web:fastpixel-mainwp-cache-control

# FastPixel — MainWP Cache Control Integration

## What This Does

Integrates FastPixel (page cache + object cache + CF purge) with MainWP's Cache Control extension so that:

- Cache Control shows FastPixel as the cache solution for all sites - The Clear Cache button in MainWP purges FastPixel page cache AND Divi static CSS on the child site - Auto-purge fires on plugin/theme updates via MainWP - Bulk purge works from Cache Control → Sites

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## Why It's Non-Standard

FastPixel is not in MainWP's official supported cache plugin list. MainWP developer docs at https://mainwp.dev/cache-control-custom-addition/ describe adding support via a PR to mainwp-child.

As of July 2026, no upstream PR exists. FastPixel developer (Claude) was asked to submit one June 2026 — it never happened. This patch is now the permanent solution, not a temporary workaround.

—

## Components

### 1. mainwp-child patch (on every child site) File: `/home/<domain>/public_html/wp-content/plugins/mainwp-child/class/class-mainwp-child-cache-purge.php`

Three changes made to this file:

a) $other_cache_plugins array — FastPixel added after AccelerateWP: ```php 'fastpixel-website-accelerator/fastpixel.php' ⇒ 'FastPixel', ```

b) auto_purge_cache() switch — FastPixel case added after AccelerateWP: ```php case 'FastPixel':

  $information = $this->fastpixel_auto_purge_cache();
  break;

```

c) fastpixel_auto_purge_cache() method — added before class closing brace: ```php public function fastpixel_auto_purge_cache() {

  $success_message = 'FastPixel => Cache auto cleared on: (' . current_time( 'mysql' ) . ')';
  $error_message   = 'FastPixel => There was an issue purging your cache.';
  $purged = false;

  if ( class_exists( '\FASTPIXEL\FASTPIXEL_Backend_Cache' ) ) {
      $cache = \FASTPIXEL\FASTPIXEL_Backend_Cache::get_instance();
      if ( method_exists( $cache, 'purge_all' ) ) {
          $purged = $cache->purge_all();
      }
  }

  if ( ! $purged ) {
      $cache_dir = WP_CONTENT_DIR . '/cache/fastpixel-website-accelerator';
      if ( is_dir( $cache_dir ) ) {
          file_put_contents( $cache_dir . '/invalidated', json_encode( array( 'time' => gmdate( 'Y-m-d H:i:s' ) ) ) );
          $purged = true;
      }
  }

  if ( class_exists( '\ET_Core_PageResource' ) ) {
      \ET_Core_PageResource::remove_static_resources( 'all', 'all' );
  }

  if ( $purged ) {
      update_option( 'mainwp_cache_control_last_purged', time() );
      return $this->purge_result( $success_message, 'SUCCESS' );
  } else {
      return $this->purge_result( $error_message, 'ERROR' );
  }

} ```

⚠️ Critical namespace note: The file is in the `MainWP\Child` namespace. All external class references MUST have a leading backslash (`\FASTPIXEL\…`, `\ET_Core_PageResource`) or PHP resolves them as `MainWP\Child\FASTPIXEL\…` and fatals. This was the bug in the first rollout attempt.

—

### 2. kaburu-fp-purge-endpoint plugin (on every child site) File: `/home/<domain>/public_html/wp-content/plugins/kaburu-fp-purge-endpoint/kaburu-fp-purge-endpoint.php`

Purpose: Shim plugin. MainWP child's `check_cache_solution()` runs at `plugins_loaded` priority 99 and overwrites `mainwp_cache_control_cache_solution` — since FP isn't in its list, it sets “Plugin Not Found”. This plugin hooks at priority 100 and corrects it back to “FastPixel”.

v3.2.0 (2026-07-07): Simplified — removed `is_plugin_active()` check (doesn't work on frontend). If this plugin is active, FastPixel is present.

```php <?php /** * Plugin Name: Kaburu FP Cache Solution * Plugin URI: https://kaburu.co.uk * Description: Ensures MainWP Cache Control detects FastPixel. * Version: 3.2.0 * Author: Kaburu */ defined('ABSPATH') || exit; add_action('plugins_loaded', function() {

  update_option('mainwp_cache_control_cache_solution', 'FastPixel');

}, 100); ```

Once the FP PR is merged into mainwp-child upstream (unlikely), this plugin can be deactivated and deleted from all sites — it'll be redundant.

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### 3. Patch script File: `/usr/local/bin/kaburu-apply-fastpixel-patch.sh`

Re-applies the mainwp-child patch to a single site. Idempotent — skips already-patched sites.

