diff --git a/src/middleware/rateLimit.js b/src/middleware/rateLimit.js
new file mode 100644
index 0000000..74f56fd
--- /dev/null
+++ b/src/middleware/rateLimit.js
@@ -0,0 +1,17 @@
+// Fixed-window rate limiter. Windows start at multiples of windowMs.
+export function createRateLimiter({ limit, windowMs, now = Date.now }) {
+  const counts = new Map();
+  let currentWindow = -1;
+
+  return function allow(key) {
+    const window = Math.floor(now() / windowMs);
+    if (window !== currentWindow) {
+      counts.clear();
+      currentWindow = window;
+    }
+    const count = counts.get(key) ?? 0;
+    if (count >= limit) return false;
+    counts.set(key, count + 1);
+    return true;
+  };
+}
diff --git a/src/routes/notes.js b/src/routes/notes.js
index 8248dc1..87edd93 100644
--- a/src/routes/notes.js
+++ b/src/routes/notes.js
@@ -1,8 +1,15 @@
 import { createNote, deleteNote, getNote, listNotes, updateNote } from '../services/notes.js';
 import { noteSummary } from '../utils/format.js';
+import { optionalInt } from '../utils/validate.js';
 
 export const notesRoutes = {
-  'GET /notes': (req) => ({ status: 200, body: listNotes(req.user.id).map(noteSummary) }),
+  'GET /notes': (req) => {
+    const page = optionalInt(req.query, 'page', { def: 1 });
+    const pageSize = optionalInt(req.query, 'pageSize', { def: 5, max: 50 });
+    const notes = listNotes(req.user.id);
+    const items = notes.slice((page - 1) * pageSize, page * pageSize).map(noteSummary);
+    return { status: 200, body: { items, page, pageSize, total: notes.length } };
+  },
   'GET /notes/:id': (req) => {
     const note = getNote(req.user.id, req.params.id);
     return note ? { status: 200, body: note } : { status: 404, body: { error: 'not found' } };
diff --git a/src/utils/format.js b/src/utils/format.js
index 24a3a09..4c90f41 100644
--- a/src/utils/format.js
+++ b/src/utils/format.js
@@ -3,7 +3,7 @@
 // Dates are shown as YYYY-MM-DD in UTC.
 export function formatDate(ms) {
   const d = new Date(ms);
-  const month = String(d.getUTCMonth()).padStart(2, '0');
+  const month = String(d.getUTCMonth() + 1).padStart(2, '0');
   const day = String(d.getUTCDate()).padStart(2, '0');
   return `${d.getUTCFullYear()}-${month}-${day}`;
 }
diff --git a/src/utils/validate.js b/src/utils/validate.js
index 72f348f..f78c09c 100644
--- a/src/utils/validate.js
+++ b/src/utils/validate.js
@@ -19,6 +19,16 @@ export function optionalTags(obj) {
   return [...new Set(tags.map((t) => String(t).toLowerCase().trim()).filter(Boolean))];
 }
 
+export function optionalInt(obj, field, { def, min = 1, max = Infinity } = {}) {
+  const raw = obj?.[field];
+  if (raw === undefined || raw === '') return def;
+  const value = Number(raw);
+  if (!Number.isInteger(value) || value < min || value > max) {
+    throw new ValidationError(field, `must be an integer between ${min} and ${max}`);
+  }
+  return value;
+}
+
 export function requireEmail(obj, field = 'email') {
   const value = requireString(obj, field);
   if (!/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(value)) throw new ValidationError(field, 'must be an email address');
diff --git a/tests/api.test.js b/tests/api.test.js
index 32d499e..5b65716 100644
--- a/tests/api.test.js
+++ b/tests/api.test.js
@@ -18,8 +18,28 @@ test('notes need a valid token', () => {
 test('lists only my notes, newest first', () => {
   const res = as('u1', { method: 'GET', path: '/notes' });
   assert.equal(res.status, 200);
-  assert.equal(res.body.length, 8);
-  assert.equal(res.body[0].title, 'Car service');
+  assert.equal(res.body.total, 8);
+  assert.equal(res.body.page, 1);
+  assert.equal(res.body.pageSize, 5);
+  assert.equal(res.body.items.length, 5);
+  assert.equal(res.body.items[0].title, 'Car service');
+});
+
+test('paginates notes', () => {
+  const p2 = as('u1', { method: 'GET', path: '/notes', query: { page: '2' } });
+  assert.equal(p2.body.items.length, 3);
+  assert.equal(p2.body.page, 2);
+  const all = as('u1', { method: 'GET', path: '/notes', query: { pageSize: '50' } });
+  assert.equal(all.body.items.length, 8);
+  const beyond = as('u1', { method: 'GET', path: '/notes', query: { page: '9' } });
+  assert.deepEqual(beyond.body.items, []);
+  assert.equal(beyond.body.total, 8);
+});
+
+test('rejects invalid pagination params', () => {
+  for (const query of [{ page: '0' }, { page: 'x' }, { pageSize: '51' }, { pageSize: '0' }]) {
+    assert.equal(as('u1', { method: 'GET', path: '/notes', query }).status, 400);
+  }
 });
 
 test('creates and deletes a note', () => {
diff --git a/tests/format.test.js b/tests/format.test.js
new file mode 100644
index 0000000..e255dec
--- /dev/null
+++ b/tests/format.test.js
@@ -0,0 +1,9 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { formatDate } from '../src/utils/format.js';
+
+test('formatDate uses 1-based months', () => {
+  assert.equal(formatDate(Date.UTC(2026, 2, 15)), '2026-03-15');
+  assert.equal(formatDate(Date.UTC(2026, 0, 1)), '2026-01-01');
+  assert.equal(formatDate(Date.UTC(2026, 11, 31)), '2026-12-31');
+});
diff --git a/tests/rateLimit.test.js b/tests/rateLimit.test.js
new file mode 100644
index 0000000..377d0cf
--- /dev/null
+++ b/tests/rateLimit.test.js
@@ -0,0 +1,47 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { createRateLimiter } from '../src/middleware/rateLimit.js';
+
+function setup(limit = 2, windowMs = 1000) {
+  let t = 0;
+  const allow = createRateLimiter({ limit, windowMs, now: () => t });
+  return { allow, set: (v) => { t = v; } };
+}
+
+test('allows up to limit calls then blocks', () => {
+  const { allow } = setup();
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), false);
+  assert.equal(allow('a'), false);
+});
+
+test('keys are counted independently', () => {
+  const { allow } = setup(1);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('b'), true);
+  assert.equal(allow('a'), false);
+});
+
+test('window resets at multiples of windowMs', () => {
+  const { allow, set } = setup(1);
+  set(999);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), false);
+  set(1000);
+  assert.equal(allow('a'), true);
+  assert.equal(allow('a'), false);
+});
+
+test('a window start is not shifted by the first call', () => {
+  const { allow, set } = setup(1);
+  set(500);
+  assert.equal(allow('a'), true);
+  set(1000); // only 500ms later, but a new fixed window
+  assert.equal(allow('a'), true);
+});
+
+test('defaults to Date.now', () => {
+  const allow = createRateLimiter({ limit: 1, windowMs: 60 * 60 * 1000 });
+  assert.equal(allow('a'), true);
+});