site root and every language base.
`MarkdownRenderMiddleware`	Uses the page field "LLM Markdown" or lets the page render and converts the HTML. For the EXT:news detail page it takes the news record (see EXT:news (tx_news)).

For normal HTML requests each middleware only compares a string and passes the request on.

The event listener AddMarkdownAlternateLink (AfterCacheableContentIsGeneratedEvent) adds the <link rel="alternate"> and <link rel="describedby"> tags when a page is rendered; the result is part of the page cache. The HTTP Link header with the same relations is added by MarkdownRenderMiddleware on every request (see Discovery links).

Classes

Class	Purpose
`Service\LlmsTxtBuilder`	Builds `llms.txt`, `llms-full.txt` and the frontmatter of page and news documents; caching
`Service\PageCollector`	Walks the page tree, language overlay (strict)
`Service\NewsCollector`	News records of EXT:news (optional)
`Service\MarkdownConverter`	HTML → Markdown with league/html-to-markdown; removes navigation, breadcrumbs, asides, forms, buttons, scripts, decorative images and links without text; accordion titles and `<summary>` become h3 headings; keeps button titles in headings; resolves lazy-loaded images; moves card links onto their heading; makes links absolute
`Service\DiscoveryLinks`	`alternate` and `describedby` links of a page, as HTML tags or HTTP `Link` header
`Service\MarkdownUrl`	Page URL ↔ `.md` URL
`Service\SiteConfig`	Site set active? Settings, included page types

PSR-14 events

Listeners of other extensions can change what the extension generates, for example list all records of a plugin that shows only the first result page.

ModifyLlmsTxtEvent

Woit\SiLlmsTxt\Event\ModifyLlmsTxtEvent is dispatched before llms.txt or llms-full.txt of a site language is built. It only runs on a cache miss.

getSite(), getLanguage(), getFileName()
getTitle() / setTitle(), getIntro() / setIntro()
getSections() / setSections(), getSection($id), addSection($id, $section, $before), removeSection($id)
addItem($sectionId, $item): a missing section is created at the end with the id as title
addCacheTags(...$tags), setCacheLifetime($seconds)

Section ids: pages, section-<uid> (top-level page), articles, news. The sections "Languages" and "Optional" are added afterwards.

A Woit\SiLlmsTxt\LlmsTxt\Section has title and items. An Woit\SiLlmsTxt\LlmsTxt\Item has title, url, description, date, includeInFull and markdown. An item goes into llms-full.txt with its markdown if set, otherwise only with includeInFull: then url must be a .md URL of the same site and is fetched like a page.

EXT:my_ext/Classes/EventListener/AddRecordsToLlmsTxt.php

use TYPO3\CMS\Core\Attribute\AsEventListener;
use Woit\SiLlmsTxt\Event\ModifyLlmsTxtEvent;
use Woit\SiLlmsTxt\LlmsTxt\Item;
use Woit\SiLlmsTxt\LlmsTxt\Section;

final class AddRecordsToLlmsTxt
{
    #[AsEventListener]
    public function __invoke(ModifyLlmsTxtEvent $event): void
    {
        $event->addSection('records', new Section('Records'), 'news');
        foreach ($this->repository->findAll() as $record) {
            $event->addItem('records', new Item(
                $record->getTitle(),
                $record->getUrl(),
                $record->getTeaser(),
            ));
        }
        $event->addCacheTags('tx_myext_record');
    }
}

ModifyMarkdownEvent

Woit\SiLlmsTxt\Event\ModifyMarkdownEvent is dispatched for every .md response of a page or EXT:news record.

getRequest(), getSite(), getLanguage()
getTable() (pages or tx_news_domain_model_news), getRecord()
getFrontmatter() / setFrontmatter(): title, description, language, date, lastmod, canonical, source, generator; empty values are not written
getMarkdown() / setMarkdown(): body without frontmatter
getHtml(): rendered page, null for the field "LLM Markdown"
setNotFound(): answer 404

A .md blocked with setNotFound() is still listed in llms.txt; remove it there with ModifyLlmsTxtEvent.

Example: list all records on a list page that renders only the first result page.

EXT:my_ext/Classes/EventListener/ListAllRecordsInMarkdown.php

use TYPO3\CMS\Core\Attribute\AsEventListener;
use Woit\SiLlmsTxt\Event\ModifyMarkdownEvent;

final class ListAllRecordsInMarkdown
{
    private const LIST_PAGE_UID = 42;

    #[AsEventListener]
    public function __invoke(ModifyMarkdownEvent $event): void
    {
        if ($event->getTable() !== 'pages' || (int)($event->getRecord()['l10n_parent'] ?: $event->getRecord()['uid']) !== self::LIST_PAGE_UID) {
            return;
        }
        $lines = [];
        foreach ($this->repository->findAll() as $record) {
            $lines[] = '- [' . $record->getTitle() . '](' . $record->getUrl() . '): ' . $record->getTeaser();
        }
        $event->setMarkdown($event->getMarkdown() . "\n\n## All records\n\n" . implode("\n", $lines));
    }
}

Example: describe the record shown on a detail page, answer 404 without a record.

EXT:my_ext/Classes/EventListener/DescribeDetailRecord.php

use TYPO3\CMS\Core\Attribute\AsEventListener;
use Woit\SiLlmsTxt\Event\ModifyMarkdownEvent;

final class DescribeDetailRecord
{
    private const DETAIL_PAGE_UID = 43;

    #[AsEventListener]
    public function __invoke(ModifyMarkdownEvent $event): void
    {
        if ($event->getTable() !== 'pages' || (int)($event->getRecord()['l10n_parent'] ?: $event->getRecord()['uid']) !== self::DETAIL_PAGE_UID) {
            return;
        }
        $arguments = $event->getRequest()->getAttribute('routing')->getArguments();
        $record = $this->repository->findByUid((int)($arguments['tx_myext_pi1']['record'] ?? 0));
        if ($record === null) {
            $event->setNotFound();
            return;
        }
        $frontmatter = $event->getFrontmatter();
        $frontmatter['title'] = $record->getTitle();
        $frontmatter['description'] = $record->getTeaser();
        $frontmatter['canonical'] = $record->getUrl();
        $event->setFrontmatter($frontmatter);
    }
}

Caching

Cache sillmstxt (database backend, group pages)
Entries for llms.txt and llms-full.txt per site language
Tags: pageId_<uid> of every listed page and the root page; with EXT:news also tx_news, tx_news_pid_<pid>, tx_news_uid_<uid>; plus the tags of ModifyLlmsTxtEvent listeners
The intro of the language is part of the cache identifier
llms-full.txt with pages that could not be fetched is kept for 5 minutes only
.md documents are not cached separately: the HTML comes from the page cache, only the conversion runs per request

Database

ext_tables.sql

CREATE TABLE pages (
    tx_sillmstxt_exclude smallint(5) unsigned DEFAULT '0' NOT NULL,
    tx_sillmstxt_priority int(11) DEFAULT '0' NOT NULL,
    tx_sillmstxt_description text,
    tx_sillmstxt_markdown mediumtext
);

tx_sillmstxt_exclude and tx_sillmstxt_priority use l10n_mode = exclude (same value in all languages).