> For the complete documentation index, see [llms.txt](https://docs.roadrunner.dev/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.roadrunner.dev/docs/plugins/centrifuge.md).

# Centrifuge (WebSockets)

The RoadRunner Centrifuge plugin provides seamless integration with [Centrifugo](https://centrifugal.dev/), a powerful websocket server. This plugin allows you to proxy events from Websocket server to PHP workers running on RoadRunner and send data back to the websocket client, enabling real-time communication between the server and the client.

The plugin provides the following features:

1. **Event Proxying:** The plugin allows RoadRunner to receive all the events from Centrifugo server such as [Connect](https://centrifugal.dev/docs/server/proxy#connect-proxy), [Refresh](https://centrifugal.dev/docs/server/proxy#refresh-proxy), [RPC](https://centrifugal.dev/docs/server/proxy#rpc-proxy), [Subscribe](https://centrifugal.dev/docs/server/proxy#subscribe-proxy), [Publish](https://centrifugal.dev/docs/server/proxy#publish-proxy), and [Sub refresh](https://centrifugal.dev/docs/server/proxy#sub-refresh-proxy). It then proxies these events into PHP workers and sends a result from PHP application back to the websocket client.
2. **RPC API**: The plugin provides an RPC API that allows you to send data to the websocket server. For example, you can publish or broadcast data into a channel from PHP application using the API.

{% hint style="info" %}
The Centrifuge plugin `[since 2.12.0]` replaces our deprecated `Websockets` and `Broadcast` plugins.
{% endhint %}

In addition, Centrifugo provides a convenient [JavaScript library](https://centrifugal.dev/docs/transports/client_api) that simplifies the development of real-time applications.

## PHP client

The RoadRunner centrifuge plugin comes with a convenient PHP package that simplifies the process of integrating the plugin with your PHP application. The package provides a set of classes and functions that handle incoming events from Centrifugo and allow you to send data back to the websocket server via RPC.

### Installation

To install the package, run the following command:

```bash
composer require roadrunner-php/centrifugo
```

### Configuration

Add a `centrifuge` section to your RoadRunner configuration. The plugin starts an incoming proxy listener and a PHP worker pool. If `proxy_address` is omitted or empty, it uses `tcp://127.0.0.1:30000`. These components also start when the application only sends outgoing API calls.

{% code title=".rr.yaml" %}

```yaml
version: "3"

rpc:
  listen: tcp://127.0.0.1:6001

server:
  command: "php centrifuge-worker.php"
  relay: pipes

centrifuge:
  # Centrifugo server proxy address (docs: https://centrifugal.dev/docs/server/proxy#grpc-proxy)
  # Optional, default: tcp://127.0.0.1:30000
  proxy_address: "tcp://127.0.0.1:30000"

  # gRPC server API address (docs: https://centrifugal.dev/docs/server/server_api#grpc-api)
  # Optional, default: 127.0.0.1:10000. Centrifugo: `grpc_api` should be set to true and `grpc_port` should be the same as in the RR's config.
  grpc_api_address: "127.0.0.1:10000"

  # Use gRPC gzip compressor
  # Optional, default: false
  use_compressor: true

  # Your application version
  # Optional, default: 1.0.0
  version: "v1.0.0"

  # Your application name
  # Optional, default: roadrunner
  name: "roadrunner"

  # TLS configuration
  # Optional, default: null
  tls:
    # TLS key
    # Required
    key: /path/to/key.pem

    # TLS certificate
    # Required
    cert: /path/to/cert.pem
```

{% endcode %}

And also you need to configure Centrifugo server to use RoadRunner as a proxy.

