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+# API 文档
+
+## 认证接口
+
+### POST /api/auth/register
+注册新用户
+
+**请求体:**
+```json
+{
+  "username": "string",
+  "password": "string",
+  "email": "string"
+}
+```
+
+**响应:**
+```json
+{
+  "token": "string",
+  "userId": number
+}
+```
+
+### POST /api/auth/login
+用户登录
+
+**请求体:**
+```json
+{
+  "username": "string",
+  "password": "string"
+}
+```
+
+**响应:**
+```json
+{
+  "token": "string",
+  "user": {
+    "id": number,
+    "username": "string",
+    "email": "string",
+    "storageUsed": number,
+    "storageLimit": number
+  }
+}
+```
+
+## 文件接口
+
+### GET /api/files
+获取文件列表
+
+**查询参数:**
+- `parentId`: 文件夹ID（可选）
+
+**响应:**
+```json
+{
+  "files": [
+    {
+      "id": 1,
+      "name": "document.pdf",
+      "type": "pdf",
+      "size": 1024000,
+      "is_folder": false,
+      "updated_at": "2026-03-10T00:00:00Z"
+    }
+  ]
+}
+```
+
+### POST /api/files/upload
+上传文件
+
+**请求体:** multipart/form-data
+
+**响应:**
+```json
+{
+  "success": true,
+  "fileId": 1,
+  "filename": "document.pdf"
+}
+```
+
+### DELETE /api/files/:id
+删除文件
+
+**响应:**
+```json
+{
+  "success": true
+}
+```
+
+## 分享接口
+
+### POST /api/share
+创建分享链接
+
+**请求体:**
+```json
+{
+  "fileId": 1,
+  "password": "optional",
+  "expiresIn": 86400
+}
+```
+
+**响应:**
+```json
+{
+  "success": true,
+  "shareToken": "abc123",
+  "shareUrl": "/share/abc123"
+}
+```