diff --git a/api/app/Enums/ShiftAssignmentStatus.php b/api/app/Enums/ShiftAssignmentStatus.php
new file mode 100644
index 00000000..ec2b8a26
--- /dev/null
+++ b/api/app/Enums/ShiftAssignmentStatus.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Enums;
+
+enum ShiftAssignmentStatus: string
+{
+    case PENDING_APPROVAL = 'pending_approval';
+    case APPROVED = 'approved';
+    case REJECTED = 'rejected';
+    case CANCELLED = 'cancelled';
+    case COMPLETED = 'completed';
+
+    /** @return list<self> */
+    public function allowedTransitions(): array
+    {
+        return match ($this) {
+            self::PENDING_APPROVAL => [self::APPROVED, self::REJECTED, self::CANCELLED],
+            self::APPROVED => [self::CANCELLED, self::COMPLETED],
+            self::REJECTED, self::CANCELLED, self::COMPLETED => [],
+        };
+    }
+
+    public function canTransitionTo(self $target): bool
+    {
+        return in_array($target, $this->allowedTransitions(), true);
+    }
+
+    public function isTerminal(): bool
+    {
+        return $this->allowedTransitions() === [];
+    }
+}
diff --git a/api/app/Http/Controllers/Api/V1/ShiftAssignmentController.php b/api/app/Http/Controllers/Api/V1/ShiftAssignmentController.php
new file mode 100644
index 00000000..7708ffab
--- /dev/null
+++ b/api/app/Http/Controllers/Api/V1/ShiftAssignmentController.php
@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Controllers\Api\V1;
+
+use App\Enums\ShiftAssignmentStatus;
+use App\Http\Controllers\Controller;
+use App\Http\Requests\Api\V1\BulkApproveShiftAssignmentRequest;
+use App\Http\Requests\Api\V1\RejectShiftAssignmentRequest;
+use App\Http\Resources\Api\V1\ShiftAssignmentResource;
+use App\Models\Event;
+use App\Models\ShiftAssignment;
+use App\Services\ShiftAssignmentService;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
+use Illuminate\Support\Facades\Gate;
+
+final class ShiftAssignmentController extends Controller
+{
+    public function __construct(
+        private readonly ShiftAssignmentService $service,
+    ) {}
+
+    public function index(Request $request, Event $event): AnonymousResourceCollection
+    {
+        Gate::authorize('viewAny', [ShiftAssignment::class, $event]);
+
+        $query = ShiftAssignment::query()
+            ->whereHas('shift.festivalSection', fn ($q) => $q->where('event_id', $event->id))
+            ->with(['person', 'shift.festivalSection', 'shift.timeSlot']);
+
+        if ($request->filled('status')) {
+            $status = ShiftAssignmentStatus::tryFrom($request->string('status')->toString());
+            if ($status !== null) {
+                $query->where('status', $status);
+            }
+        }
+
+        if ($request->filled('shift_id')) {
+            $query->where('shift_id', $request->string('shift_id')->toString());
+        }
+
+        if ($request->filled('person_id')) {
+            $query->where('person_id', $request->string('person_id')->toString());
+        }
+
+        if ($request->filled('section_id')) {
+            $query->whereHas('shift', fn ($q) => $q->where('festival_section_id', $request->string('section_id')->toString()));
+        }
+
+        $assignments = $query->orderByDesc('created_at')->paginate(50);
+
+        return ShiftAssignmentResource::collection($assignments);
+    }
+
+    public function approve(Event $event, ShiftAssignment $shiftAssignment): JsonResponse
+    {
+        Gate::authorize('approve', [$shiftAssignment, $event]);
+
+        $shiftAssignment = $this->service->approve($shiftAssignment, request()->user());
+
+        return $this->success(new ShiftAssignmentResource($shiftAssignment->load(['person', 'shift.festivalSection', 'shift.timeSlot'])));
+    }
+
+    public function reject(RejectShiftAssignmentRequest $request, Event $event, ShiftAssignment $shiftAssignment): JsonResponse
+    {
+        Gate::authorize('reject', [$shiftAssignment, $event]);
+
+        $shiftAssignment = $this->service->reject(
+            $shiftAssignment,
+            $request->user(),
+            $request->validated('reason'),
+        );
+
+        return $this->success(new ShiftAssignmentResource($shiftAssignment->load(['person', 'shift.festivalSection', 'shift.timeSlot'])));
+    }
+
+    public function cancel(Event $event, ShiftAssignment $shiftAssignment): JsonResponse
+    {
+        Gate::authorize('cancel', [$shiftAssignment, $event]);
+
+        $shiftAssignment = $this->service->cancel($shiftAssignment, request()->user());
+
+        return $this->success(new ShiftAssignmentResource($shiftAssignment->load(['person', 'shift.festivalSection', 'shift.timeSlot'])));
+    }
+
+    public function bulkApprove(BulkApproveShiftAssignmentRequest $request, Event $event): JsonResponse
+    {
+        Gate::authorize('bulkApprove', [ShiftAssignment::class, $event]);
+
+        $assignments = ShiftAssignment::whereIn('id', $request->validated('assignment_ids'))
+            ->with('shift')
+            ->get();
+
+        $results = $this->service->bulkApprove($assignments, $request->user());
+
+        return $this->success($results);
+    }
+}
diff --git a/api/app/Http/Controllers/Api/V1/ShiftController.php b/api/app/Http/Controllers/Api/V1/ShiftController.php
index b1b4e969..f595dc46 100644
--- a/api/app/Http/Controllers/Api/V1/ShiftController.php
+++ b/api/app/Http/Controllers/Api/V1/ShiftController.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Http\Controllers\Api\V1;
 
+use App\Enums\ShiftAssignmentStatus;
 use App\Http\Controllers\Controller;
 use App\Http\Requests\Api\V1\AssignShiftRequest;
 use App\Http\Requests\Api\V1\StoreShiftRequest;
@@ -12,21 +13,26 @@ use App\Http\Resources\Api\V1\ShiftAssignmentResource;
 use App\Http\Resources\Api\V1\ShiftResource;
 use App\Models\Event;
 use App\Models\FestivalSection;
+use App\Models\Person;
 use App\Models\Shift;
-use App\Models\ShiftAssignment;
+use App\Services\ShiftAssignmentService;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 use Illuminate\Support\Facades\Gate;
 
 final class ShiftController extends Controller
 {
+    public function __construct(
+        private readonly ShiftAssignmentService $shiftAssignmentService,
+    ) {}
+
     public function index(Event $event, FestivalSection $section): AnonymousResourceCollection
     {
         Gate::authorize('viewAny', [Shift::class, $event]);
 
         $shifts = $section->shifts()
             ->with(['timeSlot', 'location'])
-            ->withCount(['shiftAssignments as filled_slots' => fn ($q) => $q->where('status', 'approved')])
+            ->withCount(['shiftAssignments as filled_slots' => fn ($q) => $q->where('status', ShiftAssignmentStatus::APPROVED)])
             ->get();
 
         return ShiftResource::collection($shifts);
@@ -65,41 +71,8 @@ final class ShiftController extends Controller
     {
         Gate::authorize('assign', [$shift, $event, $section]);
 
