diff --git a/.gitignore b/.gitignore
index fe9abff..7c8cf6a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,7 +33,7 @@ logs/
 *.temp
 
 # Local models
-models
+backend/models
 
 # AI
 .gemini-clipboard/
diff --git a/backend/app/models/__init__.py b/backend/app/models/__init__.py
new file mode 100644
index 0000000..4f33205
--- /dev/null
+++ b/backend/app/models/__init__.py
@@ -0,0 +1,37 @@
+"""
+导出所有数据库模型
+"""
+from app.core.database import Base
+from app.models.user import User
+from app.models.role import Role, UserRole
+from app.models.menu import SystemMenu, RoleMenu
+from app.models.project import Project, ProjectMember, ProjectMemberRole
+from app.models.document import DocumentMeta
+from app.models.document_vector import DocumentVector
+from app.models.share import ShareLink
+from app.models.log import OperationLog
+from app.models.mcp_bot import MCPBot
+from app.models.llm_model_config import LLMModelConfig
+from app.models.chat_session import ChatSession, ChatMessage
+from app.models.project_vectorization_task import ProjectVectorizationTask
+
+__all__ = [
+    "Base",
+    "User",
+    "Role",
+    "UserRole",
+    "SystemMenu",
+    "RoleMenu",
+    "Project",
+    "ProjectMember",
+    "ProjectMemberRole",
+    "DocumentMeta",
+    "DocumentVector",
+    "ShareLink",
+    "OperationLog",
+    "MCPBot",
+    "LLMModelConfig",
+    "ChatSession",
+    "ChatMessage",
+    "ProjectVectorizationTask",
+]
diff --git a/backend/app/models/chat_session.py b/backend/app/models/chat_session.py
new file mode 100644
index 0000000..714cb9e
--- /dev/null
+++ b/backend/app/models/chat_session.py
@@ -0,0 +1,44 @@
+"""
+知识库对话会话模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, Text, Boolean
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class ChatSession(Base):
+    """对话会话表"""
+
+    __tablename__ = "chat_session"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="会话ID")
+    project_id = Column(BigInteger, nullable=False, index=True, comment="项目ID")
+    user_id = Column(BigInteger, nullable=False, index=True, comment="用户ID")
+    llm_config_id = Column(BigInteger, nullable=False, comment="LLM配置ID")
+    title = Column(String(255), nullable=False, comment="会话标题")
+    description = Column(Text, comment="会话描述")
+    is_active = Column(Boolean, nullable=False, default=True, comment="是否激活")
+    message_count = Column(Integer, nullable=False, default=0, comment="消息数")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<ChatSession(id={self.id}, project_id={self.project_id}, user_id={self.user_id})>"
+
+
+class ChatMessage(Base):
+    """对话消息表"""
+
+    __tablename__ = "chat_message"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="消息ID")
+    session_id = Column(BigInteger, nullable=False, index=True, comment="会话ID")
+    role = Column(String(32), nullable=False, comment="角色(user/assistant)")
+    content = Column(Text, nullable=False, comment="消息内容")
+    referenced_files = Column(Text, comment="参考文件(JSON数组)")
+    tokens_used = Column(Integer, comment="消耗的token数")
+    is_deleted = Column(Boolean, nullable=False, default=False, comment="是否已删除")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+
+    def __repr__(self):
+        return f"<ChatMessage(id={self.id}, session_id={self.session_id}, role='{self.role}')>"
diff --git a/backend/app/models/document.py b/backend/app/models/document.py
new file mode 100644
index 0000000..76a1814
--- /dev/null
+++ b/backend/app/models/document.py
@@ -0,0 +1,28 @@
+"""
+文档元数据模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class DocumentMeta(Base):
+    """文档元数据表模型"""
+
+    __tablename__ = "document_meta"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="元数据ID")
+    project_id = Column(BigInteger, nullable=False, index=True, comment="项目ID")
+    file_path = Column(String(500), nullable=False, comment="文件相对路径")
