diff --git a/backend/src/db/migrations/043_lab_sim_links.sql b/backend/src/db/migrations/043_lab_sim_links.sql
new file mode 100644
index 0000000..3421f67
--- /dev/null
+++ b/backend/src/db/migrations/043_lab_sim_links.sql
@@ -0,0 +1,24 @@
+-- 043_lab_sim_links.sql — Контент-движок лаборатории, Фаза 5 (курикулумная привязка).
+-- Связи симуляции с учебной программой: § учебника, тема, узел knowledge-map,
+-- задача банка вопросов. Двусторонняя навигация (sim ↔ контент).
+--
+-- kind:
+--   'textbook' — ref_id = textbooks.slug
+--   'topic'    — ref_id = topics.id (как текст)
+--   'kmap'     — ref_id = id узла графа знаний (свободная строка)
+--   'question' — ref_id = questions.id (как текст)
+-- label — необязательная человекочитаемая подпись (если не резолвится из БД).
+
+CREATE TABLE IF NOT EXISTS lab_sim_links (
+  id         INTEGER PRIMARY KEY AUTOINCREMENT,
+  sim_id     TEXT NOT NULL,
+  kind       TEXT NOT NULL,            -- textbook | topic | kmap | question
+  ref_id     TEXT NOT NULL,
+  label      TEXT,
+  created_by INTEGER REFERENCES users(id),
+  created_at TEXT NOT NULL DEFAULT (datetime('now')),
+  UNIQUE (sim_id, kind, ref_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_lab_sim_links_sim  ON lab_sim_links (sim_id);
+CREATE INDEX IF NOT EXISTS idx_lab_sim_links_ref  ON lab_sim_links (kind, ref_id);
diff --git a/backend/src/routes/lab.js b/backend/src/routes/lab.js
index 55070c6..9dfba4f 100644
--- a/backend/src/routes/lab.js
+++ b/backend/src/routes/lab.js
@@ -1,10 +1,14 @@
 'use strict';
-/* /api/lab — каталог симуляций лаборатории (контент-движок, Фаза 4).
+/* /api/lab — каталог симуляций лаборатории (контент-движок, Фазы 4-5).
  *
- * GET  /api/lab/sims        — каталог из БД (lab_sims) + legacy-флаги модуля.
- *                             Чтение: любой авторизованный пользователь.
- * PATCH /api/lab/sims/:id   — изменить enabled/featured/tags/subject/grade. admin.
- * POST  /api/lab/sims/reorder — задать порядок (массив id). admin.
+ * GET  /api/lab/sims              — каталог из БД (lab_sims) + legacy-флаги. auth.
+ * PATCH /api/lab/sims/:id         — enabled/featured/tags/subject/grade. admin.
+ * POST  /api/lab/sims/reorder     — задать порядок (массив id). admin.
+ * GET  /api/lab/sims/:id/related  — связанные § / темы / kmap / задачи. auth. (Ф5)
+ * POST  /api/lab/sims/:id/links   — добавить связь. admin. (Ф5)
+ * DELETE /api/lab/sims/:id/links/:linkId — удалить связь. admin. (Ф5)
+ * GET  /api/lab/links?kind=&ref_id= — обратный поиск: какие симуляции привязаны
+ *                                     к данному учебнику/теме. auth. (Ф5)
  *
  * Совместимость: enabled зеркалится в app_settings.sim_disabled_ids, поэтому
  * существующая логика lab.html (которая читает /api/settings/sims) продолжает
@@ -14,6 +18,7 @@ const db = require('../db/db');
 const { authMiddleware, requireRole } = require('../middleware/auth');
 
 const CATS = ['math', 'phys', 'chem', 'bio', 'game'];
+const LINK_KINDS = ['textbook', 'topic', 'kmap', 'question'];
 
 router.use(authMiddleware);
 
@@ -136,4 +141,127 @@ router.post('/sims/reorder', (req, res) => {
   res.json({ ok: true, count: order.length });
 });
 
+/* ════════════════════════════════════════════════════════════════════════
+   Курикулумная привязка (Фаза 5) — связи симуляции ↔ контент.
+   ════════════════════════════════════════════════════════════════════════ */
+
+// Безопасно прочитать связи симуляции (если таблицы ещё нет — пустой массив).
+function readLinks(simId) {
+  try {
+    return db.prepare(
+      'SELECT id, sim_id, kind, ref_id, label FROM lab_sim_links WHERE sim_id = ? ORDER BY kind, id'
+    ).all(simId);
+  } catch (e) {
+    return null; // null => таблица недоступна (нужна миграция)
+  }
+}
+
+// Обогатить связь человекочитаемой меткой и навигационным href.
