diff --git a/backend/__tests__/integration/galleryShortUrlRoute.test.js b/backend/__tests__/integration/galleryShortUrlRoute.test.js
new file mode 100644
index 00000000..fd157c84
--- /dev/null
+++ b/backend/__tests__/integration/galleryShortUrlRoute.test.js
@@ -0,0 +1,231 @@
+/**
+ * HTTP-level tests for the `/s/:shortSlug` public resolver (#699).
+ *
+ * Verifies the contract the public route is expected to honour:
+ *   - Browser UA → 302 to target_path
+ *   - Social crawler UA → 200 with OG <meta>, canonical = /s/<slug>
+ *   - Soft-deleted slug → 410 Gone (intentional-delete signal)
+ *   - Unknown slug → 404 Not Found
+ *   - Hit count increments after successful resolutions (both shapes)
+ *
+ * Mirrors the production server.js wiring but doesn't load the whole
+ * server — the surrounding middleware (CORS, helmet, rate limiters)
+ * isn't part of this route's contract.
+ */
+const express = require('express');
+const request = require('supertest');
+
+const { bootCrmDb } = require('./helpers/crmDb');
+
+jest.setTimeout(60000);
+
+let db; let cleanup; let service; let app;
+
+beforeAll(async () => {
+  ({ db, cleanup } = await bootCrmDb());
+
+  // Persist a business_profile + business_name so buildOgMetadata's
+  // settings-based fields populate consistently.
+  const { upsertAppSetting } = require('../../src/utils/appSettings');
+  await upsertAppSetting('branding_company_name', JSON.stringify('Test Studio'), 'string');
+
+  service = require('../../src/services/galleryShortUrlService');
+  const {
+    isSocialCrawler, buildOgMetadata, renderOgHtml,
+  } = require('../../src/services/galleryOgService');
+
+  app = express();
+  app.get('/s/:shortSlug', async (req, res) => {
+    try {
+      const row = await service.findByShortSlug(req.params.shortSlug);
+      if (!row) return res.status(404).type('text/plain').send('Short URL not found');
+      if (row.deleted_at) return res.status(410).type('text/plain').send('Short URL has been removed');
+
+      if (isSocialCrawler(req.get('user-agent'))) {
+        const event = await db('events').where({ id: row.event_id }).first('slug');
+        if (event?.slug) {
+          const meta = await buildOgMetadata(event.slug, req.originalUrl);
+          const base = (process.env.FRONTEND_URL || 'http://localhost:3000').replace(/\/$/, '');
+          meta.url = `${base}/s/${row.short_slug}`;
+          res.set('Cache-Control', 'public, max-age=300');
+          res.set('Content-Type', 'text/html; charset=utf-8');
+          res.send(renderOgHtml(meta));
+          service.recordHit(row.id).catch(() => {});
+          return;
+        }
+        return res.status(410).type('text/plain').send('Short URL points at a deleted event');
+      }
+
+      service.recordHit(row.id).catch(() => {});
+      return res.redirect(302, row.target_path);
+    } catch (err) {
+      return res.status(500).type('text/plain').send(err.message);
+    }
+  });
+}, 120000);
+
+afterAll(async () => { if (cleanup) await cleanup(); });
+
+async function seedEventAndShortUrl({ slug = `evt-${Date.now()}`, shortSlug }) {
+  const farFuture = new Date(Date.now() + 365 * 86400000).toISOString();
+  const [eventId] = await db('events').insert({
+    slug,
+    event_type: 'wedding',
+    event_name: 'Test Event',
+    event_date: '2026-06-05',
+    password_hash: 'x',
+    expires_at: farFuture,
+    is_active: true,
+    is_archived: false,
+    share_link: slug,
+    share_token: `tok${Math.random().toString(36).slice(2, 12)}`,
+    welcome_message: null,
+  });
+  const row = await service.createShortUrl({
+    eventId, customSlug: shortSlug,
+  });
+  return { eventId, shortUrl: row };
+}
+
+// User-agent strings the production `isSocialCrawler` helper matches.
+// Snapshot known-true samples here so the test stays in sync if the
+// helper's allowlist evolves.
+const BOT_UA_WHATSAPP = 'WhatsApp/2.23.20.0';
+const BOT_UA_FACEBOOK = 'facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)';
+const BROWSER_UA = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15';
+
+describe('GET /s/:shortSlug — browser (302 redirect)', () => {
+  it('redirects to the snapshotted target_path with a 302', async () => {
+    const { shortUrl } = await seedEventAndShortUrl({
+      slug: 'browser-redirect', shortSlug: 'go-here',
+    });
+    const res = await request(app)
+      .get('/s/go-here')
+      .set('User-Agent', BROWSER_UA);
+    expect(res.status).toBe(302);
+    expect(res.headers.location).toBe(shortUrl.target_path);
+    expect(res.headers.location).toMatch(/^\/gallery\//);
+  });
+
+  it('increments hit_count on a browser hit (fire-and-forget — wait briefly)', async () => {
+    await seedEventAndShortUrl({
+      slug: 'hit-browser', shortSlug: 'hit-from-browser',
+    });
+    await request(app).get('/s/hit-from-browser').set('User-Agent', BROWSER_UA);
+    await new Promise((r) => setTimeout(r, 50));
+    const row = await service.findByShortSlug('hit-from-browser');
+    expect(row.hit_count).toBe(1);
+    expect(row.last_hit_at).toBeTruthy();
+  });
+});
+
+describe('GET /s/:shortSlug — social crawler (OG metadata)', () => {
+  it('returns 200 with OG HTML for WhatsApp UA', async () => {
+    await seedEventAndShortUrl({
+      slug: 'whatsapp-og', shortSlug: 'wa-preview',
+    });
+    const res = await request(app)
+      .get('/s/wa-preview')
+      .set('User-Agent', BOT_UA_WHATSAPP);
+    expect(res.status).toBe(200);
+    expect(res.headers['content-type']).toMatch(/text\/html/);
+    expect(res.text).toContain('<meta');
+    expect(res.text).toMatch(/og:title/);
+    expect(res.text).toMatch(/og:url/);
+  });
+
+  it('og:url canonical points at /s/<slug>, not the underlying gallery URL', async () => {
+    await seedEventAndShortUrl({
+      slug: 'canonical-test', shortSlug: 'canonical-short',
+    });
+    const res = await request(app)
+      .get('/s/canonical-short')
+      .set('User-Agent', BOT_UA_FACEBOOK);
+    expect(res.status).toBe(200);
+    // The og:url meta tag must contain the short-URL path, not the
+    // /gallery/<slug> path — this is the cache-key invariant from #699.
+    expect(res.text).toMatch(/property="og:url"\s+content="[^"]*\/s\/canonical-short"/);
+    expect(res.text).not.toMatch(
+      /property="og:url"\s+content="[^"]*\/gallery\/canonical-test"/
+    );
+  });
+
+  it('sets a short cache header so scrapers can re-fetch when admin rotates the preview', async () => {
+    await seedEventAndShortUrl({
+      slug: 'cache-header', shortSlug: 'cache-test',
+    });
+    const res = await request(app)
+      .get('/s/cache-test')
+      .set('User-Agent', BOT_UA_WHATSAPP);
+    expect(res.headers['cache-control']).toMatch(/public/);
+    expect(res.headers['cache-control']).toMatch(/max-age=300/);
+  });
+
+  it('increments hit_count on a crawler hit as well', async () => {
+    await seedEventAndShortUrl({
+      slug: 'hit-bot', shortSlug: 'hit-from-bot',
+    });
+    await request(app).get('/s/hit-from-bot').set('User-Agent', BOT_UA_WHATSAPP);
+    await new Promise((r) => setTimeout(r, 50));
+    const row = await service.findByShortSlug('hit-from-bot');
+    expect(row.hit_count).toBe(1);
+  });
+});
+
+describe('GET /s/:shortSlug — error states', () => {
+  it('404 for an unknown slug', async () => {
+    const res = await request(app)
+      .get('/s/never-existed')
+      .set('User-Agent', BROWSER_UA);
+    expect(res.status).toBe(404);
+  });
+
+  it('410 for a soft-deleted slug (intentional-delete signal)', async () => {
+    const { shortUrl } = await seedEventAndShortUrl({
+      slug: 'gone-test', shortSlug: 'gone-slug',
+    });
+    await service.softDelete(shortUrl.id, null);
+    const res = await request(app)
+      .get('/s/gone-slug')
+      .set('User-Agent', BROWSER_UA);
+    expect(res.status).toBe(410);
+  });
+
+  it('410 if the event was hard-deleted but the short URL row somehow survives', async () => {
+    const { eventId } = await seedEventAndShortUrl({
+      slug: 'orphan-test', shortSlug: 'orphan-slug',
+    });
+    // Hard-delete the event row (FK CASCADE would normally clean up the
+    // short URL too — but if CASCADE didn't fire for whatever reason
+    // (e.g. SQLite foreign_keys pragma off in a particular runtime), the
+    // resolver should still degrade safely).
