AuthController:

```php

use CodeIgniter\Restful\ResourceController;
use CodeIgniter\Shield\Models\UserModel;
use CodeIgniter\Shield\Entities\User;

class AuthController extends ResourceController
{
	//Post
	public function register()
	{
		$rules = [
			"username" => "required|is_unique[users.username]", 
			"email" => "required|valid_email|is_unique[auth_identities.secret]",  // gets written to secret field in user table
			"password" => "required" // gets written to secret 2 field in user table
		];

		if (!$this->validate($rules)) {
			$response = [
				"status" => false,
				"message"  => $this->validator->getErrors(),
				"data" => []
			];
		} else {
			$userObject = new UserModel(); // coming from Shield
			$userEntityObject = new User([
				"username" => $this->request->getVar("username"),
				"email" => $this->request->getVar("email"),
				"password" => $this->request->getVar("password")
			]);
			$userObject->save($userEntityObject);
			$response = [
				"status" => true,
				"message" => "User saved successfully",
				"data" => []
			]
		}
		return $this->respondCreated($response);
	}	
}
```

Note: shield stores users in auth_identies. Email address should be stored in field secret.

https://onlinewebtutorblog.com/codeigniter-4-restful-api-using-shield-authentication/



My version:
```php
use CodeIgniter\Restful\ResourceController;
use CodeIgniter\Shield\Models\UserModel;
use CodeIgniter\Shield\Entities\User;

class AuthController extends ResourceController
{
	//Post
	public function register()
	{
		$rules = [
			"username" => "required|is_unique[users.username]", 
			"email" => "required|valid_email|is_unique[auth_identities.secret]",  // gets written to secret field in user table
			"password" => "required" // gets written to secret 2 field in user table
		];

		if (!$this->validate($rules)) {
			return $this->respondCreated([
				"status" => false,
				"message"  => $this->validator->getErrors(),
				"data" => []
			]
		);
			
		$um = new UserModel(); // coming from Shield
		$userEntity = new User([
			"username" => $this->request->getVar("username"),
			"email" => $this->request->getVar("email"),
			"password" => $this->request->getVar("password")
		]);
		$um->save($userEntity);
		
		return $this->respondCreated( [
			"status" => true,
			"message" => "User saved successfully",
			"data" => []
		]);
	}

}
```