+    title = Column(String(200), comment="文档标题")
+    tags = Column(String(500), comment="标签（JSON数组）")
+    author_id = Column(BigInteger, index=True, comment="作者ID")
+    word_count = Column(Integer, default=0, comment="字数统计")
+    view_count = Column(Integer, default=0, comment="浏览次数")
+    last_editor_id = Column(BigInteger, comment="最后编辑者ID")
+    last_edited_at = Column(DateTime, comment="最后编辑时间")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<DocumentMeta(id={self.id}, project_id={self.project_id}, file_path='{self.file_path}')>"
diff --git a/backend/app/models/document_vector.py b/backend/app/models/document_vector.py
new file mode 100644
index 0000000..557bb2a
--- /dev/null
+++ b/backend/app/models/document_vector.py
@@ -0,0 +1,36 @@
+"""
+文档向量化模型
+"""
+from sqlalchemy import Column, BigInteger, Integer, String, DateTime, Index, Text
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class DocumentVector(Base):
+    """文档向量表模型"""
+
+    __tablename__ = "document_vector"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="向量ID")
+    project_id = Column(BigInteger, nullable=False, index=True, comment="项目ID")
+    file_path = Column(String(500), nullable=False, comment="文件相对路径")
+    chunk_index = Column(Integer, nullable=False, default=0, comment="分块序号（0起），同一文件可有多个分块")
+    chunk_text = Column(Text, comment="分块首段文本，作为点击引用时的定位锚点")
+    content_hash = Column(String(64), comment="整个文件内容哈希值，用于判断文件是否变更")
+    zvec_id = Column(String(256), comment="ZVec返回的向量ID（每个分块独立）")
+    zvec_response = Column(Text, comment="ZVec完整响应JSON")
+    status = Column(String(32), nullable=False, default="success", comment="向量化状态：success/failed/pending")
+    error_message = Column(String(500), comment="错误信息")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    __table_args__ = (
+        Index("idx_project_file", "project_id", "file_path"),
+        Index("idx_project_file_chunk", "project_id", "file_path", "chunk_index"),
+    )
+
+    def __repr__(self):
+        return (
+            f"<DocumentVector(id={self.id}, project_id={self.project_id}, "
+            f"file_path='{self.file_path}', chunk_index={self.chunk_index}, status='{self.status}')>"
+        )
diff --git a/backend/app/models/git_repo.py b/backend/app/models/git_repo.py
new file mode 100644
index 0000000..ebf1ca4
--- /dev/null
+++ b/backend/app/models/git_repo.py
@@ -0,0 +1,30 @@
+"""
+项目Git仓库模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, SmallInteger, ForeignKey
+from sqlalchemy.sql import func
+from sqlalchemy.orm import relationship
+from app.core.database import Base
+
+
+class ProjectGitRepo(Base):
+    """项目Git仓库表模型"""
+
+    __tablename__ = "project_git_repos"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="ID")
+    project_id = Column(BigInteger, ForeignKey("projects.id", ondelete="CASCADE"), nullable=False, index=True, comment="项目ID")
+    name = Column(String(50), nullable=False, comment="仓库别名")
+    repo_url = Column(String(255), nullable=False, comment="Git仓库地址")
+    branch = Column(String(50), default="main", comment="Git分支")
+    username = Column(String(100), comment="Git用户名")
+    token = Column(String(255), comment="Git访问令牌/密码")
+    is_default = Column(SmallInteger, default=0, comment="是否默认仓库")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    # 关系
+    # project = relationship("Project", back_populates="git_repos")
+
+    def __repr__(self):
+        return f"<ProjectGitRepo(id={self.id}, name='{self.name}', repo_url='{self.repo_url}')>"
diff --git a/backend/app/models/llm_model_config.py b/backend/app/models/llm_model_config.py
new file mode 100644
index 0000000..1dc2bab
--- /dev/null
+++ b/backend/app/models/llm_model_config.py
@@ -0,0 +1,63 @@
+"""
+LLM 模型配置模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, Boolean, JSON
+from sqlalchemy.sql import func
+
+from app.core.database import Base