+    // SQLite's foreign_keys pragma is OFF by default; the migration
+    // doesn't toggle it, so this delete leaves the short URL row.
+    await db('events').where({ id: eventId }).delete();
+    const res = await request(app)
+      .get('/s/orphan-slug')
+      .set('User-Agent', BOT_UA_WHATSAPP);
+    expect(res.status).toBe(410);
+  });
+
+  it('404 for a malformed slug (rejected at validation, no DB hit)', async () => {
+    const res = await request(app)
+      .get('/s/UPPER_CASE')
+      .set('User-Agent', BROWSER_UA);
+    expect(res.status).toBe(404);
+  });
+});
+
+describe('Regression — existing URL paths must still respond the same', () => {
+  // The /s/* namespace is additive: it must NOT shadow /gallery/*
+  // or any of the OG routes. We don't load the whole app here, but we
+  // can at least pin that the route param doesn't accept slashes —
+  // i.e. /s/foo/bar must NOT be matched by our handler.
+  it('the /s/:shortSlug route does not match nested paths', async () => {
+    const res = await request(app)
+      .get('/s/foo/bar')
+      .set('User-Agent', BROWSER_UA);
+    // Express returns its default 404 when no route matches the path.
+    expect(res.status).toBe(404);
+  });
+});
diff --git a/backend/__tests__/integration/galleryShortUrls.test.js b/backend/__tests__/integration/galleryShortUrls.test.js
new file mode 100644
index 00000000..cc3b40ec
--- /dev/null
+++ b/backend/__tests__/integration/galleryShortUrls.test.js
@@ -0,0 +1,282 @@
+/**
+ * Integration tests for the branded short-URL service (#699).
+ *
+ * Exercises createShortUrl + findByShortSlug + listForEvent + softDelete
+ * + recordHit against a real SQLite DB, including the contracts that
+ * matter for production correctness:
+ *
+ *   - Custom slug + collision detection (409 with `suggested`)
+ *   - Auto-generated slug from event slug + year
+ *   - Soft-delete preserves the row (admin can audit)
+ *   - target_path snapshots at create time (toggling the global
+ *     "Use short gallery URLs" setting later doesn't change existing
+ *     short URLs — backward-compat invariant from #699)
+ *   - hit_count increments idempotently
+ *   - findByShortSlug returns soft-deleted rows (caller decides 410 vs 404)
+ *
+ * Boots one DB for the whole file (cheap on SQLite); each test seeds
+ * its own event row to keep scope clean.
+ */
+const { bootCrmDb } = require('./helpers/crmDb');
+
+jest.setTimeout(60000);
+
+let db; let cleanup; let service; let adminId;
+
+beforeAll(async () => {
+  ({ db, cleanup } = await bootCrmDb());
+
+  // Minimal admin for created_by audit.
+  const adminInsert = await db('admin_users').insert({
+    username: 'shorturl-test',
+    email: 'shorturl@example.com',
+    password_hash: 'x',
+    must_change_password: false,
+    created_at: new Date(),
+  }).returning('id');
+  adminId = adminInsert[0]?.id ?? adminInsert[0];
+
+  service = require('../../src/services/galleryShortUrlService');
+}, 120000);
+
+afterAll(async () => { if (cleanup) await cleanup(); });
+
+// Each test seeds a fresh event so collisions / counter state don't leak.
+async function seedEvent(overrides = {}) {
+  const slug = overrides.slug || `evt-${Date.now()}-${Math.random().toString(36).slice(2, 6)}`;
+  const farFuture = new Date(Date.now() + 365 * 86400000).toISOString();
+  const [id] = await db('events').insert({
+    slug,
+    event_type: 'wedding',
+    event_name: overrides.event_name || 'Test Wedding',
+    event_date: overrides.event_date || '2026-06-05',
+    password_hash: 'x',
+    expires_at: farFuture,
+    is_active: true,
+    is_archived: false,
+    share_link: slug,
+    share_token: overrides.share_token || `tok${Math.random().toString(36).slice(2, 12)}`,
+    welcome_message: null,
+  });
+  const event = await db('events').where({ id }).first();
+  return event;
+}
+
+describe('createShortUrl — custom slug', () => {
+  it('creates with a custom slug', async () => {
+    const event = await seedEvent({ slug: 'sofia-grad-1' });
+    const row = await service.createShortUrl({
+      eventId: event.id,
+      customSlug: 'sofia-graduation-1',
+      createdBy: adminId,
+    });
+    expect(row.short_slug).toBe('sofia-graduation-1');
+    expect(row.target_path).toBe(`/gallery/${event.slug}`);
+    expect(row.event_id).toBe(event.id);
+    expect(row.hit_count).toBe(0);
+  });
+
+  it('lowercases the input — operators pasting mixed-case still get a clean slug', async () => {
+    const event = await seedEvent({ slug: 'sofia-grad-2' });
+    const row = await service.createShortUrl({
+      eventId: event.id,
+      customSlug: 'Sofia-GraduAtion-2',  // mixed case
+      createdBy: adminId,
+    });
+    expect(row.short_slug).toBe('sofia-graduation-2');
+  });
+
+  it('rejects an invalid slug with INVALID_SLUG code', async () => {
+    const event = await seedEvent({ slug: 'invalid-test' });
+    await expect(service.createShortUrl({
+      eventId: event.id,
+      customSlug: 'invalid slug with spaces',
+      createdBy: adminId,
+    })).rejects.toMatchObject({ code: 'INVALID_SLUG' });
+  });
+
+  it('rejects a reserved slug with INVALID_SLUG code', async () => {
+    const event = await seedEvent({ slug: 'reserved-test' });
+    await expect(service.createShortUrl({
+      eventId: event.id,
+      customSlug: 'admin',
+      createdBy: adminId,
+    })).rejects.toMatchObject({ code: 'INVALID_SLUG' });
+  });
+
+  it('rejects a duplicate slug with SLUG_TAKEN + suggested fallback', async () => {
+    const event1 = await seedEvent({ slug: 'dup-test-1' });
+    const event2 = await seedEvent({ slug: 'dup-test-2' });
+    await service.createShortUrl({ eventId: event1.id, customSlug: 'collide-me' });
+    await expect(service.createShortUrl({
+      eventId: event2.id, customSlug: 'collide-me',
+    })).rejects.toMatchObject({
+      code: 'SLUG_TAKEN',
+      suggested: expect.any(String),
+    });
+  });
+
+  it('throws EVENT_NOT_FOUND when the event id does not exist', async () => {
+    await expect(service.createShortUrl({
+      eventId: 9999999, customSlug: 'no-event',
+    })).rejects.toMatchObject({ code: 'EVENT_NOT_FOUND' });
+  });
+});
+
+describe('createShortUrl — auto-generated slug', () => {
+  it('uses event slug + year when no custom slug provided', async () => {
+    const event = await seedEvent({
+      slug: 'autogen-wedding', event_date: '2026-06-05',
+    });
+    const row = await service.createShortUrl({
+      eventId: event.id,
+      createdBy: adminId,
+    });
+    // First-choice candidate is just the slug; takes that.
+    expect(row.short_slug).toBe('autogen-wedding');
+  });
+
+  it('falls back to slug-year when the bare slug is already taken', async () => {
+    // Both events SHARE the same canonical slug so the first-choice
+    // bare-slug candidate is burned, forcing autoGen to try the
+    // year-suffixed variant.
+    const event1 = await seedEvent({
+      slug: 'collide-base', event_date: '2026-07-01',
+    });
+    await service.createShortUrl({
+      eventId: event1.id, customSlug: 'collide-base',
+    });
+    const event2 = await seedEvent({
+      slug: 'collide-base-2', event_date: '2026-07-01',
+    });
+    // Force the bare candidate of event2 to also collide by burning it.
+    await service.createShortUrl({
+      eventId: event1.id, customSlug: 'collide-base-2',
+    });
+    const row = await service.createShortUrl({
+      eventId: event2.id,  // No custom — auto-gen from event2.slug
+    });
+    // Bare candidate `collide-base-2` is taken → year-suffixed picks.
