diff --git a/packages/backend/src/services/search.test.ts b/packages/backend/src/services/search.test.ts
new file mode 100644
index 0000000..729ed69
--- /dev/null
+++ b/packages/backend/src/services/search.test.ts
@@ -0,0 +1,70 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { makeTestDb, createUserDirect, createLessonOwnedBy } from '../tests/dbHelper.js';
+import { createCard } from './cards.js';
+import { searchAll } from './search.js';
+
+let env: ReturnType<typeof makeTestDb>;
+beforeEach(() => { env = makeTestDb(); });
+
+describe('search', () => {
+  it('returns empty for short queries', async () => {
+    const u = await createUserDirect(env.db, { email: 'u@example.com' });
+    const r = await searchAll(env.db, u.id, '', 30);
+    expect(r.lessons).toHaveLength(0);
+    expect(r.cards).toHaveLength(0);
+  });
+
+  it('finds own lessons by name', async () => {
+    const u = await createUserDirect(env.db, { email: 'u@example.com', displayName: 'Me' });
+    await createLessonOwnedBy(env.db, u.id, { name: 'Spaans basis' });
+    const r = await searchAll(env.db, u.id, 'spaans', 30);
+    expect(r.lessons).toHaveLength(1);
+    expect(r.lessons[0]!.location).toBe('library');
+  });
+
+  it('hides private lessons of other users', async () => {
+    const o = await createUserDirect(env.db, { email: 'o@example.com' });
+    const u = await createUserDirect(env.db, { email: 'u@example.com' });
+    await createLessonOwnedBy(env.db, o.id, { name: 'Geheim', visibility: 'private' });
+    const r = await searchAll(env.db, u.id, 'geheim', 30);
+    expect(r.lessons).toHaveLength(0);
+  });
+
+  it('marks shared lessons from others as marketplace', async () => {
+    const o = await createUserDirect(env.db, { email: 'o@example.com', displayName: 'Owner' });
+    const u = await createUserDirect(env.db, { email: 'u@example.com' });
+    await createLessonOwnedBy(env.db, o.id, { name: 'Public', visibility: 'shared' });
+    const r = await searchAll(env.db, u.id, 'public', 30);
+    expect(r.lessons).toHaveLength(1);
+    expect(r.lessons[0]!.location).toBe('marketplace');
+    expect(r.lessons[0]!.ownerDisplayName).toBe('Owner');
+  });
+
+  it('finds cards in readable lessons only', async () => {
+    const o = await createUserDirect(env.db, { email: 'o@example.com' });
+    const u = await createUserDirect(env.db, { email: 'u@example.com' });
+    const own = await createLessonOwnedBy(env.db, u.id, { name: 'Mine' });
+    const other = await createLessonOwnedBy(env.db, o.id, { name: 'Hers', visibility: 'private' });
+    await createCard(env.db, u.id, own.id, { question: 'hola', answer: 'hello' });
+    await createCard(env.db, o.id, other.id, { question: 'hola', answer: 'hello' });
+    const r = await searchAll(env.db, u.id, 'hola', 30);
+    expect(r.cards).toHaveLength(1);
+    expect(r.cards[0]!.lessonId).toBe(own.id);
+  });
+
+  it('search is case-insensitive', async () => {
+    const u = await createUserDirect(env.db, { email: 'u@example.com' });
+    await createLessonOwnedBy(env.db, u.id, { name: 'Frans' });
+    const r = await searchAll(env.db, u.id, 'FRA', 30);
+    expect(r.lessons).toHaveLength(1);
+  });
+
+  it('respects limit on each group', async () => {
+    const u = await createUserDirect(env.db, { email: 'u@example.com' });
+    for (let i = 0; i < 5; i++) {
+      await createLessonOwnedBy(env.db, u.id, { name: `lesson${i}` });
+    }
+    const r = await searchAll(env.db, u.id, 'lesson', 2);
+    expect(r.lessons).toHaveLength(2);
+  });
+});
diff --git a/packages/backend/src/services/search.ts b/packages/backend/src/services/search.ts
new file mode 100644
index 0000000..6a45481
--- /dev/null
+++ b/packages/backend/src/services/search.ts
@@ -0,0 +1,153 @@
+import { and, eq, inArray, or, sql } from 'drizzle-orm';
+import type { Db } from '../db/client.js';
+import { cards, lessons, lessonSubscriptions, users } from '../db/schema.js';
+
+export interface SearchLessonResult {
+  id: number;
+  name: string;
+  ownerDisplayName: string;
+  location: 'library' | 'marketplace';
+  totalCards: number;
+  isCurated: boolean;
+}
+
+export interface SearchCardResult {
+  id: number;
+  lessonId: number;
+  lessonName: string;
+  question: string;
+  snippet: string;
+}
+
+export interface SearchResult {
+  lessons: SearchLessonResult[];
+  cards: SearchCardResult[];
+}
+
+const MIN_QUERY_LEN = 2;
+const SNIPPET_LEN = 80;
+
+function snippet(text: string, term: string): string {
+  const lower = text.toLowerCase();
+  const idx = lower.indexOf(term.toLowerCase());
+  if (idx < 0) return text.slice(0, SNIPPET_LEN);
+  const start = Math.max(0, idx - 20);
+  const end = Math.min(text.length, start + SNIPPET_LEN);
+  return (start > 0 ? '…' : '') + text.slice(start, end) + (end < text.length ? '…' : '');
