diff --git a/app/Models/WorkOrder/Reply.php b/app/Models/WorkOrder/Reply.php
new file mode 100644
index 0000000..c78ce22
--- /dev/null
+++ b/app/Models/WorkOrder/Reply.php
@@ -0,0 +1,71 @@
+<?php
+
+namespace App\Models\WorkOrder;
+
+use App\Exceptions\CommonException;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+
+class Reply extends Model
+{
+    use HasFactory;
+
+    protected $table = 'work_order_replies';
+
+    protected $fillable = [
+        'content',
+        'work_order_id',
+        'user_id',
+        'is_pending',
+    ];
+
+    public function workOrder()
+    {
+        return $this->belongsTo(WorkOrder::class);
+    }
+
+    public function scopeWorkOrderId($query, $work_order_id)
+    {
+        return $query->where('work_order_id', $work_order_id);
+    }
+
+
+    // before create
+    protected static function boot()
+    {
+        parent::boot();
+        static::creating(function ($model) {
+
+            $model->is_pending = 1;
+
+
+            // load work order
+            $model->load(['workOrder']);
+
+            throw_if($model->workOrder->status == 'pending' || $model->workOrder->status == 'error', CommonException::class, '工单状态不正确');
+
+            // change work order status
+            if (auth('sanctum')->check()) {
+                $model->user_id = auth()->id();
+                $model->workOrder->status = 'user_replied';
+            }
+
+            if (auth('remote')->check()) {
+                $model->user_id = null;
+                $model->workOrder->status = 'replied';
+            }
+
+            $model->workOrder->save();
+        });
+
+        static::created(function ($model) {
+            if (auth('remote')->check()) {
+                $model->workOrder->status = 'replied';
+                $model->workOrder->save();
+            }
+            // dispatch
+            dispatch(new \App\Jobs\Remote\WorkOrder\Reply($model));
+            dispatch(new \App\Jobs\Remote\WorkOrder\WorkOrder($model->workOrder, 'put'));
+        });
+    }
+}
diff --git a/app/Models/WorkOrder/WorkOrder.php b/app/Models/WorkOrder/WorkOrder.php
new file mode 100644
index 0000000..e29a1bb
--- /dev/null
+++ b/app/Models/WorkOrder/WorkOrder.php
@@ -0,0 +1,133 @@
+<?php
+
+namespace App\Models\WorkOrder;
+
+use App\Models\Host;
+use App\Models\User;
+use App\Models\Module\Module;
+use App\Exceptions\CommonException;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+
+class WorkOrder extends Model
+{
+    use HasFactory;
+
+    protected $table = 'work_orders';
+
+    protected $fillable = [
+        'title',
+        'content',
+        'host_id',
+        'user_id',
+        'module_id',
+        'status',
+    ];
+
+    // user
+    public function user() {
+        return $this->belongsTo(User::class);
+    }
+
+    // replies
+    public function replies()
+    {
+        return $this->hasMany(Reply::class);
+    }
+
+    // host
+    public function host()
+    {
+        return $this->belongsTo(Host::class);
+    }
+
+    public function module()
+    {
+        return $this->belongsTo(Module::class);
+    }
+
+    // scope
+    public function scopeThisModule($query)
+    {
+        return $query->where('module_id', auth('remote')->id());
+    }
+
+    public function scopeUser($query)
+    {
+        return $query->where('user_id', auth()->id());
+    }
+
+
+    // on create
+    protected static function boot()
+    {
+        parent::boot();
+
+        static::creating(function ($model) {
+
+            if ($model->host_id) {
+                $model->load(['host']);
+                $model->module_id = $model->host->module_id;
+            }
+
+            // if logged
+            if (auth('sanctum')->check()) {
+                $model->user_id = auth('sanctum')->id();
+
+                if ($model->host_id) {
+                    if (!$model->user_id === $model->host->user_id) {
+                        throw new CommonException('user_id not match host user_id');
+                    }
+                }
+            } else {
+                throw new CommonException('user_id is required');
+            }
+
+
+            if ($model->host_id) {
+                $model->host->load('module');
+                $module = $model->host->module;
+
+
+                if ($module === null) {
+                    $model->status = 'open';
+                } else {
+                    $model->status = 'pending';
+                }
+            }
+        });
+
+        // 更新时获取差异部分
+        static::updating(function ($model) {
+            // $original = $model->getOriginal();
+            // // dd($original);
+            // $diff = array_diff_assoc($model->attributes, $original);
+
+            // // 如果更新了host_id，则抛出异常
+            // if (isset($diff['host_id'])) {
+            //     throw new CommonException('host_id cannot be updated');
+            // }
+
+        });
+
+        // updated
+        static::updated(function ($model) {
+            dispatch(new \App\Jobs\Remote\WorkOrder\WorkOrder($model, 'put'));
+
+            // $original = $model->getOriginal();
+            // $diff = array_diff_assoc($model->attributes, $original);
+            // // dd($diff);
+            // if (isset($diff['status'])) {
+            //     $model->load(['host']);
+            //     $model->host->load('module');
+            //     $module = $model->host->module;
+            //     if ($module === null) {
+            //         $model->status = 'open';
+            //     } else {
+            //         $model->status = 'pending';
+            //     }
+            //     $model->save();
+            // }
+        });
+    }
+}