+    expect(row.short_slug).toBe('collide-base-2-2026');
+  });
+});
+
+describe('createShortUrl — target_path snapshotting (#699 backward-compat)', () => {
+  it('uses /gallery/<slug> when the global short-URLs setting is OFF (default)', async () => {
+    const event = await seedEvent({ slug: 'snapshot-off' });
+    const row = await service.createShortUrl({
+      eventId: event.id, customSlug: 'snap-off',
+    });
+    expect(row.target_path).toBe(`/gallery/${event.slug}`);
+  });
+
+  it('uses /gallery/<share_token> when the global setting is ON at create time', async () => {
+    // Persist the setting.
+    const { upsertAppSetting } = require('../../src/utils/appSettings');
+    await upsertAppSetting('general_use_short_gallery_urls', JSON.stringify(true), 'system');
+    try {
+      const event = await seedEvent({ slug: 'snapshot-on', share_token: 'tokenAbc123' });
+      const row = await service.createShortUrl({
+        eventId: event.id, customSlug: 'snap-on',
+      });
+      expect(row.target_path).toBe(`/gallery/${event.share_token}`);
+
+      // CRITICAL backward-compat invariant: now flip the setting OFF.
+      // Existing short URLs must still resolve to the same target_path
+      // they were created with — operator's existing share links don't
+      // silently change behaviour.
+      await upsertAppSetting('general_use_short_gallery_urls', JSON.stringify(false), 'system');
+      const refetched = await service.findByShortSlug('snap-on');
+      expect(refetched.target_path).toBe(`/gallery/${event.share_token}`);
+    } finally {
+      await upsertAppSetting('general_use_short_gallery_urls', JSON.stringify(false), 'system');
+    }
+  });
+});
+
+describe('findByShortSlug + listForEvent', () => {
+  it('returns null for an unknown slug', async () => {
+    expect(await service.findByShortSlug('does-not-exist-xyz')).toBeNull();
+  });
+
+  it('returns null for a malformed slug (no DB hit)', async () => {
+    expect(await service.findByShortSlug('UPPER_CASE')).toBeNull();
+    expect(await service.findByShortSlug('with spaces')).toBeNull();
+    expect(await service.findByShortSlug('')).toBeNull();
+  });
+
+  it('returns soft-deleted rows (caller decides 410 vs 404)', async () => {
+    const event = await seedEvent({ slug: 'softdel-find' });
+    const created = await service.createShortUrl({
+      eventId: event.id, customSlug: 'find-deleted',
+    });
+    await service.softDelete(created.id, adminId);
+    const fetched = await service.findByShortSlug('find-deleted');
+    expect(fetched).not.toBeNull();
+    expect(fetched.deleted_at).toBeTruthy();
+  });
+
+  it('listForEvent excludes soft-deleted rows', async () => {
+    const event = await seedEvent({ slug: 'list-test' });
+    const live = await service.createShortUrl({
+      eventId: event.id, customSlug: 'list-live',
+    });
+    const deleted = await service.createShortUrl({
+      eventId: event.id, customSlug: 'list-deleted',
+    });
+    await service.softDelete(deleted.id, adminId);
+    const list = await service.listForEvent(event.id);
+    const ids = list.map((r) => r.id);
+    expect(ids).toContain(live.id);
+    expect(ids).not.toContain(deleted.id);
+  });
+});
+
+describe('softDelete', () => {
+  it('returns true on first call, false on second (idempotent admin clicks)', async () => {
+    const event = await seedEvent({ slug: 'softdel-idem' });
+    const created = await service.createShortUrl({
+      eventId: event.id, customSlug: 'idem-delete',
+    });
+    expect(await service.softDelete(created.id, adminId)).toBe(true);
+    expect(await service.softDelete(created.id, adminId)).toBe(false);
+  });
+
+  it('returns false for an unknown id (caller maps to 404)', async () => {
+    expect(await service.softDelete(9999999, adminId)).toBe(false);
+  });
+});
+
+describe('createShortUrl after soft-delete — slug rotation', () => {
+  it('re-creating a soft-deleted slug succeeds (purges the deleted row)', async () => {
+    const event = await seedEvent({ slug: 'rotate' });
+    const first = await service.createShortUrl({
+      eventId: event.id, customSlug: 'rotate-me',
+    });
+    await service.softDelete(first.id, adminId);
+    // The slug is now reclaimable for a fresh row.
+    const second = await service.createShortUrl({
+      eventId: event.id, customSlug: 'rotate-me',
+    });
+    expect(second.id).not.toBe(first.id);
+    expect(second.short_slug).toBe('rotate-me');
+  });
+});
+
+describe('recordHit', () => {
+  it('increments hit_count + stamps last_hit_at', async () => {
+    const event = await seedEvent({ slug: 'hit-counter' });
+    const row = await service.createShortUrl({
+      eventId: event.id, customSlug: 'count-me',
+    });
+    await service.recordHit(row.id);
+    await service.recordHit(row.id);
+    const fetched = await service.findByShortSlug('count-me');
+    expect(fetched.hit_count).toBe(2);
+    expect(fetched.last_hit_at).toBeTruthy();
+  });
+
+  it('is fire-and-forget — invalid id does not throw', async () => {
+    await expect(service.recordHit(9999999)).resolves.not.toThrow();
+  });
+});
diff --git a/backend/__tests__/utils/galleryShortUrlValidation.test.js b/backend/__tests__/utils/galleryShortUrlValidation.test.js
new file mode 100644
index 00000000..cc66d1e2
--- /dev/null
+++ b/backend/__tests__/utils/galleryShortUrlValidation.test.js
@@ -0,0 +1,120 @@
+/**
+ * Pure-function tests for the slug validator in galleryShortUrlService.
+ * The validator is the security boundary for the `/s/<slug>` public
+ * route — bad shapes leak into a UNIQUE column that's used in URLs
+ * without further escaping, so the rules need to be tight.
+ */
+
+// Provide a minimal db stub so requiring the service doesn't crash —
+// the validator path doesn't touch the DB.
+jest.mock('../../src/database/db', () => ({ db: jest.fn() }));
+jest.mock('../../src/utils/logger', () => ({
+  info: jest.fn(), warn: jest.fn(), error: jest.fn(), debug: jest.fn(),
+}));
+jest.mock('../../src/utils/appSettings', () => ({
+  getAppSetting: jest.fn().mockResolvedValue(false),
+}));
+
+const {
+  validateSlug,
+  _RESERVED_SLUGS,
+} = require('../../src/services/galleryShortUrlService');
+
+describe('validateSlug', () => {
+  describe('accepts', () => {
+    test.each([
+      'sofia-graduation',
+      'sofia',
+      'a',                   // single char (alphanumeric)
+      '1',                   // single digit
+      'abc123',
+      '123-abc',
+      'sofia-2026-06-05',
+      'sofia-2026',
+      'a-b-c-d',
+      'wedding-2026',
+      'xK7p2'.toLowerCase(), // lowercase 5-char
+      'a'.repeat(64),        // exactly at the limit
+    ])('%j', (slug) => {
+      expect(validateSlug(slug)).toBeNull();
+    });
+  });
+
+  describe('rejects', () => {
+    test.each([
+      ['', 'cannot be empty'],
+      ['   ', 'cannot be empty'],          // trimmed → empty
+      ['-sofia', 'lowercase letters'],     // leading hyphen
+      ['sofia-', 'lowercase letters'],     // trailing hyphen
+      ['Sofia', 'lowercase letters'],      // uppercase
+      ['sofia_graduation', 'lowercase letters'],  // underscore
+      ['sofia.graduation', 'lowercase letters'],  // dot
+      ['sofia graduation', 'lowercase letters'],  // space
+      ['sofia/graduation', 'lowercase letters'],  // slash (path traversal vector)
+      ['sofia%20graduation', 'lowercase letters'],
+      ['a'.repeat(65), 'at most 64'],      // one over limit
+    ])('%j → %s', (slug, expectedReason) => {
+      const result = validateSlug(slug);
+      expect(result).not.toBeNull();
+      expect(result.toLowerCase()).toContain(expectedReason);
+    });
+
+    test('null', () => {
+      expect(validateSlug(null)).toContain('must be a string');
+    });
+
+    test('undefined', () => {
+      expect(validateSlug(undefined)).toContain('must be a string');
+    });
+
+    test('number', () => {
+      expect(validateSlug(42)).toContain('must be a string');
+    });
+
+    test('object', () => {
+      expect(validateSlug({})).toContain('must be a string');
+    });
+  });
+
+  describe('reserved slugs', () => {
+    test.each([
+      'admin',
+      'api',
+      'auth',
+      'gallery',
+      'og',
+      'health',
+      's',           // can't shadow the shortener itself
+      'login',
+      'favicon.ico', // even with the dot — covered by SLUG_REGEX fail too
+    ])('reserves %j', (slug) => {
+      expect(_RESERVED_SLUGS.has(slug)).toBe(true);
+    });
+
+    test('"admin" → rejected with "reserved" reason', () => {
+      // validateSlug short-circuits at the regex for slugs containing
+      // dots (favicon.ico fails the regex first). Test a clean
+      // alphanumeric reserved word.
