Basically, when a 401 error occurs, it is an authentication-related error (authentication is not working properly), but I will write about the specific cases.

There are some obvious points, but I would like to list the possible ones.

Possibility of session timeout

This is not so much a code bug as it is the possibility that you haven't been active for a long time (for example, taking a break).

Try refreshing the page (Command+R) and check if you are logged in.

If you are not logged in, logging in should fix the issue.

Things you should check

○ Are the screens different when you are not logged in compared to when you are logged in?

○ What is the session duration setting?

Accessing an authenticated route without being authenticated

As the name suggests,

Route::group(['middleware' => ['auth','verified']], function () {
  Route::get('/user', 'UserController@index');
});

Even if you are trying to access a route that requires authentication, you may not be logged in.

⇨ How to write routes that can only be used by authenticated users

The `authorize` in the form request is set to false

If you are implementing validation with a form request,

    public function authorize()
    {
      //true requires authentication
        return true;
        //false does not require authentication
        // return false;
    }

it needs to be set to true.

Token expiration in APIs

While this is not common during development, in the case of Laravel Passport, the token expiration period is usually set to a default of one year.

It is good to remember that such expiration periods exist.

Failure to run Passport commands after resetting the DB with migration fresh

php artisan migrate:fresh

If you run this command, the oauth related DB required by Laravel Passport will be empty, so you need to run

php artisan passport:install

again.

Conclusion

I have listed five ways to address 401 errors in Laravel.

There may be other cases as well, but if you have any ideas, please tweet them along with the DM on Twitter or the article URL!

That's it!

How to deal with 401 errors in Laravel when you cannot access POST requests