Object oriented Vanilla Forums jsConnect implementation for PHP found here.

First, instantiate a Request, User, and Config object.
The Config class will throw errors if any arguments are not set. SSO will respond with a Response containing an error message if any arguments for User or Request are missing or incorrect.

  //We store these in an environment file
  $config = new $Config([
    "client_id" => "foo",
    "secret" => "bar",
    "jsTimeout" => 1440
  ]);

  $request = new Request([
      'client_id' => "Get these"
      'timestamp' => "from parsing",
      'signature' => "the url",
      'callback' => "parameters"
  ]);

  $user = new User([
    'name' => "Pull these",
    'photoUrl' => "From",
    'uniqueId' => "Your",
    'email' => "User session"
  ]);

  $sso = new SSO($request, $user, $config);

Once you've created a SSO object, all that is left is generating the response.

$response = $sso->getResponse();

SSO does all the work of validating the Request. Responses will be created according to the example from the jsConnect PHP Library, and returned as a Response object. You can add some custom validation through

$sso->addValidator(callable)

Any callable added will be run at the end of the normal validation cycle. It should return a Response object.

The Response class has a __toString() method allowing you to

echo $response;

or you can store the JSON response by casting it to a string

$response = (string)$sso->getResponse();

And that's it. You'll have the correctly formatted JSON output response.

If you need to add more fields to the response, the Response class has an addProperties() method. It will be included only when there are no validation errors.

$response->addProperties(['key' => 'value']);