Pods Blocks API examples for register a custom block type or a custom block collection. Screencast: https://share.skc.dev/12uJvZL1

my-custom-pods-block-1.php

<?php
/**
 * Plugin Name: My Custom Pods Block
 * Plugin URI: https://gist.github.com/sc0ttkclark/73930f5a4b8f093d4c0d500bdb1eca5b
 * Description: Custom block built using the Pods Block PHP API. No Javascript needed!
 * Author Name: Scott Kingsley Clark
 * Author URI: https://skc.dev/
 */

/**
 * Want a quick overview and live demo? Check out the screencast here: https://share.skc.dev/12uJvZL1
 */

/**
 * Example 1: Registering a custom block type.
 */
add_action( 'pods_blocks_api_init', 'register_my_custom_block_type' );

/**
 * Register your custom block type. Rename this function to fit your own project naming and needs.
 */
function register_my_custom_block_type() {
	/**
	 * This is your block configuration. Customize it to fit your needs.
	 */
	$block = [
		// This is unique the name of your project so it won't conflict with other blocks installed (A-Z, a-z and dashes only).
		'namespace'       => 'my-project',
		// The unique name of your block (A-Z, a-z and dashes only).
		'name'            => 'my-custom-block',
		// The block title of your block.
		'title'           => __( 'My Custom Block' ),
		// The text description of your block.
		'description'     => __( 'The description of my custom block.' ),
		// Set your category (collection): common, formatting, layout, widgets, embed, or a custom one you register (A-Z, a-z and dashes only).
		'category'        => 'my-custom-collection',
		// Dashicon name, see https://developer.wordpress.org/resource/dashicons/ for an official list, exclude the "dashicons-" prefix.
		'icon'            => 'admin-comments',
		// Limit to three keywords or phrases.
		'keywords'        => [
			'Project name',
			'keyword',
		],

		/**
		 * Important: The below options will be different depending on what render type you want to use.
		 */

		// How you want to render the block output: php or js.
		'render_type'     => 'php',
		// If `render_type` is "php", set your callback below.
		'render_callback' => 'my_custom_block_render',
		// If `render_type` is "js", set your template content below and call your fields using {@magic_tag} syntax.
		'render_template'        => '
			<div>This is an example of the value for My Magic Tag Text Field: <strong>{@my_text_field}</strong></div>
		',
	];

	/**
	 * This is a list of fields to show in your block options (shown in the "Inspector Controls" area when selecting the block.
	 */

	// If you have no fields to set, just use an empty array or don't pass `$fields` into `pods_register_block_type`.
	$fields = [];

	// If you have fields to show, set them and customize the list here. They use the same exact field config form at as normal Pod fields.
	$fields = [
		[
			'name'  => 'my_text_field',
			'label' => __( 'My Text Field' ),
			'type'  => 'text',
		],
		[
			'name'        => 'my_paragraph_field',
			'label'       => __( 'My Paragraph Field' ),
			'description' => __( 'This is a description for the field.' ),
			'type'        => 'paragraph',
		],
		[
			'name'    => 'my_number_field',
			'label'   => __( 'My Number Field' ),
			'type'    => 'number',
			'default' => 15,
		],
		[
			'name'  => 'my_checkbox_field',
			'label' => __( 'My Checkbox Field' ),
			'type'  => 'boolean',
		],
		[
			'name'    => 'my_select_field',
			'label'   => __( 'My Select Field' ),
			'type'    => 'pick',
			'data'    => [
				'one'   => __( 'Option 1' ),
				'two'   => __( 'Option 2' ),
				'three' => __( 'Option 3' ),
			],
			'default' => 'two',
		],
	];

	pods_register_block_type( $block, $fields );
}

/**
 * Render the block HTML if you want to do it with PHP. Rename this function to fit your own project naming and needs.
 *
 * @param array $attributes List of field attributes.
 *
 * @return string The content to render.
 */
function my_custom_block_render( array $attributes ) {
	return '
		<p>This is an example of the value for My Text Field: <strong>' . esc_html( $attributes['my_text_field'] ) . '</strong></p>
		<p>This is another example of the value for My Number Field: <strong>' . esc_html( $attributes['my_number_field'] ) . '</strong></p>
	';
}

/**
 * Example 2: Registering a custom block collection.
 */
add_action( 'pods_blocks_api_init', 'register_my_custom_block_collection' );

