diff --git a/tests/Feature/Production/WorkOrderApiTest.php b/tests/Feature/Production/WorkOrderApiTest.php
new file mode 100644
index 0000000..4380014
--- /dev/null
+++ b/tests/Feature/Production/WorkOrderApiTest.php
@@ -0,0 +1,299 @@
+<?php
+
+namespace Tests\Feature\Production;
+
+use App\Models\Orders\Client;
+use App\Models\Orders\Order;
+use App\Models\Process;
+use App\Models\Production\WorkOrder;
+use App\Models\Production\WorkOrderItem;
+use Tests\TestCase;
+
+class WorkOrderApiTest extends TestCase
+{
+    private Process $process;
+
+    private Order $order;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->setUpAuthenticatedUser();
+
+        // 공정
+        $this->process = Process::create([
+            'tenant_id' => $this->tenant->id,
+            'process_code' => 'PRC-'.uniqid(),
+            'process_name' => '스크린 조립',
+            'process_type' => 'assembly',
+            'is_active' => true,
+            'created_by' => $this->user->id,
+            'updated_by' => $this->user->id,
+        ]);
+
+        // 수주 (작업지시의 부모)
+        $client = Client::create([
+            'tenant_id' => $this->tenant->id,
+            'name' => '테스트 거래처',
+            'client_code' => 'CLI'.uniqid(),
+            'is_active' => true,
+            'created_by' => $this->user->id,
+        ]);
+
+        $this->order = Order::create([
+            'tenant_id' => $this->tenant->id,
+            'order_no' => 'ORD-'.uniqid(),
+            'order_type_code' => Order::TYPE_ORDER,
+            'status_code' => Order::STATUS_CONFIRMED,
+            'client_id' => $client->id,
+            'client_name' => $client->name,
+            'quantity' => 10,
+            'supply_amount' => 1000000,
+            'tax_amount' => 100000,
+            'total_amount' => 1100000,
+            'created_by' => $this->user->id,
+            'updated_by' => $this->user->id,
+        ]);
+    }
+
+    // ==================== 목록/통계 조회 ====================
+
+    public function test_작업지시_목록_조회(): void
+    {
+        $this->createWorkOrder();
+
+        $response = $this->api('get', '/api/v1/work-orders');
+
+        $this->assertApiPaginated($response);
+    }
+
+    public function test_작업지시_통계_조회(): void
+    {
+        $this->createWorkOrder();
+
+        $response = $this->api('get', '/api/v1/work-orders/stats');
+
+        $response->assertStatus(200)
+            ->assertJsonStructure(['success', 'data']);
+    }
+
+    // ==================== CRUD ====================
+
+    public function test_작업지시_생성_성공(): void
+    {
+        $response = $this->api('post', '/api/v1/work-orders', [
+            'process_id' => $this->process->id,
+            'sales_order_id' => $this->order->id,
+            'assignee_ids' => [$this->user->id],
+            'priority' => 5,
+            'scheduled_date' => now()->addDays(7)->format('Y-m-d'),
+            'memo' => '테스트 작업지시',
+        ]);
+
+        $response->assertStatus(200);
+        $this->assertTrue($response->json('success'));
+
+        $this->assertDatabaseHas('work_orders', [
+            'process_id' => $this->process->id,
+            'sales_order_id' => $this->order->id,
+            'tenant_id' => $this->tenant->id,
+        ]);
+    }
+
+    public function test_작업지시_상세_조회(): void
+    {
+        $wo = $this->createWorkOrder();
+
+        $response = $this->api('get', "/api/v1/work-orders/{$wo->id}");
+
+        $this->assertApiSuccess($response);
+
+        $data = $response->json('data');
+        $this->assertEquals($wo->id, $data['id']);
+    }
+
+    public function test_작업지시_수정(): void
+    {
+        $wo = $this->createWorkOrder();
+
+        $response = $this->api('put', "/api/v1/work-orders/{$wo->id}", [
+            'memo' => '수정된 메모',
+            'priority' => 1,
+        ]);
+
+        $response->assertStatus(200);
+
+        $this->assertDatabaseHas('work_orders', [
+            'id' => $wo->id,
+            'memo' => '수정된 메모',
+        ]);
+    }
+
+    public function test_작업지시_삭제(): void
+    {
+        $wo = $this->createWorkOrder();
+
+        $response = $this->api('delete', "/api/v1/work-orders/{$wo->id}");
+
+        $response->assertStatus(200);
+
+        $this->assertSoftDeleted('work_orders', ['id' => $wo->id]);
+    }
+
+    public function test_존재하지_않는_작업지시_조회시_404(): void
+    {
+        $response = $this->api('get', '/api/v1/work-orders/999999');
+
+        $response->assertStatus(404);
+    }
+
+    // ==================== 상태 전이 ====================