+function decorateLink(l) {
+  const out = { id: l.id, kind: l.kind, ref_id: l.ref_id, label: l.label || null };
+  if (l.kind === 'textbook') {
+    const tb = db.prepare('SELECT title, subject, grade FROM textbooks WHERE slug = ?').get(l.ref_id);
+    if (tb) { out.label = out.label || tb.title; out.subject = tb.subject; out.grade = tb.grade; }
+    out.href = '/textbooks?book=' + encodeURIComponent(l.ref_id);
+  } else if (l.kind === 'topic') {
+    const tp = db.prepare('SELECT name FROM topics WHERE id = ?').get(Number(l.ref_id));
+    if (tp) out.label = out.label || tp.name;
+  } else if (l.kind === 'question') {
+    out.href = null; // задачи открываются в банке вопросов отдельным контекстом
+  }
+  if (!out.label) out.label = l.kind + ':' + l.ref_id;
+  return out;
+}
+
+/* GET /api/lab/sims/:id/related → { sim, links:{ textbook:[], topic:[], kmap:[], question:[] } } */
+router.get('/sims/:id/related', authMiddleware, (req, res) => {
+  const id = String(req.params.id || '');
+  const sim = db.prepare('SELECT id, title FROM lab_sims WHERE id = ?').get(id);
+  // sim может отсутствовать в lab_sims (если миграция 042 не применена) — не 404,
+  // т.к. связи всё равно могут существовать; вернём то, что есть.
+  const rows = readLinks(id);
+  if (rows === null) return res.json({ sim: sim || { id }, links: {}, needs_migration: true });
+  const links = { textbook: [], topic: [], kmap: [], question: [] };
+  for (const l of rows) {
+    const d = decorateLink(l);
+    (links[l.kind] || (links[l.kind] = [])).push(d);
+  }
+  res.json({ sim: sim || { id }, links });
+});
+
+/* GET /api/lab/links?kind=textbook&ref_id=algebra-8
+   → { sims:[{id,title,cat,enabled}] } — какие (включённые) симуляции привязаны. */
+router.get('/links', (req, res) => {
+  const kind = String(req.query.kind || '');
+  const refId = String(req.query.ref_id || '');
+  if (!LINK_KINDS.includes(kind) || !refId) {
+    return res.status(400).json({ error: 'kind и ref_id обязательны' });
+  }
+  let rows;
+  try {
+    rows = db.prepare(`
+      SELECT s.id, s.title, s.cat, s.enabled
+        FROM lab_sim_links l JOIN lab_sims s ON s.id = l.sim_id
+       WHERE l.kind = ? AND l.ref_id = ?
+       ORDER BY s.sort_order, s.id
+    `).all(kind, refId);
+  } catch (e) {
+    return res.json({ sims: [], needs_migration: true });
+  }
+  const legacyDisabled = readLegacyDisabledIds();
+  const sims = rows
+    .map(r => ({ id: r.id, title: r.title, cat: r.cat, enabled: !!r.enabled && !legacyDisabled.has(r.id) }))
+    .filter(s => s.enabled); // наружу отдаём только доступные
+  res.json({ sims });
+});
+
+/* ── admin: управление связями ─────────────────────────────────────────── */
+
+/* POST /api/lab/sims/:id/links  body: { kind, ref_id, label? } */
+router.post('/sims/:id/links', requireRole('admin'), (req, res) => {
+  const simId = String(req.params.id || '');
+  if (!db.prepare('SELECT 1 FROM lab_sims WHERE id = ?').get(simId)) {
+    return res.status(404).json({ error: 'симуляция не найдена' });
+  }
+  const b = req.body || {};
+  const kind = String(b.kind || '');
+  const refId = String(b.ref_id || '').trim();
+  if (!LINK_KINDS.includes(kind)) return res.status(400).json({ error: 'неверный kind' });
+  if (!refId) return res.status(400).json({ error: 'ref_id обязателен' });
+
+  // Валидация существования цели (мягкая — kmap/question произвольны).
+  if (kind === 'textbook' && !db.prepare('SELECT 1 FROM textbooks WHERE slug = ?').get(refId)) {
+    return res.status(404).json({ error: 'учебник не найден: ' + refId });
+  }
+  if (kind === 'topic') {
+    const tid = Number(refId);
+    if (!Number.isInteger(tid) || !db.prepare('SELECT 1 FROM topics WHERE id = ?').get(tid)) {
+      return res.status(404).json({ error: 'тема не найдена: ' + refId });
+    }
+  }
+
+  const label = b.label != null ? String(b.label).trim().slice(0, 200) || null : null;
+  try {
+    const info = db.prepare(
+      'INSERT INTO lab_sim_links (sim_id, kind, ref_id, label, created_by) VALUES (?, ?, ?, ?, ?)'
