Mantis SEO

Lightweight SEO for WordPress — titles & meta, redirects, JSON-LD schema, XML sitemaps, social tags, and AI/GEO discovery in one plugin. No upsells, no feature gating.

• Plugin URI: mantiseo.com
• Requires: WordPress 6.0+ · PHP 7.4+
• License: GPL v3

Features

Titles & meta

• Global templates for homepage, posts, and pages with variable pills (e.g. %post_title%, %separator%, %site_name%, %excerpt%).
• Per-content overrides in the post/page editor: slide-out SEO Settings panel (Meta, Facebook / Open Graph, X / Twitter Cards). The focus keyword field is saved for your own reference (it is not output as a meta tag).
• Canonical URLs and robots (index/noindex, follow/nofollow).
• Open Graph and X Card tags, including default OG image and per-post image URLs.
• Search engine visibility warning: if Settings → Reading → Discourage search engines is enabled, administrators see a prominent admin notice with a link to Reading settings.

Structured data (JSON-LD)

• @graph output with linked @ids: WebSite (with SearchAction), WebPage, Article (for the post post type), BreadcrumbList, and optional Organization (name, URL, logo, sameAs social profiles).
• OG article:published_time / article:modified_time on singular URLs where appropriate.

XML sitemaps

• Index: https://yoursite.com/sitemap_index.xml
• Per post-type sitemaps (configurable public post types).
• Can be disabled in settings if you use another sitemap solution.

AI / GEO

• /llms.txt curated Markdown map for AI assistants (optional /llms-full.txt dump).
• AI crawler policies in robots.txt (allow/block/inherit per bot: OpenAI, Anthropic, Perplexity, Google-Extended, and more).
• Brand facts wizard creates a citation-ready page and links it first in llms.txt.

Redirects

• 301, 302, 303, 307, 308, 410, and 451 redirects stored in a custom database table. Plain origins match with or without a trailing slash. Regex origins use a ~ delimiter internally—literal ~ in a pattern must be written as \~.
• Redirect manager under Mantis SEO → Redirects, with search and 20 rules per page.
• Automatic redirect when a published post or page slug changes.
• Trash / delete flows integrate with redirect prompts where applicable.

Tools & migration

• Yoast SEO: detect and migrate global settings, post/term meta, and redirects (when Yoast data is present).
• Export / import plugin settings as JSON from the Tools tab.

Verification

• Google and Bing site verification meta tags from settings.

Installation

1. Copy the mantis-seo folder into wp-content/plugins/.
2. In Plugins, activate Mantis SEO.
3. Visit Mantis SEO in the admin menu and configure Titles & Meta, Social, Schema, Sitemap, AI / GEO, and Advanced.
4. After activation or sitemap / llms.txt changes, visit Settings → Permalinks and click Save once if pretty permalinks or rewrite rules need a refresh (standard WordPress behavior).

Usage

Homepage vs blog index: If the front page is a static page, that page uses the page templates. The Homepage description setting applies to the posts page when it is not the front page (is_home() && ! is_front_page()).

Sitemap URLs

With permalinks enabled and the sitemap turned on:

Submit the index URL in Google Search Console and Bing Webmaster Tools.

AI discovery URLs

With permalinks enabled and AI / GEO → Enable /llms.txt on:

After enabling, save Settings → Permalinks once if these URLs 404.

Yoast SEO migration

If Yoast SEO is installed and has data, the settings screen can offer Migrate from Yoast. That imports compatible options and meta keys into Mantis. Deactivate Yoast after migration to avoid duplicate meta tags and schema.

Uninstall

Deleting the plugin via Plugins → Delete runs uninstall.php, which:

• Drops the {prefix}mantis_redirects table.
• Removes options: mantis_settings, mantis_migrated_from_yoast, mantis_redirect_notice.

Post meta (_mantis_*) is not bulk-deleted on uninstall (common pattern so content isn’t silently stripped if you reinstall). Remove manually if you need a clean database.

Project structure

mantis-seo/
├── mantis-seo.php          # Bootstrap, constants, hooks
├── uninstall.php
├── admin/                  # Settings UI, metabox, redirects admin
├── includes/               # Meta, schema, sitemap, redirects, AI/llms.txt, Yoast importer
├── assets/                 # admin.css, template editor & metabox JS
└── languages/              # POT for translations

Releases & updates

Publishing a GitHub release triggers .github/workflows/release-plugin.yml, which builds an installable zip with a mantis-seo/ root and uploads mantis-seo.zip to that release. Installed sites check GET /repos/chrisegg/mantis-seo/releases/latest and download:

https://github.com/chrisegg/mantis-seo/releases/download/{tag}/mantis-seo.zip

Use a release tag whose version (with or without a leading v) matches Version: in mantis-seo.php for that release. Release notes on GitHub populate the WordPress “View version details” changelog when present.

This repository is private, so WordPress cannot see releases without a token. On each site, add a fine-grained personal access token that can read this repository's contents to wp-config.php:

define( 'MANTIS_SEO_GITHUB_TOKEN', 'github_pat_...' );

The same token is sent when WordPress downloads mantis-seo.zip. Without it, the Plugins screen shows no update and the Updates screen explains why.

Development

• Follow WordPress coding standards and capability checks (manage_options for settings, edit_post for metabox saves).
• Text domain: mantis-seo.
• Version constant: MANTIS_SEO_VERSION in the main plugin file.
• Per-post SEO fields are available on the WordPress REST API under meta (_mantis_* keys). See DOCUMENTATION.md.
• Agent tools: Abilities API / MCP abilities (mantis-seo/*) when supported. See DOCUMENTATION.md.

Credits

Author: Chris Eggleston — mantiseo.com

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See LICENSE.