Add documentation for cli_init hook

[Copilot]

Adds documentation for the new cli_init hook introduced in wp-cli/wp-cli#4818, which provides a dedicated event for registering custom commands during WP-CLI Runner startup.

Changes

• guides/commands-cookbook.md: Added cli_init hook example in the "Include in a plugin or theme" section as an alternative to the WP_CLI constant check, with guidance on when to use each approach

• references/internal-api/wp-cli-add-hook.md: Added cli_init to the list of available WP-CLI hooks

Example

/**
 * Register custom WP-CLI commands using the cli_init hook.
 */
function myplugin_register_cli_commands() {
	require_once dirname( __FILE__ ) . '/inc/class-plugin-cli-command.php';
	WP_CLI::add_command( 'myplugin', 'MyPlugin_CLI_Command' );
}
WP_CLI::add_hook( 'cli_init', 'myplugin_register_cli_commands' );

Both the traditional WP_CLI constant check and the new cli_init hook remain valid approaches.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/Behat/Behat/zipball/1b6b08efa995fe4135901b862d112adc7e95ecbb
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/Behat/Gherkin/zipball/34c9b59c59355a7b4c53b9f041c8dbd1c8acc3b4
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/PHPCSStandards/PHPCSExtra/zipball/8e89a01c7b8fed84a12a2a7f5a23a44cdbe4f62e
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/PHPCSStandards/PHPCSUtils/zipball/8b8e17615d04f2fc2cd46fc1d2fd888fa21b3cf9
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/PHPCSStandards/PHP_CodeSniffer/zipball/ad545ea9c1b7d270ce0fc9cbfb884161cd706119
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/PHPCSStandards/composer-installer/zipball/e9cf5e4bbf7eeaf9ef5db34938942602838fc2b1
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/PHPCompatibility/PHPCompatibility/zipball/71a1e55c148ec0d248f599faea63044f81a1952c
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/WordPress/WordPress-Coding-Standards/zipball/d2421de7cec3274ae622c22c744de9a62c7925af
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/Yoast/PHPUnit-Polyfills/zipball/1a6aecc9ebe4a9cea4e1047d0e6c496e52314c27
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/composer/pcre/zipball/b2bed4734f0cc156ee1fe9c0da2550420d99a21e
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/composer/semver/zipball/198166618906cb2de69b95d7d47e5fa8aa1b2b95
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/composer/xdebug-handler/zipball/6c1925561632e83d60a44492e0b344cf48ab85ef
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/myclabs/DeepCopy/zipball/07d290f0c47959fd5eed98c95ee5602db07e0b6a
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/nikic/PHP-Parser/zipball/3a454ca033b9e06b63282ce19562e892747449bb
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/php-fig/event-dispatcher/zipball/dbefd12671e8a14ec7f180cab83036ed26714bb0
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/php-fig/log/zipball/f16e1d5863e37f8d8c2a01719f5b34baa2b714d3
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/JjOgTZ /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/php-parallel-lint/PHP-Console-Highlighter/zipball/5b4803384d3303cf8e84141039ef56c8a123138d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/php-parallel-lint/PHP-Parallel-Lint/zipball/6db563514f27e19595a19f45a4bf757b6401194e
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/code-unit-reverse-lookup/zipball/5e3a687f7d8ae33fb362c5c0743794bbb2420a1d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/complexity/zipball/68ff824baeae169ec9f2137158ee529584553799
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/environment/zipball/8074dbcd93529b357029f5cc5058fd3e43666984
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/lines-of-code/zipball/856e7f6a75a84e339195d48c556f23be2ebf75d0
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/php-file-iterator/zipball/a95037b6d9e608ba092da1b23931e537cadc3c3c
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/php-text-template/zipball/0c7b06ff49e3d5072f057eb1fa59258bf287a748
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/phpunit/zipball/e24fb46da450d8e6a5788670513c1af1424f16ca
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/dependency-injection/zipball/82119812ab0bf3425c1234d413efd1b19bb92ae4
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/event-dispatcher-contracts/zipball/59eb412e93815df44f05f342958efa9f46b1e586
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/event-dispatcher/zipball/b7dc69e71de420ac04bc9ab830cf3ffebba48191
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/finder/zipball/9f696d2f1e340484b4683f7853b273abff94421f
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/polyfill-ctype/zipball/a3cc8b044a6ea513310cbd48ef7333b384945638
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/translation-contracts/zipball/df210c7a2573f1913b2d17cc95f90f53a73d8f7d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/translation/zipball/ec25870502d0c7072d086e8ffba1420c85965174
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/yaml/zipball/90208e2fc6f68f613eae7ca25a2458a931b1bacc
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/wp-cli/mustache.php/zipball/ca23b97ac35fbe01c160549eb634396183d04a59
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/wp-cli/php-cli-tools/zipball/f12b650d3738e471baed6dd47982d53c5c0ab1c3
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/wp-cli/spyc/zipball/6aa0b4da69ce9e9a2c8402dab8d43cf32c581cc7
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/wp-cli/wp-cli-tests/zipball/f81af5773bd40962fb973e238acd26b39b1b7341
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/oQT045 /usr/bin/composer install --no-interaction (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Update documentation for new cli_init action.</issue_title>
<issue_description>wp-cli/wp-cli#4818 introduces a "cli_init" hook during the Runner startup process that allows developers to register their custom commands by hooking into a specific event instead of checking for the definition and existence of the WP_CLI constant.

Developers can continue to check in the traditional way, but in order to communicate the existence of this hook to the broader community, we will need to update WP-CLI documentation to present examples on how this hook may be used. This includes:

• Example code showing the hook in action
• Extending the hook reference
• Checking scaffolded packages for any necessary changes

Per Alain, "the WP_CLI constant example should stay, though. Using the cli_init hook is an alternative, not a replacement, depending on what your needs are."</issue_description>

<agent_instructions>Something for the guides/commands-cookbook.md page.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Update documentation for new cli_init action. #578

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[BrianHenryIE]

I always saw the benefit of the cli_init hook being that you don't need to worry is WP CLI present at all. As this PR says

a dedicated event for command registration without needing to check for the WP_CLI constant

but the above code:

WP_CLI::add_hook( 'cli_init', 'myplugin_register_cli_commands' );

still needs a check of ~class_exists( WP_CLI::class ) which is almost equivalent (since the class probably isn't loaded before the constant is defined).

I use:

add_action( 'cli_init', 'myplugin_register_cli_commands' );

[swissspidy]

Indeed, it's a WP hook, not a WP-CLI hook after all!