+    ).run(simId, kind, refId, label, req.user.id);
+    const created = db.prepare('SELECT id, sim_id, kind, ref_id, label FROM lab_sim_links WHERE id = ?')
+      .get(info.lastInsertRowid);
+    res.json({ ok: true, link: decorateLink(created) });
+  } catch (e) {
+    if (/UNIQUE/i.test(e.message)) return res.status(409).json({ error: 'такая связь уже есть' });
+    throw e;
+  }
+});
+
+/* DELETE /api/lab/sims/:id/links/:linkId */
+router.delete('/sims/:id/links/:linkId', requireRole('admin'), (req, res) => {
+  const simId = String(req.params.id || '');
+  const linkId = Number(req.params.linkId);
+  if (!Number.isInteger(linkId)) return res.status(400).json({ error: 'неверный linkId' });
+  const info = db.prepare('DELETE FROM lab_sim_links WHERE id = ? AND sim_id = ?').run(linkId, simId);
+  if (!info.changes) return res.status(404).json({ error: 'связь не найдена' });
+  res.json({ ok: true });
+});
+
 module.exports = router;
diff --git a/backend/tests/lab-links.test.js b/backend/tests/lab-links.test.js
new file mode 100644
index 0000000..39e281c
--- /dev/null
+++ b/backend/tests/lab-links.test.js
@@ -0,0 +1,174 @@
+'use strict';
+/**
+ * Integration tests: /api/lab — curriculum links (Phase 5).
+ * Covers: related (auth), reverse lookup, admin add/delete, validation,
+ * role-gating, textbook/topic existence checks, enabled-filtering of reverse.
+ */
+const { describe, it, before, after } = require('node:test');
+const assert = require('node:assert/strict');
+const { app, db, inject, getToken, cleanup } = require('./setup');
+
+// Mount /api/lab on the shared test app.
+app.use('/api/lab', require('../src/routes/lab'));
+
+after(() => cleanup());
+
+/**
+ * Schema-robust insert: fills every NOT NULL column (without a default) that the
+ * caller didn't provide with a safe placeholder, then inserts. Returns lastInsertRowid.
+ * Protects the seed from schema drift (e.g. textbooks.html_path NOT NULL) introduced
+ * by parallel sessions on this branch.
+ */
+function seedRow(table, provided) {
+  const cols = db.prepare(`PRAGMA table_info(${table})`).all();
+  const row = { ...provided };
+  for (const c of cols) {
+    if (c.pk) continue;                          // skip primary key (autoincrement)
+    if (c.name in row) continue;                 // caller-provided
+    if (c.notnull && c.dflt_value === null) {    // required, no default → fill placeholder
+      row[c.name] = /INT|REAL|NUM/i.test(c.type) ? 0 : '';
+    }
+  }
+  const names = Object.keys(row);
+  const ph = names.map(() => '?').join(', ');
+  const info = db.prepare(`INSERT INTO ${table} (${names.join(', ')}) VALUES (${ph})`)
+    .run(...names.map(n => row[n]));
+  return info.lastInsertRowid;
+}
+
+describe('/api/lab curriculum links', () => {
+  let adminToken, studentToken, tbSlug, topicId;
+
+  before(async () => {
+    adminToken = (await getToken('admin')).token;
+    studentToken = (await getToken('student')).token;
+    // Seed a textbook + topic to link against.