+      const result = validateSlug('admin');
+      expect(result).toBe('short_slug is reserved');
+    });
+  });
+
+  describe('path-traversal + URL-injection vectors are rejected at the regex', () => {
+    test.each([
+      '../etc/passwd',
+      'foo/../bar',
+      'foo?query=1',
+      'foo#fragment',
+      'foo&bar',
+      'foo bar',
+      'foo<script>',
+      'foo>',
+      'foo"',
+      'foo\'',
+      'foo;rm -rf',
+    ])('%j', (slug) => {
+      expect(validateSlug(slug)).not.toBeNull();
+    });
+  });
+});
diff --git a/backend/migrations/core/150_add_gallery_short_urls.js b/backend/migrations/core/150_add_gallery_short_urls.js
new file mode 100644
index 00000000..5032c932
--- /dev/null
+++ b/backend/migrations/core/150_add_gallery_short_urls.js
@@ -0,0 +1,67 @@
+/**
+ * Migration 150: branded URL shortener for gallery share links (#699).
+ *
+ * Lets admins create custom-named short URLs that resolve to a gallery's
+ * full link (e.g. `/s/sofia-graduation` → `/gallery/<slug>`). The short
+ * URL itself answers bot-UA requests with server-rendered OG metadata,
+ * so the SHORT URL is the one that shows the rich preview in iMessage /
+ * Facebook / WhatsApp — not just the destination.
+ *
+ * Backward-compat invariant: this migration only ADDS a new table. No
+ * existing route, table, or column is touched. Operators upgrading
+ * through this migration can opt into creating short URLs per event,
+ * but every existing `/gallery/...` link continues to resolve identically
+ * — the new feature is additive.
+ */
+exports.up = async function (knex) {
+  if (await knex.schema.hasTable('gallery_short_urls')) return;
+
+  await knex.schema.createTable('gallery_short_urls', (t) => {
+    t.increments('id').primary();
+    // Public-facing slug — what appears in /s/<short_slug>. Case-folded
+    // to lowercase at write time by the service; the UNIQUE index here
+    // is the last line of defence against collisions.
+    t.string('short_slug', 64).notNullable().unique();
+    // Hard FK to events — when an admin deletes an event, its short
+    // URLs go with it. ON DELETE CASCADE is the natural model: a short
+    // URL that points at a vanished gallery has no useful behaviour.
+    t.integer('event_id').notNullable()
+      .references('id').inTable('events').onDelete('CASCADE');
+    // Where the short URL resolves to — usually `/gallery/<slug>` or
+    // `/gallery/<share_token>` depending on the operator's #525
+    // "Use short gallery URLs" setting at create time. Stored at create
+    // time so a later flip of the global toggle doesn't silently change
+    // what existing short URLs redirect to.
+    t.text('target_path').notNullable();
+    // For the audit trail + admin UI ("created by Alex two days ago").
+    t.integer('created_by').references('id').inTable('admin_users');
+    t.timestamp('created_at').notNullable().defaultTo(knex.fn.now());
+    // Tiny analytics — admins want to know "is this branded link
+    // actually being clicked?" without a separate analytics service.
+    t.integer('hit_count').notNullable().defaultTo(0);
+    t.timestamp('last_hit_at');
+    // Soft-delete semantics: a deleted short URL returns 410 Gone (not
+    // 404) so the admin sees their delete was intentional, and so a
+    // re-create with the same slug is an explicit "yes, replace" rather
+    // than accidentally taking over a stale link. The UNIQUE constraint
+    // on short_slug means re-create after delete requires either NULLing
+    // the deleted row's slug or hard-deleting it; service layer handles
+    // that explicitly.
+    t.timestamp('deleted_at');
+    t.integer('deleted_by').references('id').inTable('admin_users');
+  });
+
+  // Read patterns:
+  //  - /s/:slug hot path — UNIQUE constraint on short_slug already
+  //    provides the index. No additional index needed.
+  //  - Admin UI "list short URLs for this event" — index event_id.
+  await knex.schema.alterTable('gallery_short_urls', (t) => {
+    t.index(['event_id'], 'gallery_short_urls_event_id_idx');
+  });
+};
+
+exports.down = async function (knex) {
+  if (await knex.schema.hasTable('gallery_short_urls')) {
+    await knex.schema.dropTable('gallery_short_urls');
+  }
+};
diff --git a/backend/server.js b/backend/server.js
index f1e57809..165d4342 100644
--- a/backend/server.js
+++ b/backend/server.js
@@ -543,6 +543,68 @@ app.get('/og/gallery/:slug', handleGalleryOgRequest);
 // returns 404 unless the opt-in is on AND a hero_photo_id is set.
 app.get('/og/gallery/:slug/cover', handleGalleryOgCover);
 
+// Branded URL shortener (#699). /s/<short_slug> is bot-UA aware:
+//   - Social crawler → server-render OG for the target event so the
+//     SHORT URL itself is what scrapes cache against. The og:url canonical
+//     in the rendered HTML points back at /s/<slug>, not the underlying
+//     gallery URL — so a re-share of the same short URL keeps the cache
+//     warm even if the underlying gallery slug rotates.
+//   - Browser → 302 to the stored target_path. The target_path was
+//     captured at create time from the event's slug + share_token + the
+//     global "Use short gallery URLs" setting, so it doesn't silently
+//     change later.
+//   - Soft-deleted → 410 Gone so the admin can tell their delete worked
+//     vs. a typo'd unknown slug (which returns 404).
+const galleryShortUrlService = require('./src/services/galleryShortUrlService');
+const { buildOgMetadata, renderOgHtml } = require('./src/services/galleryOgService');
+app.get('/s/:shortSlug', async (req, res) => {
+  try {
+    const row = await galleryShortUrlService.findByShortSlug(req.params.shortSlug);
+    if (!row) {
+      return res.status(404).type('text/plain').send('Short URL not found');
+    }
+    if (row.deleted_at) {
+      return res.status(410).type('text/plain').send('Short URL has been removed');
+    }
+
+    // Bot UA → render OG metadata for the target event. We look up the
+    // event via the short URL's event_id rather than re-parsing the
+    // target_path so a future migration that adds new target shapes
+    // (slideshow, client-access) doesn't need to rewrite the URL parser.
+    if (isSocialCrawler(req.get('user-agent'))) {
+      const event = await require('./src/database/db').db('events')
+        .where({ id: row.event_id })
+        .first('slug');
+      if (event?.slug) {
+        const meta = await buildOgMetadata(event.slug, req.originalUrl);
+        // Override the canonical to point at the SHORT URL itself —
+        // social platforms cache OG by URL, and the short URL is the
+        // one operators actually share, so that's the cache key we
+        // want them to stick with.
+        const base = (process.env.FRONTEND_URL || 'http://localhost:3000').replace(/\/$/, '');
+        meta.url = `${base}/s/${row.short_slug}`;
+        res.set('Cache-Control', 'public, max-age=300');
+        res.set('Content-Type', 'text/html; charset=utf-8');
+        res.send(renderOgHtml(meta));
+        // Hit accounting is fire-and-forget — don't block the bot.
+        galleryShortUrlService.recordHit(row.id).catch(() => {});
+        return;
+      }
+      // Event disappeared (FK CASCADE in flight, or admin hard-deleted
+      // outside the normal soft-delete path) — fall through to 410 so
+      // the scraper sees a clean signal.
+      return res.status(410).type('text/plain').send('Short URL points at a deleted event');
+    }
+
+    // Browser path: redirect. Hit accounting is fire-and-forget.
