An example of automatically including header and footer templates using Slim hooks.

hooks.php

$app->hook('slim.before.dispatch', function () use ($app) {
	$app->render('/views/header.php');
});
  
$app->hook('slim.after.dispatch', function () use ($app) {
	$app->render('/views/footer.php');
});

index.php

require_once 'slim/Slim.php';
$app = new Slim();

require 'hooks.php';
require 'routes.php';

$app->run();

routes.php

$app->get('/users/:id/?', function ($id) use ($app) {
	$app->render('/views/user_profile.php', array('id' => $id));
});

Very helpful, thanks

There are no hooks in Slim 3.
Use middleware instead of hooks for Slim 3 https://www.slimframework.com/docs/start/upgrade.html