+
+    public function test_상태_미배정에서_대기로_변경(): void
+    {
+        $wo = $this->createWorkOrder(WorkOrder::STATUS_UNASSIGNED);
+
+        $response = $this->api('patch', "/api/v1/work-orders/{$wo->id}/status", [
+            'status' => WorkOrder::STATUS_PENDING,
+        ]);
+
+        $response->assertStatus(200);
+
+        $this->assertDatabaseHas('work_orders', [
+            'id' => $wo->id,
+            'status' => WorkOrder::STATUS_PENDING,
+        ]);
+    }
+
+    public function test_상태_대기에서_준비중으로_변경(): void
+    {
+        $wo = $this->createWorkOrder(WorkOrder::STATUS_PENDING);
+
+        $response = $this->api('patch', "/api/v1/work-orders/{$wo->id}/status", [
+            'status' => WorkOrder::STATUS_WAITING,
+        ]);
+
+        $response->assertStatus(200);
+
+        $this->assertDatabaseHas('work_orders', [
+            'id' => $wo->id,
+            'status' => WorkOrder::STATUS_WAITING,
+        ]);
+    }
+
+    public function test_상태_준비중에서_진행중으로_변경(): void
+    {
+        $wo = $this->createWorkOrder(WorkOrder::STATUS_WAITING);
+
+        $response = $this->api('patch', "/api/v1/work-orders/{$wo->id}/status", [
+            'status' => WorkOrder::STATUS_IN_PROGRESS,
+        ]);
+
+        $response->assertStatus(200);
+
+        $this->assertDatabaseHas('work_orders', [
+            'id' => $wo->id,
+            'status' => WorkOrder::STATUS_IN_PROGRESS,
+        ]);
+    }
+
+    public function test_상태_진행중에서_완료로_변경(): void
+    {
+        $wo = $this->createWorkOrder(WorkOrder::STATUS_IN_PROGRESS);
+
+        $response = $this->api('patch', "/api/v1/work-orders/{$wo->id}/status", [
+            'status' => WorkOrder::STATUS_COMPLETED,
+        ]);
+
+        $response->assertStatus(200);
+
+        $this->assertDatabaseHas('work_orders', [
+            'id' => $wo->id,
+            'status' => WorkOrder::STATUS_COMPLETED,
+        ]);
+    }
+
+    // ==================== 담당자 배정 ====================
+
+    public function test_담당자_배정(): void
+    {
+        $wo = $this->createWorkOrder(WorkOrder::STATUS_UNASSIGNED);
+
+        $response = $this->api('patch', "/api/v1/work-orders/{$wo->id}/assign", [
+            'assignee_id' => $this->user->id,
+        ]);
+
+        $response->assertStatus(200);
+
+        $this->assertDatabaseHas('work_orders', [
+            'id' => $wo->id,
+            'assignee_id' => $this->user->id,
+        ]);
+    }
+
+    // ==================== 공정 단계 ====================
+
+    public function test_공정_단계_진행_조회(): void
+    {
+        $wo = $this->createWorkOrder();
+
+        $response = $this->api('get', "/api/v1/work-orders/{$wo->id}/step-progress");
+
+        $response->assertStatus(200)
+            ->assertJsonStructure(['success', 'data']);
+    }
+
+    // ==================== 자재 ====================
+
+    public function test_자재_목록_조회(): void
+    {
+        $wo = $this->createWorkOrder();
+
+        $response = $this->api('get', "/api/v1/work-orders/{$wo->id}/materials");
+
+        $response->assertStatus(200)
+            ->assertJsonStructure(['success', 'data']);
+    }
+
+    public function test_자재_투입_이력_조회(): void
+    {
+        $wo = $this->createWorkOrder();
+
+        $response = $this->api('get', "/api/v1/work-orders/{$wo->id}/material-input-history");
+
+        $response->assertStatus(200)
+            ->assertJsonStructure(['success', 'data']);
+    }
+
+    // ==================== 인증 ====================
+
+    public function test_미인증_요청시_401(): void
+    {
+        $response = $this->withHeaders([
+            'X-API-KEY' => $this->apiKey,
+            'Accept' => 'application/json',
+        ])->getJson('/api/v1/work-orders');
+
+        $response->assertStatus(401);
+    }
+
+    // ==================== 헬퍼 ====================
+
+    private function createWorkOrder(string $status = WorkOrder::STATUS_UNASSIGNED): WorkOrder
+    {
+        return WorkOrder::create([
+            'tenant_id' => $this->tenant->id,
+            'work_order_no' => 'WO-'.uniqid(),
+            'sales_order_id' => $this->order->id,
+            'process_id' => $this->process->id,
+            'project_name' => '테스트 프로젝트',
+            'status' => $status,
+            'priority' => 5,
+            'scheduled_date' => now()->addDays(7),
+            'memo' => '테스트 작업지시',
+            'is_active' => true,
+            'created_by' => $this->user->id,
+            'updated_by' => $this->user->id,
+        ]);
+    }
+}