diff --git a/api/app/Models/Event.php b/api/app/Models/Event.php
index 649e442d..445e24cc 100644
--- a/api/app/Models/Event.php
+++ b/api/app/Models/Event.php
@@ -221,17 +221,21 @@ final class Event extends Model
         return $query->whereIn('event_type', ['festival', 'series']);
     }
 
-    public function scopeWithChildren(Builder $query): Builder
+    public function scopeWithChildren(Builder $query, string $eventId): Builder
     {
-        return $query->where(function (Builder $q) {
-            $q->whereIn('id', function ($sub) {
-                $sub->select('id')->from('events')->whereNull('parent_event_id');
-            })->orWhereIn('parent_event_id', function ($sub) {
-                $sub->select('id')->from('events')->whereNull('parent_event_id');
-            });
+        return $query->where(function (Builder $q) use ($eventId) {
+            $q->where('id', $eventId)
+                ->orWhere('parent_event_id', $eventId);
         });
     }
 
+    public function scopeForFestival(Builder $query, Event $event): Builder
+    {
+        $rootId = $event->parent_event_id ?? $event->id;
+
+        return $query->withChildren($rootId);
+    }
+
     // ----- Helpers -----
 
     public function isFestival(): bool
diff --git a/api/database/seeders/DevSeeder.php b/api/database/seeders/DevSeeder.php
index 90dffc1d..05d09f30 100644
--- a/api/database/seeders/DevSeeder.php
+++ b/api/database/seeders/DevSeeder.php
@@ -6,7 +6,10 @@ namespace Database\Seeders;
 
 use App\Models\CrowdType;
 use App\Models\Event;
+use App\Models\FestivalSection;
 use App\Models\Organisation;
+use App\Models\Person;
+use App\Models\TimeSlot;
 use App\Models\User;
 use Illuminate\Database\Seeder;
 use Illuminate\Support\Facades\Hash;
@@ -114,14 +117,18 @@ class DevSeeder extends Seeder
             ],
         );
 
-        // 6. Festival with sub-events
+        // =============================================
+        // 6. Festival: Echt Feesten 2026
+        // =============================================
+
         $festival = Event::firstOrCreate(
-            ['organisation_id' => $org->id, 'slug' => 'echt-zomer-feesten-2026'],
+            ['organisation_id' => $org->id, 'slug' => 'echt-feesten-2026'],
             [
-                'name' => 'Echt Zomer Feesten 2026',
+                'name' => 'Echt Feesten 2026',
                 'start_date' => '2026-07-10',
-                'end_date' => '2026-07-11',
-                'status' => 'draft',
+                'end_date' => '2026-07-12',
+                'timezone' => 'Europe/Amsterdam',
+                'status' => 'registration_open',
                 'event_type' => 'festival',
                 'event_type_label' => 'Festival',
                 'sub_event_label' => 'Programmaonderdeel',
@@ -129,30 +136,173 @@ class DevSeeder extends Seeder
             ],
         );
 
-        // Sub-event 1: Dance Festival
-        Event::firstOrCreate(
-            ['organisation_id' => $org->id, 'slug' => 'dance-festival-2026'],
+        // --- Sub-events ---
+
+        $vrijdag = Event::firstOrCreate(
+            ['organisation_id' => $org->id, 'slug' => 'echt-feesten-2026-vrijdag'],
             [
-                'name' => 'Dance Festival',
+                'name' => 'Vrijdag',
                 'start_date' => '2026-07-10',
                 'end_date' => '2026-07-10',
-                'status' => 'draft',
+                'timezone' => 'Europe/Amsterdam',
+                'status' => 'registration_open',
                 'event_type' => 'event',
                 'parent_event_id' => $festival->id,
             ],
         );
 
