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Overview

AppManager is responsible for the complete lifecycle of third-party apps within a user session. It handles app starting, stopping, connection management, webhook triggering, and state tracking. This manager encapsulates all app-related functionality that was previously scattered throughout the codebase. File: packages/cloud/src/services/session/AppManager.ts

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Key Responsibilities

  1. App Lifecycle Management: Starting, stopping, and restarting apps
  2. Connection Management: WebSocket connections and heartbeat monitoring
  3. State Tracking: Connection states, pending operations, and app status
  4. Webhook Communication: Triggering app webhooks for session initialization
  5. Hardware Compatibility: Checking app requirements against device capabilities
  6. Grace Period Handling: Managing reconnections during network interruptions

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State Management

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Connection States

enum AppConnectionState {
  RUNNING = "running",           // Active WebSocket connection
  GRACE_PERIOD = "grace_period", // Waiting for natural reconnection (5s)
  RESURRECTING = "resurrecting", // System actively restarting app
  STOPPING = "stopping",         // User/system initiated stop in progress
  DISCONNECTED = "disconnected"  // Available for resurrection
}

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Internal State

class AppManager {
  // Pending app start operations
  private pendingConnections = new Map<string, PendingConnection>();
  
  // Connection states for Apps
  private connectionStates = new Map<string, AppConnectionState>();
  
  // Heartbeat intervals for App connections
  private heartbeatIntervals = new Map<string, NodeJS.Timeout>();
  
  // App start times for session duration calculation
  private appStartTimes = new Map<string, number>();
}

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App Starting Process

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Start Flow

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Implementation

async startApp(packageName: string): Promise<AppStartResult> {
  // Check if already running
  if (this.isAppRunning(packageName)) {
    return { success: true };
  }
  
  // Get app details
  const app = await appService.getApp(packageName);
  
  // Check hardware compatibility
  if (this.userSession.capabilities) {
    const compatibility = HardwareCompatibilityService.checkCompatibility(
      app, 
      this.userSession.capabilities
    );
    
    if (!compatibility.isCompatible) {
      return {
        success: false,
        error: {
          stage: "HARDWARE_CHECK",
          message: `Missing required hardware: ${compatibility.missingRequired.join(", ")}`
        }
      };
    }
  }
  
  // Create promise for connection tracking
  return new Promise((resolve, reject) => {
    const startTime = Date.now();
    
    // Set timeout for connection
    const timeout = setTimeout(async () => {
      // Handle timeout...
      resolve({
        success: false,
        error: {
          stage: "TIMEOUT",
          message: `Connection timeout after ${APP_SESSION_TIMEOUT_MS}ms`
        }
      });
    }, APP_SESSION_TIMEOUT_MS);
    
    // Store pending connection
    this.pendingConnections.set(packageName, {
      packageName,
      resolve,
      reject,
      timeout,
      startTime
    });
    
    // Trigger webhook
    this.triggerAppWebhookInternal(app, resolve, reject, startTime);
  });
}

​
Webhook Triggering

private async triggerAppWebhookInternal(
  app: AppI,
  resolve: (result: AppStartResult) => void,
  reject: (error: Error) => void,
  startTime: number
): Promise<void> {
  // Determine WebSocket URL based on environment
  let augmentOSWebsocketUrl = "";
  
  if (app.isSystemApp) {
    // Internal URLs for system apps
    if (process.env.PORTER_APP_NAME) {
      // Kubernetes environment
      augmentOSWebsocketUrl = `ws://${process.env.PORTER_APP_NAME}-cloud.default.svc.cluster.local:80/app-ws`;
    } else if (process.env.CONTAINER_ENVIRONMENT === "true") {
      // Docker Compose
      augmentOSWebsocketUrl = "ws://cloud/app-ws";
    } else {
      // Local development
      augmentOSWebsocketUrl = "ws://localhost:8002/app-ws";
    }
  } else {
    // Public URL for third-party apps
    augmentOSWebsocketUrl = `wss://${CLOUD_PUBLIC_HOST_NAME}/app-ws`;
  }
  