-        $personId = $request->validated('person_id');
-
-        // Check if shift is full
-        $approvedCount = $shift->shiftAssignments()->where('status', 'approved')->count();
-        if ($approvedCount >= $shift->slots_total) {
-            return $this->error('Shift is vol — alle slots zijn bezet.', 422);
-        }
-
-        // Check overlap conflict if allow_overlap is false
-        if (! $shift->allow_overlap) {
-            $conflict = ShiftAssignment::where('person_id', $personId)
-                ->where('time_slot_id', $shift->time_slot_id)
-                ->whereNotIn('status', ['rejected', 'cancelled'])
-                ->exists();
-
-            if ($conflict) {
-                return $this->error('Deze persoon is al ingepland voor dit tijdslot.', 422);
-            }
-        }
-
-        $assignment = $shift->shiftAssignments()->create([
-            'person_id' => $personId,
-            'time_slot_id' => $shift->time_slot_id,
-            'status' => 'approved',
-            'auto_approved' => false,
-            'assigned_by' => $request->user()->id,
-            'assigned_at' => now(),
-            'approved_at' => now(),
-        ]);
-
-        // Update shift status if full
-        $newApprovedCount = $shift->shiftAssignments()->where('status', 'approved')->count();
-        if ($newApprovedCount >= $shift->slots_total) {
-            $shift->update(['status' => 'full']);
-        }
+        $person = Person::findOrFail($request->validated('person_id'));
+        $assignment = $this->shiftAssignmentService->assign($shift, $person, $request->user());
 
         return $this->created(new ShiftAssignmentResource($assignment));
     }
@@ -108,39 +81,8 @@ final class ShiftController extends Controller
     {
         Gate::authorize('claim', [$shift, $event, $section]);
 
-        $personId = $request->validated('person_id');
-
-        // Check claiming slots available
-        $claimedCount = $shift->shiftAssignments()
-            ->whereNotIn('status', ['rejected', 'cancelled'])
-            ->count();
-
-        if ($shift->slots_open_for_claiming <= 0 || $claimedCount >= $shift->slots_open_for_claiming) {
-            return $this->error('Geen claimbare slots beschikbaar voor deze shift.', 422);
-        }
-
-        // Check overlap conflict if allow_overlap is false
-        if (! $shift->allow_overlap) {
-            $conflict = ShiftAssignment::where('person_id', $personId)
-                ->where('time_slot_id', $shift->time_slot_id)
-                ->whereNotIn('status', ['rejected', 'cancelled'])
-                ->exists();
-
-            if ($conflict) {
-                return $this->error('Deze persoon is al ingepland voor dit tijdslot.', 422);
-            }
-        }
-
-        $autoApprove = $section->crew_auto_accepts;
-
-        $assignment = $shift->shiftAssignments()->create([
-            'person_id' => $personId,
-            'time_slot_id' => $shift->time_slot_id,
-            'status' => $autoApprove ? 'approved' : 'pending_approval',
-            'auto_approved' => $autoApprove,
-            'assigned_at' => now(),
-            'approved_at' => $autoApprove ? now() : null,
-        ]);
+        $person = Person::findOrFail($request->validated('person_id'));
+        $assignment = $this->shiftAssignmentService->claim($shift, $person);
 
         return $this->created(new ShiftAssignmentResource($assignment));
     }
diff --git a/api/app/Http/Controllers/Api/V1/VolunteerAvailabilityController.php b/api/app/Http/Controllers/Api/V1/VolunteerAvailabilityController.php
new file mode 100644
index 00000000..193e1db1
--- /dev/null
+++ b/api/app/Http/Controllers/Api/V1/VolunteerAvailabilityController.php
@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Controllers\Api\V1;
+
+use App\Http\Controllers\Controller;
+use App\Http\Requests\Api\V1\SyncVolunteerAvailabilityRequest;
+use App\Models\Event;
+use App\Models\Person;
+use App\Models\TimeSlot;
+use App\Models\VolunteerAvailability;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Support\Facades\Gate;
+use Illuminate\Validation\ValidationException;
+
+final class VolunteerAvailabilityController extends Controller
+{
+    public function index(Event $event, Person $person): JsonResponse
+    {
+        Gate::authorize('view', [$person, $event]);
+
+        $availabilities = VolunteerAvailability::where('person_id', $person->id)
+            ->with('timeSlot')
+            ->get()
+            ->map(fn (VolunteerAvailability $a) => [
+                'id' => $a->id,
+                'time_slot_id' => $a->time_slot_id,
+                'preference_level' => $a->preference_level,
+                'submitted_at' => $a->submitted_at?->toIso8601String(),
+                'time_slot' => $a->timeSlot ? [
+                    'id' => $a->timeSlot->id,
+                    'name' => $a->timeSlot->name,
+                    'date' => $a->timeSlot->date?->toDateString(),
+                    'start_time' => $a->timeSlot->start_time,
+                    'end_time' => $a->timeSlot->end_time,
+                ] : null,
+            ]);
+
+        return response()->json(['data' => $availabilities]);
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function sync(SyncVolunteerAvailabilityRequest $request, Event $event, Person $person): JsonResponse
+    {
+        Gate::authorize('update', [$person, $event]);
+
+        $availabilities = $request->validated('availabilities');
+
+        // Validate all time_slot_ids belong to the event (or parent festival)
+        $validTimeSlotIds = $event->getAllRelevantTimeSlots()->pluck('id')->toArray();
+
+        $invalidSlots = collect($availabilities)
+            ->pluck('time_slot_id')
+            ->diff($validTimeSlotIds);
+
+        if ($invalidSlots->isNotEmpty()) {
+            throw ValidationException::withMessages([
+                'availabilities' => ['Een of meer tijdsloten behoren niet tot dit evenement.'],
+            ]);
+        }
+
+        // Validate time slots have person_type matching the person's crowd_type system_type
+        $personSystemType = $person->crowdType?->system_type;
+        if ($personSystemType !== null) {
+            $requestedSlotIds = collect($availabilities)->pluck('time_slot_id')->toArray();
+            $mismatchedSlots = TimeSlot::whereIn('id', $requestedSlotIds)
+                ->where('person_type', '!=', $personSystemType)
+                ->exists();
+
+            if ($mismatchedSlots) {
+                throw ValidationException::withMessages([
+                    'availabilities' => ['Een of meer tijdsloten komen niet overeen met het type van deze persoon.'],
+                ]);
+            }
+        }
+
+        // Delete existing availabilities for this person
+        VolunteerAvailability::where('person_id', $person->id)->delete();
+
+        // Create new availabilities
+        $now = now();
+        foreach ($availabilities as $item) {
+            VolunteerAvailability::create([
+                'person_id' => $person->id,
+                'time_slot_id' => $item['time_slot_id'],
+                'preference_level' => $item['preference_level'] ?? 3,
+                'submitted_at' => $now,
+            ]);
+        }
+
+        activity('volunteer_availability')
+            ->causedBy($request->user())
+            ->performedOn($person)
+            ->withProperties([
+                'count' => count($availabilities),
+                'time_slot_ids' => collect($availabilities)->pluck('time_slot_id')->toArray(),
+            ])
+            ->log('volunteer_availability.synced');
+
+        return $this->success(null, 'Beschikbaarheid opgeslagen.');
+    }
+}
diff --git a/api/app/Http/Requests/Api/V1/BulkApproveShiftAssignmentRequest.php b/api/app/Http/Requests/Api/V1/BulkApproveShiftAssignmentRequest.php
new file mode 100644
index 00000000..16baf643
--- /dev/null
+++ b/api/app/Http/Requests/Api/V1/BulkApproveShiftAssignmentRequest.php
@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Requests\Api\V1;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+final class BulkApproveShiftAssignmentRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /** @return array<string, mixed> */
+    public function rules(): array
+    {
+        return [
+            'assignment_ids' => ['required', 'array', 'min:1', 'max:100'],
+            'assignment_ids.*' => ['required', 'ulid', 'exists:shift_assignments,id'],
+        ];
+    }
+}
diff --git a/api/app/Http/Requests/Api/V1/RejectShiftAssignmentRequest.php b/api/app/Http/Requests/Api/V1/RejectShiftAssignmentRequest.php
new file mode 100644
index 00000000..a0567b79
--- /dev/null
+++ b/api/app/Http/Requests/Api/V1/RejectShiftAssignmentRequest.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Requests\Api\V1;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+final class RejectShiftAssignmentRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /** @return array<string, mixed> */
+    public function rules(): array
+    {
+        return [
+            'reason' => ['nullable', 'string', 'max:1000'],
+        ];
+    }
+}
diff --git a/api/app/Http/Requests/Api/V1/SyncVolunteerAvailabilityRequest.php b/api/app/Http/Requests/Api/V1/SyncVolunteerAvailabilityRequest.php
new file mode 100644
index 00000000..f6571ce0
--- /dev/null
+++ b/api/app/Http/Requests/Api/V1/SyncVolunteerAvailabilityRequest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Requests\Api\V1;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+final class SyncVolunteerAvailabilityRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /** @return array<string, mixed> */
+    public function rules(): array
+    {
+        return [
+            'availabilities' => ['required', 'array'],
+            'availabilities.*.time_slot_id' => ['required', 'ulid', 'exists:time_slots,id'],
+            'availabilities.*.preference_level' => ['sometimes', 'integer', 'min:1', 'max:5'],
+        ];
+    }
+}
diff --git a/api/app/Http/Resources/Api/V1/ShiftAssignmentResource.php b/api/app/Http/Resources/Api/V1/ShiftAssignmentResource.php
index a0eaf4d7..d654c378 100644
--- a/api/app/Http/Resources/Api/V1/ShiftAssignmentResource.php
+++ b/api/app/Http/Resources/Api/V1/ShiftAssignmentResource.php
@@ -15,10 +15,24 @@ final class ShiftAssignmentResource extends JsonResource
             'id' => $this->id,
             'shift_id' => $this->shift_id,
             'person_id' => $this->person_id,
-            'status' => $this->status,
+            'time_slot_id' => $this->time_slot_id,
+            'status' => $this->status->value,
             'auto_approved' => $this->auto_approved,
+            'assigned_by' => $this->assigned_by,
             'assigned_at' => $this->assigned_at?->toIso8601String(),
+            'approved_by' => $this->approved_by,
             'approved_at' => $this->approved_at?->toIso8601String(),
+            'rejection_reason' => $this->rejection_reason,
+            'hours_expected' => $this->hours_expected,
+            'hours_completed' => $this->hours_completed,
+            'checked_in_at' => $this->checked_in_at?->toIso8601String(),
+            'checked_out_at' => $this->checked_out_at?->toIso8601String(),
+            'is_cancellable' => $this->isCancellable(),
+            'is_approvable' => $this->isApprovable(),
+            'created_at' => $this->created_at?->toIso8601String(),
+
+            'person' => new PersonResource($this->whenLoaded('person')),
+            'shift' => new ShiftResource($this->whenLoaded('shift')),
         ];
     }
 }
diff --git a/api/app/Models/Person.php b/api/app/Models/Person.php
index ed1ecf2d..905019b2 100644
--- a/api/app/Models/Person.php
+++ b/api/app/Models/Person.php
@@ -76,6 +76,11 @@ final class Person extends Model
         return $this->hasMany(ShiftAssignment::class);
     }
 
