diff --git a/apps/ui/src/hooks/use-query-invalidation.ts b/apps/ui/src/hooks/use-query-invalidation.ts
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+++ b/apps/ui/src/hooks/use-query-invalidation.ts
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+/**
+ * Query Invalidation Hooks
+ *
+ * These hooks connect WebSocket events to React Query cache invalidation,
+ * ensuring the UI stays in sync with server-side changes without manual refetching.
+ */
+
+import { useEffect } from 'react';
+import { useQueryClient } from '@tanstack/react-query';
+import { getElectronAPI } from '@/lib/electron';
+import { queryKeys } from '@/lib/query-keys';
+import type { AutoModeEvent, SpecRegenerationEvent } from '@/types/electron';
+import type { IssueValidationEvent } from '@automaker/types';
+
+/**
+ * Invalidate queries based on auto mode events
+ *
+ * This hook subscribes to auto mode events (feature start, complete, error, etc.)
+ * and invalidates relevant queries to keep the UI in sync.
+ *
+ * @param projectPath - Current project path
+ *
+ * @example
+ * ```tsx
+ * function BoardView() {
+ *   const projectPath = useAppStore(s => s.currentProject?.path);
+ *   useAutoModeQueryInvalidation(projectPath);
+ *   // ...
+ * }
+ * ```
+ */
+export function useAutoModeQueryInvalidation(projectPath: string | undefined) {
+  const queryClient = useQueryClient();
+
+  useEffect(() => {
+    if (!projectPath) return;
+
+    const api = getElectronAPI();
+    const unsubscribe = api.autoMode.onEvent((event: AutoModeEvent) => {
+      // Invalidate features when agent completes, errors, or receives plan approval
+      if (
+        event.type === 'auto_mode_feature_complete' ||
+        event.type === 'auto_mode_error' ||
+        event.type === 'plan_approval_required' ||
+        event.type === 'plan_approved' ||
+        event.type === 'plan_rejected' ||
+        event.type === 'pipeline_step_complete'
+      ) {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.features.all(projectPath),
+        });
+      }
+
+      // Invalidate running agents on any status change
+      if (
+        event.type === 'auto_mode_feature_start' ||
+        event.type === 'auto_mode_feature_complete' ||
+        event.type === 'auto_mode_error' ||
+        event.type === 'auto_mode_resuming_features'
+      ) {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.runningAgents.all(),
+        });
+      }
+
+      // Invalidate specific feature when it starts or has phase changes
+      if (
+        (event.type === 'auto_mode_feature_start' ||
+          event.type === 'auto_mode_phase' ||
+          event.type === 'auto_mode_phase_complete' ||
+          event.type === 'pipeline_step_started') &&
+        'featureId' in event
+      ) {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.features.single(projectPath, event.featureId),
+        });
+      }
+
+      // Invalidate agent output during progress updates
+      if (event.type === 'auto_mode_progress' && 'featureId' in event) {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.features.agentOutput(projectPath, event.featureId),
+        });
+      }
+
+      // Invalidate worktree queries when feature completes (may have created worktree)
+      if (event.type === 'auto_mode_feature_complete' && 'featureId' in event) {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.worktrees.all(projectPath),
+        });
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.worktrees.single(projectPath, event.featureId),
+        });
+      }
+    });
+
+    return unsubscribe;
+  }, [projectPath, queryClient]);
+}
+
+/**
+ * Invalidate queries based on spec regeneration events
+ *
+ * @param projectPath - Current project path
+ */
+export function useSpecRegenerationQueryInvalidation(projectPath: string | undefined) {
+  const queryClient = useQueryClient();
+
+  useEffect(() => {
+    if (!projectPath) return;
+
+    const api = getElectronAPI();
+    const unsubscribe = api.specRegeneration.onEvent((event: SpecRegenerationEvent) => {
+      // Only handle events for the current project
+      if (event.projectPath !== projectPath) return;
+
+      if (event.type === 'spec_regeneration_complete') {
+        // Invalidate features as new ones may have been generated
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.features.all(projectPath),
+        });
+
+        // Invalidate spec regeneration status
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.specRegeneration.status(projectPath),
+        });
+      }
+    });
+
+    return unsubscribe;
+  }, [projectPath, queryClient]);
+}
+
+/**
+ * Invalidate queries based on GitHub validation events
+ *
+ * @param projectPath - Current project path
+ */
+export function useGitHubValidationQueryInvalidation(projectPath: string | undefined) {
+  const queryClient = useQueryClient();
+
+  useEffect(() => {
+    if (!projectPath) return;
+
+    const api = getElectronAPI();
+    const unsubscribe = api.github?.onValidationEvent((event: IssueValidationEvent) => {
+      if (event.type === 'validation_complete' || event.type === 'validation_error') {
+        // Invalidate all validations for this project
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.github.validations(projectPath),
+        });
+
+        // Also invalidate specific issue validation if we have the issue number
+        if ('issueNumber' in event && event.issueNumber) {
+          queryClient.invalidateQueries({
+            queryKey: queryKeys.github.validation(projectPath, event.issueNumber),
+          });
+        }
+      }
+    });
+
+    return unsubscribe;
+  }, [projectPath, queryClient]);
+}
+
+/**
+ * Invalidate session queries based on agent stream events
+ *
+ * @param sessionId - Current session ID
+ */
+export function useSessionQueryInvalidation(sessionId: string | undefined) {
+  const queryClient = useQueryClient();
+
+  useEffect(() => {
+    if (!sessionId) return;
+
+    const api = getElectronAPI();
+    const unsubscribe = api.agent.onStream((event) => {
+      // Only handle events for the current session
+      if ('sessionId' in event && event.sessionId !== sessionId) return;
+
+      // Invalidate session history when a message is complete
+      if (event.type === 'complete' || event.type === 'message') {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.sessions.history(sessionId),
+        });
+      }
+
+      // Invalidate sessions list when any session changes
+      if (event.type === 'complete') {
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.sessions.all(),
+        });
+      }
+    });
+
+    return unsubscribe;
+  }, [sessionId, queryClient]);
+}
+
+/**
+ * Combined hook that sets up all query invalidation subscriptions
+ *
+ * Use this hook at the app root or in a layout component to ensure
+ * all WebSocket events properly invalidate React Query caches.
+ *
+ * @param projectPath - Current project path
+ * @param sessionId - Current session ID (optional)
+ *
+ * @example
+ * ```tsx
+ * function AppLayout() {
+ *   const projectPath = useAppStore(s => s.currentProject?.path);
+ *   const sessionId = useAppStore(s => s.currentSessionId);
+ *   useQueryInvalidation(projectPath, sessionId);
+ *   // ...
+ * }
+ * ```
+ */
+export function useQueryInvalidation(
+  projectPath: string | undefined,
+  sessionId?: string | undefined
+) {
+  useAutoModeQueryInvalidation(projectPath);
+  useSpecRegenerationQueryInvalidation(projectPath);
+  useGitHubValidationQueryInvalidation(projectPath);
+  useSessionQueryInvalidation(sessionId);
+}