fix: memory leaks and performance optimizations

- WebServer: Store session listener refs for explicit cleanup on delete
- RespawnController: Fix clearInterval bug (was using clearTimeout)
- RespawnController: Add try/catch to interval callbacks
- PlanOrchestrator: Guarantee progressInterval cleanup with try/finally
- SubagentWatcher: Guard idle timer against deleted agents
- Session: Add threshold validation for auto-clear/compact (1k-500k)
- Session: Add token sum overflow check in restoreTokens
- Session: Use LRUMap for _recentTaskDescriptions auto-eviction

Commit from flight QR118 in an Airbus A350-1000, stable connection thanks to Starlink!

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/plan-orchestrator.ts

@@ -394,17 +394,17 @@ export class PlanOrchestrator {
 
     this.runningSessions.add(session);
 
+    const prompt = RESEARCH_AGENT_PROMPT.replace('{TASK}', taskDescription);
+
+    // Start progress interval before try block to ensure cleanup in finally
+    const progressInterval = setInterval(() => {
+      const elapsed = Math.floor((Date.now() - startTime) / 1000);
+      onSubagent?.({ type: 'progress', agentId, agentType: 'research', model: MODEL, status: 'running', detail: `${elapsed}s elapsed` });
+    }, 30000);
+
     try {
-      const prompt = RESEARCH_AGENT_PROMPT.replace('{TASK}', taskDescription);
-
-      const progressInterval = setInterval(() => {
-        const elapsed = Math.floor((Date.now() - startTime) / 1000);
-        onSubagent?.({ type: 'progress', agentId, agentType: 'research', model: MODEL, status: 'running', detail: `${elapsed}s elapsed` });
-      }, 30000);
-
       const { result: response } = await session.runPrompt(prompt, { model: MODEL });
 
-      clearInterval(progressInterval);
       this.runningSessions.delete(session);
 
       const durationMs = Date.now() - startTime;
@@ -446,6 +446,9 @@ export class PlanOrchestrator {
       const error = err instanceof Error ? err.message : String(err);
       onSubagent?.({ type: 'failed', agentId, agentType: 'research', model: MODEL, status: 'failed', error, durationMs });
       return { success: false, findings: { externalResources: [], codebasePatterns: [], technicalRecommendations: [], potentialChallenges: [], recommendedTools: [] }, enrichedTaskDescription: taskDescription, error, durationMs };
+    } finally {
+      // Always clear the progress interval to prevent memory leaks
+      clearInterval(progressInterval);
     }
   }
 
@@ -473,19 +476,19 @@ export class PlanOrchestrator {
 
     this.runningSessions.add(session);
 
+    const prompt = PLANNER_PROMPT
+      .replace('{TASK}', taskDescription)
+      .replace('{RESEARCH_CONTEXT}', researchContext || '');
+
+    // Start progress interval before try block to ensure cleanup in finally
+    const progressInterval = setInterval(() => {
+      const elapsed = Math.floor((Date.now() - startTime) / 1000);
+      onSubagent?.({ type: 'progress', agentId, agentType: 'planner', model: MODEL, status: 'running', detail: `${elapsed}s elapsed` });
+    }, 30000);
+
     try {
-      const prompt = PLANNER_PROMPT
-        .replace('{TASK}', taskDescription)
-        .replace('{RESEARCH_CONTEXT}', researchContext || '');
-
-      const progressInterval = setInterval(() => {
-        const elapsed = Math.floor((Date.now() - startTime) / 1000);
-        onSubagent?.({ type: 'progress', agentId, agentType: 'planner', model: MODEL, status: 'running', detail: `${elapsed}s elapsed` });
-      }, 30000);
-
       const { result: response } = await session.runPrompt(prompt, { model: MODEL });
 
-      clearInterval(progressInterval);
       this.runningSessions.delete(session);
 
       const durationMs = Date.now() - startTime;
@@ -520,6 +523,9 @@ export class PlanOrchestrator {
       const error = err instanceof Error ? err.message : String(err);
       onSubagent?.({ type: 'failed', agentId, agentType: 'planner', model: MODEL, status: 'failed', error, durationMs });
       return { success: false, error };
+    } finally {
+      // Always clear the progress interval to prevent memory leaks
+      clearInterval(progressInterval);
     }
   }
 }

