Yoast SEO (WordPress) Integration

Auto-append your xpay agent-payment block to Yoast’s generated llms.txt without breaking Yoast’s auto-updates.

The problem

Yoast SEO (v27+) auto-generates llms.txt at your WordPress root. It’s regenerated every time you publish, edit, or delete a post.

If you edit that file directly via the WordPress media manager or FTP, WordPress saves it as a static file, which overrides Yoast’s auto-generated version. Yoast keeps regenerating in the background, but the static file wins — so your llms.txt freezes on the day you edited it.

This means a naive “paste the xpay block at the bottom” approach is incompatible with Yoast.

The fix

A small, single-file WordPress plugin that:

1. Hooks into the same save_post / deleted_post events Yoast uses.
2. Runs a delayed append (~60s after the post change) so it always runs after Yoast finishes regenerating.
3. Reads llms.txt, strips any prior xpay block (using hidden markers), and appends a fresh copy at the end.
4. Idempotent — re-running never duplicates.

The xpay block is configurable in WP admin (Settings → xpay llms.txt), so you can paste any block you generate from your dashboard.

Setup

How it works

You publish a post
   ↓
WordPress fires save_post
   ↓ (Yoast also listens here)
Yoast regenerates llms.txt → writes static file at WP root
   ↓
Plugin schedules a single WP-Cron event 60s in the future
   ↓
Cron fires → reads llms.txt → strips old xpay block (between markers)
                            → appends fresh xpay block + markers
                            → writes back atomically

The 60-second delay avoids racing Yoast’s file write. The marker-based strip-and-replace makes the operation idempotent — running it ten times produces the same file as running it once.

Safety guarantees

The plugin only operates if all of the following are true:

• The xpay block setting is non-empty
• llms.txt exists at the resolved path (respects Yoast’s wpseo_llmstxt_filesystem_path filter if you’ve set a custom location)
• The file is writable
• The file contains the string Yoast SEO — a guard so the plugin refuses to touch files Yoast didn’t generate

If any check fails, the plugin silently bails. It will never overwrite a non-Yoast llms.txt or destroy unrelated content.

Uninstall

Deactivating the plugin clears its scheduled cron events. Your llms.txt will retain whatever the last append produced — the next time Yoast regenerates (after a post change), the static file will be replaced with a fresh Yoast-only version, and the xpay block will be gone.

To remove the xpay block immediately:

1. Deactivate the plugin
2. Either edit/republish any post (forces Yoast to regenerate without the xpay block), or
3. Delete llms.txt at your WP root and let Yoast regenerate it on the next post save

Compatibility

• Yoast SEO: v27.0+
• WordPress: 6.0+
• PHP: 7.4+
• Hosting: any (works behind Cloudflare, Hostinger Cache, Ezoic JS-Integration, etc. — operates at the WordPress origin, before any CDN)

Source code

The plugin is a single PHP file, MIT-licensed. View or fork: files.xpay.sh/setup/plugins/xpay-yoast-llms-append.php