+
+
+class LLMModelConfig(Base):
+    """大模型配置表模型"""
+
+    __tablename__ = "llm_model_config"
+
+    config_id = Column(BigInteger, primary_key=True, autoincrement=True, comment="配置ID")
+    model_code = Column(String(128), nullable=False, unique=True, index=True, comment="模型编码")
+    model_name = Column(String(255), nullable=False, comment="模型名称")
+    model_type = Column(String(32), nullable=False, default="chat", index=True, comment="模型类型: chat/embedding")
+    provider = Column(String(64), comment="模型提供方")
+    endpoint_url = Column(String(512), comment="接口地址")
+    api_key = Column(String(512), comment="API Key")
+    llm_model_name = Column(String(128), nullable=False, comment="模型名称/部署名")
+    llm_timeout = Column(Integer, nullable=False, default=120, comment="超时时间（秒）")
+    type_config = Column(JSON, nullable=False, default=dict, comment="模型类型差异参数")
+    description = Column(String(500), comment="描述")
+    is_active = Column(Boolean, nullable=False, default=True, index=True, comment="是否启用")
+    is_default = Column(Boolean, nullable=False, default=False, comment="是否默认")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def _type_config_value(self, key, default=None):
+        return (self.type_config or {}).get(key, default)
+
+    @property
+    def llm_temperature(self):
+        return self._type_config_value("temperature", 0.70)
+
+    @property
+    def llm_top_p(self):
+        return self._type_config_value("top_p", 0.90)
+
+    @property
+    def llm_max_tokens(self):
+        return self._type_config_value("max_tokens", 8192)
+
+    @property
+    def llm_system_prompt(self):
+        return self._type_config_value("system_prompt")
+
+    @property
+    def embedding_dimension(self):
+        return self._type_config_value("dimension")
+
+    @property
+    def chunk_size(self):
+        return self._type_config_value("chunk_size", 800)
+
+    @property
+    def chunk_overlap(self):
+        return self._type_config_value("chunk_overlap", 150)
+
+    def __repr__(self):
+        return f"<LLMModelConfig(config_id={self.config_id}, model_code='{self.model_code}')>"
diff --git a/backend/app/models/log.py b/backend/app/models/log.py
new file mode 100644
index 0000000..428e26e
--- /dev/null
+++ b/backend/app/models/log.py
@@ -0,0 +1,28 @@
+"""
+操作日志模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, SmallInteger, Text
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class OperationLog(Base):
+    """操作日志表模型"""
+
+    __tablename__ = "operation_logs"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="日志ID")
+    user_id = Column(BigInteger, index=True, comment="操作用户ID")
+    username = Column(String(50), comment="用户名")
+    operation_type = Column(String(50), nullable=False, comment="操作类型")
+    resource_type = Column(String(50), nullable=False, index=True, comment="资源类型")
+    resource_id = Column(BigInteger, index=True, comment="资源ID")
+    detail = Column(Text, comment="操作详情（JSON）")
+    ip_address = Column(String(50), comment="IP地址")
+    user_agent = Column(String(500), comment="用户代理")
+    status = Column(SmallInteger, default=1, comment="状态：0-失败 1-成功")
+    error_message = Column(Text, comment="错误信息")
+    created_at = Column(DateTime, server_default=func.now(), index=True, comment="操作时间")
+
+    def __repr__(self):
+        return f"<OperationLog(id={self.id}, operation_type='{self.operation_type}')>"
diff --git a/backend/app/models/mcp_bot.py b/backend/app/models/mcp_bot.py
new file mode 100644
index 0000000..b7f4ef4
--- /dev/null
+++ b/backend/app/models/mcp_bot.py
@@ -0,0 +1,25 @@
+"""
+MCP bot credential model.
+"""
+from sqlalchemy import Column, BigInteger, String, DateTime, SmallInteger
+from sqlalchemy.sql import func
+
+from app.core.database import Base
+
+
+class MCPBot(Base):
+    """Stores MCP access credentials mapped to a NexDocs user."""