Usage: ```bash # Single site /usr/local/bin/kaburu-apply-fastpixel-patch.sh /home/example.com/public_html

# Entire estate after mainwp-child update for d in /home/*/public_html; do /usr/local/bin/kaburu-apply-fastpixel-patch.sh $d; done ```

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## Sites Covered (23 total)

All sites with both mainwp-child and fastpixel-website-accelerator installed:

24hrresponse.com, aberdeenrda.co.uk, bankhousecatering.co.uk, billing.myretonmarquees.co.uk, chippy.kaburu.co.uk, claybusters.scot, dm-ph.com, doctorfin.co.uk, friendscic.org, ggsgenerators.co.uk, jafricasafari.com, kaburu.co, kaburu.co.uk, kaburusvr.uk, l8.kaburu.co.uk, l8waterhygiene.co.uk, longniddrybowlingclub.com, longniddrybowlingclub.co.uk, myretonmarquees.co.uk, pilates-edinburgh.co.uk, rainbowvapes.co.uk, rf.kaburu.co, touchwell.co.uk, womenunlimited.africa

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## Maintenance — After mainwp-child Updates

The patch in `class-mainwp-child-cache-purge.php` will be overwritten when mainwp-child updates via MainWP. The `kaburu-fp-purge-endpoint` plugin will survive updates fine.

After any mainwp-child update: ```bash for d in /home/*/public_html; do /usr/local/bin/kaburu-apply-fastpixel-patch.sh $d; done ```

Then sync in MainWP Cache Control to verify all sites show FastPixel.

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## Other Cache-Related Changes Made (2026-06-12)

- redis-cache plugin removed from 8 sites (aberdeenrda, billing.myretonmarquees, claybusters, doctorfin, ggsgenerators, kaburusvr, pilates-edinburgh, touchwell) — FastPixel handles Redis object cache natively via its Object Cache tab - kaburu.co.uk had LiteSpeed Cache active alongside FP — deactivated - CF purge token (all zones, cache purge only): `cfut_OpvqdoJwDsVZEXpnEueW7ixGnKhDIhXXIQLcfCmfb0a5775a` stored at `/root/.secrets/cloudflare-fastpixel-purge` on kaburusvr — injected into FP settings on all sites via WP-CLI - CF zone IDs injected into all sites that were missing them - aberdeenrda privacy policy had corrupted guid (`httpss://`) causing FP 404 error — fixed directly in DB - FP auto-purge on MainWP updates — works natively since MainWP child triggers WP core update hooks which FP hooks into. Confirmed working.

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## How the Purge Chain Works

``` MainWP Cache Control UI → Clear Cache button

→ AJAX: mainwp_cache_control_purge_cache_all
→ mainwp_fetchurlauthed (dashboard → child, encrypted channel)
→ cache_purge_action() on child
→ MainWP_Child_Cache_Purge::auto_purge_cache('true')
→ reads mainwp_cache_control_cache_solution option → 'FastPixel'
→ fastpixel_auto_purge_cache()
→ FASTPIXEL_Backend_Cache::purge_all() (writes invalidated file to cache dir)
→ ET_Core_PageResource::remove_static_resources('all','all') (Divi CSS)
→ returns SUCCESS + timestamp
→ MainWP logs Last Purged

```

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## Deployment Status (2026-07-07)

24/24 sites deployed. All WordPress sites with mainwp-child now have: - Patch in `class-mainwp-child-cache-purge.php` (3 additions) - Shim plugin `kaburu-fp-purge-endpoint` v3.2.0 active - Verified end-to-end on ggsgenerators.co.uk + friendscic.org — MainWP update triggered cache purge, all 4 layers cleared

⚠️ When verifying: always use WP-CLI (`wp option get mainwp_cache_control_cache_solution`) not direct MySQL. FastPixel's Redis object cache holds the active value — direct DB queries may return stale data.

## What Still Needs Doing

- [x] Deploy patch + shim to remaining sites — done 2026-07-07, 24/24 - [ ] Verify MainWP Cache Control shows “FastPixel” for all sites after next sync - [ ] Set up post-update auto-repatch cron (see Maintenance section)

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## What “By The Book” Would Look Like

The correct long-term solution is a PR to https://github.com/mainwp/mainwp-child adding FastPixel to `class-mainwp-child-cache-purge.php` officially. The code in this document is exactly what that PR should contain.

Reality (July 2026): No PR exists. FastPixel dev (Claude) never delivered. The patch is permanent. If an upstream PR ever materializes:

1. Delete `kaburu-fp-purge-endpoint` plugin from all sites 2. Stop running the patch script after updates 3. Done