  // Trigger boot screen
  this.userSession.displayManager.handleAppStart(app.packageName);
  
  // Send webhook
  await this.triggerWebhook(`${app.publicUrl}/webhook`, {
    type: WebhookRequestType.SESSION_REQUEST,
    sessionId: `${this.userSession.userId}-${app.packageName}`,
    userId: this.userSession.userId,
    timestamp: new Date().toISOString(),
    augmentOSWebsocketUrl
  });
}

​
Connection Handling

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App Initialization

When an app connects via WebSocket: 
async handleAppInit(ws: WebSocket, initMessage: AppConnectionInit): Promise<void> {
  const { packageName, apiKey, sessionId } = initMessage;
  
  // Validate API key
  const isValidApiKey = await developerService.validateApiKey(
    packageName, 
    apiKey, 
    this.userSession
  );
  
  if (!isValidApiKey) {
    this.resolvePendingConnectionWithError(
      packageName,
      "AUTHENTICATION",
      "Invalid API key"
    );
    ws.close(1008, "Invalid API key");
    return;
  }
  
  // Check app is in loading state
  if (!this.userSession.loadingApps.has(packageName) && 
      !this.userSession.runningApps.has(packageName)) {
    ws.close(1008, "App not started for this session");
    return;
  }
  
  // Store WebSocket connection
  this.userSession.appWebsockets.set(packageName, ws);
  
  // Set up close handler
  ws.on("close", (code, reason) => {
    this.handleAppConnectionClosed(packageName, code, reason.toString());
  });
  
  // Set up heartbeat
  this.setupAppHeartbeat(packageName, ws);
  
  // Update state
  this.setAppConnectionState(packageName, AppConnectionState.RUNNING);
  this.userSession.runningApps.add(packageName);
  this.userSession.loadingApps.delete(packageName);
  
  // Send connection acknowledgment
  const connectionAck = {
    type: CloudToAppMessageType.CONNECTION_ACK,
    sessionId: `${this.userSession.userId}-${packageName}`,
    userId: this.userSession.userId,
    capabilities: this.userSession.capabilities,
    timestamp: new Date()
  };
  
  ws.send(JSON.stringify(connectionAck));
  
  // Resolve pending connection
  this.resolvePendingConnection(packageName);
}

​
Heartbeat System

Maintains connection health: 
private setupAppHeartbeat(packageName: string, ws: WebSocket): void {
  const HEARTBEAT_INTERVAL = 10000; // 10 seconds
  
  // Clear any existing heartbeat
  this.clearAppHeartbeat(packageName);
  
  // Set up new heartbeat
  const heartbeatInterval = setInterval(() => {
    if (ws.readyState === WebSocket.OPEN) {
      ws.ping();
    } else {
      this.clearAppHeartbeat(packageName);
    }
  }, HEARTBEAT_INTERVAL);
  
  this.heartbeatIntervals.set(packageName, heartbeatInterval);
  
  // Set up pong handler
  ws.on("pong", () => {
    // Connection still alive
  });
}

​
App Stopping

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Stop Process

async stopApp(packageName: string): Promise<void> {
  if (!this.isAppRunning(packageName)) {
    return;
  }
  
  // Set state to STOPPING
  this.setAppConnectionState(packageName, AppConnectionState.STOPPING);
  
  // Remove from running apps
  this.userSession.runningApps.delete(packageName);
  
  // Clear subscriptions
  subscriptionService.removeSubscriptions(
    this.userSession.userId, 
    packageName
  );
  
  // Send stop message and close connection
  const appWebsocket = this.userSession.appWebsockets.get(packageName);
  if (appWebsocket?.readyState === WebSocket.OPEN) {
    const message = {
      type: CloudToAppMessageType.APP_STOPPED,
      reason: "USER_REQUEST",
      timestamp: new Date()
    };
    
    appWebsocket.send(JSON.stringify(message));
    appWebsocket.close(1000, "App stopped");
  }
  