-        // Sub-event 2: Zomerfestival
         Event::firstOrCreate(
-            ['organisation_id' => $org->id, 'slug' => 'zomerfestival-2026'],
+            ['organisation_id' => $org->id, 'slug' => 'echt-feesten-2026-zaterdag'],
             [
-                'name' => 'Zomerfestival',
+                'name' => 'Zaterdag',
                 'start_date' => '2026-07-11',
                 'end_date' => '2026-07-11',
-                'status' => 'draft',
+                'timezone' => 'Europe/Amsterdam',
+                'status' => 'registration_open',
                 'event_type' => 'event',
                 'parent_event_id' => $festival->id,
             ],
         );
+
+        Event::firstOrCreate(
+            ['organisation_id' => $org->id, 'slug' => 'echt-feesten-2026-zondag'],
+            [
+                'name' => 'Zondag',
+                'start_date' => '2026-07-12',
+                'end_date' => '2026-07-12',
+                'timezone' => 'Europe/Amsterdam',
+                'status' => 'registration_open',
+                'event_type' => 'event',
+                'parent_event_id' => $festival->id,
+            ],
+        );
+
+        // --- Festival-level sections (on the parent) ---
+
+        FestivalSection::firstOrCreate(
+            ['event_id' => $festival->id, 'name' => 'EHBO'],
+            [
+                'type' => 'cross_event',
+                'category' => 'Veiligheid',
+                'icon' => 'tabler-first-aid-kit',
+                'sort_order' => 1,
+                'responder_self_checkin' => true,
+                'crew_auto_accepts' => false,
+            ],
+        );
+
+        FestivalSection::firstOrCreate(
+            ['event_id' => $festival->id, 'name' => 'Nachtsecurity'],
+            [
+                'type' => 'standard',
+                'category' => 'Veiligheid',
+                'icon' => 'tabler-shield',
+                'sort_order' => 2,
+                'responder_self_checkin' => true,
+                'crew_auto_accepts' => false,
+            ],
+        );
+
+        // --- Sub-event sections (on Vrijdag) ---
+
+        FestivalSection::firstOrCreate(
+            ['event_id' => $vrijdag->id, 'name' => 'Hoofdpodium Bar'],
+            [
+                'type' => 'standard',
+                'category' => 'Bar',
+                'icon' => 'tabler-beer',
+                'sort_order' => 1,
+                'responder_self_checkin' => true,
+                'crew_auto_accepts' => false,
+            ],
+        );
+
+        FestivalSection::firstOrCreate(
+            ['event_id' => $vrijdag->id, 'name' => 'Backstage'],
+            [
+                'type' => 'standard',
+                'category' => 'Hospitality',
+                'icon' => 'tabler-armchair',
+                'sort_order' => 2,
+                'responder_self_checkin' => true,
+                'crew_auto_accepts' => false,
+            ],
+        );
+
+        // --- Festival-level time slots (on the parent) ---
+
+        TimeSlot::firstOrCreate(
+            ['event_id' => $festival->id, 'name' => 'Opbouw'],
+            [
+                'date' => '2026-07-09',
+                'start_time' => '08:00:00',
+                'end_time' => '18:00:00',
+                'duration_hours' => 10.00,
+                'person_type' => 'CREW',
+            ],
+        );
+
+        TimeSlot::firstOrCreate(
+            ['event_id' => $festival->id, 'name' => 'Afbraak'],
+            [
+                'date' => '2026-07-13',
+                'start_time' => '08:00:00',
+                'end_time' => '18:00:00',
+                'duration_hours' => 10.00,
+                'person_type' => 'CREW',
+            ],
+        );
+
+        // --- Sub-event time slots (on Vrijdag) ---
+
+        TimeSlot::firstOrCreate(
+            ['event_id' => $vrijdag->id, 'name' => 'Vrijdag Avond'],
+            [
+                'date' => '2026-07-10',
+                'start_time' => '18:00:00',
+                'end_time' => '02:00:00',
+                'duration_hours' => 8.00,
+                'person_type' => 'VOLUNTEER',
+            ],
+        );
+
+        TimeSlot::firstOrCreate(
+            ['event_id' => $vrijdag->id, 'name' => 'Vrijdag Nacht'],
+            [
+                'date' => '2026-07-10',
+                'start_time' => '22:00:00',
+                'end_time' => '04:00:00',
+                'duration_hours' => 6.00,
+                'person_type' => 'CREW',
+            ],
+        );
+
+        // --- Festival-level persons (5 volunteers on the parent) ---
+
+        $volunteerType = CrowdType::where('organisation_id', $org->id)
+            ->where('system_type', 'VOLUNTEER')
+            ->first();
+
+        $festivalPersons = [