src/respawn-controller.ts

@@ -1160,8 +1160,12 @@ export class RespawnController extends EventEmitter {
   private startDetectionUpdates(): void {
     this.stopDetectionUpdates();
     this.detectionUpdateTimer = setInterval(() => {
-      if (this._state !== 'stopped') {
-        this.emit('detectionUpdate', this.getDetectionStatus());
+      try {
+        if (this._state !== 'stopped') {
+          this.emit('detectionUpdate', this.getDetectionStatus());
+        }
+      } catch (err) {
+        console.error(`[RespawnController] Error in detectionUpdateTimer:`, err);
       }
     }, 500);
   }
@@ -1724,7 +1728,7 @@ export class RespawnController extends EventEmitter {
       this.hookConfirmTimer = null;
     }
     if (this.stuckStateTimer) {
-      clearTimeout(this.stuckStateTimer);
+      clearInterval(this.stuckStateTimer);
       this.stuckStateTimer = null;
     }
     // Clear all tracked timers
@@ -1743,7 +1747,7 @@ export class RespawnController extends EventEmitter {
 
     // Clear existing timer
     if (this.stuckStateTimer) {
-      clearTimeout(this.stuckStateTimer);
+      clearInterval(this.stuckStateTimer);
       this.stuckStateTimer = null;
     }
 
@@ -1751,7 +1755,11 @@ export class RespawnController extends EventEmitter {
     const checkIntervalMs = Math.min(this.config.stuckStateWarningMs, 60000); // Check every minute max
 
     this.stuckStateTimer = setInterval(() => {
-      this.checkStuckState();
+      try {
+        this.checkStuckState();
+      } catch (err) {
+        console.error(`[RespawnController] Error in stuckStateTimer:`, err);
+      }
     }, checkIntervalMs);
   }
 

src/session.ts

@@ -27,6 +27,7 @@ import { RalphTracker } from './ralph-tracker.js';
 import { BashToolParser } from './bash-tool-parser.js';
 import { ScreenManager } from './screen-manager.js';
 import { BufferAccumulator } from './utils/buffer-accumulator.js';
+import { LRUMap } from './utils/lru-map.js';
 import {
   ANSI_ESCAPE_PATTERN_FULL,
   TOKEN_PATTERN,
@@ -299,6 +300,10 @@ export class Session extends EventEmitter {
   readonly createdAt: number;
   readonly mode: SessionMode;
 
+  /** Maximum number of task descriptions to keep (LRUMap handles size limit automatically) */
+  private static readonly MAX_TASK_DESCRIPTIONS = 100;
+  private static readonly TASK_DESCRIPTION_MAX_AGE_MS = 30000; // Keep descriptions for 30 seconds
+
   private _name: string;
   private ptyProcess: pty.IPty | null = null;
   private _pid: number | null = null;
@@ -403,8 +408,8 @@ export class Session extends EventEmitter {
 
   // Task descriptions parsed from terminal output (e.g., "Explore(Description)")
   // Used to correlate with SubagentWatcher discoveries for better window titles
-  private _recentTaskDescriptions: Map<number, string> = new Map(); // timestamp -> description
-  private static readonly TASK_DESCRIPTION_MAX_AGE_MS = 30000; // Keep descriptions for 30 seconds
+  // Uses LRUMap for automatic eviction at MAX_TASK_DESCRIPTIONS limit
+  private _recentTaskDescriptions: LRUMap<number, string> = new LRUMap({ maxSize: Session.MAX_TASK_DESCRIPTIONS });
 
   constructor(config: Partial<SessionConfig> & {
     workingDir: string;
@@ -636,11 +641,16 @@ export class Session extends EventEmitter {
    * Called when recovering sessions after server restart.
    */
   restoreTokens(inputTokens: number, outputTokens: number, totalCost: number): void {
-    // Sanity check: reject absurdly large values
+    // Sanity check: reject absurdly large individual values
     if (inputTokens > MAX_SESSION_TOKENS || outputTokens > MAX_SESSION_TOKENS) {
       console.warn(`[Session ${this.id}] Rejected absurd restored tokens: input=${inputTokens}, output=${outputTokens}`);
       return;
     }
+    // Check token sum doesn't overflow MAX_SESSION_TOKENS
+    if (inputTokens + outputTokens > MAX_SESSION_TOKENS) {
+      console.warn(`[Session ${this.id}] Rejected token sum overflow: input=${inputTokens} + output=${outputTokens} = ${inputTokens + outputTokens} > ${MAX_SESSION_TOKENS}`);
+      return;
+    }
     // Reject negative values
     if (inputTokens < 0 || outputTokens < 0 || totalCost < 0) {
       console.warn(`[Session ${this.id}] Rejected negative restored tokens: input=${inputTokens}, output=${outputTokens}, cost=${totalCost}`);
@@ -668,10 +678,25 @@ export class Session extends EventEmitter {
     this._name = value;
   }
 