+    public function volunteerAvailabilities(): HasMany
+    {
+        return $this->hasMany(VolunteerAvailability::class);
+    }
+
     public function identityMatches(): HasMany
     {
         return $this->hasMany(PersonIdentityMatch::class);
diff --git a/api/app/Models/Shift.php b/api/app/Models/Shift.php
index c1357051..334709d7 100644
--- a/api/app/Models/Shift.php
+++ b/api/app/Models/Shift.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Models;
 
+use App\Enums\ShiftAssignmentStatus;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Casts\Attribute;
 use Illuminate\Database\Eloquent\Concerns\HasUlids;
@@ -99,7 +100,7 @@ final class Shift extends Model
                 return (int) $this->attributes['filled_slots'];
             }
 
-            return $this->shiftAssignments()->where('status', 'approved')->count();
+            return $this->shiftAssignments()->where('status', ShiftAssignmentStatus::APPROVED)->count();
         });
     }
 
diff --git a/api/app/Models/ShiftAssignment.php b/api/app/Models/ShiftAssignment.php
index ed9b7d6c..832e8324 100644
--- a/api/app/Models/ShiftAssignment.php
+++ b/api/app/Models/ShiftAssignment.php
@@ -4,6 +4,8 @@ declare(strict_types=1);
 
 namespace App\Models;
 
+use App\Enums\ShiftAssignmentStatus;
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Concerns\HasUlids;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
@@ -36,11 +38,14 @@ final class ShiftAssignment extends Model
     protected function casts(): array
     {
         return [
+            'status' => ShiftAssignmentStatus::class,
             'auto_approved' => 'boolean',
             'assigned_at' => 'datetime',
             'approved_at' => 'datetime',
             'checked_in_at' => 'datetime',
             'checked_out_at' => 'datetime',
+            'hours_expected' => 'decimal:2',
+            'hours_completed' => 'decimal:2',
         ];
     }
 