+    galleryShortUrlService.recordHit(row.id).catch(() => {});
+    return res.redirect(302, row.target_path);
+  } catch (err) {
+    logger.error('Short URL resolver failed', { slug: req.params.shortSlug, error: err.message });
+    return res.status(500).type('text/plain').send('Internal server error');
+  }
+});
+
 // robots.txt endpoint (dynamic, served from DB settings)
 const { generateRobotsTxt } = require('./src/services/robotsTxtService');
 app.get('/robots.txt', async (req, res) => {
@@ -638,6 +700,10 @@ app.use('/api/gallery', require('./src/routes/galleryGuests'));
 app.use('/api/admin', adminRoutes);
 app.use('/api/admin/auth', adminAuthRoutes);
 app.use('/api/admin/system', require('./src/routes/adminSystem'));
+// Branded URL shortener admin CRUD (#699) — list/create/delete short URLs
+// per event. Mounted at /api/admin so the routes appear at
+// /api/admin/events/:eventId/short-urls and /api/admin/short-urls/:id.
+app.use('/api/admin', require('./src/routes/adminShortUrls'));
 app.use('/api/admin/feature-flags', require('./src/routes/adminFeatureFlags'));
 app.use('/api/admin/whatsapp', require('./src/routes/adminWhatsapp'));
 app.use('/api/admin/backup', require('./src/routes/adminBackup'));
diff --git a/backend/src/routes/adminShortUrls.js b/backend/src/routes/adminShortUrls.js
new file mode 100644
index 00000000..6a3d2759
--- /dev/null
+++ b/backend/src/routes/adminShortUrls.js
@@ -0,0 +1,114 @@
+/**
+ * Admin CRUD for the branded URL shortener (#699).
+ *
+ * - GET    /api/admin/events/:eventId/short-urls   — list per event
+ * - POST   /api/admin/events/:eventId/short-urls   — create (custom or auto-generated slug)
+ * - DELETE /api/admin/short-urls/:id               — soft-delete
+ *
+ * All paths require admin auth + `settings.view` permission (read) /
+ * `events.edit` permission (mutate) — short URLs are a per-event admin
+ * concern, gated by the same permission as editing the event itself.
+ */
+const express = require('express');
+const { body, param, validationResult } = require('express-validator');
+const { adminAuth } = require('../middleware/auth');
+const { requirePermission } = require('../middleware/permissions');
+const { requireEventOwnership } = require('../middleware/ownership');
+const galleryShortUrlService = require('../services/galleryShortUrlService');
+const logger = require('../utils/logger');
+
+const router = express.Router();
+
+router.use(adminAuth);
+
+/**
+ * GET /api/admin/events/:eventId/short-urls
+ * List live short URLs for an event.
+ */
+router.get(
+  '/events/:eventId/short-urls',
+  requirePermission('events.view'),
+  param('eventId').isInt({ min: 1 }),
+  requireEventOwnership,
+  async (req, res) => {
+    const errors = validationResult(req);
+    if (!errors.isEmpty()) return res.status(400).json({ errors: errors.array() });
+    try {
+      const rows = await galleryShortUrlService.listForEvent(parseInt(req.params.eventId, 10));
+      res.json({ shortUrls: rows });
+    } catch (err) {
+      logger.error('adminShortUrls.list failed', { error: err.message, eventId: req.params.eventId });
+      res.status(500).json({ error: 'Failed to list short URLs' });
+    }
+  },
+);
+
+/**
+ * POST /api/admin/events/:eventId/short-urls
+ * Body: { customSlug?: string }   — omit for auto-generated slug.
+ */
+router.post(
+  '/events/:eventId/short-urls',
+  requirePermission('events.edit'),
+  param('eventId').isInt({ min: 1 }),
+  body('customSlug').optional({ nullable: true })
+    .isString().isLength({ min: 1, max: 64 }),
+  requireEventOwnership,
+  async (req, res) => {
+    const errors = validationResult(req);
+    if (!errors.isEmpty()) return res.status(400).json({ errors: errors.array() });
+    try {
+      const row = await galleryShortUrlService.createShortUrl({
+        eventId: parseInt(req.params.eventId, 10),
+        customSlug: req.body.customSlug || null,
+        createdBy: req.admin?.id || null,
+      });
+      res.status(201).json(row);
+    } catch (err) {
+      // Structured-error fallthrough — the service tags collisions and
+      // validation failures with a `code` so the UI can surface a
+      // useful message + a suggested alternative slug.
+      if (err.code === 'INVALID_SLUG') {
+        return res.status(400).json({ error: err.message, code: err.code });
+      }
+      if (err.code === 'SLUG_TAKEN') {
+        return res.status(409).json({
+          error: err.message, code: err.code, suggested: err.suggested,
+        });
+      }
+      if (err.code === 'EVENT_NOT_FOUND') {
+        return res.status(404).json({ error: err.message, code: err.code });
+      }
+      logger.error('adminShortUrls.create failed', { error: err.message });
+      res.status(500).json({ error: 'Failed to create short URL' });
+    }
+  },
+);
+
+/**
+ * DELETE /api/admin/short-urls/:id
+ * Soft-delete. The public route serves 410 Gone on a deleted row so the
+ * admin can tell their delete worked (vs. 404 for an unknown slug).
+ */
+router.delete(
+  '/short-urls/:id',
+  requirePermission('events.edit'),
+  param('id').isInt({ min: 1 }),
+  async (req, res) => {
+    const errors = validationResult(req);
+    if (!errors.isEmpty()) return res.status(400).json({ errors: errors.array() });
+    try {
+      const ok = await galleryShortUrlService.softDelete(
+        parseInt(req.params.id, 10),
+        req.admin?.id || null,
+      );
+      if (!ok) return res.status(404).json({ error: 'Short URL not found' });
+      res.status(204).end();
+    } catch (err) {
+      logger.error('adminShortUrls.delete failed', { error: err.message });
+      res.status(500).json({ error: 'Failed to delete short URL' });
+    }
+  },
+);
+
+module.exports = router;
diff --git a/backend/src/services/galleryShortUrlService.js b/backend/src/services/galleryShortUrlService.js
new file mode 100644
index 00000000..c97972a1
--- /dev/null
+++ b/backend/src/services/galleryShortUrlService.js
@@ -0,0 +1,275 @@
+/**
+ * Branded URL shortener for gallery share links (#699).
+ *
+ * Admins create `/s/<short_slug>` URLs that resolve to a gallery's full
+ * link AND answer social-crawler scrapes with the gallery's OG preview.
+ * The short URL is what photographers actually paste into chat — the
+ * og:url canonical points back at the short URL itself, so each social
+ * platform's cache is keyed on the slug the operator chose, not the
+ * underlying gallery URL that may rotate.
+ *
+ * Behaviour decisions worth pinning here (and in the migration comment):
+ *   - Soft-delete with `deleted_at` so an accidental delete is recoverable.
+ *     Public route serves 410 Gone (not 404) on a soft-deleted slug so
+ *     the admin sees their delete was intentional in scrapes/logs.
+ *   - Re-creating a soft-deleted slug rotates ownership: the old row is
+ *     hard-deleted, the new row is created. The UNIQUE constraint on
+ *     short_slug enforces this — you can't have two live rows for the
+ *     same public path.
+ *   - target_path is captured AT CREATE TIME from the event's current
+ *     state (slug + share_token + the global "Use short gallery URLs"
+ *     toggle). A later flip of that toggle doesn't silently change
+ *     where existing short URLs resolve. Same principle as quote PDFs
+ *     snapshotting at issuance time.
+ */
+const { db } = require('../database/db');
+const logger = require('../utils/logger');
+const { getAppSetting } = require('../utils/appSettings');
+
+// Slug rules:
+//   - Lowercase a-z, digits, hyphens only
+//   - Must start with a letter or digit (no leading hyphen, no double-hyphen-leading)
+//   - 1-64 chars
+//   - Trailing hyphen disallowed to keep URLs tidy
+const SLUG_REGEX = /^[a-z0-9](?:[a-z0-9-]{0,62}[a-z0-9])?$/;
+
+// Reserved top-level paths the application already uses. Allowing a
+// short URL to shadow any of these would break either the app itself
+// (admin/api/auth) or future routes we may add (assets/static). The
+// public route is mounted at `/s/<slug>` so technically the only real
+// risk is shadowing other things mounted at `/s/...` — but operators
+// occasionally point Cloudflare rules at top-level paths, and keeping
+// a sane blocklist costs nothing.
+const RESERVED_SLUGS = new Set([
+  'admin', 'api', 'auth', 'assets', 'static', 'public', 'gallery',
+  'og', 'health', 'metrics', 'robots.txt', 's', 'docs', 'login',
+  'logout', 'signup', 'register', 'reset', 'reset-password', 'app',
+  'manifest.json', 'favicon.ico', 'sitemap.xml',
+]);
+
+/**
+ * Validate a candidate short slug.
+ * @returns {string|null} null if valid; otherwise a human-readable reason.