+  /** Minimum valid threshold for auto-clear/compact (1000 tokens) */
+  private static readonly MIN_AUTO_THRESHOLD = 1000;
+  /** Maximum valid threshold for auto-clear/compact (500k tokens) */
+  private static readonly MAX_AUTO_THRESHOLD = 500_000;
+  /** Default auto-clear threshold when invalid value provided */
+  private static readonly DEFAULT_AUTO_CLEAR_THRESHOLD = 140_000;
+  /** Default auto-compact threshold when invalid value provided */
+  private static readonly DEFAULT_AUTO_COMPACT_THRESHOLD = 110_000;
+
   setAutoClear(enabled: boolean, threshold?: number): void {
     this._autoClearEnabled = enabled;
     if (threshold !== undefined) {
-      this._autoClearThreshold = threshold;
+      // Validate threshold bounds
+      if (threshold < Session.MIN_AUTO_THRESHOLD || threshold > Session.MAX_AUTO_THRESHOLD) {
+        console.warn(`[Session ${this.id}] Invalid autoClear threshold ${threshold}, must be between ${Session.MIN_AUTO_THRESHOLD} and ${Session.MAX_AUTO_THRESHOLD}. Using default ${Session.DEFAULT_AUTO_CLEAR_THRESHOLD}.`);
+        this._autoClearThreshold = Session.DEFAULT_AUTO_CLEAR_THRESHOLD;
+      } else {
+        this._autoClearThreshold = threshold;
+      }
     }
   }
 
@@ -690,7 +715,13 @@ export class Session extends EventEmitter {
   setAutoCompact(enabled: boolean, threshold?: number, prompt?: string): void {
     this._autoCompactEnabled = enabled;
     if (threshold !== undefined) {
-      this._autoCompactThreshold = threshold;
+      // Validate threshold bounds
+      if (threshold < Session.MIN_AUTO_THRESHOLD || threshold > Session.MAX_AUTO_THRESHOLD) {
+        console.warn(`[Session ${this.id}] Invalid autoCompact threshold ${threshold}, must be between ${Session.MIN_AUTO_THRESHOLD} and ${Session.MAX_AUTO_THRESHOLD}. Using default ${Session.DEFAULT_AUTO_COMPACT_THRESHOLD}.`);
+        this._autoCompactThreshold = Session.DEFAULT_AUTO_COMPACT_THRESHOLD;
+      } else {
+        this._autoCompactThreshold = threshold;
+      }
     }
     if (prompt !== undefined) {
       this._autoCompactPrompt = prompt;
@@ -1515,32 +1546,21 @@ export class Session extends EventEmitter {
     }
   }
 
-  /** Maximum number of task descriptions to keep */
-  private static readonly MAX_TASK_DESCRIPTIONS = 100;
-
   /**
    * Remove task descriptions older than TASK_DESCRIPTION_MAX_AGE_MS.
-   * Also enforces MAX_TASK_DESCRIPTIONS size limit.
+   * Size limit is handled automatically by LRUMap eviction on set().
    */
   private cleanupOldTaskDescriptions(): void {
     const cutoff = Date.now() - Session.TASK_DESCRIPTION_MAX_AGE_MS;
-    // Collect keys to delete first, then delete (avoids modifying Map during iteration)
-    const keysToDelete: number[] = [];
-    for (const [timestamp] of this._recentTaskDescriptions) {
+    // Keys are timestamps - iterate and delete expired entries
+    // LRUMap maintains insertion order, so we can break early once we find a non-expired entry
+    for (const timestamp of this._recentTaskDescriptions.keysInOrder()) {
       if (timestamp < cutoff) {
-        keysToDelete.push(timestamp);
-      }
-    }
-    for (const key of keysToDelete) {
-      this._recentTaskDescriptions.delete(key);
-    }
-
-    // Enforce size limit by removing oldest entries
-    if (this._recentTaskDescriptions.size > Session.MAX_TASK_DESCRIPTIONS) {
-      const sortedKeys = Array.from(this._recentTaskDescriptions.keys()).sort((a, b) => a - b);
-      const keysToRemove = sortedKeys.slice(0, this._recentTaskDescriptions.size - Session.MAX_TASK_DESCRIPTIONS);
-      for (const key of keysToRemove) {
-        this._recentTaskDescriptions.delete(key);
+        this._recentTaskDescriptions.delete(timestamp);
+      } else {
+        // Keys are ordered by insertion time (which is the timestamp)
+        // Once we find a non-expired one, all subsequent are also non-expired
+        break;
       }
     }
   }

