feat(action-items): Deep-link to Linear create-sub-issue form for action items

frontend/src/routes/$incidentId/components/ActionItemsList.test.tsx

@@ -1,5 +1,6 @@
 import {QueryClient, QueryClientProvider} from '@tanstack/react-query';
 import {render, screen, waitFor} from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
 import {TooltipProvider} from 'components/Tooltip';
 import {afterEach, beforeEach, describe, expect, it, vi} from 'vitest';
 
@@ -151,4 +152,49 @@ describe('ActionItemsList', () => {
     expect(screen.getByRole('button', {name: 'Sync action items'})).toBeInTheDocument();
     expect(screen.getByRole('button', {name: 'Create action item'})).toBeInTheDocument();
   });
+
+  it('opens Linear create-sub-issue URL when parent issue ID is available', async () => {
+    mockApiGet.mockResolvedValue([]);
+    const windowOpenSpy = vi.spyOn(window, 'open').mockImplementation(() => null);
+
+    renderWithProviders(
+      <ActionItemsList
+        incidentId="INC-1"
+        linearUrl="https://linear.app/myworkspace/issue/INC-1"
+        linearParentIssueId="abc-123-def"
+      />
+    );
+
+    await userEvent.click(screen.getByRole('button', {name: 'Create action item'}));
+    await userEvent.click(screen.getByRole('button', {name: 'Create in Linear'}));
+
+    expect(windowOpenSpy).toHaveBeenCalledWith(
+      'https://linear.app/myworkspace/new?parentId=abc-123-def',
+      '_blank',
+      'noopener,noreferrer'
+    );
+    windowOpenSpy.mockRestore();
+  });
+
+  it('falls back to parent issue URL when parent issue ID is not available', async () => {
+    mockApiGet.mockResolvedValue([]);
+    const windowOpenSpy = vi.spyOn(window, 'open').mockImplementation(() => null);
+
+    renderWithProviders(
+      <ActionItemsList
+        incidentId="INC-1"
+        linearUrl="https://linear.app/myworkspace/issue/INC-1"
+      />
+    );
+
+    await userEvent.click(screen.getByRole('button', {name: 'Create action item'}));
+    await userEvent.click(screen.getByRole('button', {name: 'Create in Linear'}));
+
+    expect(windowOpenSpy).toHaveBeenCalledWith(
+      'https://linear.app/myworkspace/issue/INC-1',
+      '_blank',
+      'noopener,noreferrer'
+    );
+    windowOpenSpy.mockRestore();
+  });
 });

frontend/src/routes/$incidentId/components/ActionItemsList.tsx

@@ -62,12 +62,28 @@ function ActionItemCard({item}: {item: ActionItem}) {
   );
 }
 
+function buildLinearCreateUrl(linearUrl: string, parentIssueId: string): string | null {
+  try {
+    const url = new URL(linearUrl);
+    const workspace = url.pathname.split('/')[1];
+    if (!workspace) return null;
+    return `https://linear.app/${workspace}/new?parentId=${parentIssueId}`;
+  } catch {
+    return null;
+  }
+}
+
 interface ActionItemsListProps {
   incidentId: string;
   linearUrl?: string;
+  linearParentIssueId?: string | null;
 }
 
-export function ActionItemsList({incidentId, linearUrl}: ActionItemsListProps) {
+export function ActionItemsList({
+  incidentId,
+  linearUrl,
+  linearParentIssueId,
+}: ActionItemsListProps) {
   const queryClient = useQueryClient();
   const syncMutation = useMutation(
     syncActionItemsMutationOptions(queryClient, incidentId)
@@ -127,8 +143,8 @@ export function ActionItemsList({incidentId, linearUrl}: ActionItemsListProps) {
           title="Create Action Item"
           message={
             <>
-              You'll be taken to the parent Linear issue for the incident. Create your
-              action item as a sub-issue or related issue there.
+              You'll be taken to Linear to create a sub-issue under the parent incident
+              issue.
               <br />
               <br />
               Make sure to assign the issue to the appropriate team as issues in the
@@ -154,9 +170,11 @@ export function ActionItemsList({incidentId, linearUrl}: ActionItemsListProps) {
               </ul>
             </>
           }
-          confirmLabel="Open Linear"
+          confirmLabel="Create in Linear"
           onConfirm={() => {
-            window.open(linearUrl, '_blank', 'noopener,noreferrer');
+            const createUrl =
+              linearParentIssueId && buildLinearCreateUrl(linearUrl, linearParentIssueId);
+            window.open(createUrl || linearUrl, '_blank', 'noopener,noreferrer');
             setShowCreateDialog(false);
           }}
           onCancel={() => setShowCreateDialog(false)}

frontend/src/routes/$incidentId/index.tsx

@@ -66,6 +66,7 @@ function Incident() {
           <ActionItemsList
             incidentId={params.incidentId}
             linearUrl={incident.external_links.linear}
+            linearParentIssueId={incident.linear_parent_issue_id}
           />
         </section>
 

frontend/src/routes/$incidentId/queries/incidentDetailQueryOptions.ts

@@ -39,6 +39,7 @@ const IncidentDetailSchema = z.object({
   impact_type_tags: z.array(z.string()),
   participants: z.array(ParticipantSchema),
   external_links: ExternalLinksSchema,
+  linear_parent_issue_id: z.string().nullable(),
   time_started: z.string().nullable(),
   time_detected: z.string().nullable(),
   time_analyzed: z.string().nullable(),

src/firetower/incidents/serializers.py

@@ -157,6 +157,7 @@ class Meta:
             "root_cause_tags",
             "impact_type_tags",
             "external_links",
+            "linear_parent_issue_id",
             "created_at",
             "updated_at",
             "time_started",
@@ -168,6 +169,7 @@ class Meta:
         ]
         read_only_fields = [
             "id",
+            "linear_parent_issue_id",
             "created_at",
             "updated_at",
             "time_started",

src/firetower/incidents/tests/test_serializers.py

@@ -148,6 +148,9 @@ def test_incident_detail_serialization(self):
         assert "linear" not in data["external_links"]  # Not set, so not included
         assert len(data["external_links"]) == 1
 
+        # Check linear_parent_issue_id is exposed (null when not set)
+        assert data["linear_parent_issue_id"] is None
+
 
 @pytest.mark.django_db
 class TestIncidentWriteSerializerHooks: