---
title: "Hooks - GeneratePerf"
description: "Every filter of GeneratePerf, what it changes and its default, with a ready-to-use example in the child theme."
url: "https://generateperf.com/docs/hooks/"
lang: "en-US"
published: "2026-09-24T15:00:12+02:00"
modified: "2026-11-02T10:22:04+01:00"
---

[Docs](https://generateperf.com/docs/) / Developers

# Hooks

Every filter of GeneratePerf, what it changes and its default, with a ready-to-use example in the child theme.

Every hook below is listed, commented out and with an example, in `inc/functions-custom.php` of the [GeneratePerf child theme](https://generateperf.com/docs/recommended-setup/): uncomment the one you need and adapt it. The settings screen also shows them in each tab, under **Available hooks**.

## Summary

| Filter | What it changes | Default |
| --- | --- | --- |
| `generateperf_toc_max_title_level` | Deepest heading level listed in the table of contents (2 to 6) | `4` |

## Related content

| Filter | What it changes | Default |
| --- | --- | --- |
| `generateperf_related_articles_inside_content_limit` | Maximum number of related posts inserted in the text; short posts get fewer (at least three paragraphs between two) | `6` |
| `generateperf_related_articles_after_content_limit` | Number of related posts after the content | `6` |
| `generateperf_related_articles_sidebar_limit` | Number of related posts in the sidebar | `6` |
| `generateperf_related_articles_before_footer_limit` | Number of related posts before the footer | `6` |
| `generateperf_related_posts_taxonomies` | Taxonomies used to find related posts: array `taxonomy => terms` of the current post | tags and categories |
| `generateperf_intext_related_posts_template` | HTML of a related post inserted in the text; receives the default HTML, the related post and the current post | a link with label and title |

## Social share and authors

| Filter | What it changes | Default |
| --- | --- | --- |
| `generateperf_social_share_details` | HTML shown under the title of the share component | empty |
| `generateperf_add_user_social_link` | Social networks of user profiles and of the author box: `key => [ name, prefix, icon ]`; the icon must be in `images/icons/` of the child theme | built-in networks |
| `generateperf_trim_author_description` | Number of words kept in the author description of the author box | `false` (full text) |

## Design and images

| Filter | What it changes | Default |
| --- | --- | --- |
| `generateperf_active_fonts` | Fonts loaded by GeneratePerf (stylesheet, preload of the variable file, block editor): catalogue stacks (`Poppins, Poppins-fallback, sans-serif`) or family names (`Poppins`); return an empty array to load none | fonts of the GeneratePress typography and of the GenerateBlocks Global Styles |
| `generateperf_layout_custom_border_radius` | Border radius of buttons, fields and cards (CSS variable `--border-radius`) | Design → Border radius |
| `generateperf_max_image_size` | Largest size kept for uploaded images, in pixels; the WordPress sizes above it are not generated | `1200` |

## Performance

| Filter | What it changes | Default |
| --- | --- | --- |
| `generateperf_css_concatenation` | Whether stylesheets are kept as files for a concatenation tool: `true` sets the WordPress inline limit (`styles_inline_size_limit`) to 0, `false` keeps the WordPress limit, so small stylesheets (fonts, GeneratePerf, GeneratePress, GP Premium, GenerateBlocks Pro, the child theme, WP Armour) are printed in the page instead of blocking it; receives the detected value and the slug of the tool | `true` only when a CSS concatenation setting is active: WP Rocket before 3.15, Autoptimize, LiteSpeed Cache, SiteGround Speed Optimizer, W3 Total Cache, WP-Optimize, Breeze, WP Fastest Cache, Jetpack Boost |

## robots.txt

| Filter | What it changes | Default |
| --- | --- | --- |
| `generateperf_list_block_agents` | User agents blocked (`Disallow: /`); applied last, so it overrides the AI crawlers setting | the AI crawlers of the level set in SEO → AI crawlers |
| `generateperf_ai_bots` | AI crawlers of each category: `[ 'training' => [...], 'inference' => [...] ]` | list maintained with each release |
| `generateperf_content_signal` | Value of the `Content-Signal` directive (usage preference declared in the `User-agent: *` group); receives the value and the level, an empty string removes it | `search=yes, ai-input=yes, ai-train=no` (training only), `search=yes, ai-input=no, ai-train=no` (training and inference), none (none) |
| `generateperf_list_bot_agents` | User agents with a limited crawl rate (`Crawl-delay: 180`) | SEO tools and aggressive crawlers |

The **AI crawlers** setting (SEO tab) picks the level: none, training only (default for new installs) or training and inference. Training crawlers (GPTBot, ClaudeBot, CCBot, Google-Extended, Applebot-Extended, Meta-ExternalAgent, Amazonbot…) collect pages to train models; inference crawlers (OAI-SearchBot, ChatGPT-User, Claude-SearchBot, PerplexityBot…) fetch them to cite the site in answers. Sites installed before 3.1.4 keep the level « none ». With Yoast SEO active, the rules are written in the Yoast block of robots.txt; otherwise GeneratePerf adds them itself.

## Example

```php
// inc/functions-custom.php of the child theme: list h2 and h3 only in the table of contents
add_filter( 'generateperf_toc_max_title_level', function () {
    return 3;
} );
```