@@ -58,4 +63,37 @@ final class ShiftAssignment extends Model
     {
         return $this->belongsTo(TimeSlot::class);
     }
+
+    public function assignedByUser(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'assigned_by');
+    }
+
+    public function approvedByUser(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'approved_by');
+    }
+
+    public function scopeActive(Builder $query): Builder
+    {
+        return $query->whereIn('status', [
+            ShiftAssignmentStatus::PENDING_APPROVAL,
+            ShiftAssignmentStatus::APPROVED,
+        ]);
+    }
+
+    public function scopeForStatus(Builder $query, ShiftAssignmentStatus $status): Builder
+    {
+        return $query->where('status', $status);
+    }
+
+    public function isCancellable(): bool
+    {
+        return $this->status->canTransitionTo(ShiftAssignmentStatus::CANCELLED);
+    }
+
+    public function isApprovable(): bool
+    {
+        return $this->status->canTransitionTo(ShiftAssignmentStatus::APPROVED);
+    }
 }
diff --git a/api/app/Models/VolunteerAvailability.php b/api/app/Models/VolunteerAvailability.php
new file mode 100644
index 00000000..b82f7af4
--- /dev/null
+++ b/api/app/Models/VolunteerAvailability.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Concerns\HasUlids;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+final class VolunteerAvailability extends Model
+{
+    use HasFactory;
+    use HasUlids;
+
+    public $timestamps = false;
+
+    protected $table = 'volunteer_availabilities';
+
+    protected $fillable = [
+        'person_id',
+        'time_slot_id',
+        'preference_level',
+        'submitted_at',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'preference_level' => 'integer',
+            'submitted_at' => 'datetime',
+        ];
+    }
+
+    public function person(): BelongsTo
+    {
+        return $this->belongsTo(Person::class);
+    }
+
+    public function timeSlot(): BelongsTo
+    {
+        return $this->belongsTo(TimeSlot::class);
+    }
+}
diff --git a/api/app/Policies/ShiftAssignmentPolicy.php b/api/app/Policies/ShiftAssignmentPolicy.php
new file mode 100644
index 00000000..b23c6534
--- /dev/null
+++ b/api/app/Policies/ShiftAssignmentPolicy.php
@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Policies;
+
+use App\Models\Event;
+use App\Models\ShiftAssignment;
+use App\Models\User;
+
+final class ShiftAssignmentPolicy
+{
+    public function viewAny(User $user, Event $event): bool
+    {
+        return $user->hasRole('super_admin')
+            || $event->organisation->users()->where('user_id', $user->id)->exists();
+    }
+
+    public function approve(User $user, ShiftAssignment $assignment, Event $event): bool
+    {
+        return $this->canManageEvent($user, $event);
+    }
+
+    public function reject(User $user, ShiftAssignment $assignment, Event $event): bool
+    {
+        return $this->canManageEvent($user, $event);
+    }
+
+    public function cancel(User $user, ShiftAssignment $assignment, Event $event): bool
+    {
+        if ($this->canManageEvent($user, $event)) {
+            return true;
+        }
+
+        // Volunteers can cancel their own assignments
+        $person = $assignment->person;
+
+        return $person->user_id !== null && $person->user_id === $user->id;
+    }
+
+    public function bulkApprove(User $user, Event $event): bool
+    {
+        return $this->canManageEvent($user, $event);
+    }
+
+    private function canManageEvent(User $user, Event $event): bool
+    {
+        if ($user->hasRole('super_admin')) {
+            return true;
+        }
+
+        $isOrgAdmin = $event->organisation->users()
+            ->where('user_id', $user->id)
+            ->wherePivot('role', 'org_admin')
+            ->exists();
+
+        if ($isOrgAdmin) {
+            return true;
+        }
+
+        return $event->users()
+            ->where('user_id', $user->id)
+            ->wherePivot('role', 'event_manager')
+            ->exists();
+    }
+}
diff --git a/api/app/Services/ShiftAssignmentService.php b/api/app/Services/ShiftAssignmentService.php
new file mode 100644
index 00000000..dcadbe68
--- /dev/null
+++ b/api/app/Services/ShiftAssignmentService.php
@@ -0,0 +1,377 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services;
+
+use App\Enums\ShiftAssignmentStatus;
+use App\Models\Person;
+use App\Models\Shift;
+use App\Models\ShiftAssignment;
+use App\Models\User;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Validation\ValidationException;
+
+final class ShiftAssignmentService
+{
+    /**
+     * @throws ValidationException
+     */
+    public function claim(Shift $shift, Person $person): ShiftAssignment
+    {
+        return DB::transaction(function () use ($shift, $person): ShiftAssignment {
+            $this->validateShiftIsOpen($shift);
+            $this->validatePersonApproved($person);
+            $this->validateClaimCapacity($shift);
+            $this->validateNoConflict($shift, $person);
+
+            $autoApprove = $shift->festivalSection->crew_auto_accepts;
+            $status = $autoApprove
+                ? ShiftAssignmentStatus::APPROVED
+                : ShiftAssignmentStatus::PENDING_APPROVAL;
+
+            $assignment = $shift->shiftAssignments()->create([
+                'person_id' => $person->id,
+                'time_slot_id' => $shift->time_slot_id,
+                'status' => $status,
+                'auto_approved' => $autoApprove,
+                'assigned_at' => now(),
+                'approved_at' => $autoApprove ? now() : null,
+            ]);
+
+            $this->updateShiftStatusIfFull($shift);
+
+            activity('shift_assignment')
+                ->causedBy(auth()->user())
+                ->performedOn($assignment)
+                ->withProperties([
+                    'shift_id' => $shift->id,
+                    'person_id' => $person->id,
+                    'auto_approved' => $autoApprove,
+                ])
+                ->log('shift_assignment.claimed');
+
+            if ($autoApprove) {
+                activity('shift_assignment')
+                    ->causedBy(auth()->user())
+                    ->performedOn($assignment)
+                    ->withProperties(['shift_id' => $shift->id])
+                    ->log('shift_assignment.auto_approved');
+            }
+
+            return $assignment;
+        });
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function assign(Shift $shift, Person $person, User $assignedBy): ShiftAssignment
+    {
+        return DB::transaction(function () use ($shift, $person, $assignedBy): ShiftAssignment {
+            $this->validateShiftIsOpen($shift);
+            $this->validateAssignCapacity($shift);
+            $this->validateNoConflict($shift, $person);
+
+            $assignment = $shift->shiftAssignments()->create([
+                'person_id' => $person->id,
+                'time_slot_id' => $shift->time_slot_id,
+                'status' => ShiftAssignmentStatus::APPROVED,
+                'auto_approved' => false,
+                'assigned_by' => $assignedBy->id,
+                'assigned_at' => now(),
+                'approved_by' => $assignedBy->id,
+                'approved_at' => now(),
+            ]);
+
+            $this->updateShiftStatusIfFull($shift);
+
+            activity('shift_assignment')
+                ->causedBy($assignedBy)
+                ->performedOn($assignment)
+                ->withProperties([
+                    'shift_id' => $shift->id,
+                    'person_id' => $person->id,
+                    'assigned_by' => $assignedBy->id,
+                ])
+                ->log('shift_assignment.assigned');
+
+            return $assignment;
+        });
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function approve(ShiftAssignment $assignment, User $approvedBy): ShiftAssignment
+    {
+        return DB::transaction(function () use ($assignment, $approvedBy): ShiftAssignment {
+            $this->validateStatusTransition($assignment, ShiftAssignmentStatus::APPROVED);
+
+            $shift = $assignment->shift;
+            $approvedCount = $shift->shiftAssignments()
+                ->where('status', ShiftAssignmentStatus::APPROVED)
+                ->count();
+
+            if ($approvedCount >= $shift->slots_total) {
+                throw ValidationException::withMessages([
+                    'shift' => ['Shift is vol — alle slots zijn bezet.'],
+                ]);
+            }
+
+            $oldStatus = $assignment->status;
+
+            $assignment->update([
+                'status' => ShiftAssignmentStatus::APPROVED,
+                'approved_by' => $approvedBy->id,
+                'approved_at' => now(),
+            ]);
+
+            $this->updateShiftStatusIfFull($shift);
+
+            activity('shift_assignment')
+                ->causedBy($approvedBy)
+                ->performedOn($assignment)
+                ->withProperties([
+                    'old_status' => $oldStatus->value,
+                    'new_status' => ShiftAssignmentStatus::APPROVED->value,
+                ])
+                ->log('shift_assignment.approved');
+
+            return $assignment->fresh();
+        });
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function reject(ShiftAssignment $assignment, User $rejectedBy, ?string $reason = null): ShiftAssignment
+    {
+        $this->validateStatusTransition($assignment, ShiftAssignmentStatus::REJECTED);
+
+        $oldStatus = $assignment->status;
+
+        $assignment->update([
+            'status' => ShiftAssignmentStatus::REJECTED,
+            'rejection_reason' => $reason,
+        ]);
+
+        activity('shift_assignment')
+            ->causedBy($rejectedBy)
+            ->performedOn($assignment)
+            ->withProperties([
+                'old_status' => $oldStatus->value,
+                'new_status' => ShiftAssignmentStatus::REJECTED->value,
+                'reason' => $reason,
+            ])
+            ->log('shift_assignment.rejected');
+
+        return $assignment->fresh();
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function cancel(ShiftAssignment $assignment, User $cancelledBy): ShiftAssignment
+    {
+        return DB::transaction(function () use ($assignment, $cancelledBy): ShiftAssignment {
+            $this->validateStatusTransition($assignment, ShiftAssignmentStatus::CANCELLED);
+
+            $wasApproved = $assignment->status === ShiftAssignmentStatus::APPROVED;
+            $oldStatus = $assignment->status;
+
+            $assignment->update([
+                'status' => ShiftAssignmentStatus::CANCELLED,
+            ]);
+
+            if ($wasApproved) {
+                $this->updateShiftStatusAfterCancellation($assignment->shift);
+            }
+
+            activity('shift_assignment')
+                ->causedBy($cancelledBy)
+                ->performedOn($assignment)
+                ->withProperties([
+                    'old_status' => $oldStatus->value,
+                    'new_status' => ShiftAssignmentStatus::CANCELLED->value,
+                ])
+                ->log('shift_assignment.cancelled');
+
+            return $assignment->fresh();
+        });
+    }
+
+    /**
+     * @return Collection<int, array{assignment_id: string, status: string}>
+     */
+    public function bulkApprove(Collection $assignments, User $approvedBy): Collection
+    {
+        return DB::transaction(function () use ($assignments, $approvedBy): Collection {
+            return $assignments->map(function (ShiftAssignment $assignment) use ($approvedBy): array {
+                if ($assignment->status !== ShiftAssignmentStatus::PENDING_APPROVAL) {
+                    return [
+                        'assignment_id' => $assignment->id,
+                        'status' => 'skipped',
+                        'reason' => "Status is {$assignment->status->value}, not pending_approval.",
+                    ];
+                }
+
+                $shift = $assignment->shift;
+                $approvedCount = $shift->shiftAssignments()
+                    ->where('status', ShiftAssignmentStatus::APPROVED)
+                    ->count();
+
+                if ($approvedCount >= $shift->slots_total) {
+                    return [
+                        'assignment_id' => $assignment->id,
+                        'status' => 'skipped',
+                        'reason' => 'Shift is vol.',
+                    ];
+                }
+
+                $assignment->update([
+                    'status' => ShiftAssignmentStatus::APPROVED,
+                    'approved_by' => $approvedBy->id,
+                    'approved_at' => now(),
+                ]);
+
+                $this->updateShiftStatusIfFull($shift);
+
+                activity('shift_assignment')
+                    ->causedBy($approvedBy)
+                    ->performedOn($assignment)
+                    ->withProperties([
+                        'old_status' => ShiftAssignmentStatus::PENDING_APPROVAL->value,
+                        'new_status' => ShiftAssignmentStatus::APPROVED->value,
+                    ])
+                    ->log('shift_assignment.approved');
+
+                return [
+                    'assignment_id' => $assignment->id,
+                    'status' => 'approved',
+                ];
+            });
+        });
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    private function validateShiftIsOpen(Shift $shift): void
+    {
+        if ($shift->status !== 'open') {
+            throw ValidationException::withMessages([
+                'shift' => ['Shift is niet open voor inschrijvingen.'],
+            ]);
+        }
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    private function validatePersonApproved(Person $person): void
+    {
+        if ($person->status !== 'approved') {
+            throw ValidationException::withMessages([
+                'person' => ['Persoon is nog niet goedgekeurd.'],
+            ]);
+        }
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    private function validateClaimCapacity(Shift $shift): void
+    {
+        if ($shift->slots_open_for_claiming <= 0) {
+            throw ValidationException::withMessages([
+                'shift' => ['Geen claimbare slots beschikbaar voor deze shift.'],
+            ]);
+        }
+
+        $activeCount = $shift->shiftAssignments()
+            ->whereNotIn('status', [
+                ShiftAssignmentStatus::REJECTED,
+                ShiftAssignmentStatus::CANCELLED,
+            ])
+            ->count();
+
+        if ($activeCount >= $shift->slots_open_for_claiming) {
+            throw ValidationException::withMessages([
+                'shift' => ['Geen claimbare slots beschikbaar voor deze shift.'],
+            ]);
+        }
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    private function validateAssignCapacity(Shift $shift): void
+    {
+        $approvedCount = $shift->shiftAssignments()
+            ->where('status', ShiftAssignmentStatus::APPROVED)
+            ->count();
+
+        if ($approvedCount >= $shift->slots_total) {
+            throw ValidationException::withMessages([
+                'shift' => ['Shift is vol — alle slots zijn bezet.'],
+            ]);
+        }
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    private function validateNoConflict(Shift $shift, Person $person): void
+    {
+        if ($shift->allow_overlap) {
+            return;
+        }
+
+        $conflict = ShiftAssignment::where('person_id', $person->id)
+            ->where('time_slot_id', $shift->time_slot_id)
+            ->active()
+            ->exists();
+
+        if ($conflict) {
+            throw ValidationException::withMessages([
+                'person_id' => ['Deze persoon is al ingepland voor dit tijdslot.'],
+            ]);
+        }
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    private function validateStatusTransition(ShiftAssignment $assignment, ShiftAssignmentStatus $target): void
+    {
+        if (! $assignment->status->canTransitionTo($target)) {
+            throw ValidationException::withMessages([
+                'status' => ["Statusovergang van '{$assignment->status->value}' naar '{$target->value}' is niet toegestaan."],
+            ]);
+        }
+    }
+
+    private function updateShiftStatusIfFull(Shift $shift): void
+    {
+        $approvedCount = $shift->shiftAssignments()
+            ->where('status', ShiftAssignmentStatus::APPROVED)
+            ->count();
+
+        if ($approvedCount >= $shift->slots_total && $shift->status === 'open') {
+            $shift->update(['status' => 'full']);
+        }
+    }
+
+    private function updateShiftStatusAfterCancellation(Shift $shift): void
+    {
+        $approvedCount = $shift->shiftAssignments()
+            ->where('status', ShiftAssignmentStatus::APPROVED)
+            ->count();
+
+        if ($approvedCount < $shift->slots_total && $shift->status === 'full') {
+            $shift->update(['status' => 'open']);
+        }
+    }
+}
diff --git a/api/database/factories/ShiftAssignmentFactory.php b/api/database/factories/ShiftAssignmentFactory.php
index 7bc3d84f..a4b7e0ab 100644
--- a/api/database/factories/ShiftAssignmentFactory.php
+++ b/api/database/factories/ShiftAssignmentFactory.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace Database\Factories;
 