/**
 * Register your custom block collection. Rename this function to fit your own project naming and needs.
 */
function register_my_custom_block_collection() {
	/**
	 * This is your block collection configuration. Customize it to fit your needs.
	 */
	$collection = [
		// The unique name of your block collection (A-Z, a-z and dashes only).
		'namespace' => 'my-custom-collection',
		// The block title of your block collection.
		'title'     => __( 'My Custom Collection' ),
		// Dashicon name, see https://developer.wordpress.org/resource/dashicons/ for an official list, exclude the "dashicons-" prefix.
		'icon'      => 'admin-customizer',
	];

	pods_register_block_collection( $collection );
}

my-custom-pods-block-2.php

<?php
/**
 * Plugin Name: My Custom Pods Block using a Pod Template
 * Plugin URI: https://gist.github.com/sc0ttkclark/73930f5a4b8f093d4c0d500bdb1eca5b
 * Description: Custom block built using the Pods Block PHP API. No Javascript needed!
 * Author Name: Scott Kingsley Clark
 * Author URI: https://skc.dev/
 */

/**
 * Example 1: Registering a custom block type.
 */
add_action( 'pods_blocks_api_init', 'register_my_custom_block_type2' );

/**
 * Register your custom block type. Rename this function to fit your own project naming and needs.
 */
function register_my_custom_block_type2() {
	/**
	 * This is your block configuration. Customize it to fit your needs.
	 */
	$block = [
		// This is unique the name of your project so it won't conflict with other blocks installed (A-Z, a-z and dashes only).
		'namespace'       => 'my-project',
		// The unique name of your block (A-Z, a-z and dashes only).
		'name'            => 'my-custom-block2',
		// The block title of your block.
		'title'           => __( 'My Custom Block 2' ),
		// The text description of your block.
		'description'     => __( 'The description of my custom block 2.' ),
		// Set your category (collection): common, formatting, layout, widgets, embed, or a custom one you register (A-Z, a-z and dashes only).
		'category'        => 'my-custom-collection2',
		// Dashicon name, see https://developer.wordpress.org/resource/dashicons/ for an official list, exclude the "dashicons-" prefix.
		'icon'            => 'admin-comments',
		// Limit to three keywords or phrases.
		'keywords'        => [
			'Project name',
			'keyword',
		],

		/**
		 * Important: The below options will be different depending on what render type you want to use.
		 */

		// How you want to render the block output: php or js.
		'render_type'     => 'php',
		// If `render_type` is "php", set your callback below.
		'render_callback' => 'my_custom_block_render2',
		// If `render_type` is "js", set your template content below and call your fields using {@magic_tag} syntax.
		'render_template'        => '
			<div>This is an example of the value for My Magic Tag Text Field: <strong>{@my_text_field}</strong></div>
		',
	];

	/**
	 * This is a list of fields to show in your block options (shown in the "Inspector Controls" area when selecting the block.
	 */

	// If you have no fields to set, just use an empty array or don't pass `$fields` into `pods_register_block_type`.
	$fields = [];

	// If you have fields to show, set them and customize the list here. They use the same exact field config form at as normal Pod fields.
	$fields = [
		[
			'name'     => 'book_id',
			'label'    => __( 'Book ID' ),
			'type'     => 'text',
			'default'  => '',
			'required' => true,
		],
	];

	pods_register_block_type( $block, $fields );
}

/**
 * Render the block HTML if you want to do it with PHP. Rename this function to fit your own project naming and needs.
 *
 * @param array $attributes List of field attributes.
 *
 * @return string The content to render.
 */
function my_custom_block_render2( array $attributes ) {
	// Check that we have a Book ID set.
	if ( empty( $attributes['book_id'] ) ) {
		return 'Please set the Book ID.';
	}

	$pod = pods( 'book_pods', $attributes['book_id'], false );

	// Check that the book exists.
	if ( ! $pod->exists() ) {
		return 'That book does not exist.';
	}

	// Return the template for the item.
	return $pod->template( '', '
		<h2><a href="{@permalink,esc_url}">{@post_title}</a></h2>
		
		<p><a href="{@permalink,esc_url}">{@post_thumbnail.full}</a></p>
		
		<p><strong>ISBN:</strong> {@isbn}</p>
	' );
}

/**
 * Example 2: Registering a custom block collection.
 */
add_action( 'pods_blocks_api_init', 'register_my_custom_block_collection2' );

/**
 * Register your custom block collection. Rename this function to fit your own project naming and needs.
 */
function register_my_custom_block_collection2() {
	/**
	 * This is your block collection configuration. Customize it to fit your needs.
	 */
	$collection = [
		// The unique name of your block collection (A-Z, a-z and dashes only).
		'namespace' => 'my-custom-collection2',
		// The block title of your block collection.
		'title'     => __( 'My Custom Collection 2' ),
		// Dashicon name, see https://developer.wordpress.org/resource/dashicons/ for an official list, exclude the "dashicons-" prefix.
		'icon'      => 'admin-customizer',
	];

	pods_register_block_collection( $collection );
}

Very interesting!!! in the gist you say that we can use all kind of PODS fields ... but i'm having an hard time trying to use the correct configuration. May i have other field config examples? like media (with multiple uploads, and thumb preview) e CPT (other pods to show via block). thanks a lot!!!