src/subagent-watcher.ts

@@ -1327,8 +1327,14 @@ export class SubagentWatcher extends EventEmitter {
     }
 
     const timer = setTimeout(() => {
+      // Guard against race condition: agent may have been deleted before timer fires
       const info = this.agentInfo.get(agentId);
-      if (info && info.status === 'active') {
+      if (!info) {
+        // Agent was deleted - clean up timer reference
+        this.idleTimers.delete(agentId);
+        return;
+      }
+      if (info.status === 'active') {
         info.status = 'idle';
       }
     }, IDLE_TIMEOUT_MS);

src/web/server.ts

@@ -268,6 +268,35 @@ function getOrCreateSelfSignedCert(): { key: string; cert: string } {
   };
 }
 
+/** Stored listener references for session cleanup (prevents memory leaks) */
+interface SessionListenerRefs {
+  output: (data: string) => void;
+  terminal: (data: string) => void;
+  clearTerminal: () => void;
+  message: (msg: ClaudeMessage) => void;
+  error: (error: string) => void;
+  completion: (result: string, cost: number) => void;
+  exit: (code: number | null) => void;
+  working: () => void;
+  idle: () => void;
+  taskCreated: (task: BackgroundTask) => void;
+  taskUpdated: (task: BackgroundTask) => void;
+  taskCompleted: (task: BackgroundTask) => void;
+  taskFailed: (task: BackgroundTask, error: string) => void;
+  autoClear: (data: { tokens: number; threshold: number }) => void;
+  autoCompact: (data: { tokens: number; threshold: number; prompt?: string }) => void;
+  cliInfoUpdated: (data: { version?: string; model?: string; accountType?: string; latestVersion?: string }) => void;
+  ralphLoopUpdate: (state: RalphTrackerState) => void;
+  ralphTodoUpdate: (todos: RalphTodoItem[]) => void;
+  ralphCompletionDetected: (phrase: string) => void;
+  ralphStatusBlockDetected: (block: import('../types.js').RalphStatusBlock) => void;
+  ralphCircuitBreakerUpdate: (status: import('../types.js').CircuitBreakerStatus) => void;
+  ralphExitGateMet: (data: { completionIndicators: number; exitSignal: boolean }) => void;
+  bashToolStart: (tool: ActiveBashTool) => void;
+  bashToolEnd: (tool: ActiveBashTool) => void;
+  bashToolsUpdate: (tools: ActiveBashTool[]) => void;
+}
+
 export class WebServer extends EventEmitter {
   private app: FastifyInstance;
   private sessions: Map<string, Session> = new Map();
@@ -275,6 +304,8 @@ export class WebServer extends EventEmitter {
   private respawnTimers: Map<string, { timer: NodeJS.Timeout; endAt: number; startedAt: number }> = new Map();
   private runSummaryTrackers: Map<string, RunSummaryTracker> = new Map();
   private transcriptWatchers: Map<string, TranscriptWatcher> = new Map();
+  // Store session listener references for explicit cleanup (prevents memory leaks)
+  private sessionListenerRefs: Map<string, SessionListenerRefs> = new Map();
   private scheduledRuns: Map<string, ScheduledRun> = new Map();
   private sseClients: Set<FastifyReply> = new Set();
   private store = getStore();
@@ -3509,6 +3540,37 @@ NOW: Generate the implementation plan for the task above. Think step by step.`;
         console.log(`[Server] Added to global stats: ${session.inputTokens + session.outputTokens} tokens, $${session.totalCost.toFixed(4)} from session ${sessionId}`);
       }
 