+use App\Enums\ShiftAssignmentStatus;
 use App\Models\Person;
 use App\Models\Shift;
 use App\Models\ShiftAssignment;
@@ -20,15 +21,16 @@ final class ShiftAssignmentFactory extends Factory
             'shift_id' => Shift::factory(),
             'person_id' => Person::factory(),
             'time_slot_id' => TimeSlot::factory(),
-            'status' => 'pending_approval',
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
             'auto_approved' => false,
+            'assigned_at' => now(),
         ];
     }
 
     public function approved(): static
     {
         return $this->state(fn () => [
-            'status' => 'approved',
+            'status' => ShiftAssignmentStatus::APPROVED,
             'approved_at' => now(),
         ]);
     }
@@ -36,7 +38,7 @@ final class ShiftAssignmentFactory extends Factory
     public function autoApproved(): static
     {
         return $this->state(fn () => [
-            'status' => 'approved',
+            'status' => ShiftAssignmentStatus::APPROVED,
             'auto_approved' => true,
             'approved_at' => now(),
         ]);
diff --git a/api/database/factories/VolunteerAvailabilityFactory.php b/api/database/factories/VolunteerAvailabilityFactory.php
new file mode 100644
index 00000000..b26bb64a
--- /dev/null
+++ b/api/database/factories/VolunteerAvailabilityFactory.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories;
+
+use App\Models\Person;
+use App\Models\TimeSlot;
+use App\Models\VolunteerAvailability;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<VolunteerAvailability> */
+final class VolunteerAvailabilityFactory extends Factory
+{
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        return [
+            'person_id' => Person::factory(),
+            'time_slot_id' => TimeSlot::factory(),
+            'preference_level' => fake()->numberBetween(1, 5),
+            'submitted_at' => now(),
+        ];
+    }
+}
diff --git a/api/routes/api.php b/api/routes/api.php
index bbdd6ad1..c223bd1d 100644
--- a/api/routes/api.php
+++ b/api/routes/api.php
@@ -17,8 +17,10 @@ use App\Http\Controllers\Api\V1\OrganisationController;
 use App\Http\Controllers\Api\V1\PersonController;
 use App\Http\Controllers\Api\V1\PersonIdentityMatchController;
 use App\Http\Controllers\Api\V1\PersonTagController;
+use App\Http\Controllers\Api\V1\ShiftAssignmentController;
 use App\Http\Controllers\Api\V1\ShiftController;
 use App\Http\Controllers\Api\V1\TimeSlotController;
+use App\Http\Controllers\Api\V1\VolunteerAvailabilityController;
 use App\Http\Controllers\Api\V1\UserOrganisationTagController;
 use App\Models\FestivalSection;
 use App\Models\Organisation;
@@ -129,8 +131,19 @@ Route::middleware('auth:sanctum')->group(function () {
             Route::post('shifts/{shift}/claim', [ShiftController::class, 'claim']);
         });
 
