diff --git a/services/platform-service/src/modules/comments/routes.test.ts b/services/platform-service/src/modules/comments/routes.test.ts
new file mode 100644
index 00000000..a10b190c
--- /dev/null
+++ b/services/platform-service/src/modules/comments/routes.test.ts
@@ -0,0 +1,182 @@
+/**
+ * Route-level tests for comments module — Fastify inject.
+ */
+
+import Fastify from 'fastify';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+const commentRepoMock = {
+  listByItem: vi.fn(),
+  create: vi.fn(),
+  getById: vi.fn(),
+  update: vi.fn(),
+  remove: vi.fn(),
+};
+
+const itemRepoMock = {
+  getById: vi.fn(),
+  incrementCommentCount: vi.fn(),
+};
+
+const authMock = {
+  extractAuth: vi.fn(),
+};
+
+vi.mock('./repository.js', () => commentRepoMock);
+vi.mock('../items/repository.js', () => itemRepoMock);
+vi.mock('../../lib/auth.js', () => authMock);
+
+const baseItem = {
+  id: 'item_1',
+  productId: 'lysnrai',
+  title: 'Feature request',
+};
+
+const baseComment = {
+  id: 'cmt_1',
+  itemId: 'item_1',
+  productId: 'lysnrai',
+  authorId: 'user_1',
+  authorEmail: 'user1@example.com',
+  body: 'Looks good',
+  createdAt: '2026-02-16T00:00:00Z',
+  updatedAt: '2026-02-16T00:00:00Z',
+};
+
+describe('commentRoutes', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    authMock.extractAuth.mockResolvedValue({ sub: 'user_1', email: 'user1@example.com', role: 'user' });
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('GET /items/:itemId/comments returns list', async () => {
+    itemRepoMock.getById.mockResolvedValue(baseItem);
+    commentRepoMock.listByItem.mockResolvedValue([baseComment]);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({ method: 'GET', url: '/api/items/item_1/comments' });
+
+    expect(res.statusCode).toBe(200);
+    const data = JSON.parse(res.body);
+    expect(data.comments).toHaveLength(1);
+    expect(data.count).toBe(1);
+  });
+
+  it('POST /items/:itemId/comments creates comment', async () => {
+    itemRepoMock.getById.mockResolvedValue(baseItem);
+    commentRepoMock.create.mockResolvedValue(baseComment);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/items/item_1/comments',
+      payload: { body: 'Looks good' },
+    });
+
+    expect(res.statusCode).toBe(201);
+    expect(itemRepoMock.incrementCommentCount).toHaveBeenCalledWith('item_1', 1);
+  });
+
+  it('POST /items/:itemId/comments returns 400 for invalid payload', async () => {
+    itemRepoMock.getById.mockResolvedValue(baseItem);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/items/item_1/comments',
+      payload: { body: '' },
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
+
+  it('PUT /items/:itemId/comments/:id updates comment for author', async () => {
+    commentRepoMock.getById.mockResolvedValue(baseComment);
+    commentRepoMock.update.mockResolvedValue({ ...baseComment, body: 'Updated' });
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({
+      method: 'PUT',
+      url: '/api/items/item_1/comments/cmt_1',
+      payload: { body: 'Updated' },
+    });
+
+    expect(res.statusCode).toBe(200);
+    const data = JSON.parse(res.body);
+    expect(data.body).toBe('Updated');
+  });
+
+  it('PUT /items/:itemId/comments/:id returns 403 for non-author user', async () => {
+    authMock.extractAuth.mockResolvedValue({ sub: 'user_2', email: 'user2@example.com', role: 'user' });
+    commentRepoMock.getById.mockResolvedValue(baseComment);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({
+      method: 'PUT',
+      url: '/api/items/item_1/comments/cmt_1',
+      payload: { body: 'Updated' },
+    });
+
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('DELETE /items/:itemId/comments/:id deletes for author', async () => {
+    commentRepoMock.getById.mockResolvedValue(baseComment);
+    commentRepoMock.remove.mockResolvedValue(undefined);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({ method: 'DELETE', url: '/api/items/item_1/comments/cmt_1' });
+
+    expect(res.statusCode).toBe(200);
+    const data = JSON.parse(res.body);
+    expect(data.success).toBe(true);
+    expect(itemRepoMock.incrementCommentCount).toHaveBeenCalledWith('item_1', -1);
+  });
+
+  it('DELETE /items/:itemId/comments/:id allows admin to delete', async () => {
+    authMock.extractAuth.mockResolvedValue({ sub: 'admin_1', email: 'admin@example.com', role: 'admin' });
+    commentRepoMock.getById.mockResolvedValue(baseComment);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({ method: 'DELETE', url: '/api/items/item_1/comments/cmt_1' });
+
+    expect(res.statusCode).toBe(200);
+  });
+
+  it('DELETE /items/:itemId/comments/:id returns 404 when comment missing', async () => {
+    commentRepoMock.getById.mockResolvedValue(null);
+
+    const { commentRoutes } = await import('./routes.js');
+    const app = Fastify({ logger: false });
+    await app.register(commentRoutes, { prefix: '/api' });
+
+    const res = await app.inject({ method: 'DELETE', url: '/api/items/item_1/comments/missing' });
+
+    expect(res.statusCode).toBe(404);
+  });
+});