+      // Explicitly remove stored listeners to break closure references (prevents memory leak)
+      const listeners = this.sessionListenerRefs.get(sessionId);
+      if (listeners) {
+        session.off('output', listeners.output);
+        session.off('terminal', listeners.terminal);
+        session.off('clearTerminal', listeners.clearTerminal);
+        session.off('message', listeners.message);
+        session.off('error', listeners.error);
+        session.off('completion', listeners.completion);
+        session.off('exit', listeners.exit);
+        session.off('working', listeners.working);
+        session.off('idle', listeners.idle);
+        session.off('taskCreated', listeners.taskCreated);
+        session.off('taskUpdated', listeners.taskUpdated);
+        session.off('taskCompleted', listeners.taskCompleted);
+        session.off('taskFailed', listeners.taskFailed);
+        session.off('autoClear', listeners.autoClear);
+        session.off('autoCompact', listeners.autoCompact);
+        session.off('cliInfoUpdated', listeners.cliInfoUpdated);
+        session.off('ralphLoopUpdate', listeners.ralphLoopUpdate);
+        session.off('ralphTodoUpdate', listeners.ralphTodoUpdate);
+        session.off('ralphCompletionDetected', listeners.ralphCompletionDetected);
+        session.off('ralphStatusBlockDetected', listeners.ralphStatusBlockDetected);
+        session.off('ralphCircuitBreakerUpdate', listeners.ralphCircuitBreakerUpdate);
+        session.off('ralphExitGateMet', listeners.ralphExitGateMet);
+        session.off('bashToolStart', listeners.bashToolStart);
+        session.off('bashToolEnd', listeners.bashToolEnd);
+        session.off('bashToolsUpdate', listeners.bashToolsUpdate);
+        this.sessionListenerRefs.delete(sessionId);
+      }
+
       session.removeAllListeners();
       // Close any active file streams for this session
       fileStreamManager.closeSessionStreams(sessionId);
@@ -3540,211 +3602,244 @@ NOW: Generate the implementation plan for the task above. Think step by step.`;
       imageWatcher.watchSession(session.id, session.workingDir);
     }
 
-    session.on('output', (data) => {
-      // Use batching for better performance at high throughput
-      this.batchOutputData(session.id, data);
-    });
+    // Store all listener references for explicit cleanup on session delete
+    // This prevents memory leaks from closure references keeping objects alive
+    const listeners: SessionListenerRefs = {
+      output: (data) => {
+        // Use batching for better performance at high throughput
+        this.batchOutputData(session.id, data);
+      },
 
-    session.on('terminal', (data) => {
-      // Use batching for better performance at high throughput
-      this.batchTerminalData(session.id, data);
-    });
+      terminal: (data) => {
+        // Use batching for better performance at high throughput
+        this.batchTerminalData(session.id, data);
+      },
 
-    session.on('clearTerminal', () => {
-      // Tell clients to clear their terminal (after screen attach)
-      this.broadcast('session:clearTerminal', { id: session.id });
-    });
+      clearTerminal: () => {
+        // Tell clients to clear their terminal (after screen attach)
+        this.broadcast('session:clearTerminal', { id: session.id });
+      },
 
-    session.on('message', (msg: ClaudeMessage) => {
-      this.broadcast('session:message', { id: session.id, message: msg });
-    });
+      message: (msg: ClaudeMessage) => {
+        this.broadcast('session:message', { id: session.id, message: msg });
+      },
 
-    session.on('error', (error) => {
-      this.broadcast('session:error', { id: session.id, error });
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) tracker.recordError('Session error', String(error));
-    });
+      error: (error) => {
+        this.broadcast('session:error', { id: session.id, error });
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) tracker.recordError('Session error', String(error));
+      },
 
-    session.on('completion', (result, cost) => {
-      this.broadcast('session:completion', { id: session.id, result, cost });
-      this.broadcast('session:updated', this.getSessionStateWithRespawn(session));
-      this.persistSessionState(session);
-      // Track tokens in run summary (completion event has updated token values)
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) tracker.recordTokens(session.inputTokens, session.outputTokens);
-    });
-
-    session.on('exit', (code) => {
-      // Wrap in try/catch to ensure cleanup always happens
-      try {
-        this.broadcast('session:exit', { id: session.id, code });
+      completion: (result, cost) => {
+        this.broadcast('session:completion', { id: session.id, result, cost });
         this.broadcast('session:updated', this.getSessionStateWithRespawn(session));
         this.persistSessionState(session);
-      } catch (err) {
-        console.error(`[Server] Error broadcasting session exit for ${session.id}:`, err);
-      }
+        // Track tokens in run summary (completion event has updated token values)
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) tracker.recordTokens(session.inputTokens, session.outputTokens);
+      },
 