+        // Shift assignments (event-level)
+        Route::get('shift-assignments', [ShiftAssignmentController::class, 'index']);
+        Route::post('shift-assignments/{shiftAssignment}/approve', [ShiftAssignmentController::class, 'approve']);
+        Route::post('shift-assignments/{shiftAssignment}/reject', [ShiftAssignmentController::class, 'reject']);
+        Route::post('shift-assignments/{shiftAssignment}/cancel', [ShiftAssignmentController::class, 'cancel']);
+        Route::post('shift-assignments/bulk-approve', [ShiftAssignmentController::class, 'bulkApprove']);
+
         Route::apiResource('persons', PersonController::class);
         Route::post('persons/{person}/approve', [PersonController::class, 'approve']);
+
+        // Volunteer availabilities
+        Route::get('persons/{person}/availabilities', [VolunteerAvailabilityController::class, 'index']);
+        Route::post('persons/{person}/availabilities/sync', [VolunteerAvailabilityController::class, 'sync']);
         Route::apiResource('crowd-lists', CrowdListController::class)
             ->except(['show']);
         Route::get('crowd-lists/{crowdList}/persons', [CrowdListController::class, 'persons']);
diff --git a/api/tests/Feature/Api/V1/ShiftAssignmentWorkflowTest.php b/api/tests/Feature/Api/V1/ShiftAssignmentWorkflowTest.php
new file mode 100644
index 00000000..da303d24
--- /dev/null
+++ b/api/tests/Feature/Api/V1/ShiftAssignmentWorkflowTest.php
@@ -0,0 +1,788 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\Api\V1;
+
+use App\Enums\ShiftAssignmentStatus;
+use App\Models\CrowdType;
+use App\Models\Event;
+use App\Models\FestivalSection;
+use App\Models\Organisation;
+use App\Models\Person;
+use App\Models\Shift;
+use App\Models\ShiftAssignment;
+use App\Models\TimeSlot;
+use App\Models\User;
+use App\Models\VolunteerAvailability;
+use Database\Seeders\RoleSeeder;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Laravel\Sanctum\Sanctum;
+use Tests\TestCase;
+
+class ShiftAssignmentWorkflowTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private User $orgAdmin;
+    private User $outsider;
+    private User $volunteer;
+    private Organisation $organisation;
+    private Organisation $otherOrganisation;
+    private Event $event;
+    private FestivalSection $section;
+    private TimeSlot $timeSlot;
+    private CrowdType $crowdType;
+    private Person $person;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->seed(RoleSeeder::class);
+
+        $this->organisation = Organisation::factory()->create();
+        $this->otherOrganisation = Organisation::factory()->create();
+
+        $this->orgAdmin = User::factory()->create();
+        $this->organisation->users()->attach($this->orgAdmin, ['role' => 'org_admin']);
+
+        $this->outsider = User::factory()->create();
+        $this->otherOrganisation->users()->attach($this->outsider, ['role' => 'org_admin']);
+
+        $this->volunteer = User::factory()->create();
+        $this->organisation->users()->attach($this->volunteer, ['role' => 'org_member']);
+
+        $this->event = Event::factory()->create(['organisation_id' => $this->organisation->id]);
+        $this->section = FestivalSection::factory()->create([
+            'event_id' => $this->event->id,
+            'crew_auto_accepts' => false,
+        ]);
+        $this->timeSlot = TimeSlot::factory()->create(['event_id' => $this->event->id]);
+        $this->crowdType = CrowdType::factory()->systemType('VOLUNTEER')->create([
+            'organisation_id' => $this->organisation->id,
+        ]);
+        $this->person = Person::factory()->approved()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+            'user_id' => $this->volunteer->id,
+        ]);
+    }
+
+    private function createOpenShift(array $overrides = []): Shift
+    {
+        return Shift::factory()->open()->create(array_merge([
+            'festival_section_id' => $this->section->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'slots_total' => 4,
+            'slots_open_for_claiming' => 3,
+        ], $overrides));
+    }
+
+    // =========================================================================
+    // Claim workflow
+    // =========================================================================
+
+    public function test_volunteer_can_claim_open_shift(): void
+    {
+        $shift = $this->createOpenShift();
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertCreated()
+            ->assertJsonPath('data.status', 'pending_approval')
+            ->assertJsonPath('data.person_id', $this->person->id);
+
+        $this->assertDatabaseHas('shift_assignments', [
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL->value,
+        ]);
+    }
+
+    public function test_volunteer_can_claim_auto_approve_shift(): void
+    {
+        $autoSection = FestivalSection::factory()->create([
+            'event_id' => $this->event->id,
+            'crew_auto_accepts' => true,
+        ]);
+        $shift = $this->createOpenShift(['festival_section_id' => $autoSection->id]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$autoSection->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertCreated()
+            ->assertJsonPath('data.status', 'approved')
+            ->assertJsonPath('data.auto_approved', true);
+    }
+
+    public function test_claim_rejected_when_shift_is_full(): void
+    {
+        $shift = $this->createOpenShift(['slots_open_for_claiming' => 1]);
+
+        // Fill the claimable slot
+        ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_claim_rejected_when_shift_status_not_open(): void
+    {
+        $shift = Shift::factory()->create([
+            'festival_section_id' => $this->section->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'slots_total' => 4,
+            'slots_open_for_claiming' => 3,
+            'status' => 'draft',
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_claim_rejected_with_conflicting_assignment(): void
+    {
+        $shift1 = $this->createOpenShift();
+        $shift2 = $this->createOpenShift();
+
+        // Create existing active assignment for the same time slot
+        ShiftAssignment::factory()->create([
+            'shift_id' => $shift1->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::APPROVED,
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift2->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_claim_allowed_when_shift_allows_overlap(): void
+    {
+        $shift1 = $this->createOpenShift();
+        $shift2 = $this->createOpenShift(['allow_overlap' => true]);
+
+        // Create existing assignment
+        ShiftAssignment::factory()->create([
+            'shift_id' => $shift1->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::APPROVED,
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift2->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertCreated();
+    }
+
+    public function test_claim_rejected_when_person_not_approved(): void
+    {
+        $pendingPerson = Person::factory()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+            'status' => 'pending',
+        ]);
+        $shift = $this->createOpenShift();
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $pendingPerson->id],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_unauthenticated_claim_returns_401(): void
+    {
+        $shift = $this->createOpenShift();
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertUnauthorized();
+    }
+
+    // =========================================================================
+    // Assign workflow
+    // =========================================================================
+
+    public function test_organizer_can_assign_person_to_shift(): void
+    {
+        $shift = $this->createOpenShift();
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/assign",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertCreated()
+            ->assertJsonPath('data.status', 'approved')
+            ->assertJsonPath('data.person_id', $this->person->id);
+
+        $this->assertDatabaseHas('shift_assignments', [
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'status' => ShiftAssignmentStatus::APPROVED->value,
+            'assigned_by' => $this->orgAdmin->id,
+            'approved_by' => $this->orgAdmin->id,
+        ]);
+    }
+
+    public function test_assign_uses_slots_total_not_claiming(): void
+    {
+        // slots_open_for_claiming = 0, but slots_total = 4
+        $shift = $this->createOpenShift(['slots_open_for_claiming' => 0]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/assign",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertCreated();
+    }
+
+    public function test_assign_rejected_when_capacity_full(): void
+    {
+        $shift = $this->createOpenShift(['slots_total' => 1]);
+
+        // Fill the slot
+        ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift->id,
+            'person_id' => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/assign",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_assign_rejected_with_conflict(): void
+    {
+        $shift1 = $this->createOpenShift();
+        $shift2 = $this->createOpenShift();
+
+        ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift1->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift2->id}/assign",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_non_organizer_cannot_assign(): void
+    {
+        $shift = $this->createOpenShift();
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/assign",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertForbidden();
+    }
+
+    // =========================================================================
+    // Approve / Reject / Cancel
+    // =========================================================================
+
+    public function test_organizer_approves_pending_assignment(): void
+    {
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/approve",
+        );
+
+        $response->assertOk()
+            ->assertJsonPath('data.status', 'approved');
+
+        $this->assertDatabaseHas('shift_assignments', [
+            'id' => $assignment->id,
+            'status' => ShiftAssignmentStatus::APPROVED->value,
+            'approved_by' => $this->orgAdmin->id,