+            ['name' => 'Sanne de Vries', 'email' => 'sanne.devries@example.nl', 'phone' => '+31612345001'],
+            ['name' => 'Pieter Jansen', 'email' => 'pieter.jansen@example.nl', 'phone' => '+31612345002'],
+            ['name' => 'Marieke van den Berg', 'email' => 'marieke.vandenberg@example.nl', 'phone' => '+31612345003'],
+            ['name' => 'Thijs Bakker', 'email' => 'thijs.bakker@example.nl', 'phone' => '+31612345004'],
+            // Uses the seeded orgAdmin email to test identity matching later
+            ['name' => 'Org Admin Volunteer', 'email' => 'orgadmin@crewli.test', 'phone' => '+31612345005'],
+        ];
+
+        foreach ($festivalPersons as $personData) {
+            Person::firstOrCreate(
+                ['event_id' => $festival->id, 'email' => $personData['email']],
+                [
+                    'crowd_type_id' => $volunteerType->id,
+                    'name' => $personData['name'],
+                    'phone' => $personData['phone'],
+                    'status' => 'approved',
+                    'is_blacklisted' => false,
+                ],
+            );
+        }
     }
 }
diff --git a/api/tests/Feature/Event/EventScopesTest.php b/api/tests/Feature/Event/EventScopesTest.php
new file mode 100644
index 00000000..46948b90
--- /dev/null
+++ b/api/tests/Feature/Event/EventScopesTest.php
@@ -0,0 +1,210 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\Event;
+
+use App\Models\Event;
+use App\Models\Organisation;
+use App\Models\Scopes\OrganisationScope;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class EventScopesTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private Organisation $org;
+    private Organisation $otherOrg;
+    private Event $flatEvent;
+    private Event $festival;
+    private Event $subEvent1;
+    private Event $subEvent2;
+    private Event $subEvent3;
+    private Event $otherOrgEvent;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->org = Organisation::factory()->create();
+        $this->otherOrg = Organisation::factory()->create();
+
+        // Flat event (no parent, no children)
+        $this->flatEvent = Event::factory()->create([
+            'organisation_id' => $this->org->id,
+            'event_type' => 'event',
+            'parent_event_id' => null,
+        ]);
+
+        // Festival with 3 sub-events
+        $this->festival = Event::factory()->festival()->create([
+            'organisation_id' => $this->org->id,
+        ]);
+
+        $this->subEvent1 = Event::factory()->subEvent($this->festival)->create([
+            'name' => 'Vrijdag',
+        ]);
+        $this->subEvent2 = Event::factory()->subEvent($this->festival)->create([
+            'name' => 'Zaterdag',
+        ]);
+        $this->subEvent3 = Event::factory()->subEvent($this->festival)->create([
+            'name' => 'Zondag',
+        ]);
+
+        // Event in a different organisation (must never appear)
+        $this->otherOrgEvent = Event::factory()->create([
+            'organisation_id' => $this->otherOrg->id,
+            'event_type' => 'event',
+            'parent_event_id' => null,
+        ]);
+    }
+
+    // --- scopeTopLevel ---
+
+    public function test_scope_top_level_returns_only_events_without_parent(): void
+    {
+        $results = Event::withoutGlobalScopes()->topLevel()->pluck('id');
+
+        $this->assertTrue($results->contains($this->flatEvent->id));
+        $this->assertTrue($results->contains($this->festival->id));
+        $this->assertTrue($results->contains($this->otherOrgEvent->id));
+
+        $this->assertFalse($results->contains($this->subEvent1->id));
+        $this->assertFalse($results->contains($this->subEvent2->id));
+        $this->assertFalse($results->contains($this->subEvent3->id));
+    }
+
+    // --- scopeChildren ---
+
+    public function test_scope_children_returns_only_events_with_parent(): void
+    {
+        $results = Event::withoutGlobalScopes()->children()->pluck('id');
+
+        $this->assertTrue($results->contains($this->subEvent1->id));
+        $this->assertTrue($results->contains($this->subEvent2->id));
+        $this->assertTrue($results->contains($this->subEvent3->id));
+
+        $this->assertFalse($results->contains($this->flatEvent->id));
+        $this->assertFalse($results->contains($this->festival->id));
+        $this->assertFalse($results->contains($this->otherOrgEvent->id));
+    }
+
+    // --- scopeWithChildren ---
+
+    public function test_scope_with_children_returns_parent_and_its_children(): void
+    {
+        $results = Event::withoutGlobalScopes()
+            ->withChildren($this->festival->id)
+            ->pluck('id');
+
+        $this->assertCount(4, $results);
+        $this->assertTrue($results->contains($this->festival->id));