+ */
+function validateSlug(slug) {
+  if (typeof slug !== 'string') return 'short_slug must be a string';
+  const trimmed = slug.trim();
+  if (!trimmed) return 'short_slug cannot be empty';
+  if (trimmed.length > 64) return 'short_slug must be at most 64 characters';
+  if (!SLUG_REGEX.test(trimmed)) {
+    return 'short_slug must be lowercase letters, digits, and hyphens, starting and ending with a letter or digit';
+  }
+  if (RESERVED_SLUGS.has(trimmed)) return 'short_slug is reserved';
+  return null;
+}
+
+/**
+ * Compute the target path for a gallery short URL based on the event's
+ * current state + the global "Use short gallery URLs" setting. Snapshot
+ * this value at create time so future toggle flips don't silently
+ * change what existing short URLs resolve to.
+ */
+async function targetPathForEvent(event) {
+  if (!event) throw new Error('event required');
+  const useShortGallery = (await getAppSetting('general_use_short_gallery_urls', false)) === true;
+  if (useShortGallery && event.share_token) {
+    return `/gallery/${event.share_token}`;
+  }
+  return `/gallery/${event.slug}`;
+}
+
+/**
+ * Build candidate auto-generated slugs in preference order. Walks each
+ * candidate against the UNIQUE constraint and returns the first that's
+ * free. Falls back to a 6-char random alphanum if every shaped
+ * candidate collides.
+ *
+ *   <slug>           — when short and clean
+ *   <slug>-<year>    — e.g. senior-2026
+ *   <slug>-<random>  — last-ditch
+ */
+async function autoGenerateSlug(event) {
+  const base = String(event.slug || '').toLowerCase()
+    .replace(/[^a-z0-9]+/g, '-')
+    .replace(/^-+|-+$/g, '')
+    .slice(0, 48); // leave headroom for suffix
+  const year = event.event_date
+    ? new Date(event.event_date).getFullYear()
+    : new Date().getFullYear();
+
+  const candidates = [];
+  if (base) candidates.push(base);
+  if (base) candidates.push(`${base}-${year}`);
+
+  for (const cand of candidates) {
+    const validity = validateSlug(cand);
+    if (validity) continue; // skip if it'd fail validation (e.g. trailing hyphen)
+    const taken = await db('gallery_short_urls')
+      .where({ short_slug: cand })
+      .whereNull('deleted_at')
+      .first();
+    if (!taken) return cand;
+  }
+
+  // Random fallback. Six alphanum chars = ~31 bits of entropy; for a
+  // namespace of at-most-N-galleries-per-instance this is more than
+  // enough to avoid collisions in practice.
+  for (let attempt = 0; attempt < 5; attempt += 1) {
+    const random = Math.random().toString(36).slice(2, 8).replace(/[^a-z0-9]/g, '');
+    if (random.length < 6) continue;
+    const taken = await db('gallery_short_urls')
+      .where({ short_slug: random })
+      .whereNull('deleted_at')
+      .first();
+    if (!taken) return random;
+  }
+  throw new Error('Failed to auto-generate a unique short slug after 5 attempts');
+}
+
+/**
+ * Create a short URL for an event. `customSlug` is optional — when
+ * absent, we auto-generate from the event slug + year.
+ *
+ * Returns { id, short_slug, target_path, ... }.
+ *
+ * Throws on collision with a structured error:
+ *   { code: 'SLUG_TAKEN', suggested: 'sofia-graduation-2' }
+ */
+async function createShortUrl({ eventId, customSlug = null, createdBy = null }) {
+  const event = await db('events').where({ id: eventId }).first();
+  if (!event) {
+    const err = new Error('Event not found');
+    err.code = 'EVENT_NOT_FOUND';
+    throw err;
+  }
+
+  let slug;
+  if (customSlug != null) {
+    const lowered = String(customSlug).toLowerCase().trim();
+    const validityError = validateSlug(lowered);
+    if (validityError) {
+      const err = new Error(validityError);
+      err.code = 'INVALID_SLUG';
+      throw err;
+    }
+    // Collision check (only against live rows; soft-deleted rows are
+    // hard-deleted on conflict to keep the UNIQUE constraint sane).
+    const existing = await db('gallery_short_urls')
+      .where({ short_slug: lowered })
+      .first();
+    if (existing && !existing.deleted_at) {
+      const err = new Error(`Short slug '${lowered}' is already in use`);
+      err.code = 'SLUG_TAKEN';
+      err.suggested = await autoGenerateSlug({ ...event, slug: lowered });
+      throw err;
+    }
+    if (existing && existing.deleted_at) {
+      // Soft-deleted row in the way of the UNIQUE constraint — purge
+      // it so the admin can re-claim the slug. This is the intended
+      // "yes, replace the old link" path; if the admin wanted the old
+      // link back, they'd restore the soft-deleted row, not create a
+      // new one.
+      await db('gallery_short_urls').where({ id: existing.id }).delete();
+    }
+    slug = lowered;
+  } else {
+    slug = await autoGenerateSlug(event);
+  }
+
+  const targetPath = await targetPathForEvent(event);
+
+  const inserted = await db('gallery_short_urls').insert({
+    short_slug: slug,
+    event_id: event.id,
+    target_path: targetPath,
+    created_by: createdBy,
+    created_at: new Date(),
+    hit_count: 0,
+  }).returning(['id', 'short_slug', 'target_path', 'created_at']);
+
+  const row = inserted[0] || {};
+  logger.info('gallery_short_urls: created', {
+    shortSlug: slug, eventId: event.id, createdBy,
+  });
+  return {
+    id: row.id,
+    short_slug: row.short_slug || slug,
+    event_id: event.id,
+    target_path: row.target_path || targetPath,
+    created_at: row.created_at,
+    hit_count: 0,
+    last_hit_at: null,
+  };
+}
+
+/**
+ * Look up a short URL by its public slug. Returns null if not found.
+ * Soft-deleted rows are NOT filtered out here — callers decide how to
+ * present them (the public route uses presence-of-deleted_at to send
+ * 410 Gone instead of 404).
+ */
+async function findByShortSlug(slug) {
+  if (!slug || typeof slug !== 'string') return null;
+  const lowered = slug.toLowerCase().trim();
+  if (validateSlug(lowered)) return null; // malformed input — no lookup
+  const row = await db('gallery_short_urls').where({ short_slug: lowered }).first();
+  return row || null;
+}
+
+/**
+ * List all live short URLs for an event, newest first.
+ */
+async function listForEvent(eventId) {
+  const rows = await db('gallery_short_urls')
+    .where({ event_id: eventId })
+    .whereNull('deleted_at')
+    .orderBy('created_at', 'desc')
+    .select('id', 'short_slug', 'target_path', 'hit_count', 'last_hit_at', 'created_at', 'created_by');
+  return rows;
+}
+
+/**
+ * Soft-delete a short URL. Returns true if a row was affected, false
+ * otherwise (caller can map false → 404).
+ */
+async function softDelete(id, deletedBy = null) {
+  const affected = await db('gallery_short_urls')
+    .where({ id })
+    .whereNull('deleted_at')
+    .update({ deleted_at: new Date(), deleted_by: deletedBy });
+  if (affected) {
+    logger.info('gallery_short_urls: soft-deleted', { id, deletedBy });
+  }
+  return affected > 0;
+}
+
+/**
+ * Increment hit_count + stamp last_hit_at. Called from the public route
+ * AFTER the response has been queued so the user doesn't wait on the
+ * write. Wrapped in try/catch so a DB blip can't 500 the redirect.
+ */
+async function recordHit(id) {
+  try {
+    await db('gallery_short_urls').where({ id }).update({
+      hit_count: db.raw('hit_count + 1'),
+      last_hit_at: new Date(),
+    });
+  } catch (err) {
+    logger.warn('gallery_short_urls: recordHit failed (non-fatal)', {
+      id, error: err.message,
+    });
+  }
+}
+
+module.exports = {
+  validateSlug,
+  targetPathForEvent,
+  autoGenerateSlug,
+  createShortUrl,
+  findByShortSlug,
+  listForEvent,
+  softDelete,
+  recordHit,
+  // Exposed for tests
+  _RESERVED_SLUGS: RESERVED_SLUGS,
+};
diff --git a/frontend/src/components/admin/ShortUrlsCard.tsx b/frontend/src/components/admin/ShortUrlsCard.tsx
new file mode 100644
index 00000000..8d3a84e8
--- /dev/null
+++ b/frontend/src/components/admin/ShortUrlsCard.tsx
@@ -0,0 +1,238 @@
+/**
+ * Branded short-URL management for a single event (#699).