For example:

{% code title="config.json" %}

```json
{
  "admin": true,
  "api_key": "secret",
  "admin_password": "password",
  "admin_secret": "admin_secret",
  "allowed_origins": [
    "*"
  ],
  "proxy_publish": true,
  "proxy_subscribe": true,
  "allow_subscribe_for_client": true,
  "proxy_connect_endpoint": "grpc://127.0.0.1:30000",
  "proxy_connect_timeout": "10s",
  "proxy_publish_endpoint": "grpc://127.0.0.1:30000",
  "proxy_publish_timeout": "10s",
  "proxy_subscribe_endpoint": "grpc://127.0.0.1:30000",
  "proxy_subscribe_timeout": "10s",
  "proxy_refresh_endpoint": "grpc://127.0.0.1:30000",
  "proxy_refresh_timeout": "10s",
  "proxy_rpc_endpoint": "grpc://127.0.0.1:30000",
  "proxy_rpc_timeout": "10s"
}
```

{% endcode %}

{% hint style="info" %}
`proxy_connect_endpoint`, `proxy_publish_endpoint`, `proxy_subscribe_endpoint`, `proxy_refresh_endpoint`, `proxy_rpc_endpoint` - endpoint address of roadrunner server with activated centrifuge plugin.
{% endhint %}

### Unix Socket

Configure [Unix socket attributes](/docs/general/config.md#unix-socket-attributes) for the incoming proxy listener:

{% code title=".rr.yaml fragment" %}

```yaml
centrifuge:
  proxy_address: "unix:///run/roadrunner/centrifuge.sock"
  proxy_socket:
    mode: "0660"
```

{% endcode %}

Configure Centrifugo to connect to the same Unix socket. `proxy_socket` does not configure `grpc_api_address` or the TLS client used for outgoing API calls.

### PHP worker example

This worker authenticates one configured service account with a bearer token. Set `APP_CENTRIFUGO_USER` to that account's ID in the RoadRunner process environment. Generate a token with the following command:

```bash
php -r 'echo bin2hex(random_bytes(32)), PHP_EOL;'
```

Set `APP_CENTRIFUGO_TOKEN` to the command output in the RoadRunner process environment. Give the token only to that account. Send it in the Centrifugo client's connection `data` as `{"token": "<token>"}`. Use WSS outside local tests. Do not put the token in public JavaScript or logs. The worker obtains the user ID from server configuration, not from client data. It rejects missing or incorrect credentials.

Connections expire after five minutes. The refresh handler marks them as expired, so clients must reconnect and authenticate again. To revoke the token, replace it. Then restart RoadRunner. Existing connections remain valid until they expire or you disconnect them through the Centrifugo API.

For multiple users, validate a separate credential for each user against your application's session or token store. The subscribe, publish, and RPC handlers below are examples, not per-channel authorization rules. Replace the sample admin and API credentials in the Centrifugo configuration before exposing the server.

