workflow-channel-{name}/
  workflow-channel-{name}.php       # Main plugin file (hooks + asset loading)
  includes/
    class-{name}-channel.php        # Channel class extending NotificationChannel

<?php
/**
 * Plugin Name: Workflow {Display Name} Channel
 * Description: Sends VIP Workflows notifications to {service}.
 * Version: 1.0.0
 * Requires Plugins: vip-workflows
 * Text Domain: workflow-channel-{name}
 *
 * @package WorkflowChannel{PascalName}
 */

declare( strict_types=1 );

namespace WorkflowChannel{PascalName};

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

define( 'WORKFLOW_CHANNEL_{UPPER_NAME}_DIR', plugin_dir_path( __FILE__ ) );

add_action( 'vip_workflows_register_notification_channels', function( $dispatcher ) {
    require_once WORKFLOW_CHANNEL_{UPPER_NAME}_DIR . 'includes/class-{name}-channel.php';
    $dispatcher->register_channel( new {PascalName}Channel() );
} );

<?php
declare( strict_types=1 );

namespace WorkflowChannel{PascalName};

use VIPWorkflows\Notifications\NotificationChannel;
use VIPWorkflows\Notifications\Notification;
use WP_Error;

class {PascalName}Channel extends NotificationChannel {

    public function get_id(): string {
        return '{name}';
    }

    public function get_name(): string {
        return __( '{Display Name}', 'workflow-channel-{name}' );
    }

    public function get_description(): string {
        return __( 'Send notifications to {service}.', 'workflow-channel-{name}' );
    }

    public function get_icon(): string {
        return 'search';
    }

    /**
     * Check if the channel has the required configuration to send.
     */
    public function is_configured(): bool {
        $settings = $this->get_settings();
        return ! empty( $settings['webhook_url'] );
    }

    /**
     * Define settings fields. Auto-rendered in the admin UI.
     */
    public function get_settings_schema(): array {
        return array(
            'webhook_url' => array(
                'type'        => 'string',
                'label'       => __( 'Webhook URL', 'workflow-channel-{name}' ),
                'description' => __( 'The incoming webhook URL from {service}.', 'workflow-channel-{name}' ),
                'required'    => true,
            ),
            // Add more fields as needed:
            // 'channel' => array(
            //     'type'    => 'string',
            //     'label'   => __( 'Channel', 'workflow-channel-{name}' ),
            //     'default' => '#general',
            // ),
        );
    }

    /**
     * Send a notification to the service.
     *
     * @param Notification $notification Contains ->get_subject(), ->get_body(),
     *                                   ->get_post_id(), ->get_event_type(), etc.
     * @return bool True on success.
     */
    public function send( Notification $notification ): bool {
        $settings    = $this->get_settings();
        $webhook_url = $settings['webhook_url'] ?? '';

        if ( empty( $webhook_url ) ) {
            return false;
        }

        // Build the payload for your service.
        // Adapt this to match the service's expected format.
        $payload = array(
            'text' => sprintf(
                "**%s**\n%s",
                $notification->get_subject(),
                $notification->get_body()
            ),
        );

        $response = wp_remote_post( $webhook_url, array(
            'headers' => array( 'Content-Type' => 'application/json' ),
            'body'    => wp_json_encode( $payload ),
            'timeout' => 10,
        ) );

        if ( is_wp_error( $response ) ) {
            return false;
        }

        $code = wp_remote_retrieve_response_code( $response );
        return $code >= 200 && $code < 300;
    }

    /**
     * Test the channel connection with a sample message.
     *
     * @return true|WP_Error
     */
    public function test_connection() {
        $settings    = $this->get_settings();
        $webhook_url = $settings['webhook_url'] ?? '';

        if ( empty( $webhook_url ) ) {
            return new WP_Error( 'not_configured', __( 'Webhook URL is not set.', 'workflow-channel-{name}' ) );
        }

        $payload = array(
            'text' => 'Test notification from VIP Workflows.',
        );

        $response = wp_remote_post( $webhook_url, array(
            'headers' => array( 'Content-Type' => 'application/json' ),
            'body'    => wp_json_encode( $payload ),
            'timeout' => 10,
        ) );

        if ( is_wp_error( $response ) ) {
            return $response;
        }

        $code = wp_remote_retrieve_response_code( $response );
        if ( $code < 200 || $code >= 300 ) {
            return new WP_Error(
                'send_failed',
                sprintf( __( 'Service returned HTTP %d.', 'workflow-channel-{name}' ), $code )
            );
        }

        return true;
    }

    /**
     * Sanitize settings input.
     *
     * @param array $input Raw form input.
     * @return array Sanitized settings.
     */
    public function sanitize_settings( array $input ): array {
        return array(
            'webhook_url' => esc_url_raw( $input['webhook_url'] ?? '' ),
        );
    }
}