+        ]);
+    }
+
+    public function test_organizer_rejects_with_reason(): void
+    {
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/reject",
+            ['reason' => 'Onvoldoende ervaring voor deze rol.'],
+        );
+
+        $response->assertOk()
+            ->assertJsonPath('data.status', 'rejected')
+            ->assertJsonPath('data.rejection_reason', 'Onvoldoende ervaring voor deze rol.');
+    }
+
+    public function test_cannot_approve_already_approved(): void
+    {
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/approve",
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_volunteer_can_cancel_own_pending_assignment(): void
+    {
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/cancel",
+        );
+
+        $response->assertOk()
+            ->assertJsonPath('data.status', 'cancelled');
+    }
+
+    public function test_volunteer_can_cancel_own_approved_assignment(): void
+    {
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/cancel",
+        );
+
+        $response->assertOk()
+            ->assertJsonPath('data.status', 'cancelled');
+    }
+
+    public function test_volunteer_cannot_cancel_someone_elses_assignment(): void
+    {
+        $otherPerson = Person::factory()->approved()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $otherPerson->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        Sanctum::actingAs($this->volunteer);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/cancel",
+        );
+
+        $response->assertForbidden();
+    }
+
+    public function test_organizer_can_cancel_any_assignment(): void
+    {
+        $otherPerson = Person::factory()->approved()->create([
+            'event_id' => $this->event->id,
+            'crowd_type_id' => $this->crowdType->id,
+        ]);
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $otherPerson->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/cancel",
+        );
+
+        $response->assertOk()
+            ->assertJsonPath('data.status', 'cancelled');
+    }
+
+    // =========================================================================
+    // Bulk approve
+    // =========================================================================
+
+    public function test_bulk_approve_multiple_pending(): void
+    {
+        $shift = $this->createOpenShift();
+
+        $assignments = collect([1, 2])->map(fn () => ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]));
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/bulk-approve",
+            ['assignment_ids' => $assignments->pluck('id')->toArray()],
+        );
+
+        $response->assertOk();
+
+        foreach ($assignments as $assignment) {
+            $this->assertDatabaseHas('shift_assignments', [
+                'id' => $assignment->id,
+                'status' => ShiftAssignmentStatus::APPROVED->value,
+            ]);
+        }
+    }
+
+    public function test_bulk_approve_skips_non_pending(): void
+    {
+        $shift = $this->createOpenShift();
+
+        $pending = ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        $approved = ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift->id,
+            'person_id' => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/bulk-approve",
+            ['assignment_ids' => [$pending->id, $approved->id]],
+        );
+
+        $response->assertOk();
+
+        $results = $response->json('data');
+        $this->assertCount(2, $results);
+
+        $pendingResult = collect($results)->firstWhere('assignment_id', $pending->id);
+        $approvedResult = collect($results)->firstWhere('assignment_id', $approved->id);
+
+        $this->assertEquals('approved', $pendingResult['status']);
+        $this->assertEquals('skipped', $approvedResult['status']);
+    }
+
+    // =========================================================================
+    // Index / listing
+    // =========================================================================
+
+    public function test_index_returns_assignments_for_event(): void
+    {
+        $shift = $this->createOpenShift();
+
+        ShiftAssignment::factory()->count(3)->create([
+            'shift_id' => $shift->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'person_id' => fn () => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/shift-assignments");
+
+        $response->assertOk();
+        $this->assertCount(3, $response->json('data'));
+    }
+
+    public function test_index_filterable_by_status(): void
+    {
+        $shift = $this->createOpenShift();
+
+        ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'person_id' => $this->person->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'person_id' => Person::factory()->approved()->create([
+                'event_id' => $this->event->id,
+                'crowd_type_id' => $this->crowdType->id,
+            ])->id,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/shift-assignments?status=pending_approval");
+
+        $response->assertOk();
+        $this->assertCount(1, $response->json('data'));
+        $this->assertEquals('pending_approval', $response->json('data.0.status'));
+    }
+
+    // =========================================================================
+    // Multi-tenancy
+    // =========================================================================
+
+    public function test_cannot_claim_shift_in_different_organisation(): void
+    {
+        $shift = $this->createOpenShift();
+
+        Sanctum::actingAs($this->outsider);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/sections/{$this->section->id}/shifts/{$shift->id}/claim",
+            ['person_id' => $this->person->id],
+        );
+
+        $response->assertForbidden();
+    }
+
+    public function test_cannot_approve_assignment_in_different_organisation(): void
+    {
+        $shift = $this->createOpenShift();
+        $assignment = ShiftAssignment::factory()->create([
+            'shift_id' => $shift->id,
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
+        ]);
+
+        Sanctum::actingAs($this->outsider);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/shift-assignments/{$assignment->id}/approve",
+        );
+
+        $response->assertForbidden();
+    }
+
+    // =========================================================================
+    // Volunteer Availabilities
+    // =========================================================================
+
+    public function test_sync_availabilities_for_person(): void
+    {
+        $slot2 = TimeSlot::factory()->create(['event_id' => $this->event->id]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/persons/{$this->person->id}/availabilities/sync",
+            [
+                'availabilities' => [
+                    ['time_slot_id' => $this->timeSlot->id, 'preference_level' => 5],
+                    ['time_slot_id' => $slot2->id, 'preference_level' => 2],
+                ],
+            ],
+        );
+
+        $response->assertOk();
+
+        $this->assertDatabaseCount('volunteer_availabilities', 2);
+        $this->assertDatabaseHas('volunteer_availabilities', [
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'preference_level' => 5,
+        ]);
+    }
+
+    public function test_sync_replaces_existing_availabilities(): void
+    {
+        // Create initial availabilities
+        VolunteerAvailability::factory()->create([
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'preference_level' => 3,
+        ]);
+
+        $slot2 = TimeSlot::factory()->create(['event_id' => $this->event->id]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/persons/{$this->person->id}/availabilities/sync",
+            [
+                'availabilities' => [
+                    ['time_slot_id' => $slot2->id, 'preference_level' => 4],
+                ],
+            ],
+        );
+
+        $response->assertOk();
+
+        // Old one removed, only new one exists
+        $this->assertDatabaseCount('volunteer_availabilities', 1);
+        $this->assertDatabaseHas('volunteer_availabilities', [
+            'person_id' => $this->person->id,
+            'time_slot_id' => $slot2->id,
+            'preference_level' => 4,
+        ]);
+        $this->assertDatabaseMissing('volunteer_availabilities', [
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+        ]);
+    }
+
+    public function test_sync_rejects_time_slot_from_wrong_event(): void
+    {
+        $otherEvent = Event::factory()->create(['organisation_id' => $this->otherOrganisation->id]);
+        $otherSlot = TimeSlot::factory()->create(['event_id' => $otherEvent->id]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/persons/{$this->person->id}/availabilities/sync",
+            [
+                'availabilities' => [
+                    ['time_slot_id' => $otherSlot->id, 'preference_level' => 3],
+                ],
+            ],
+        );
+
+        $response->assertUnprocessable();
+    }
+
+    public function test_unauthenticated_sync_returns_401(): void
+    {
+        $response = $this->postJson(
+            "/api/v1/events/{$this->event->id}/persons/{$this->person->id}/availabilities/sync",
+            ['availabilities' => []],
+        );
+
+        $response->assertUnauthorized();
+    }
+
+    public function test_list_availabilities_for_person(): void
+    {
+        VolunteerAvailability::factory()->create([
+            'person_id' => $this->person->id,
+            'time_slot_id' => $this->timeSlot->id,
+            'preference_level' => 4,
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson(
+            "/api/v1/events/{$this->event->id}/persons/{$this->person->id}/availabilities",
+        );
+
+        $response->assertOk();
+        $this->assertCount(1, $response->json('data'));
+        $this->assertEquals(4, $response->json('data.0.preference_level'));
+    }
+}
diff --git a/api/tests/Feature/Event/FestivalEventTest.php b/api/tests/Feature/Event/FestivalEventTest.php
index a18cff3e..08fd57d4 100644
--- a/api/tests/Feature/Event/FestivalEventTest.php
+++ b/api/tests/Feature/Event/FestivalEventTest.php
@@ -541,7 +541,7 @@ class FestivalEventTest extends TestCase
         ]);
 