+
+    __tablename__ = "mcp_bots"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="Bot credential ID")
+    user_id = Column(BigInteger, nullable=False, unique=True, index=True, comment="Owner user ID")
+    bot_id = Column(String(64), nullable=False, unique=True, index=True, comment="External MCP bot id")
+    bot_secret = Column(String(255), nullable=False, comment="External MCP bot secret")
+    status = Column(SmallInteger, default=1, index=True, comment="Status: 0-disabled 1-enabled")
+    last_used_at = Column(DateTime, comment="Last successful MCP access time")
+    created_at = Column(DateTime, server_default=func.now(), comment="Created at")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="Updated at")
+
+    def __repr__(self):
+        return f"<MCPBot(user_id={self.user_id}, bot_id='{self.bot_id}')>"
diff --git a/backend/app/models/menu.py b/backend/app/models/menu.py
new file mode 100644
index 0000000..71eaed9
--- /dev/null
+++ b/backend/app/models/menu.py
@@ -0,0 +1,44 @@
+"""
+菜单模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, SmallInteger
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class SystemMenu(Base):
+    """系统菜单表模型"""
+
+    __tablename__ = "system_menus"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="菜单ID")
+    parent_id = Column(BigInteger, default=0, comment="父菜单ID（0表示根菜单）")
+    menu_name = Column(String(50), nullable=False, comment="菜单名称")
+    menu_code = Column(String(50), nullable=False, unique=True, index=True, comment="菜单编码")
+    menu_type = Column(SmallInteger, nullable=False, comment="菜单类型：1-目录 2-菜单 3-按钮/权限点")
+    path = Column(String(255), comment="路由路径")
+    component = Column(String(255), comment="组件路径")
+    icon = Column(String(100), comment="图标")
+    sort_order = Column(Integer, default=0, comment="排序号")
+    visible = Column(SmallInteger, default=1, comment="是否可见：0-隐藏 1-显示")
+    status = Column(SmallInteger, default=1, index=True, comment="状态：0-禁用 1-启用")
+    permission = Column(String(100), comment="权限字符串")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<SystemMenu(id={self.id}, menu_name='{self.menu_name}')>"
+
+
+class RoleMenu(Base):
+    """角色菜单授权表模型"""
+
+    __tablename__ = "role_menus"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="关联ID")
+    role_id = Column(BigInteger, nullable=False, index=True, comment="角色ID")
+    menu_id = Column(BigInteger, nullable=False, index=True, comment="菜单ID")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+
+    def __repr__(self):
+        return f"<RoleMenu(role_id={self.role_id}, menu_id={self.menu_id})>"
diff --git a/backend/app/models/notification.py b/backend/app/models/notification.py
new file mode 100644
index 0000000..3a9f20b
--- /dev/null
+++ b/backend/app/models/notification.py
@@ -0,0 +1,26 @@
+"""
+通知模型
+"""
+from sqlalchemy import Column, BigInteger, String, DateTime, SmallInteger, Text, ForeignKey
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class Notification(Base):
+    """用户通知表模型"""
+
+    __tablename__ = "notifications"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="通知ID")
+    user_id = Column(BigInteger, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True, comment="接收用户ID")
+    type = Column(String(20), default="info", comment="类型：info, success, warning, error")
+    category = Column(String(50), default="system", comment="分类：system, project, collaboration")
+    title = Column(String(200), nullable=False, comment="标题")
+    content = Column(Text, comment="内容")
+    link = Column(String(255), comment="跳转链接")
+    is_read = Column(SmallInteger, default=0, comment="是否已读：0-未读 1-已读")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    read_at = Column(DateTime, comment="阅读时间")
+
+    def __repr__(self):
+        return f"<Notification(id={self.id}, user_id={self.user_id}, title='{self.title}')>"
diff --git a/backend/app/models/project.py b/backend/app/models/project.py
new file mode 100644
index 0000000..e92ed94
--- /dev/null
+++ b/backend/app/models/project.py
@@ -0,0 +1,59 @@
