diff --git a/apps/frontend/src/main/ipc-handlers/github/investigation-handlers.ts b/apps/frontend/src/main/ipc-handlers/github/investigation-handlers.ts
index a8f1ca12..2b5871b2 100644
--- a/apps/frontend/src/main/ipc-handlers/github/investigation-handlers.ts
+++ b/apps/frontend/src/main/ipc-handlers/github/investigation-handlers.ts
@@ -36,7 +36,7 @@ import { readSettingsFile } from '../../settings-utils';
 import { AgentManager } from '../../agent';
 import { getGitHubConfig, githubFetch } from './utils';
 import type { GitHubAPIComment } from './types';
-import { createSpecForIssue, buildIssueContext, buildInvestigationTask } from './spec-utils';
+import { createSpecForIssue, buildIssueContext, buildInvestigationTask, updateImplementationPlanStatus } from './spec-utils';
 import { createContextLogger } from './utils/logger';
 import { withProjectOrNull } from './utils/project-middleware';
 import { createIPCCommunicators } from './utils/ipc-communicator';
diff --git a/apps/frontend/src/preload/api/modules/github-api.ts b/apps/frontend/src/preload/api/modules/github-api.ts
index d8304fd0..36f55841 100644
--- a/apps/frontend/src/preload/api/modules/github-api.ts
+++ b/apps/frontend/src/preload/api/modules/github-api.ts
@@ -233,6 +233,7 @@ export interface GitHubAPI {
   // Investigation operations (new system)
   startInvestigation: (projectId: string, issueNumber: number) => void;
   cancelInvestigation: (projectId: string, issueNumber: number) => void;
+  cancelAllInvestigations: (projectId: string) => void;
   createTaskFromInvestigation: (projectId: string, issueNumber: number) => Promise<IPCResult<{ specId: string }>>;
   dismissIssue: (projectId: string, issueNumber: number, reason: InvestigationDismissReason) => Promise<IPCResult>;
   postInvestigationToGitHub: (projectId: string, issueNumber: number) => Promise<IPCResult<{ commentId: number }>>;
@@ -715,6 +716,9 @@ export const createGitHubAPI = (): GitHubAPI => ({
   cancelInvestigation: (projectId: string, issueNumber: number): void =>
     sendIpc(IPC_CHANNELS.GITHUB_INVESTIGATION_CANCEL, projectId, issueNumber),
 
+  cancelAllInvestigations: (projectId: string): void =>
+    sendIpc(IPC_CHANNELS.GITHUB_INVESTIGATION_CANCEL_ALL, projectId),
+
   createTaskFromInvestigation: (projectId: string, issueNumber: number): Promise<IPCResult<{ specId: string }>> =>
     invokeIpc(IPC_CHANNELS.GITHUB_INVESTIGATION_CREATE_TASK, projectId, issueNumber),
 
diff --git a/apps/frontend/src/renderer/components/github-issues/components/IssueListHeader.tsx b/apps/frontend/src/renderer/components/github-issues/components/IssueListHeader.tsx
index c6245716..6558250c 100644
--- a/apps/frontend/src/renderer/components/github-issues/components/IssueListHeader.tsx
+++ b/apps/frontend/src/renderer/components/github-issues/components/IssueListHeader.tsx
@@ -1,5 +1,5 @@
 import { useTranslation } from 'react-i18next';
-import { Github, RefreshCw, Search, Filter, Wand2, Loader2, Layers, EyeOff, Eye } from 'lucide-react';
+import { Github, RefreshCw, Search, Filter, Wand2, Loader2, Layers, EyeOff, Eye, XCircle } from 'lucide-react';
 import { Badge } from '../../ui/badge';
 import { Button } from '../../ui/button';
 import { Input } from '../../ui/input';
@@ -85,6 +85,7 @@ export function IssueListHeader({
   showDismissed,
   onToggleShowDismissed,
   activeInvestigationCount,
+  onCancelAllInvestigations,
 }: IssueListHeaderProps) {
   const { t } = useTranslation('common');
 