-      // Always clean up respawn controller, even if broadcast failed
-      try {
-        const controller = this.respawnControllers.get(session.id);
-        if (controller) {
-          controller.stop();
-          controller.removeAllListeners();
-          this.respawnControllers.delete(session.id);
+      exit: (code) => {
+        // Wrap in try/catch to ensure cleanup always happens
+        try {
+          this.broadcast('session:exit', { id: session.id, code });
+          this.broadcast('session:updated', this.getSessionStateWithRespawn(session));
+          this.persistSessionState(session);
+        } catch (err) {
+          console.error(`[Server] Error broadcasting session exit for ${session.id}:`, err);
         }
-        // Also clean up the respawn timer to prevent orphaned timers
-        const timerInfo = this.respawnTimers.get(session.id);
-        if (timerInfo) {
-          clearTimeout(timerInfo.timer);
-          this.respawnTimers.delete(session.id);
+
+        // Always clean up respawn controller, even if broadcast failed
+        try {
+          const controller = this.respawnControllers.get(session.id);
+          if (controller) {
+            controller.stop();
+            controller.removeAllListeners();
+            this.respawnControllers.delete(session.id);
+          }
+          // Also clean up the respawn timer to prevent orphaned timers
+          const timerInfo = this.respawnTimers.get(session.id);
+          if (timerInfo) {
+            clearTimeout(timerInfo.timer);
+            this.respawnTimers.delete(session.id);
+          }
+        } catch (err) {
+          console.error(`[Server] Error cleaning up respawn controller for ${session.id}:`, err);
         }
-      } catch (err) {
-        console.error(`[Server] Error cleaning up respawn controller for ${session.id}:`, err);
-      }
-    });
+      },
 
-    session.on('working', () => {
-      this.broadcast('session:working', { id: session.id });
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) {
-        tracker.recordWorking();
-        tracker.recordTokens(session.inputTokens, session.outputTokens);
-      }
-    });
+      working: () => {
+        this.broadcast('session:working', { id: session.id });
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) {
+          tracker.recordWorking();
+          tracker.recordTokens(session.inputTokens, session.outputTokens);
+        }
+      },
 
-    session.on('idle', () => {
-      this.broadcast('session:idle', { id: session.id });
-      // Use debounced state update (idle can fire frequently)
-      this.broadcastSessionStateDebounced(session.id);
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) {
-        tracker.recordIdle();
-        tracker.recordTokens(session.inputTokens, session.outputTokens);
-      }
-    });
+      idle: () => {
+        this.broadcast('session:idle', { id: session.id });
+        // Use debounced state update (idle can fire frequently)
+        this.broadcastSessionStateDebounced(session.id);
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) {
+          tracker.recordIdle();
+          tracker.recordTokens(session.inputTokens, session.outputTokens);
+        }
+      },
 
-    // Background task events - use debounced state updates to reduce serialization overhead
-    session.on('taskCreated', (task: BackgroundTask) => {
-      this.broadcast('task:created', { sessionId: session.id, task });
-      this.broadcastSessionStateDebounced(session.id);
-    });
+      // Background task events - use debounced state updates to reduce serialization overhead
+      taskCreated: (task: BackgroundTask) => {
+        this.broadcast('task:created', { sessionId: session.id, task });
+        this.broadcastSessionStateDebounced(session.id);
+      },
 
-    session.on('taskUpdated', (task: BackgroundTask) => {
-      // Use batching for better performance at high update rates
-      this.batchTaskUpdate(session.id, task);
-    });
+      taskUpdated: (task: BackgroundTask) => {
+        // Use batching for better performance at high update rates
+        this.batchTaskUpdate(session.id, task);
+      },
 
-    session.on('taskCompleted', (task: BackgroundTask) => {
-      this.broadcast('task:completed', { sessionId: session.id, task });
-      this.broadcastSessionStateDebounced(session.id);
-    });
+      taskCompleted: (task: BackgroundTask) => {
+        this.broadcast('task:completed', { sessionId: session.id, task });
+        this.broadcastSessionStateDebounced(session.id);
+      },
 
-    session.on('taskFailed', (task: BackgroundTask, error: string) => {
-      this.broadcast('task:failed', { sessionId: session.id, task, error });
-      this.broadcastSessionStateDebounced(session.id);
-    });
+      taskFailed: (task: BackgroundTask, error: string) => {
+        this.broadcast('task:failed', { sessionId: session.id, task, error });
+        this.broadcastSessionStateDebounced(session.id);
+      },
 
-    session.on('autoClear', (data: { tokens: number; threshold: number }) => {
-      this.broadcast('session:autoClear', { sessionId: session.id, ...data });
-      this.broadcastSessionStateDebounced(session.id);
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) tracker.recordAutoClear(data.tokens, data.threshold);
-    });
+      autoClear: (data: { tokens: number; threshold: number }) => {
+        this.broadcast('session:autoClear', { sessionId: session.id, ...data });
+        this.broadcastSessionStateDebounced(session.id);
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) tracker.recordAutoClear(data.tokens, data.threshold);
+      },
 