+        $this->assertTrue($results->contains($this->subEvent1->id));
+        $this->assertTrue($results->contains($this->subEvent2->id));
+        $this->assertTrue($results->contains($this->subEvent3->id));
+
+        $this->assertFalse($results->contains($this->flatEvent->id));
+        $this->assertFalse($results->contains($this->otherOrgEvent->id));
+    }
+
+    public function test_scope_with_children_for_flat_event_returns_only_self(): void
+    {
+        $results = Event::withoutGlobalScopes()
+            ->withChildren($this->flatEvent->id)
+            ->pluck('id');
+
+        $this->assertCount(1, $results);
+        $this->assertTrue($results->contains($this->flatEvent->id));
+    }
+
+    // --- scopeFestivals ---
+
+    public function test_scope_festivals_returns_only_festival_and_series_types(): void
+    {
+        $series = Event::factory()->series()->create([
+            'organisation_id' => $this->org->id,
+        ]);
+
+        $results = Event::withoutGlobalScopes()->festivals()->pluck('id');
+
+        $this->assertTrue($results->contains($this->festival->id));
+        $this->assertTrue($results->contains($series->id));
+
+        $this->assertFalse($results->contains($this->flatEvent->id));
+        $this->assertFalse($results->contains($this->subEvent1->id));
+        $this->assertFalse($results->contains($this->otherOrgEvent->id));
+    }
+
+    // --- scopeForFestival ---
+
+    public function test_scope_for_festival_given_child_returns_parent_and_all_siblings(): void
+    {
+        $results = Event::withoutGlobalScopes()
+            ->forFestival($this->subEvent1)
+            ->pluck('id');
+
+        $this->assertCount(4, $results);
+        $this->assertTrue($results->contains($this->festival->id));
+        $this->assertTrue($results->contains($this->subEvent1->id));
+        $this->assertTrue($results->contains($this->subEvent2->id));
+        $this->assertTrue($results->contains($this->subEvent3->id));
+    }
+
+    public function test_scope_for_festival_given_parent_returns_self_and_all_children(): void
+    {
+        $results = Event::withoutGlobalScopes()
+            ->forFestival($this->festival)
+            ->pluck('id');
+
+        $this->assertCount(4, $results);
+        $this->assertTrue($results->contains($this->festival->id));
+        $this->assertTrue($results->contains($this->subEvent1->id));
+        $this->assertTrue($results->contains($this->subEvent2->id));
+        $this->assertTrue($results->contains($this->subEvent3->id));
+    }
+
+    public function test_scope_for_festival_given_flat_event_returns_only_self(): void
+    {
+        $results = Event::withoutGlobalScopes()
+            ->forFestival($this->flatEvent)
+            ->pluck('id');
+
+        $this->assertCount(1, $results);
+        $this->assertTrue($results->contains($this->flatEvent->id));
+    }
+
+    // --- OrganisationScope respect ---
+
+    public function test_scopes_respect_organisation_scope(): void
+    {
+        $scopedQuery = Event::withoutGlobalScopes()
+            ->withGlobalScope('organisation', new OrganisationScope($this->org->id));
+
+        // topLevel within org should not contain other org's event
+        $topLevel = (clone $scopedQuery)->topLevel()->pluck('id');
+        $this->assertTrue($topLevel->contains($this->flatEvent->id));
+        $this->assertTrue($topLevel->contains($this->festival->id));
+        $this->assertFalse($topLevel->contains($this->otherOrgEvent->id));
+
+        // children within org
+        $children = (clone $scopedQuery)->children()->pluck('id');
+        $this->assertTrue($children->contains($this->subEvent1->id));
+        $this->assertFalse($children->contains($this->otherOrgEvent->id));
+
+        // withChildren within org
+        $withChildren = (clone $scopedQuery)->withChildren($this->festival->id)->pluck('id');
+        $this->assertCount(4, $withChildren);
+        $this->assertFalse($withChildren->contains($this->otherOrgEvent->id));
+
+        // festivals within org
+        $festivals = (clone $scopedQuery)->festivals()->pluck('id');
+        $this->assertTrue($festivals->contains($this->festival->id));
+        $this->assertFalse($festivals->contains($this->otherOrgEvent->id));
+
+        // forFestival within org
+        $forFestival = (clone $scopedQuery)->forFestival($this->subEvent1)->pluck('id');
+        $this->assertCount(4, $forFestival);
+        $this->assertFalse($forFestival->contains($this->otherOrgEvent->id));
+    }
+}
diff --git a/dev-docs/BACKLOG.md b/dev-docs/BACKLOG.md
index 68252087..302fd226 100644
--- a/dev-docs/BACKLOG.md
+++ b/dev-docs/BACKLOG.md
@@ -381,23 +381,11 @@ mogelijk fragiel door gewijzigde factory-setup.
 
