diff --git a/src/baby_monitor/main.py b/src/baby_monitor/main.py
index a7c6e21..c4082dc 100644
--- a/src/baby_monitor/main.py
+++ b/src/baby_monitor/main.py
@@ -11,6 +11,7 @@ from fastapi.staticfiles import StaticFiles
 
 from baby_monitor.routers.auth import router as auth_router
 from baby_monitor.routers.auth import verify_token
+from baby_monitor.routers.admin import router as admin_router
 from baby_monitor.routers.health import router as health_router
 from baby_monitor.repositories.dependencies.get_database import init_db
 
@@ -45,15 +46,35 @@ app.mount("/static", StaticFiles(directory=str(static_path)), name="static")
 
 # Include routers
 app.include_router(auth_router)
+app.include_router(admin_router)
 app.include_router(health_router)
 
 
+# Serve HTML pages at root level
 @app.get("/", include_in_schema=False)
 def serve_home() -> FileResponse:
     """Serve the home page (handles auth check client-side)."""
     return FileResponse(static_path / "index.html")
 
 
+@app.get("/login.html", include_in_schema=False)
+def serve_login() -> FileResponse:
+    """Serve the login page."""
+    return FileResponse(static_path / "login.html")
+
+
+@app.get("/register.html", include_in_schema=False)
+def serve_register() -> FileResponse:
+    """Serve the registration page."""
+    return FileResponse(static_path / "register.html")
+
+
+@app.get("/admin.html", include_in_schema=False)
+def serve_admin() -> FileResponse:
+    """Serve the admin page."""
+    return FileResponse(static_path / "admin.html")
+
+
 @app.get("/api/")
 def read_root(token: Annotated[str, Depends(verify_token)]) -> dict:
     """API root endpoint (requires authentication)."""
diff --git a/src/baby_monitor/models/auth.py b/src/baby_monitor/models/auth.py
index 62a6a20..2b4ae0f 100644
--- a/src/baby_monitor/models/auth.py
+++ b/src/baby_monitor/models/auth.py
@@ -16,4 +16,23 @@ class LoginResponse(BaseModel):
     message: str
     username: str
     access_token: str
+    is_admin: bool
+    token_type: str = "bearer"
+
+
+class RegisterRequest(BaseModel):
+    """Request model for user registration."""
+
+    username: str
+    password: str
+    invitation_token: str
+
+
+class RegisterResponse(BaseModel):
+    """Response model for successful registration."""
+
+    message: str
+    username: str
+    access_token: str
+    is_admin: bool
     token_type: str = "bearer"
diff --git a/src/baby_monitor/models/db/user.py b/src/baby_monitor/models/db/user.py
index 31f3bdc..c4f4be2 100644
--- a/src/baby_monitor/models/db/user.py
+++ b/src/baby_monitor/models/db/user.py
@@ -1,9 +1,15 @@
 """Database models."""
 
-from sqlalchemy import Column, Integer, String, DateTime
+from typing import TYPE_CHECKING
+from sqlalchemy import Column, Integer, String, DateTime, Boolean
 from datetime import datetime
 
-from baby_monitor.repositories.dependencies.get_database import Base
+if TYPE_CHECKING:
+    from sqlalchemy.orm import DeclarativeBase
+
+    Base = DeclarativeBase
+else:
+    from baby_monitor.repositories.dependencies.get_database import Base
 
 
 class User(Base):
@@ -14,6 +20,7 @@ class User(Base):
     id = Column(Integer, primary_key=True, index=True)
     username = Column(String, unique=True, index=True, nullable=False)
     hashed_password = Column(String, nullable=False)
+    is_admin = Column(Boolean, default=False, nullable=False)
     created_at = Column(DateTime, default=datetime.utcnow, nullable=False)
 