-    session.on('autoCompact', (data: { tokens: number; threshold: number; prompt?: string }) => {
-      this.broadcast('session:autoCompact', { sessionId: session.id, ...data });
-      this.broadcastSessionStateDebounced(session.id);
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) tracker.recordAutoCompact(data.tokens, data.threshold);
-    });
+      autoCompact: (data: { tokens: number; threshold: number; prompt?: string }) => {
+        this.broadcast('session:autoCompact', { sessionId: session.id, ...data });
+        this.broadcastSessionStateDebounced(session.id);
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) tracker.recordAutoCompact(data.tokens, data.threshold);
+      },
 
-    // Claude Code CLI info parsed from terminal (version, model, account)
-    session.on('cliInfoUpdated', (data: { version?: string; model?: string; accountType?: string; latestVersion?: string }) => {
-      this.broadcast('session:cliInfo', { sessionId: session.id, ...data });
-      this.broadcastSessionStateDebounced(session.id);
-    });
+      // Claude Code CLI info parsed from terminal (version, model, account)
+      cliInfoUpdated: (data: { version?: string; model?: string; accountType?: string; latestVersion?: string }) => {
+        this.broadcast('session:cliInfo', { sessionId: session.id, ...data });
+        this.broadcastSessionStateDebounced(session.id);
+      },
 
-    // Ralph tracking events
-    session.on('ralphLoopUpdate', (state: RalphTrackerState) => {
-      this.broadcast('session:ralphLoopUpdate', { sessionId: session.id, state });
-      // Persist Ralph state
-      this.store.updateRalphState(session.id, { loop: state });
-    });
+      // Ralph tracking events
+      ralphLoopUpdate: (state: RalphTrackerState) => {
+        this.broadcast('session:ralphLoopUpdate', { sessionId: session.id, state });
+        // Persist Ralph state
+        this.store.updateRalphState(session.id, { loop: state });
+      },
 
-    session.on('ralphTodoUpdate', (todos: RalphTodoItem[]) => {
-      this.broadcast('session:ralphTodoUpdate', { sessionId: session.id, todos });
-      // Persist Ralph state
-      this.store.updateRalphState(session.id, { todos });
-    });
+      ralphTodoUpdate: (todos: RalphTodoItem[]) => {
+        this.broadcast('session:ralphTodoUpdate', { sessionId: session.id, todos });
+        // Persist Ralph state
+        this.store.updateRalphState(session.id, { todos });
+      },
 
-    session.on('ralphCompletionDetected', (phrase: string) => {
-      this.broadcast('session:ralphCompletionDetected', { sessionId: session.id, phrase });
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) tracker.recordRalphCompletion(phrase);
-    });
+      ralphCompletionDetected: (phrase: string) => {
+        this.broadcast('session:ralphCompletionDetected', { sessionId: session.id, phrase });
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) tracker.recordRalphCompletion(phrase);
+      },
 
-    // RALPH_STATUS block events
-    session.on('ralphStatusBlockDetected', (block: import('../types.js').RalphStatusBlock) => {
-      this.broadcast('session:ralphStatusUpdate', { sessionId: session.id, block });
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) {
-        tracker.addEvent(
-          block.status === 'BLOCKED' ? 'warning' : 'idle_detected',
-          block.status === 'BLOCKED' ? 'warning' : 'info',
-          `Ralph Status: ${block.status}`,
-          `Tasks: ${block.tasksCompletedThisLoop}, Files: ${block.filesModified}, Tests: ${block.testsStatus}`
-        );
-      }
-    });
+      // RALPH_STATUS block events
+      ralphStatusBlockDetected: (block: import('../types.js').RalphStatusBlock) => {
+        this.broadcast('session:ralphStatusUpdate', { sessionId: session.id, block });
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) {
+          tracker.addEvent(
+            block.status === 'BLOCKED' ? 'warning' : 'idle_detected',
+            block.status === 'BLOCKED' ? 'warning' : 'info',
+            `Ralph Status: ${block.status}`,
+            `Tasks: ${block.tasksCompletedThisLoop}, Files: ${block.filesModified}, Tests: ${block.testsStatus}`
+          );
+        }
+      },
 