 ---
 
-### TECH-02 — scopeForFestival helper op Event model
-
-**Aanleiding:** Queries die door parent/child heen moeten werken.
-**Wat:** `Event::scopeWithChildren()` en `Event::scopeForFestival()`
-helper scopes zodat queries automatisch parent + children bevatten.
+### ~~TECH-02 — scopeForFestival helper op Event model~~ ✅ OPGELOST
 
 ---
 
-### TECH-03 — DevSeeder uitbreiden met festival-structuur
-
-**Aanleiding:** Na festival/event refactor heeft de DevSeeder
-realistische testdata nodig met parent/child events.
-**Wat:** DevSeeder aanpassen met:
-
-- Test festival (parent)
-- 2-3 sub-events (children)
-- Personen op festival-niveau
+### ~~TECH-03 — DevSeeder uitbreiden met festival-structuur~~ ✅ OPGELOST
 
 ---
 
@@ -409,6 +397,8 @@ realistische testdata nodig met parent/child events.
 
 De volgende items zijn geïmplementeerd en afgerond:
 
+- ~~TECH-02: scopeForFestival + scopeWithChildren helper scopes op Event model~~ ✅
+- ~~TECH-03: DevSeeder uitgebreid met festival-structuur (secties, tijdsloten, personen)~~ ✅
 - ~~TECH-04: EventController.store() redundante ternary~~ ✅
 - ~~Auth race condition (CTRL+R fix)~~ ✅
 - ~~Section edit dialog bug~~ ✅