+ *
+ * Each event can have multiple `/s/<slug>` short URLs pointing at it.
+ * The public route is bot-UA aware: scrapes get OG (so the short URL
+ * is what shows the rich preview in chat), browsers get a 302 to the
+ * gallery URL stored at create time.
+ *
+ * Renders inside the event detail page as a Card. Form to create
+ * (custom or auto-generated slug), list of existing short URLs with
+ * copy + delete buttons. Errors from the backend's structured codes
+ * (INVALID_SLUG, SLUG_TAKEN) surface inline with a "use suggested"
+ * shortcut when the server proposes an alternative.
+ */
+import React, { useState } from 'react';
+import { useTranslation } from 'react-i18next';
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { Copy, Link as LinkIcon, Trash2, Plus, Check } from 'lucide-react';
+import { Button, Card, Input } from '../common';
+import { shortUrlsService, type GalleryShortUrl } from '../../services/shortUrls.service';
+import { useLocalizedDate } from '../../hooks/useLocalizedDate';
+import { toast } from 'react-toastify';
+
+interface Props {
+  eventId: number;
+}
+
+function buildShortUrl(slug: string): string {
+  // Build from window.location so it survives reverse-proxy + custom-
+  // domain setups without needing a separate FRONTEND_URL config in the
+  // browser bundle. SSR-safe fallback: just the relative path.
+  if (typeof window === 'undefined') return `/s/${slug}`;
+  return `${window.location.origin}/s/${slug}`;
+}
+
+export const ShortUrlsCard: React.FC<Props> = ({ eventId }) => {
+  const { t } = useTranslation();
+  const { formatDateTime } = useLocalizedDate();
+  const qc = useQueryClient();
+
+  const [customSlug, setCustomSlug] = useState('');
+  const [error, setError] = useState<string | undefined>();
+  const [suggested, setSuggested] = useState<string | undefined>();
+  const [copiedId, setCopiedId] = useState<number | null>(null);
+
+  const { data: shortUrls = [], isLoading } = useQuery({
+    queryKey: ['short-urls', eventId],
+    queryFn: () => shortUrlsService.listForEvent(eventId),
+  });
+
+  const createMutation = useMutation({
+    mutationFn: (slug?: string) => shortUrlsService.create(eventId, slug),
+    onSuccess: () => {
+      setCustomSlug('');
+      setError(undefined);
+      setSuggested(undefined);
+      qc.invalidateQueries({ queryKey: ['short-urls', eventId] });
+      toast.success(t('events.shortUrls.created', 'Short URL created'));
+    },
+    onError: (err: any) => {
+      const code = err?.response?.data?.code;
+      const msg = err?.response?.data?.error;
+      if (code === 'SLUG_TAKEN') {
+        setSuggested(err?.response?.data?.suggested);
+        setError(t(
+          'events.shortUrls.errors.slugTaken',
+          'That short URL is already taken — try {{suggested}} instead.',
+          { suggested: err?.response?.data?.suggested || '' },
+        ) as string);
+      } else if (code === 'INVALID_SLUG') {
+        setSuggested(undefined);
+        setError(msg || (t('events.shortUrls.errors.invalidSlug',
+          'Short URLs must be lowercase letters, digits, and hyphens (1–64 chars).') as string));
+      } else {
+        setSuggested(undefined);
+        setError(msg || (t('common.error', 'Something went wrong') as string));
+      }
+    },
+  });
+
+  const deleteMutation = useMutation({
+    mutationFn: (id: number) => shortUrlsService.remove(id),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['short-urls', eventId] });
+      toast.success(t('events.shortUrls.deleted', 'Short URL deleted'));
+    },
+  });
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    createMutation.mutate(customSlug.trim() || undefined);
+  };
+
+  const handleUseSuggested = () => {
+    if (suggested) {
+      setCustomSlug(suggested);
+      setError(undefined);
+      setSuggested(undefined);
+    }
+  };
+
+  const handleCopy = async (row: GalleryShortUrl) => {
+    const url = buildShortUrl(row.short_slug);
+    try {
+      await navigator.clipboard.writeText(url);
+      setCopiedId(row.id);
+      setTimeout(() => setCopiedId((current) => (current === row.id ? null : current)), 1500);
+    } catch {
+      toast.error(t('common.copyFailed', 'Could not copy to clipboard') as string);
+    }
+  };
+
+  const handleDelete = (row: GalleryShortUrl) => {
+    const confirm = window.confirm(t(
+      'events.shortUrls.confirmDelete',
+      'Delete short URL /s/{{slug}}? The link will stop working immediately.',
+      { slug: row.short_slug },
+    ) as string);
+    if (confirm) deleteMutation.mutate(row.id);
+  };
+
+  return (
+    <Card padding="md">
+      <div className="flex items-center gap-2 mb-3">
+        <LinkIcon className="w-5 h-5 text-primary-600 dark:text-primary-400" />
+        <h3 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100">
+          {t('events.shortUrls.title', 'Branded short URLs')}
+        </h3>
+      </div>
+      <p className="text-sm text-neutral-600 dark:text-neutral-400 mb-4">
+        {t(
+          'events.shortUrls.description',
+          'Create memorable links like /s/sofia-graduation that resolve to this gallery. The short URL itself shows the rich social preview when shared — so iMessage, Facebook, WhatsApp etc. see the gallery photo + name even when pasting the short link.',
+        )}
+      </p>
+
+      {/* Create form */}
+      <form onSubmit={handleSubmit} className="mb-4">
+        <div className="flex flex-col sm:flex-row gap-2">
+          <div className="flex-1">
+            <Input
+              value={customSlug}
+              onChange={(e) => {
+                setCustomSlug(e.target.value.toLowerCase());
+                if (error) setError(undefined);
+                if (suggested) setSuggested(undefined);
+              }}
+              placeholder={t('events.shortUrls.slugPlaceholder', 'sofia-graduation (optional)') as string}
+              maxLength={64}
+              error={error}
+            />
+          </div>
+          <Button
+            type="submit"
+            variant="primary"
+            disabled={createMutation.isPending}
+            leftIcon={<Plus className="w-4 h-4" />}
+          >
+            {t('events.shortUrls.create', 'Create')}
+          </Button>
+        </div>
+        {suggested && (
+          <button
+            type="button"
+            onClick={handleUseSuggested}
+            className="mt-2 text-xs text-primary-600 dark:text-primary-400 underline hover:no-underline"
+          >
+            {t('events.shortUrls.useSuggested', 'Use “{{suggested}}” instead', { suggested })}
+          </button>
+        )}
+        <p className="mt-2 text-xs text-neutral-500 dark:text-neutral-400">
+          {t(
+            'events.shortUrls.slugHelp',
+            'Leave empty to auto-generate from the gallery name. Allowed characters: lowercase letters, digits, hyphens.',
+          )}
+        </p>
+      </form>
+
+      {/* Existing short URLs */}
+      {isLoading ? (
+        <p className="text-sm text-neutral-500 dark:text-neutral-400">
+          {t('common.loading', 'Loading…')}
+        </p>
+      ) : shortUrls.length === 0 ? (
+        <p className="text-sm text-neutral-500 dark:text-neutral-400">
+          {t('events.shortUrls.empty', 'No short URLs yet. Create one above to share this gallery with a memorable link.')}
+        </p>
+      ) : (
+        <ul className="divide-y divide-neutral-200 dark:divide-neutral-700">
+          {shortUrls.map((row) => (
+            <li key={row.id} className="py-3 flex items-start justify-between gap-3">
+              <div className="flex-1 min-w-0">
+                <div className="font-mono text-sm text-neutral-900 dark:text-neutral-100 break-all">
+                  /s/{row.short_slug}
+                </div>
+                <div className="mt-1 text-xs text-neutral-500 dark:text-neutral-400">
+                  {t('events.shortUrls.hits', '{{count}} hits', { count: row.hit_count })}
+                  {row.last_hit_at && (
+                    <>
+                      {' · '}
+                      {t('events.shortUrls.lastHit', 'last {{when}}', { when: formatDateTime(row.last_hit_at) })}
+                    </>
+                  )}
+                  {' · '}
+                  {t('events.shortUrls.createdAt', 'created {{when}}', { when: formatDateTime(row.created_at) })}