+"""
+项目模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, SmallInteger, Enum
+from sqlalchemy.sql import func
+from app.core.database import Base
+import enum
+
+
+class ProjectMemberRole(str, enum.Enum):
+    """项目成员角色枚举"""
+    ADMIN = "admin"
+    EDITOR = "editor"
+    VIEWER = "viewer"
+
+
+class Project(Base):
+    """项目表模型"""
+
+    __tablename__ = "projects"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="项目ID")
+    name = Column(String(100), nullable=False, index=True, comment="项目名称")
+    description = Column(String(500), comment="项目描述")
+    storage_key = Column(String(36), nullable=False, unique=True, comment="磁盘存储UUID")
+    owner_id = Column(BigInteger, nullable=False, index=True, comment="项目所有者ID")
+    is_public = Column(SmallInteger, default=0, comment="是否公开：0-私有 1-公开")
+    is_template = Column(SmallInteger, default=0, comment="是否模板项目：0-否 1-是")
+    status = Column(SmallInteger, default=1, index=True, comment="状态：0-归档 1-活跃")
+    cover_image = Column(String(255), comment="封面图")
+    sort_order = Column(Integer, default=0, comment="排序号")
+    visit_count = Column(Integer, default=0, comment="访问次数")
+    access_pass = Column(String(100), comment="访问密码（用于分享链接）")
+    created_at = Column(DateTime, server_default=func.now(), index=True, comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<Project(id={self.id}, name='{self.name}')>"
+
+
+class ProjectMember(Base):
+    """项目成员表模型"""
+
+    __tablename__ = "project_members"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="成员ID")
+    project_id = Column(BigInteger, nullable=False, index=True, comment="项目ID")
+    user_id = Column(BigInteger, nullable=False, index=True, comment="用户ID")
+    role = Column(
+        String(20),
+        default="viewer",
+        index=True,
+        comment="项目角色: admin/editor/viewer"
+    )
+    invited_by = Column(BigInteger, comment="邀请人ID")
+    joined_at = Column(DateTime, server_default=func.now(), comment="加入时间")
+
+    def __repr__(self):
+        return f"<ProjectMember(project_id={self.project_id}, user_id={self.user_id}, role='{self.role}')>"
diff --git a/backend/app/models/project_vectorization_task.py b/backend/app/models/project_vectorization_task.py
new file mode 100644
index 0000000..261ddb8
--- /dev/null
+++ b/backend/app/models/project_vectorization_task.py
@@ -0,0 +1,37 @@
+"""
+项目向量化任务模型
+"""
+from sqlalchemy import BigInteger, Column, DateTime, Index, Integer, String, Text
+from sqlalchemy.sql import func
+
+from app.core.database import Base
+
+
+class ProjectVectorizationTask(Base):
+    """项目向量化后台任务表"""
+
+    __tablename__ = "project_vectorization_task"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="任务ID")
+    task_id = Column(String(64), nullable=False, unique=True, index=True, comment="任务唯一标识")
+    project_id = Column(BigInteger, nullable=False, index=True, comment="项目ID")
+    user_id = Column(BigInteger, nullable=False, index=True, comment="触发用户ID")
+    task_type = Column(String(32), nullable=False, comment="任务类型：incremental/full")
+    status = Column(String(32), nullable=False, default="pending", index=True, comment="任务状态：pending/running/success/failed")
+    total = Column(Integer, nullable=False, default=0, comment="文件总数")
+    processed = Column(Integer, nullable=False, default=0, comment="处理成功数")
+    skipped = Column(Integer, nullable=False, default=0, comment="跳过数")
+    failed = Column(Integer, nullable=False, default=0, comment="失败数")
+    error_message = Column(Text, comment="错误信息")
+    started_at = Column(DateTime, comment="开始时间")
+    finished_at = Column(DateTime, comment="完成时间")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    __table_args__ = (
+        Index("idx_vector_task_project_status", "project_id", "status"),
+        Index("idx_vector_task_created_at", "created_at"),
+    )
+
+    def __repr__(self):
+        return f"<ProjectVectorizationTask(task_id='{self.task_id}', project_id={self.project_id}, status='{self.status}')>"
diff --git a/backend/app/models/role.py b/backend/app/models/role.py