+    db.prepare(`INSERT INTO textbooks (slug, title, subject, grade, is_active)
+                VALUES ('phys-test', 'Физика тест', 'physics', 9, 1)
+                ON CONFLICT(slug) DO NOTHING`).run();
+    tbSlug = 'phys-test';
+    const subj = db.prepare(`INSERT INTO subjects (name) VALUES ('LinkTest Subj')`).run();
+    const tp = db.prepare(`INSERT INTO topics (subject_id, name) VALUES (?, 'Колебания тест')`)
+      .run(subj.lastInsertRowid);
+    topicId = tp.lastInsertRowid;
+  });
+
+  it('GET /related requires auth (401)', async () => {
+    const res = await inject('GET', '/api/lab/sims/pendulum/related', null, null);
+    assert.equal(res.status, 401, `got ${res.status}`);
+  });
+
+  it('GET /related returns empty link buckets for a sim with no links', async () => {
+    const res = await inject('GET', '/api/lab/sims/pendulum/related', null, studentToken);
+    assert.equal(res.status, 200, `got ${res.status}`);
+    assert.equal(res.body.sim.id, 'pendulum');
+    assert.deepEqual(res.body.links.textbook, []);
+    assert.deepEqual(res.body.links.topic, []);
+  });
+
+  it('POST /links is admin-only (student → 403)', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'textbook', ref_id: tbSlug }, studentToken);
+    assert.equal(res.status, 403, `got ${res.status}`);
+  });
+
+  it('admin can add a textbook link; label resolved from textbooks', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'textbook', ref_id: tbSlug }, adminToken);
+    assert.equal(res.status, 200, `got ${res.status}`);
+    assert.equal(res.body.link.kind, 'textbook');
+    assert.equal(res.body.link.ref_id, tbSlug);
+    assert.equal(res.body.link.label, 'Физика тест', 'label resolved from textbook title');
+    assert.ok(res.body.link.href.includes(tbSlug), 'href points to textbook');
+  });
+
+  it('related now shows the textbook link', async () => {
+    const res = await inject('GET', '/api/lab/sims/pendulum/related', null, studentToken);
+    assert.equal(res.status, 200);
+    assert.equal(res.body.links.textbook.length, 1);
+    assert.equal(res.body.links.textbook[0].ref_id, tbSlug);
+  });
+
+  it('admin can add a topic link; label resolved from topics', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'topic', ref_id: String(topicId) }, adminToken);
+    assert.equal(res.status, 200, `got ${res.status}`);
+    assert.equal(res.body.link.label, 'Колебания тест');
+  });
+
+  it('duplicate link → 409', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'textbook', ref_id: tbSlug }, adminToken);
+    assert.equal(res.status, 409, `got ${res.status}`);
+  });
+
+  it('validation: bad kind → 400', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'nope', ref_id: 'x' }, adminToken);
+    assert.equal(res.status, 400);
+  });
+
+  it('validation: missing ref_id → 400', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'textbook' }, adminToken);
+    assert.equal(res.status, 400);
+  });
+
+  it('validation: unknown textbook → 404', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'textbook', ref_id: 'ghost-book' }, adminToken);
+    assert.equal(res.status, 404);
+  });
+
+  it('validation: unknown topic → 404', async () => {
+    const res = await inject('POST', '/api/lab/sims/pendulum/links',
+      { kind: 'topic', ref_id: '999999' }, adminToken);
+    assert.equal(res.status, 404);
+  });
+
+  it('POST link to unknown sim → 404', async () => {
+    const res = await inject('POST', '/api/lab/sims/ghostsim/links',
+      { kind: 'textbook', ref_id: tbSlug }, adminToken);
+    assert.equal(res.status, 404);
+  });
+
+  it('reverse lookup: GET /links?kind=textbook&ref_id= returns linked enabled sims', async () => {
+    const res = await inject('GET',
+      `/api/lab/links?kind=textbook&ref_id=${encodeURIComponent(tbSlug)}`, null, studentToken);
+    assert.equal(res.status, 200, `got ${res.status}`);
+    assert.ok(res.body.sims.some(s => s.id === 'pendulum'), 'pendulum in reverse lookup');
+  });
+
+  it('reverse lookup excludes disabled sims', async () => {
+    await inject('PATCH', '/api/lab/sims/pendulum', { enabled: false }, adminToken);
+    const res = await inject('GET',
+      `/api/lab/links?kind=textbook&ref_id=${encodeURIComponent(tbSlug)}`, null, studentToken);
+    assert.ok(!res.body.sims.some(s => s.id === 'pendulum'), 'disabled pendulum excluded');
+    await inject('PATCH', '/api/lab/sims/pendulum', { enabled: true }, adminToken); // restore
+  });
+
+  it('reverse lookup: bad kind → 400', async () => {
+    const res = await inject('GET', '/api/lab/links?kind=nope&ref_id=x', null, studentToken);
+    assert.equal(res.status, 400);
+  });
+
+  it('admin can delete a link; related reflects removal', async () => {
+    // find the textbook link id
+    const rel = await inject('GET', '/api/lab/sims/pendulum/related', null, adminToken);
+    const linkId = rel.body.links.textbook[0].id;
+    const del = await inject('DELETE', `/api/lab/sims/pendulum/links/${linkId}`, null, adminToken);
+    assert.equal(del.status, 200, `got ${del.status}`);
+    const rel2 = await inject('GET', '/api/lab/sims/pendulum/related', null, adminToken);
+    assert.equal(rel2.body.links.textbook.length, 0, 'textbook link gone');
+  });
+
+  it('delete unknown link → 404', async () => {
+    const res = await inject('DELETE', '/api/lab/sims/pendulum/links/999999', null, adminToken);
+    assert.equal(res.status, 404);
+  });
+
+  it('delete is admin-only (student → 403)', async () => {
+    const res = await inject('DELETE', '/api/lab/sims/pendulum/links/1', null, studentToken);
+    assert.equal(res.status, 403);
+  });
+});