feat(projects): Filter by award category

src/app/queries/projects.ts

@@ -38,6 +38,7 @@ export function useProjects(
   yearId: string,
   kind?: 'project' | 'idea',
   group?: string,
+  category?: string,
   search?: string,
   hasVideo?: boolean,
   cursor?: string,
@@ -48,11 +49,21 @@ export function useProjects(
   });
   if (kind) query.set('kind', kind);
   if (group) query.set('group', group);
+  if (category) query.set('category', category);
   if (search) query.set('q', search);
   if (hasVideo) query.set('hasVideo', 'true');
   if (cursor) query.set('cursor', cursor);
   return useQuery({
-    queryKey: ['projects', yearId, kind, group, search, hasVideo, cursor ?? null],
+    queryKey: [
+      'projects',
+      yearId,
+      kind,
+      group,
+      category,
+      search,
+      hasVideo,
+      cursor ?? null,
+    ],
     queryFn: () => apiRequest<ProjectsResponse>(`/projects?${query}`),
     placeholderData: keepPreviousData,
   });

src/app/routes/ProjectsPage.tsx

@@ -38,6 +38,7 @@ export function ProjectsPage({isAdmin = false}: {isAdmin?: boolean}) {
   const [searchParams, setSearchParams] = useSearchParams();
   const [kind, setKind] = useState<'project' | 'idea'>('project');
   const group = searchParams.get('group') ?? '';
+  const [category, setCategory] = useState('');
   const [hasVideoOnly, setHasVideoOnly] = useState(false);
   const [searchInput, setSearchInput] = useState('');
   const [search, setSearch] = useState('');
@@ -52,6 +53,7 @@ export function ProjectsPage({isAdmin = false}: {isAdmin?: boolean}) {
     yearId,
     kind,
     kind === 'project' ? group || undefined : undefined,
+    kind === 'project' ? category || undefined : undefined,
     search || undefined,
     kind === 'project' && hasVideoOnly ? true : undefined,
     cursor,
@@ -217,6 +219,7 @@ export function ProjectsPage({isAdmin = false}: {isAdmin?: boolean}) {
                 className={kind === 'idea' ? 'active' : ''}
                 onClick={() => {
                   setKind('idea');
+                  setCategory('');
                   setHasVideoOnly(false);
                   resetPagination();
                 }}
@@ -241,6 +244,25 @@ export function ProjectsPage({isAdmin = false}: {isAdmin?: boolean}) {
                   </select>
                 </label>
               )}
+              {kind === 'project' && ballot.data && ballot.data.categories.length > 0 && (
+                <label>
+                  <span>Award category</span>
+                  <select
+                    value={category}
+                    onChange={(event) => {
+                      setCategory(event.target.value);
+                      resetPagination();
+                    }}
+                  >
+                    <option value="">All award categories</option>
+                    {ballot.data.categories.map((item) => (
+                      <option value={item.id} key={item.id}>
+                        {item.name}
+                      </option>
+                    ))}
+                  </select>
+                </label>
+              )}
               {kind === 'project' && (
                 <label className="projectVideoFilter">
                   <input

src/worker/repositories/projects.ts

@@ -191,6 +191,7 @@ export async function listProjects(
     yearId: string;
     kind?: 'project' | 'idea';
     groupId?: string;
+    categoryId?: string;
     search?: string;
     hasVideo?: boolean;
     limit: number;
@@ -216,6 +217,22 @@ export async function listProjects(
     conditions.push(readyVideoExistsSql);
     countConditions.push(readyVideoExistsSql);
   }
+  if (options.categoryId) {
+    // Empty nominations mean the project is open to every award category.
+    const categoryCondition = `(
+      NOT EXISTS (
+        SELECT 1 FROM project_nominations pn WHERE pn.project_id = p.id
+      )
+      OR EXISTS (
+        SELECT 1 FROM project_nominations pn
+        WHERE pn.project_id = p.id AND pn.award_category_id = ?
+      )
+    )`;
+    conditions.push(categoryCondition);
+    countConditions.push(categoryCondition);
+    bindings.push(options.categoryId);
+    countBindings.push(options.categoryId);
+  }
   let relevanceOrder = '';
   if (options.search) {
     const escapedSearch = escapeLikePattern(options.search);

src/worker/routes/projects.ts

@@ -41,6 +41,7 @@ projectsRoutes.get('/', async (c) => {
       yearId,
       kind,
       groupId: c.req.query('group'),
+      categoryId: c.req.query('category'),
       search,
       hasVideo: hasVideoQuery === 'true',
       limit,

test/app/routes.test.tsx

@@ -1237,6 +1237,41 @@ describe('clickable project routes', () => {
     );
   });
 
+  it('filters projects by eligible award category', async () => {
+    mockProjectsOverview({
+      categories: [
+        {id: 'delight', yearId: '2026', name: 'Delight'},
+        {id: 'impact', yearId: '2026', name: 'Impact'},
+      ],
+      projects: [projectFixture],
+    });
+
+    renderRoute(<ProjectsPage />, '/years/2026/projects', '/years/:yearId/projects');
+    await screen.findByRole('heading', {name: 'A small machine'});
+
+    await userEvent.selectOptions(
+      await screen.findByLabelText('Award category'),
+      'delight',
+    );
+
+    await waitFor(() =>
+      expect(fetchMock).toHaveBeenCalledWith(
+        expect.stringMatching(
+          /\/api\/projects\?(?=.*year=2026)(?=.*kind=project)(?=.*category=delight)/,
+        ),
+        undefined,
+      ),
+    );
+
+    await userEvent.click(screen.getByRole('button', {name: /Ideas/}));
+    expect(screen.queryByLabelText('Award category')).toBeNull();
+    await userEvent.click(screen.getByRole('button', {name: /Projects/}));
+    const categorySelect = await screen.findByLabelText('Award category');
+    expect(categorySelect).toBeInstanceOf(HTMLSelectElement);
+    if (!(categorySelect instanceof HTMLSelectElement)) throw new Error();
+    expect(categorySelect.value).toBe('');
+  });
+
   it('live-updates server search without replacing the current list', async () => {
     let resolveSearch!: (response: Response) => void;
     const pendingSearch = new Promise<Response>((resolve) => {

test/projects/projects.test.ts

@@ -504,6 +504,39 @@ describe('project and history APIs', () => {
     ]);
   });
 
+  it('filters projects by eligible award category', async () => {
+    const open = await createProject(memberToken, {
+      name: 'Open project',
+      nominationCategoryIds: [],
+    });
+    const delight = await createProject(memberToken, {
+      name: 'Delightful project',
+      nominationCategoryIds: [categoryId],
+    });
+    await createProject(memberToken, {
+      name: 'Craft project',
+      nominationCategoryIds: [secondCategoryId],
+    });
+    const both = await createProject(memberToken, {
+      name: 'Both categories',
+      nominationCategoryIds: [categoryId, secondCategoryId],
+    });
+
+    const matches = await api(
+      `/projects?year=${yearId}&kind=project&category=${categoryId}`,
+      memberToken,
+    );
+
+    expect(matches.status).toBe(200);
+    expect(matches.body.projects.map((project: {id: string}) => project.id)).toEqual([
+      both.id,
+      delight.id,
+      open.id,
+    ]);
+    expect(matches.body.projectCount).toBe(3);
+    expect(matches.body.ideaCount).toBe(0);
+  });
+
   it('searches titles and descriptions before pagination with relevant results first', async () => {
     const exact = await createProject(memberToken, {
       name: 'Signal',