+}
+
+export async function searchAll(
+  db: Db, userId: number, q: string, limit: number
+): Promise<SearchResult> {
+  const term = q.trim();
+  if (term.length < MIN_QUERY_LEN) return { lessons: [], cards: [] };
+
+  const lower = term.toLowerCase();
+  const pattern = `%${lower}%`;
+
+  const ownerLessons = db.select().from(lessons).where(eq(lessons.ownerId, userId)).all();
+  const subRoots = db.select({ id: lessonSubscriptions.lessonId }).from(lessonSubscriptions)
+    .where(eq(lessonSubscriptions.userId, userId)).all();
+
+  const allLessons = db.select().from(lessons).all();
+  const byParent = new Map<number | null, typeof allLessons>();
+  for (const l of allLessons) {
+    const k = l.parentId ?? null;
+    if (!byParent.has(k)) byParent.set(k, []);
+    byParent.get(k)!.push(l);
+  }
+  const readableIds = new Set<number>();
+  for (const l of ownerLessons) readableIds.add(l.id);
+  const stack: number[] = [];
+  for (const sr of subRoots) stack.push(sr.id);
+  for (const l of allLessons) if (l.visibility === 'shared' && l.isCurated) stack.push(l.id);
+  while (stack.length) {
+    const cur = stack.pop()!;
+    if (readableIds.has(cur)) continue;
+    readableIds.add(cur);
+    for (const c of byParent.get(cur) ?? []) stack.push(c.id);
+  }
+
+  const matchesLesson = (l: typeof allLessons[number]) =>
+    l.name.toLowerCase().includes(lower) || (l.description ?? '').toLowerCase().includes(lower);
+
+  const libraryMatches = allLessons.filter((l) => readableIds.has(l.id) && matchesLesson(l));
+
+  const sharedIds = new Set(allLessons.filter((l) => l.visibility === 'shared').map((l) => l.id));
+  const marketplaceMatches = allLessons.filter((l) =>
+    l.visibility === 'shared'
+    && l.ownerId !== userId
+    && !readableIds.has(l.id)
+    && (l.parentId === null || !sharedIds.has(l.parentId))
+    && matchesLesson(l)
+  );
+
+  const ownerIds = Array.from(new Set([...libraryMatches, ...marketplaceMatches]
+    .map((l) => l.ownerId).filter((id): id is number => id !== null && id !== undefined)));
+  const ownerRows = ownerIds.length === 0 ? [] :
+    db.select({ id: users.id, displayName: users.displayName }).from(users)
+      .where(inArray(users.id, ownerIds)).all();
+  const ownerMap = new Map(ownerRows.map((u) => [u.id, u.displayName]));
+
+  const matchingLessonIds = [...libraryMatches, ...marketplaceMatches].map((l) => l.id);
+  const cardCounts = matchingLessonIds.length === 0 ? [] :
+    db.select({ lessonId: cards.lessonId, c: sql<number>`count(*)`.as('c') }).from(cards)
+      .where(inArray(cards.lessonId, matchingLessonIds))
+      .groupBy(cards.lessonId).all();
+  const cardCountByLesson = new Map(cardCounts.map((r) => [r.lessonId, Number(r.c)]));
+
+  const lessonResults: SearchLessonResult[] = [
+    ...libraryMatches.map((l): SearchLessonResult => ({
+      id: l.id, name: l.name,
+      ownerDisplayName: ownerMap.get(l.ownerId ?? -1) ?? '—',
+      location: 'library',
+      totalCards: cardCountByLesson.get(l.id) ?? 0,
+      isCurated: l.isCurated,
+    })),
+    ...marketplaceMatches.map((l): SearchLessonResult => ({
+      id: l.id, name: l.name,
+      ownerDisplayName: ownerMap.get(l.ownerId ?? -1) ?? '—',
+      location: 'marketplace',
+      totalCards: cardCountByLesson.get(l.id) ?? 0,
+      isCurated: l.isCurated,
+    })),
+  ];
+  lessonResults.sort((a, b) =>
+    a.location === b.location ? a.name.localeCompare(b.name) : a.location === 'library' ? -1 : 1
+  );
+
+  const readableIdsArr = Array.from(readableIds);
+  const cardMatches = readableIdsArr.length === 0 ? [] :
+    db.select({
+      id: cards.id, lessonId: cards.lessonId, question: cards.question,
+      answer: cards.answer, hint: cards.hint, lessonName: lessons.name,
+    }).from(cards)
+      .innerJoin(lessons, eq(lessons.id, cards.lessonId))
+      .where(and(
+        inArray(cards.lessonId, readableIdsArr),
+        or(
+          sql`lower(${cards.question}) like ${pattern}`,
+          sql`lower(${cards.answer}) like ${pattern}`,
+          sql`lower(${cards.hint}) like ${pattern}`,
+        )!
+      ))
+      .all();
+
+  const cardResults: SearchCardResult[] = cardMatches.map((c) => {
+    const matched = c.question.toLowerCase().includes(lower)
+      ? c.question
+      : c.answer.toLowerCase().includes(lower)
+      ? c.answer
+      : (c.hint ?? c.question);
+    return {
+      id: c.id, lessonId: c.lessonId, lessonName: c.lessonName,
+      question: c.question, snippet: snippet(matched, term),
+    };
+  });
+  cardResults.sort((a, b) => a.lessonName.localeCompare(b.lessonName) || a.question.localeCompare(b.question));
+
+  return {
+    lessons: lessonResults.slice(0, limit),
+    cards: cardResults.slice(0, limit),
+  };
+}