diff --git a/frontend-web-vanilla/src/PeerConnection.ts b/frontend-web-vanilla/src/PeerConnection.ts
index 011e6e3..02c5321 100644
--- a/frontend-web-vanilla/src/PeerConnection.ts
+++ b/frontend-web-vanilla/src/PeerConnection.ts
@@ -1,5 +1,5 @@
 import {Subject, ReadOnlySubject, Disposable, DisposableList, EventPublisher, type IEvent, type IDisposable} from '@techniker-me/tools';
-import type { IPeerConnectionOperations } from './interfaces/IPeerConnectionOperations';
+import type {IPeerConnectionOperations} from './interfaces/IPeerConnectionOperations';
 
 export default class PeerConnection implements IPeerConnectionOperations {
   private readonly _disposables: DisposableList = new DisposableList();
diff --git a/frontend-web-vanilla/src/User.ts b/frontend-web-vanilla/src/User.ts
index 2a73012..d3e07b9 100644
--- a/frontend-web-vanilla/src/User.ts
+++ b/frontend-web-vanilla/src/User.ts
@@ -1,19 +1,24 @@
 import type {ILogger} from '@techniker-me/logger';
 import {LoggerFactory} from '@techniker-me/logger';
 import {ReadOnlySubject, Subject, type IEvent} from '@techniker-me/tools';
-import PeerConnection from './PeerConnection';
+import type { IPeerConnectionOperations } from './interfaces/IPeerConnectionOperations';
 import type { ISignalingClient } from './interfaces/ISignalingClient';
 
+/**
+ * User class - manages local and remote media streams
+ * Follows Single Responsibility Principle - only handles media stream management
+ * Follows Dependency Inversion Principle - depends on abstractions (interfaces)
+ */
 export default class User {
     private readonly _logger: ILogger = LoggerFactory.getLogger('User');
     private readonly _localVideoElement: HTMLVideoElement;
     private readonly _remoteVideoElement: HTMLVideoElement;
-    private readonly _peerConnection: PeerConnection;
+    private readonly _peerConnection: IPeerConnectionOperations;
     private readonly _signalingClient: ISignalingClient;
     private readonly _mediaStream: Subject<MediaStream | null> = new Subject(null);
     private readonly _readOnlyMediaStream: ReadOnlySubject<MediaStream | null> = new ReadOnlySubject(this._mediaStream);
 
-    constructor(localVideoElement: HTMLVideoElement, remoteVideoElement: HTMLVideoElement, peerConnection: PeerConnection, signalingClient: ISignalingClient) {
+    constructor(localVideoElement: HTMLVideoElement, remoteVideoElement: HTMLVideoElement, peerConnection: IPeerConnectionOperations, signalingClient: ISignalingClient) {
         this._localVideoElement = localVideoElement;
         this._remoteVideoElement = remoteVideoElement;
         this._peerConnection = peerConnection;
@@ -25,7 +30,7 @@ export default class User {
         return this._localVideoElement;
     }
 
-    get peerConnection(): PeerConnection {
+    get peerConnection(): IPeerConnectionOperations {
         return this._peerConnection;
     }
 
diff --git a/frontend-web-vanilla/src/interfaces/IPeerConnectionOperations.ts b/frontend-web-vanilla/src/interfaces/IPeerConnectionOperations.ts
index f7091b8..9f28860 100644
--- a/frontend-web-vanilla/src/interfaces/IPeerConnectionOperations.ts
+++ b/frontend-web-vanilla/src/interfaces/IPeerConnectionOperations.ts
@@ -1,6 +1,9 @@
+import type { IEvent, IDisposable } from '@techniker-me/tools';
+
 /**
  * Interface for peer connection operations
  * Follows Interface Segregation Principle - focused interface for WebRTC operations
+ * Follows Dependency Inversion Principle - abstracts peer connection capabilities
  */
 export interface IPeerConnectionOperations {
   /**
@@ -27,5 +30,18 @@ export interface IPeerConnectionOperations {
    * Get the current signaling state
    */
   getSignalingState(): RTCSignalingState;
+
+  /**
+   * Add a media stream to the peer connection
+   */
+  addMediaStream(mediaStream: MediaStream): void;
+
+  /**
+   * Subscribe to peer connection events
+   * @param event Event name (e.g., 'icecandidate', 'track')
+   * @param callback Event handler function
+   * @returns Disposable to unsubscribe from the event
+   */
+  on<T>(event: string, callback: (event: IEvent<T>) => void | Promise<void>): IDisposable;
 }