PHP

Source code

This is a minimal server application built for PHP that allows:

• Generating LiveKit tokens on demand for any application client.
• Receiving LiveKit webhook events.

It internally uses LiveKit PHP SDK.

Running this application

Download the tutorial code:

git clone https://github.com/OpenVidu/openvidu-livekit-tutorials.git

To run this server application, you need PHP and Composer installed on your device.

1. Navigate into the server directory

   cd openvidu-livekit-tutorials/application-server/php
   

2. Install dependencies

   composer install
   

3. Run the application

   composer start
   

Info

You can run any Application Client to test against this server right away.

Warning

LiveKit PHP SDK requires library BCMath. This is available out-of-the-box in PHP for Windows, but a manual installation might be necessary in other OS. Run sudo apt install php-bcmath or sudo yum install php-bcmath

Understanding the code

The application is a simple PHP app with a single file index.php that exports two endpoints:

• /token : generate a token for a given Room name and Participant name.
• /webhook : receive LiveKit webhook events.

Let's see the code of the index.php file:

<?php
require __DIR__ . "/vendor/autoload.php";

use Agence104\LiveKit\AccessToken; // (1)!
use Agence104\LiveKit\AccessTokenOptions;
use Agence104\LiveKit\VideoGrant;
use Agence104\LiveKit\WebhookReceiver;
use Dotenv\Dotenv;

Dotenv::createImmutable(__DIR__)->safeLoad();

header("Access-Control-Allow-Origin: *"); // (2)!
header("Access-Control-Allow-Headers: Content-Type, Authorization");
header("Content-type: application/json");

$LIVEKIT_API_KEY = $_ENV["LIVEKIT_API_KEY"] ?? "devkey"; // (3)!
$LIVEKIT_API_SECRET = $_ENV["LIVEKIT_API_SECRET"] ?? "secret"; // (4)!

1. Import all necessary dependencies from the PHP LiveKit library.
2. Configure HTTP headers for the web server: enable CORS support, allow the Content-Type and Authorization headers and set the response content type to application/json.
3. The API key of LiveKit Server.
4. The API secret of LiveKit Server.

The index.php file imports the required dependencies, sets the HTTP headers for the web server and loads the necessary environment variables:

• LIVEKIT_API_KEY: the API key of LiveKit Server.
• LIVEKIT_API_SECRET: the API secret of LiveKit Server.

---

Create token

The endpoint /token accepts POST requests with a payload of type application/json, containing the following fields:

• roomName: the name of the Room where the user wants to connect.
• participantName: the name of the participant that wants to connect to the Room.

<?php
if (isset($_SERVER["REQUEST_METHOD"]) && $_SERVER["REQUEST_METHOD"] === "POST" && $_SERVER["PATH_INFO"] === "/token") {
    $data = json_decode(file_get_contents("php://input"), true);

    $roomName = $data["roomName"] ?? null;
    $participantName = $data["participantName"] ?? null;

    if (!$roomName || !$participantName) {
        http_response_code(400);
        echo json_encode(["errorMessage" => "roomName and participantName are required"]);
        exit();
    }

    $tokenOptions = (new AccessTokenOptions()) // (1)!
        ->setIdentity($participantName);
    $videoGrant = (new VideoGrant()) // (2)!
        ->setRoomJoin()
        ->setRoomName($roomName);
    $token = (new AccessToken($LIVEKIT_API_KEY, $LIVEKIT_API_SECRET)) // (3)!
        ->init($tokenOptions)
        ->setGrant($videoGrant)
        ->toJwt();

    echo json_encode(["token" => $token]); // (4)!
    exit();
}

1. Create an AccessTokenOptions object with the participant's identity.
2. Create a VideoGrant object setting the necessary video grants options. setRoomJoin allows the user to join a room and setRoomName determines the specific room. Check out all Video Grants.
3. We create the AccessToken providing the LIVEKIT_API_KEY and LIVEKIT_API_SECRET, initialize it with the token options, set the video grants and generate the JWT token.
4. Finally, the token is sent back to the client.

The endpoint first obtains the roomName and participantName parameters from the request body. If they are not available, it returns a 400 error.

If required fields are available, a new JWT token is created. For that we use the LiveKit PHP SDK:

1. Create an AccessTokenOptions object with the participant's identity.
2. Create a VideoGrant object setting the necessary video grants options. setRoomJoin allows the user to join a room and setRoomName determines the specific room. Check out all Video Grants.
3. We create the AccessToken providing the LIVEKIT_API_KEY and LIVEKIT_API_SECRET, initialize it with the token options, set the video grants and generate the JWT token.
4. Finally, the token is sent back to the client.

---

Receive webhook

The endpoint /webhook accepts POST requests with a payload of type application/webhook+json. This is the endpoint where LiveKit Server will send webhook events.

<?php
$webhookReceiver = (new WebhookReceiver($LIVEKIT_API_KEY, $LIVEKIT_API_SECRET)); // (1)!

if (isset($_SERVER["REQUEST_METHOD"]) && $_SERVER["REQUEST_METHOD"] === "POST" && $_SERVER["PATH_INFO"] === "/webhook") {
    $headers = getallheaders();
    $authHeader = $headers["Authorization"]; // (2)!
    $body = file_get_contents("php://input"); // (3)!
    try {
        $event = $webhookReceiver->receive($body, $authHeader); // (4)!
        error_log("LiveKit Webhook:");
        error_log(print_r($event->getEvent(), true)); // (5)!
        exit();
    } catch (Exception $e) {
        http_response_code(401);
        echo "Error validating webhook event";
        echo json_encode($e->getMessage());
        exit();
    }
}

1. Create a new WebhookReceiver object providing the LIVEKIT_API_KEY and LIVEKIT_API_SECRET. It will help validating and decoding incoming webhook events.
2. The Authorization header of the HTTP request.
3. The raw body of the HTTP request as a string.
4. Obtain the WebhookEvent object using the WebhookReceiver#receive method. It takes the raw body as a String and the Authorization header of the request.
5. Consume the event as you wish.

We first create a WebhookReceiver object using the LIVEKIT_API_KEY and LIVEKIT_API_SECRET. Then we must retrieve the Authorization header and the raw body of the HTTP request. We need both of them to validate and decode the incoming webhook event.

Finally, we obtain the WebhookEvent object using the WebhookReceiver#receive method. It takes the raw body as a String and the Authorization header of the request. We can consume the event as we wish (in this case, we just log it using the error output).