     def __repr__(self) -> str:
diff --git a/src/baby_monitor/models/invitation.py b/src/baby_monitor/models/invitation.py
new file mode 100644
index 0000000..7d381cf
--- /dev/null
+++ b/src/baby_monitor/models/invitation.py
@@ -0,0 +1,37 @@
+"""Invitation token model for user registration.
+
+Note: DateTime(timezone=True) is used for PostgreSQL compatibility.
+SQLite will store as naive UTC, which is handled in the repository layer.
+"""
+
+from datetime import datetime
+from typing import TYPE_CHECKING
+from sqlalchemy import Boolean, DateTime, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+if TYPE_CHECKING:
+    from sqlalchemy.orm import DeclarativeBase
+
+    Base = DeclarativeBase
+else:
+    from baby_monitor.repositories.dependencies.get_database import Base
+
+
+class Invitation(Base):
+    """Invitation token for new user registration."""
+
+    __tablename__ = "invitations"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    token: Mapped[str] = mapped_column(String, unique=True, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
+    expires_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
+    created_by_user_id: Mapped[int] = mapped_column(Integer, nullable=False)
+    is_consumed: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
+    consumed_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
diff --git a/src/baby_monitor/repositories/dependencies/get_database.py b/src/baby_monitor/repositories/dependencies/get_database.py
index 6c9e0b8..4c32397 100644
--- a/src/baby_monitor/repositories/dependencies/get_database.py
+++ b/src/baby_monitor/repositories/dependencies/get_database.py
@@ -3,9 +3,13 @@
 import os
 from pathlib import Path
 from collections.abc import Generator
+from typing import TYPE_CHECKING
 from sqlalchemy import create_engine
 from sqlalchemy.orm import declarative_base, sessionmaker, Session
 
+if TYPE_CHECKING:
+    from sqlalchemy.orm import DeclarativeBase
+
 # Database directory
 DATA_DIR = Path(os.getenv("DATA_DIR", "/data"))
 
@@ -23,11 +27,16 @@ engine = create_engine(
 SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
 