         // Create a shift on the sub-event section using festival time slot
-        $shift = Shift::factory()->create([
+        $shift = Shift::factory()->open()->create([
             'festival_section_id' => $section->id,
             'time_slot_id' => $festivalTimeSlot->id,
             'slots_total' => 5,
@@ -566,7 +566,7 @@ class FestivalEventTest extends TestCase
             'event_id' => $this->subEvent->id,
         ]);
 
-        $shift2 = Shift::factory()->create([
+        $shift2 = Shift::factory()->open()->create([
             'festival_section_id' => $section2->id,
             'time_slot_id' => $festivalTimeSlot->id,
             'slots_total' => 5,
diff --git a/api/tests/Feature/Shift/ShiftTest.php b/api/tests/Feature/Shift/ShiftTest.php
index 61c6b3cd..77da9dfa 100644
--- a/api/tests/Feature/Shift/ShiftTest.php
+++ b/api/tests/Feature/Shift/ShiftTest.php
@@ -207,6 +207,7 @@ class ShiftTest extends TestCase
             'time_slot_id' => $this->timeSlot->id,
             'slots_total' => 4,
             'allow_overlap' => false,
+            'status' => 'open',
         ]);
 
         $person = Person::factory()->create([
@@ -229,6 +230,7 @@ class ShiftTest extends TestCase
             'time_slot_id' => $this->timeSlot->id,
             'slots_total' => 4,
             'allow_overlap' => false,
+            'status' => 'open',
         ]);
 
         Sanctum::actingAs($this->orgAdmin);
@@ -247,6 +249,7 @@ class ShiftTest extends TestCase
             'time_slot_id' => $this->timeSlot->id,
             'slots_total' => 4,
             'allow_overlap' => true,
+            'status' => 'open',
         ]);
 
         $person = Person::factory()->create([
@@ -269,6 +272,7 @@ class ShiftTest extends TestCase
             'time_slot_id' => $this->timeSlot->id,
             'slots_total' => 4,
             'allow_overlap' => true,
+            'status' => 'open',
         ]);
 
         Sanctum::actingAs($this->orgAdmin);
@@ -286,6 +290,7 @@ class ShiftTest extends TestCase
             'festival_section_id' => $this->section->id,
             'time_slot_id' => $this->timeSlot->id,
             'slots_total' => 1,
+            'status' => 'open',
         ]);
 
         $person1 = Person::factory()->create([
diff --git a/dev-docs/API.md b/dev-docs/API.md
index 7311d18d..497ac10a 100644
--- a/dev-docs/API.md
+++ b/dev-docs/API.md
@@ -136,6 +136,126 @@ Returns 422 with `errors`, `current_status`, `requested_status`, and `allowed_tr
 > in the URL must be the parent festival's ID (matching `section.event_id`), not the
 > sub-event's ID.
 
+## Shift Assignments
+
+- `GET /events/{event}/shift-assignments` — list assignments for event (paginated, 50/page)
+- `POST /events/{event}/shift-assignments/{shiftAssignment}/approve` — approve pending assignment
+- `POST /events/{event}/shift-assignments/{shiftAssignment}/reject` — reject pending assignment
+- `POST /events/{event}/shift-assignments/{shiftAssignment}/cancel` — cancel assignment
+- `POST /events/{event}/shift-assignments/bulk-approve` — bulk approve multiple assignments
+
+### Query Parameters (index)
+
+- `status` — filter by assignment status (`pending_approval`, `approved`, `rejected`, `cancelled`, `completed`)
+- `shift_id` — filter by shift
+- `person_id` — filter by person
+- `section_id` — filter by festival section
+
+### Assign Body
+
+`POST /events/{event}/sections/{section}/shifts/{shift}/assign`
+
+```json
+{ "person_id": "01JXYZ..." }
+```
+
+Organizer manually assigns a person. Assignment is pre-approved (status = `approved`).
+Validates: shift must be `open`, capacity not full (`slots_total`), no time slot conflict.
+
+### Claim Body
+
+`POST /events/{event}/sections/{section}/shifts/{shift}/claim`
+
+```json
+{ "person_id": "01JXYZ..." }
+```
+
+Volunteer claims a shift. Status depends on `festival_section.crew_auto_accepts`:
+- `true` → status = `approved`, `auto_approved = true`
+- `false` → status = `pending_approval`
+
+Validates: shift must be `open`, person must be `approved`, claiming capacity not full (`slots_open_for_claiming`), no time slot conflict.
+
+### Reject Body
+
+```json
+{ "reason": "Onvoldoende ervaring voor deze rol." }
+```
+
+### Bulk Approve Body
+
+```json
+{ "assignment_ids": ["ulid1", "ulid2", ...] }
+```
+
+Response includes per-assignment result: `approved` or `skipped` (with reason).
+
+### ShiftAssignmentResource
+
+```json
+{
+  "id": "01JXYZ...",
+  "shift_id": "01JXYZ...",
+  "person_id": "01JXYZ...",
+  "time_slot_id": "01JXYZ...",
+  "status": "pending_approval",
+  "auto_approved": false,
+  "assigned_by": null,
+  "assigned_at": "2026-04-10T12:00:00+00:00",
+  "approved_by": null,
+  "approved_at": null,
+  "rejection_reason": null,
+  "hours_expected": null,
+  "hours_completed": null,
+  "checked_in_at": null,
+  "checked_out_at": null,
+  "is_cancellable": true,
+  "is_approvable": true,
+  "created_at": "2026-04-10T12:00:00+00:00",
+  "person": { "..." },
+  "shift": { "..." }
+}
+```
+
+### Status Transitions
+
+- `pending_approval` → `approved`, `rejected`, `cancelled`
+- `approved` → `cancelled`, `completed`
+- `rejected` → (terminal)
+- `cancelled` → (terminal)
+- `completed` → (terminal)
+
+### Authorization
+
+| Action | Who |
+|--------|-----|
+| assign | org_admin, event_manager |
+| claim | authenticated org member |
+| approve / reject / bulk-approve | org_admin, event_manager |
+| cancel | org_admin, event_manager, or the volunteer's own user |
+
+## Volunteer Availabilities
+
+- `GET /events/{event}/persons/{person}/availabilities` — list availabilities
+- `POST /events/{event}/persons/{person}/availabilities/sync` — sync (replace all)
+
+### Sync Body
+
+```json
+{
+  "availabilities": [
+    { "time_slot_id": "01JXYZ...", "preference_level": 5 },
+    { "time_slot_id": "01JABC...", "preference_level": 2 }
+  ]
+}
+```
+
+Replaces all existing availabilities for the person. `preference_level` is optional (default: 3, range: 1–5).
+
+Validates:
+- All `time_slot_id`s must belong to the event (or parent festival)
+- Time slot `person_type` must match the person's crowd type `system_type`
+
 ## Persons
 
 - `GET /events/{event}/persons`