+                </div>
+                <div className="mt-0.5 text-xs text-neutral-500 dark:text-neutral-400 truncate">
+                  → {row.target_path}
+                </div>
+              </div>
+              <div className="flex items-center gap-1 flex-shrink-0">
+                <button
+                  type="button"
+                  onClick={() => handleCopy(row)}
+                  className="p-2 text-neutral-500 hover:text-primary-600 dark:hover:text-primary-400"
+                  title={t('common.copy', 'Copy') as string}
+                  aria-label={t('common.copy', 'Copy') as string}
+                >
+                  {copiedId === row.id ? <Check className="w-4 h-4 text-green-600" /> : <Copy className="w-4 h-4" />}
+                </button>
+                <button
+                  type="button"
+                  onClick={() => handleDelete(row)}
+                  disabled={deleteMutation.isPending}
+                  className="p-2 text-neutral-500 hover:text-red-600"
+                  title={t('common.delete', 'Delete') as string}
+                  aria-label={t('common.delete', 'Delete') as string}
+                >
+                  <Trash2 className="w-4 h-4" />
+                </button>
+              </div>
+            </li>
+          ))}
+        </ul>
+      )}
+    </Card>
+  );
+};
diff --git a/frontend/src/i18n/locales/de.json b/frontend/src/i18n/locales/de.json
index 3d5890bd..fabc4e7e 100644
--- a/frontend/src/i18n/locales/de.json
+++ b/frontend/src/i18n/locales/de.json
@@ -998,6 +998,25 @@
     "expires": "Läuft ab",
     "shareWithGuests": "Teilen Sie diesen Link mit Gästen. Sie benötigen das Passwort, um auf die Galerie zuzugreifen.",
     "shareWithGuestsPublic": "Teilen Sie diesen Link mit Gästen. Für diese Galerie ist kein Passwort erforderlich.",
+    "shortUrls": {
+      "title": "Gebrandete Kurz-URLs",
+      "description": "Erstelle einprägsame Links wie /s/sofia-abschluss, die zu dieser Galerie führen. Die Kurz-URL zeigt selbst die reiche Social-Vorschau — iMessage, Facebook, WhatsApp etc. sehen das Galerie-Foto + den Namen auch beim Einfügen des kurzen Links.",
+      "slugPlaceholder": "sofia-abschluss (optional)",
+      "slugHelp": "Leer lassen für automatische Generierung aus dem Galerienamen. Erlaubte Zeichen: Kleinbuchstaben, Ziffern, Bindestriche.",
+      "create": "Erstellen",
+      "created": "Kurz-URL erstellt",
+      "deleted": "Kurz-URL gelöscht",
+      "empty": "Noch keine Kurz-URLs. Erstelle oben eine, um diese Galerie mit einem einprägsamen Link zu teilen.",
+      "hits": "{{count}} Aufrufe",
+      "lastHit": "zuletzt {{when}}",
+      "createdAt": "erstellt {{when}}",
+      "useSuggested": "Stattdessen „{{suggested}}\" verwenden",
+      "confirmDelete": "Kurz-URL /s/{{slug}} löschen? Der Link funktioniert sofort nicht mehr.",
+      "errors": {
+        "slugTaken": "Diese Kurz-URL ist bereits vergeben — versuche stattdessen {{suggested}}.",
+        "invalidSlug": "Kurz-URLs müssen aus Kleinbuchstaben, Ziffern und Bindestrichen bestehen (1–64 Zeichen)."
+      }
+    },
     "resetGalleryPassword": "Galerie-Passwort zurücksetzen",
     "resendCreationEmail": "Erstellungs-E-Mail erneut senden",
     "creationEmailResent": "Die Erstellungs-E-Mail wurde zur Warteschlange hinzugefügt",
diff --git a/frontend/src/i18n/locales/en.json b/frontend/src/i18n/locales/en.json
index f5af8100..8daea867 100644
--- a/frontend/src/i18n/locales/en.json
+++ b/frontend/src/i18n/locales/en.json
@@ -552,6 +552,25 @@
     "expires": "Expires",
     "shareWithGuests": "Share this link with guests. They'll need the password to access the gallery.",
     "shareWithGuestsPublic": "Share this link with guests. No password is required for this gallery.",
+    "shortUrls": {
+      "title": "Branded short URLs",
+      "description": "Create memorable links like /s/sofia-graduation that resolve to this gallery. The short URL itself shows the rich social preview when shared — so iMessage, Facebook, WhatsApp etc. see the gallery photo + name even when pasting the short link.",
+      "slugPlaceholder": "sofia-graduation (optional)",
+      "slugHelp": "Leave empty to auto-generate from the gallery name. Allowed characters: lowercase letters, digits, hyphens.",
+      "create": "Create",
+      "created": "Short URL created",
+      "deleted": "Short URL deleted",
+      "empty": "No short URLs yet. Create one above to share this gallery with a memorable link.",
+      "hits": "{{count}} hits",
+      "lastHit": "last {{when}}",
+      "createdAt": "created {{when}}",
+      "useSuggested": "Use \"{{suggested}}\" instead",
+      "confirmDelete": "Delete short URL /s/{{slug}}? The link will stop working immediately.",
+      "errors": {
+        "slugTaken": "That short URL is already taken — try {{suggested}} instead.",
+        "invalidSlug": "Short URLs must be lowercase letters, digits, and hyphens (1–64 chars)."
+      }
+    },
     "resetGalleryPassword": "Reset Gallery Password",
     "resendCreationEmail": "Resend Creation Email",
     "creationEmailResent": "Creation email has been queued for sending",
diff --git a/frontend/src/pages/admin/EventDetailsPage.tsx b/frontend/src/pages/admin/EventDetailsPage.tsx
index 2d7b1097..3c5e4e4f 100644
--- a/frontend/src/pages/admin/EventDetailsPage.tsx
+++ b/frontend/src/pages/admin/EventDetailsPage.tsx
@@ -63,6 +63,7 @@ import { EventCategoryManager, AdminPhotoGrid, AdminPhotoViewer, PhotoFilters, P
 import { CustomerAccountPicker } from '../../components/admin/CustomerAccountPicker';
 import { EventReminderOverrideCard } from '../../components/admin/EventReminderOverrideCard';
 import { SlideshowSettingsCard } from '../../components/admin/SlideshowSettingsCard';
+import { ShortUrlsCard } from '../../components/admin/ShortUrlsCard';
 import { useFeatureFlags } from '../../contexts/FeatureFlagsContext';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { eventsService } from '../../services/events.service';
@@ -2029,6 +2030,11 @@ export const EventDetailsPage: React.FC = () => {
             )}
           </Card>
 
+          {/* Branded short URLs (#699). Sits between the canonical share-link
+              card and the Client Access card — same "things you share with
+              the customer" cluster. */}
+          <ShortUrlsCard eventId={event.id} />
+
           {/* Client Access (#172) */}
           <Card padding="md">
             <h2 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100 mb-4 flex items-center gap-2">
diff --git a/frontend/src/services/shortUrls.service.ts b/frontend/src/services/shortUrls.service.ts
new file mode 100644
index 00000000..956f80eb
--- /dev/null
+++ b/frontend/src/services/shortUrls.service.ts
@@ -0,0 +1,47 @@
+import { api } from '../config/api';
+
+export interface GalleryShortUrl {
+  id: number;
+  short_slug: string;
+  target_path: string;
+  hit_count: number;
+  last_hit_at: string | null;
+  created_at: string;
+  created_by: number | null;
+}
+
+/**
+ * Branded URL shortener (#699). Each event can have multiple short URLs
+ * pointing at it; the public route lives at `/s/<short_slug>` and is
+ * bot-UA aware (serves OG to scrapers, 302 to browsers).
+ */
+export const shortUrlsService = {
+  async listForEvent(eventId: number): Promise<GalleryShortUrl[]> {
+    const { data } = await api.get(`/admin/events/${eventId}/short-urls`);
+    return data?.shortUrls ?? [];
+  },
+
+  /**
+   * Create a short URL for an event. `customSlug` is optional — omit to
+   * let the backend auto-generate from the event's slug + year.
+   *
+   * Surfaces structured errors:
+   *   - 400 INVALID_SLUG  → bad shape (letters/digits/hyphens, 1-64 chars)
+   *   - 409 SLUG_TAKEN    → another live row holds the slug; the response
+   *                         body includes `suggested` with an available
+   *                         alternative the caller can pre-fill in the
+   *                         input on retry.
+   */
+  async create(
+    eventId: number,
+    customSlug?: string,
+  ): Promise<GalleryShortUrl> {
+    const body = customSlug ? { customSlug } : {};
+    const { data } = await api.post(`/admin/events/${eventId}/short-urls`, body);
+    return data;
+  },
+
+  async remove(id: number): Promise<void> {
+    await api.delete(`/admin/short-urls/${id}`);
+  },
+};