README

Search and generative engine optimization: meta tags, social cards, JSON-LD, sitemap, robots and AI crawlers, llms.txt, Markdown twins, redirects and on-page checks. Every collection with pages gets an SEO panel, and the home screen a widget with what to fix first.

Install

From Plugins → Store in the admin, or:

composer require letterncms/seo

Settings

Under Settings → SEO, kept in config/seo.yaml:

• Title Format (title_format): the <title> of every page, from {title} and {site}.
• Home Page Title (home_title): the home page's title; the site name when empty.
• Default Social Image (default_image): shown for shared links of pages without their own.
• Type, Name, Logo, Profiles (org_type, org_name, org_logo, same_as): who the site is by, for structured data.
• Summary for AI (llms.txt) (llms_summary): who you are and what you offer, at the top of the site's /llms.txt, where SEO also gives each page its description and its Markdown twin and leaves out what search engines may not list.
• Publish Markdown Versions of Pages (markdown_twins): each page also at its address with .md. On by default.
• Block These AI Crawlers (blocked_crawlers): crawlers robots.txt turns away.
• Security Contact (security_contact): where to report vulnerabilities; publishes /.well-known/security.txt.
• Discourage All Indexing (discourage_indexing): for staging sites.

The Redirects tab beside them edits content/redirects.yaml.

Abilities

• seo/analyze: the on-page checks of one entry, with a score. Needs to view the entry's collection.
• seo/health: the same checks across published pages: average score, common issues and the lowest-scoring pages. Needs admin.access.
• seo/markdown: the Markdown version of a page that AI crawlers receive. Needs admin.access.
• redirects/list: the redirects. Needs seo.manage.
• redirects/create: adds one redirect. Needs seo.manage.
• redirects/set: puts the whole redirect list in place; what is left out is gone. Needs seo.manage.

Each says what it answers with (output). The permission seo.manage (Manage SEO Settings and Redirects) comes with the Editor role.

Hooks

• seo.alternates (filter): fn (array $alternates, Entry $entry): array. The same page in other languages, each ['locale' => 'fr', 'uri' => '/fr/about'], for hreflang links in the head and the sitemap.
• seo.sitemap (filter): fn (array $urls, ?string $locale): array. Addresses your plugin answers itself, each ['uri' => '/shop', 'updated' => '2026-11-01'], added to the sitemap. With 'locale' => 'de' an address goes in that language's sitemap, without in the default language's; $locale is the language being written, null on a site with one.
• redirects.saved (action): after the redirect list changed.
• render.structured (action it listens to): dispatch('render.structured', string $key, array $data) while a page renders adds a node to the page's JSON-LD.

This repository is published from letterncms/plugins-public. Open issues and pull requests there.