new file mode 100644
index 0000000..7fdbb58
--- /dev/null
+++ b/backend/app/models/role.py
@@ -0,0 +1,38 @@
+"""
+角色模型
+"""
+from sqlalchemy import Column, BigInteger, String, DateTime, SmallInteger
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class Role(Base):
+    """角色表模型"""
+
+    __tablename__ = "roles"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="角色ID")
+    role_name = Column(String(50), nullable=False, unique=True, comment="角色名称")
+    role_code = Column(String(50), nullable=False, unique=True, index=True, comment="角色编码")
+    description = Column(String(255), comment="角色描述")
+    status = Column(SmallInteger, default=1, index=True, comment="状态：0-禁用 1-启用")
+    is_system = Column(SmallInteger, default=0, comment="是否系统角色：0-否 1-是")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<Role(id={self.id}, role_code='{self.role_code}')>"
+
+
+class UserRole(Base):
+    """用户角色关联表模型"""
+
+    __tablename__ = "user_roles"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="关联ID")
+    user_id = Column(BigInteger, nullable=False, index=True, comment="用户ID")
+    role_id = Column(BigInteger, nullable=False, index=True, comment="角色ID")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+
+    def __repr__(self):
+        return f"<UserRole(user_id={self.user_id}, role_id={self.role_id})>"
diff --git a/backend/app/models/share.py b/backend/app/models/share.py
new file mode 100644
index 0000000..368ffd3
--- /dev/null
+++ b/backend/app/models/share.py
@@ -0,0 +1,27 @@
+"""
+分享链接模型
+"""
+from sqlalchemy import Column, BigInteger, String, DateTime, SmallInteger
+from sqlalchemy.sql import func
+
+from app.core.database import Base
+
+
+class ShareLink(Base):
+    """项目分享/文件分享链接"""
+
+    __tablename__ = "share_links"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="分享ID")
+    project_id = Column(BigInteger, nullable=False, index=True, comment="项目ID")
+    share_type = Column(String(20), nullable=False, index=True, comment="分享类型: project/file")
+    share_code = Column(String(64), nullable=False, unique=True, index=True, comment="公开分享码")
+    file_path = Column(String(500), comment="文件路径，仅文件分享使用")
+    access_pass = Column(String(100), comment="访问密码")
+    created_by = Column(BigInteger, index=True, comment="创建人ID")
+    status = Column(SmallInteger, default=1, index=True, comment="状态：0-禁用 1-启用")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<ShareLink(id={self.id}, type='{self.share_type}', code='{self.share_code}')>"
diff --git a/backend/app/models/user.py b/backend/app/models/user.py
new file mode 100644
index 0000000..fc3e75a
--- /dev/null
+++ b/backend/app/models/user.py
@@ -0,0 +1,29 @@
+"""
+用户模型
+"""
+from sqlalchemy import Column, BigInteger, String, Integer, DateTime, SmallInteger
+from sqlalchemy.sql import func
+from app.core.database import Base
+
+
+class User(Base):
+    """用户表模型"""
+
+    __tablename__ = "users"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True, comment="用户ID")
+    username = Column(String(50), nullable=False, unique=True, index=True, comment="用户名")
+    password_hash = Column(String(255), nullable=False, comment="密码哈希")
+    nickname = Column(String(50), comment="昵称")
+    email = Column(String(100), index=True, comment="邮箱")
+    phone = Column(String(20), comment="手机号")
+    avatar = Column(String(255), comment="头像URL")
+    status = Column(SmallInteger, default=1, index=True, comment="状态：0-禁用 1-启用")
+    is_superuser = Column(SmallInteger, default=0, comment="是否超级管理员：0-否 1-是")
+    last_login_at = Column(DateTime, comment="最后登录时间")
+    last_login_ip = Column(String(50), comment="最后登录IP")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    def __repr__(self):
+        return f"<User(id={self.id}, username='{self.username}')>"
diff --git a/backend/requirements.txt b/backend/requirements.txt
index 63a9295..a2329be 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -49,3 +49,4 @@ sentence-transformers>=3.0,<6
 weasyprint==61.2
 pydyf<0.11.0
 mcp==1.26.0
+zvec==0.6.0