{% code title="centrifuge-worker.php" %}

```php
<?php

require __DIR__ . '/vendor/autoload.php';

use RoadRunner\Centrifugo\CentrifugoWorker;
use RoadRunner\Centrifugo\Payload;
use RoadRunner\Centrifugo\Request;
use RoadRunner\Centrifugo\Request\RequestFactory;
use Spiral\RoadRunner\Worker;

$authToken = (string) getenv('APP_CENTRIFUGO_TOKEN');
$authUser = (string) getenv('APP_CENTRIFUGO_USER');
if (strlen($authToken) < 64 || $authUser === '') {
    throw new \RuntimeException('Configure APP_CENTRIFUGO_TOKEN and APP_CENTRIFUGO_USER.');
}

$worker = Worker::create();
$requestFactory = new RequestFactory($worker);

// Create a new Centrifugo Worker from global environment
$centrifugoWorker = new CentrifugoWorker($worker, $requestFactory);

while ($request = $centrifugoWorker->waitRequest()) {

    if ($request instanceof Request\Invalid) {
        $errorMessage = $request->getException()->getMessage();

        if ($request->getException() instanceof \RoadRunner\Centrifugo\Exception\InvalidRequestTypeException) {
            $payload = $request->getException()->payload;
        }

        // Handle invalid request
        // $logger->error($errorMessage, $payload ?? []);

        continue;
    }

    if ($request instanceof Request\Connect) {
        $token = $request->getData()['token'] ?? null;
        if (!is_string($token) || !hash_equals($authToken, $token)) {
            $request->error(1000, 'Invalid credentials.');
            continue;
        }

        $request->respond(new Payload\ConnectResponse(
            user: $authUser,
            expireAt: time() + 300,
        ));
        continue;
    }

    if ($request instanceof Request\Refresh) {
        try {
            $request->respond(new Payload\RefreshResponse(
                expired: true,
            ));
        } catch (\Throwable $e) {
            $request->error($e->getCode(), $e->getMessage());
        }

        continue;
    }

    if ($request instanceof Request\Subscribe) {
        try {
            // Do something
            $request->respond(new Payload\SubscribeResponse(
                // ...
            ));

            // Use disconnect() instead of respond() to reject a connection.
        } catch (\Throwable $e) {
            $request->error($e->getCode(), $e->getMessage());
        }

        continue;
    }

    if ($request instanceof Request\Publish) {
        try {
            // Do something
            $request->respond(new Payload\PublishResponse(
                // ...
            ));

            // Use disconnect() instead of respond() to reject a connection.
        } catch (\Throwable $e) {
            $request->error($e->getCode(), $e->getMessage());
        }

        continue;
    }

    if ($request instanceof Request\RPC) {
        try {
            $request->respond(new Payload\RPCResponse(
                data: $request->getData(),
            ));
        } catch (\Throwable $e) {
            $request->error($e->getCode(), $e->getMessage());
        }

        continue;
    }
}
```

{% endcode %}

## Protobuf API

To make it easy to use the Centrifugo proto API in PHP, we provide a [GitHub repository](https://github.com/roadrunner-php/roadrunner-api-dto), that contains all the generated PHP DTO classes for the Centrifugo proxy and API proto files, making it easy to work with these files in your PHP application.

### Proxy interface

* [Docs](https://centrifugal.dev/docs/server/proxy#grpc-proxy)

RR follows the [proxy.proto](https://github.com/centrifugal/centrifugo/blob/master/internal/proxyproto/proxy.proto) specifications and proxies these events to the PHP worker. To determine what proxy method was called inside the PHP, RR adds a `type` : `endpoint` metadata. For example, if the `Subscribe` method was called, RR will add `type`:`subscribe` metadata to the worker's context.

The proxy supports the unary events listed below. Unidirectional and bidirectional subscription streams are not implemented.

### RPC

You may also use RPC methods to communicate with Centrifugo server. RR follows the official [Centrifugo proto API](https://github.com/centrifugal/centrifugo/blob/master/internal/apiproto/api.proto). Official documentation available [here](https://centrifugal.dev/docs/server/server_api#grpc-api)

{% hint style="warning" %}
The v6 plugin no longer exposes `centrifuge.RateLimit`. Remove calls to this RPC before upgrading. The plugin does not provide a replacement method.
{% endhint %}

### Proxy events

With the incoming payload, RoadRunner also adds the type of the proxied request to the headers before sending it to the PHP worker. The key in the headers is called `type`. Here is the complete list of types supported by RoadRunner:

* `connect`: Connect proxy request.
* `refresh`: Refresh proxy request.
* `subscribe`: Subscribe proxy request.
* `publish`: Publish proxy request.
* `rpc`: RPC proxy request.
* `subrefresh`: Subscription refresh proxy request.
* `notifycacheempty`: Notify cache empty proxy request (`NotifyCacheEmpty`).
* `notifychannelstate`: Notify channel state proxy request.

To handle `NotifyCacheEmpty`, use a PHP DTO package and worker request handler that support this method. RoadRunner forwards the event with `type: notifycacheempty`.

## Metrics

RoadRunner has a [metrics plugin](/docs/logging-and-observability/metrics.md) that provides metrics for the Centrifuge plugin, which can be used with Prometheus.

![centrifuge-metrics](https://user-images.githubusercontent.com/773481/235842147-5f39a812-c67e-4b96-8dc6-dc2d61ceee3b.png)