-    session.on('ralphCircuitBreakerUpdate', (status: import('../types.js').CircuitBreakerStatus) => {
-      this.broadcast('session:circuitBreakerUpdate', { sessionId: session.id, status });
-      // Track state changes in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker && status.state === 'OPEN') {
-        tracker.addEvent(
-          'warning',
-          'warning',
-          'Circuit Breaker Opened',
-          status.reason
-        );
-      }
-    });
+      ralphCircuitBreakerUpdate: (status: import('../types.js').CircuitBreakerStatus) => {
+        this.broadcast('session:circuitBreakerUpdate', { sessionId: session.id, status });
+        // Track state changes in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker && status.state === 'OPEN') {
+          tracker.addEvent(
+            'warning',
+            'warning',
+            'Circuit Breaker Opened',
+            status.reason
+          );
+        }
+      },
 
-    session.on('ralphExitGateMet', (data: { completionIndicators: number; exitSignal: boolean }) => {
-      this.broadcast('session:exitGateMet', { sessionId: session.id, ...data });
-      // Track in run summary
-      const tracker = this.runSummaryTrackers.get(session.id);
-      if (tracker) {
-        tracker.addEvent(
-          'ralph_completion',
-          'success',
-          'Exit Gate Met',
-          `Indicators: ${data.completionIndicators}, EXIT_SIGNAL: ${data.exitSignal}`
-        );
-      }
-    });
+      ralphExitGateMet: (data: { completionIndicators: number; exitSignal: boolean }) => {
+        this.broadcast('session:exitGateMet', { sessionId: session.id, ...data });
+        // Track in run summary
+        const tracker = this.runSummaryTrackers.get(session.id);
+        if (tracker) {
+          tracker.addEvent(
+            'ralph_completion',
+            'success',
+            'Exit Gate Met',
+            `Indicators: ${data.completionIndicators}, EXIT_SIGNAL: ${data.exitSignal}`
+          );
+        }
+      },
 
-    // Bash tool tracking events (for clickable file paths)
-    session.on('bashToolStart', (tool: ActiveBashTool) => {
-      this.broadcast('session:bashToolStart', { sessionId: session.id, tool });
-    });
+      // Bash tool tracking events (for clickable file paths)
+      bashToolStart: (tool: ActiveBashTool) => {
+        this.broadcast('session:bashToolStart', { sessionId: session.id, tool });
+      },
 
-    session.on('bashToolEnd', (tool: ActiveBashTool) => {
-      this.broadcast('session:bashToolEnd', { sessionId: session.id, tool });
-    });
+      bashToolEnd: (tool: ActiveBashTool) => {
+        this.broadcast('session:bashToolEnd', { sessionId: session.id, tool });
+      },
 
-    session.on('bashToolsUpdate', (tools: ActiveBashTool[]) => {
-      this.broadcast('session:bashToolsUpdate', { sessionId: session.id, tools });
-    });
+      bashToolsUpdate: (tools: ActiveBashTool[]) => {
+        this.broadcast('session:bashToolsUpdate', { sessionId: session.id, tools });
+      },
+    };
 
+    // Store listener refs for cleanup
+    this.sessionListenerRefs.set(session.id, listeners);
+
+    // Attach all listeners to the session
+    session.on('output', listeners.output);
+    session.on('terminal', listeners.terminal);
+    session.on('clearTerminal', listeners.clearTerminal);
+    session.on('message', listeners.message);
+    session.on('error', listeners.error);
+    session.on('completion', listeners.completion);
+    session.on('exit', listeners.exit);
+    session.on('working', listeners.working);
+    session.on('idle', listeners.idle);
+    session.on('taskCreated', listeners.taskCreated);
+    session.on('taskUpdated', listeners.taskUpdated);
+    session.on('taskCompleted', listeners.taskCompleted);
+    session.on('taskFailed', listeners.taskFailed);
+    session.on('autoClear', listeners.autoClear);
+    session.on('autoCompact', listeners.autoCompact);
+    session.on('cliInfoUpdated', listeners.cliInfoUpdated);
+    session.on('ralphLoopUpdate', listeners.ralphLoopUpdate);
+    session.on('ralphTodoUpdate', listeners.ralphTodoUpdate);
+    session.on('ralphCompletionDetected', listeners.ralphCompletionDetected);
+    session.on('ralphStatusBlockDetected', listeners.ralphStatusBlockDetected);
+    session.on('ralphCircuitBreakerUpdate', listeners.ralphCircuitBreakerUpdate);
+    session.on('ralphExitGateMet', listeners.ralphExitGateMet);
+    session.on('bashToolStart', listeners.bashToolStart);
+    session.on('bashToolEnd', listeners.bashToolEnd);
+    session.on('bashToolsUpdate', listeners.bashToolsUpdate);
   }
 
   private setupRespawnListeners(sessionId: string, controller: RespawnController): void {