@@ -119,10 +120,23 @@ export function IssueListHeader({
             {t('issues.openCount', { count: openIssuesCount })}
           </Badge>
           {activeInvestigationCount != null && activeInvestigationCount > 0 && (
-            <Badge variant="secondary" className="text-xs bg-blue-100 text-blue-800 dark:bg-blue-900/30 dark:text-blue-300">
-              <Loader2 className="h-3 w-3 mr-1 animate-spin" />
-              {t('investigation.stateFilters.activeCount', { count: activeInvestigationCount, defaultValue: '{{count}} investigating' })}
-            </Badge>
+            <>
+              <Badge variant="secondary" className="text-xs bg-blue-100 text-blue-800 dark:bg-blue-900/30 dark:text-blue-300">
+                <Loader2 className="h-3 w-3 mr-1 animate-spin" />
+                {t('investigation.stateFilters.activeCount', { count: activeInvestigationCount, defaultValue: '{{count}} investigating' })}
+              </Badge>
+              {onCancelAllInvestigations && (
+                <Button
+                  variant="ghost"
+                  size="sm"
+                  onClick={onCancelAllInvestigations}
+                  className="h-6 px-2 text-xs text-destructive hover:text-destructive"
+                >
+                  <XCircle className="h-3 w-3 mr-1" />
+                  {t('investigation.button.cancelAll', 'Cancel All')}
+                </Button>
+              )}
+            </>
           )}
           {/* Legacy triage mode toggle — kept for backwards compat */}
           {onToggleTriageMode && (
diff --git a/apps/frontend/src/renderer/stores/github/index.ts b/apps/frontend/src/renderer/stores/github/index.ts
index 93590626..c065c7d9 100644
--- a/apps/frontend/src/renderer/stores/github/index.ts
+++ b/apps/frontend/src/renderer/stores/github/index.ts
@@ -37,6 +37,7 @@ export {
   cleanupInvestigationListeners,
   startIssueInvestigation,
   cancelIssueInvestigation,
+  cancelAllIssueInvestigations,
   investigateGitHubIssue,
   loadPersistedInvestigations,
   type IssueInvestigationState
diff --git a/apps/frontend/src/shared/constants/ipc.ts b/apps/frontend/src/shared/constants/ipc.ts
index 829750dc..51ef3711 100644
--- a/apps/frontend/src/shared/constants/ipc.ts
+++ b/apps/frontend/src/shared/constants/ipc.ts
@@ -269,6 +269,7 @@ export const IPC_CHANNELS = {
   // GitHub Investigation operations (renderer -> main)
   GITHUB_INVESTIGATION_START: 'github:investigation:start',
   GITHUB_INVESTIGATION_CANCEL: 'github:investigation:cancel',
+  GITHUB_INVESTIGATION_CANCEL_ALL: 'github:investigation:cancelAll',
   GITHUB_INVESTIGATION_CREATE_TASK: 'github:investigation:createTask',
   GITHUB_INVESTIGATION_DISMISS: 'github:investigation:dismiss',
   GITHUB_INVESTIGATION_POST_GITHUB: 'github:investigation:postGitHub',
diff --git a/apps/frontend/src/shared/types/ipc.ts b/apps/frontend/src/shared/types/ipc.ts
index 358cbf3d..e533e6b3 100644
--- a/apps/frontend/src/shared/types/ipc.ts
+++ b/apps/frontend/src/shared/types/ipc.ts
@@ -542,6 +542,7 @@ export interface ElectronAPI {
   // GitHub Investigation operations (new system)
   startInvestigation: (projectId: string, issueNumber: number) => void;
   cancelInvestigation: (projectId: string, issueNumber: number) => void;
+  cancelAllInvestigations: (projectId: string) => void;
   createTaskFromInvestigation: (projectId: string, issueNumber: number) => Promise<IPCResult<{ specId: string }>>;
   dismissIssue: (projectId: string, issueNumber: number, reason: InvestigationDismissReason) => Promise<IPCResult>;
   postInvestigationToGitHub: (projectId: string, issueNumber: number) => Promise<IPCResult<{ commentId: number }>>;