---
title: "Managing Middleware"
package: "WebSocketBundle"
version: "1.x"
canonical_url: "https://www.babdev.com/open-source/packages/websocketbundle/docs/1.x/managing-middleware"
package_supported: true
version_released: false
notice:
  - "Version 1.x of WebSocketBundle has not been released yet. Its API may change before release."
---
# Managing Middleware

By default, this bundle registers [server middleware](/open-source/packages/websocket-server/docs/1.x/middleware) by finding all services with the `babdev_websocket_server.server_middleware` tag and sorting them by priority.

Below is the list of middleware provided by this bundle and the library and their default priorities:

| Middleware Class                                                            | Service ID                                                                          | Priority |
|-----------------------------------------------------------------------------|-------------------------------------------------------------------------------------|----------|
| `BabDev\WebSocket\Server\WAMP\Middleware\DispatchMessageToHandler`          | `babdev_websocket_server.server.server_middleware.dispatch_to_message_handler`      | 0        |
| `BabDev\WebSocket\Server\WAMP\Middleware\UpdateTopicSubscriptions`          | `babdev_websocket_server.server.server_middleware.update_topic_subscriptions`       | -10      |
| `BabDev\WebSocket\Server\WAMP\Middleware\ParseWAMPMessage`                  | `babdev_websocket_server.server.server_middleware.parse_wamp_message`               | -20      |
| `BabDev\WebSocket\Server\WebSocket\Middleware\EstablishWebSocketConnection` | `babdev_websocket_server.server.server_middleware.establish_websocket_connection`   | -30      |
| `BabDev\WebSocketBundle\Server\Middleware\AuthenticateUser`                 | `babdev_websocket_server.server.server_middleware.authenticate_user`                | -40      |
| `BabDev\WebSocket\Server\Session\Middleware\InitializeSession`              | `babdev_websocket_server.server.server_middleware.initialize_session`               | -50      |
| `BabDev\WebSocket\Server\Http\Middleware\RestrictToAllowedOrigins`          | `babdev_websocket_server.server.server_middleware.restrict_to_allowed_origins`      | -60      |
| `BabDev\WebSocket\Server\Http\Middleware\RejectBlockedIpAddress`            | `babdev_websocket_server.server.server_middleware.reject_blocked_ip_address`        | -70      |
| `BabDev\WebSocket\Server\Http\Middleware\ResolveForwardedClientAddress`     | `babdev_websocket_server.server.server_middleware.resolve_forwarded_client_address` | -80      |
| `BabDev\WebSocket\Server\Http\Middleware\ParseHttpRequest`                  | `babdev_websocket_server.server.server_middleware.parse_http_request`               | -90      |

## Adding Middleware

New middleware should be added with a priority lower than 0 as the `BabDev\WebSocket\Server\WAMP\Middleware\DispatchMessageToHandler` middleware should be the last middleware in the stack.

Middleware added between the WAMP middleware must implement the interface expected by the middleware decorating it:

- Middleware with a priority between -20 and 0 is decorated by the `BabDev\WebSocket\Server\WAMP\Middleware\ParseWAMPMessage` or `BabDev\WebSocket\Server\WAMP\Middleware\UpdateTopicSubscriptions` middleware, and must implement `BabDev\WebSocket\Server\WAMPServerMiddleware`
- Middleware with a priority between -30 and -20 is decorated by the `BabDev\WebSocket\Server\WebSocket\Middleware\EstablishWebSocketConnection` middleware, and should implement `BabDev\WebSocket\Server\WebSocketServerMiddleware` and return the sub-protocols of the middleware it decorates from `getSubProtocols()`; otherwise, the `wamp` sub-protocol is not supported and clients are rejected when the [strict sub-protocol check](/open-source/packages/websocketbundle/docs/1.x/running-the-server#wamp-protocol-options) is enabled

Middleware must have the decorated middleware as the first parameter in the constructor, and cannot use a named parameter in the service definition (i.e. `$middleware: !abstract decorated middleware` for YAML); this is required for the compiler pass which builds the middleware stack to correctly set the arguments.

The bundle supports autoconfiguration of `BabDev\WebSocket\Server\ServerMiddleware` classes using the `#[AsServerMiddleware]` attribute on your middleware class.

```php
<?php declare(strict_types=1);

namespace App\WebSocket\Middleware;

use BabDev\WebSocket\Server\ServerMiddleware;
use BabDev\WebSocketBundle\Attribute\AsServerMiddleware;

#[AsServerMiddleware(priority: -100)]
final readonly class EarlyMiddleware implements ServerMiddleware
{
    public function __construct(
        private ServerMiddleware $middleware,
    ) {}

    /* Class implementation */
}
```

If you are not using autoconfiguration, the service should be tagged with the `babdev_websocket_server.server_middleware` service tag and the priority specified.

```yaml
# config/services.yaml
services:
  App\WebSocket\Middleware\EarlyMiddleware:
    arguments:
      - !abstract decorated middleware
    tags:
      - { name: babdev_websocket_server.server_middleware, priority: -100 }
```