  // Update database
  const user = await User.findByEmail(this.userSession.userId);
  await user?.removeRunningApp(packageName);
  
  // Clean up connections
  this.userSession.appWebsockets.delete(packageName);
  
  // Clean up display and dashboard
  this.userSession.displayManager.handleAppStop(packageName);
  this.userSession.dashboardManager.cleanupAppContent(packageName);
  
  // Track metrics
  const startTime = this.appStartTimes.get(packageName);
  if (startTime) {
    const sessionDuration = Date.now() - startTime;
    await PosthogService.trackEvent("app_stop", this.userSession.userId, {
      packageName,
      sessionDuration
    });
  }
}

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Grace Period Handling

When an app disconnects unexpectedly: 
private handleAppConnectionClosed(
  packageName: string, 
  code: number, 
  reason: string
): void {
  const currentState = this.getAppConnectionState(packageName);
  
  // If intentionally stopping, clean up immediately
  if (currentState === AppConnectionState.STOPPING) {
    this.cleanupAppConnection(packageName);
    return;
  }
  
  // Start grace period
  this.setAppConnectionState(packageName, AppConnectionState.GRACE_PERIOD);
  
  // Set reconnection timer (5 seconds)
  const timer = setTimeout(() => {
    const state = this.getAppConnectionState(packageName);
    
    if (state === AppConnectionState.GRACE_PERIOD) {
      // Grace period expired, clean up
      this.cleanupAppConnection(packageName);
    }
  }, 5000);
  
  this.userSession._reconnectionTimers.set(packageName, timer);
}

​
Message Handling

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Send Message to App

async sendMessageToApp(
  packageName: string, 
  message: any
): Promise<AppMessageResult> {
  const ws = this.userSession.appWebsockets.get(packageName);
  
  if (ws?.readyState === WebSocket.OPEN) {
    ws.send(JSON.stringify(message));
    return { sent: true, resurrectionTriggered: false };
  }
  
  // Try resurrection if disconnected
  const state = this.getAppConnectionState(packageName);
  if (state === AppConnectionState.DISCONNECTED) {
    const startResult = await this.startApp(packageName);
    return {
      sent: false,
      resurrectionTriggered: true,
      error: startResult.success ? undefined : "Failed to resurrect app"
    };
  }
  
  return {
    sent: false,
    resurrectionTriggered: false,
    error: `App in ${state} state`
  };
}

​
Cleanup

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Disposal

dispose(): void {
  // Stop all running apps
  for (const packageName of this.userSession.runningApps) {
    this.stopApp(packageName).catch(error => {
      this.logger.error(`Error stopping app ${packageName} during disposal:`, error);
    });
  }
  
  // Clear all heartbeats
  for (const [packageName, interval] of this.heartbeatIntervals) {
    clearInterval(interval);
  }
  this.heartbeatIntervals.clear();
  
  // Clear pending connections
  for (const [packageName, pending] of this.pendingConnections) {
    clearTimeout(pending.timeout);
    pending.reject(new Error("Session disposed"));
  }
  this.pendingConnections.clear();
  
  // Clear reconnection timers
  for (const timer of this.userSession._reconnectionTimers.values()) {
    clearTimeout(timer);
  }
  this.userSession._reconnectionTimers.clear();
}

​
Environment Configuration

AppManager adapts WebSocket URLs based on environment:
  • Local Development: ws://localhost:8002/app-ws
  • Docker Compose: ws://cloud/app-ws (for system apps)
  • Kubernetes (Porter): ws://${APP_NAME}-cloud.default.svc.cluster.local:80/app-ws
  • Production: wss://${CLOUD_PUBLIC_HOST_NAME}/app-ws

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Best Practices

  1. Always check hardware compatibility before starting apps
  2. Handle connection timeouts to prevent hanging operations
  3. Implement grace periods for network interruptions
  4. Track app metrics for usage analytics
  5. Clean up resources when apps stop
  6. Use appropriate URLs based on environment and app type