 # Base class for declarative models
-Base = declarative_base()
+Base: "type[DeclarativeBase]" = declarative_base()
 
 
 def init_db() -> None:
     """Initialize the database by creating all tables."""
+    # Import models to register them with Base.metadata
+    # This must be done before create_all() is called
+    from baby_monitor.models.db.user import User  # noqa: F401
+    from baby_monitor.models.invitation import Invitation  # noqa: F401
+
     # Ensure data directory exists
     DATA_DIR.mkdir(parents=True, exist_ok=True)
     Base.metadata.create_all(bind=engine)
diff --git a/src/baby_monitor/repositories/dependencies/get_invitation_repository.py b/src/baby_monitor/repositories/dependencies/get_invitation_repository.py
new file mode 100644
index 0000000..fce80f8
--- /dev/null
+++ b/src/baby_monitor/repositories/dependencies/get_invitation_repository.py
@@ -0,0 +1,25 @@
+"""Dependency injection for invitation repository."""
+
+from typing import Annotated
+from fastapi import Depends
+from sqlalchemy.orm import Session
+
+from baby_monitor.repositories.dependencies.get_database import get_database
+from baby_monitor.repositories.invitation.sqlite_invitation import (
+    SQLiteInvitationRepository,
+)
+
+
+def get_invitation_repository(
+    db: Annotated[Session, Depends(get_database)],
+) -> SQLiteInvitationRepository:
+    """
+    Provide an invitation repository instance.
+
+    Args:
+        db: Database session from dependency injection
+
+    Returns:
+        SQLiteInvitationRepository instance
+    """
+    return SQLiteInvitationRepository(db)
diff --git a/src/baby_monitor/repositories/interfaces/__init__.py b/src/baby_monitor/repositories/interfaces/__init__.py
index 0f318da..21a8cac 100644
--- a/src/baby_monitor/repositories/interfaces/__init__.py
+++ b/src/baby_monitor/repositories/interfaces/__init__.py
@@ -3,6 +3,9 @@
 from .credentials_repository_interface import (
     CredentialsRepositoryInterface,
 )
+from .invitation_repository_interface import (
+    InvitationRepositoryInterface,
+)
 from .token_repository_interface import (
     TokenRepositoryInterface,
 )
@@ -14,4 +17,5 @@ __all__ = [
     "UserRepositoryInterface",
     "TokenRepositoryInterface",
     "CredentialsRepositoryInterface",
+    "InvitationRepositoryInterface",
 ]
diff --git a/src/baby_monitor/repositories/interfaces/invitation_repository_interface.py b/src/baby_monitor/repositories/interfaces/invitation_repository_interface.py
new file mode 100644
index 0000000..cd8453c
--- /dev/null
+++ b/src/baby_monitor/repositories/interfaces/invitation_repository_interface.py
@@ -0,0 +1,49 @@
+"""Interface for invitation repository operations."""
+
+from abc import ABC, abstractmethod
+from datetime import datetime
+
+
+class InvitationRepositoryInterface(ABC):
+    """Interface for managing invitation tokens."""
+
+    @abstractmethod
+    def create_invitation(
+        self, token: str, created_by_user_id: int, expires_at: datetime
+    ) -> None:
+        """
+        Create a new invitation token.
+
+        Args:
+            token: The invitation token string
+            created_by_user_id: ID of the user creating the invitation
+            expires_at: Expiration datetime for the invitation
+        """
+
+    @abstractmethod
+    def verify_invitation(self, token: str) -> bool:
+        """
+        Verify if an invitation token is valid and not consumed.
+
+        Args:
+            token: The invitation token to verify
+
+        Returns:
+            True if valid and not consumed, False otherwise
+        """
+
+    @abstractmethod
+    def consume_invitation(self, token: str) -> bool:
+        """
+        Mark an invitation token as consumed.
+
+        Args:
+            token: The invitation token to consume
+
+        Returns:
+            True if successfully consumed, False if invalid or already used
+        """
+
+    @abstractmethod
+    def cleanup_expired(self) -> None:
+        """Remove expired invitation tokens from storage."""
diff --git a/src/baby_monitor/repositories/invitation/__init__.py b/src/baby_monitor/repositories/invitation/__init__.py
new file mode 100644
index 0000000..2ddabc3
--- /dev/null
+++ b/src/baby_monitor/repositories/invitation/__init__.py
@@ -0,0 +1,7 @@
+"""Invitation repository implementations."""
+
+from baby_monitor.repositories.invitation.sqlite_invitation import (
+    SQLiteInvitationRepository,
+)
+
+__all__ = ["SQLiteInvitationRepository"]
diff --git a/src/baby_monitor/repositories/invitation/sqlite_invitation.py b/src/baby_monitor/repositories/invitation/sqlite_invitation.py
new file mode 100644
index 0000000..e51882c
--- /dev/null
+++ b/src/baby_monitor/repositories/invitation/sqlite_invitation.py
@@ -0,0 +1,112 @@
+"""SQLite implementation of invitation repository.
+
+Note: SQLite does not support timezone-aware datetimes natively.
+All datetimes are stored as naive UTC and converted at the application layer.
+"""
+
+from datetime import datetime, UTC
+from sqlalchemy.orm import Session
+
+from baby_monitor.models.invitation import Invitation
+from baby_monitor.repositories.interfaces.invitation_repository_interface import (
+    InvitationRepositoryInterface,
+)
+
+
+class SQLiteInvitationRepository(InvitationRepositoryInterface):
+    """SQLite implementation for managing invitation tokens."""
+
+    def __init__(self, db: Session) -> None:
+        """Initialize the repository with a database session."""
+        self.db = db
+
+    def create_invitation(
+        self, token: str, created_by_user_id: int, expires_at: datetime
+    ) -> None:
+        """
+        Create a new invitation token.
+
+        Args:
+            token: The invitation token string
+            created_by_user_id: ID of the user creating the invitation
+            expires_at: Expiration datetime for the invitation
+        """
+        # Convert timezone-aware datetimes to naive UTC for SQLite
+        created_at_utc = datetime.now(UTC).replace(tzinfo=None)
+        expires_at_utc = (
+            expires_at.replace(tzinfo=None) if expires_at.tzinfo else expires_at
+        )
+
+        invitation = Invitation(
+            token=token,
+            created_at=created_at_utc,
+            expires_at=expires_at_utc,
+            created_by_user_id=created_by_user_id,
+            is_consumed=False,
+            consumed_at=None,
+        )
+        self.db.add(invitation)
+        self.db.commit()
+
+    def verify_invitation(self, token: str) -> bool:
+        """
+        Verify if an invitation token is valid and not consumed.
+
+        Args:
+            token: The invitation token to verify
+
+        Returns:
+            True if valid and not consumed, False otherwise
+        """
+        invitation = self.db.query(Invitation).filter(Invitation.token == token).first()
+
+        if not invitation:
+            return False
+
+        # Compare as naive UTC datetimes (SQLite stores without timezone)
+        now_utc = datetime.now(UTC).replace(tzinfo=None)
+        if invitation.expires_at < now_utc:
+            return False
+
+        # Check if already consumed
+        if invitation.is_consumed:
+            return False
+
+        return True
+
+    def consume_invitation(self, token: str) -> bool:
+        """
+        Mark an invitation token as consumed.
+
+        Args:
+            token: The invitation token to consume
+
+        Returns:
+            True if successfully consumed, False if invalid or already used
+        """
+        invitation = self.db.query(Invitation).filter(Invitation.token == token).first()
+
+        if not invitation:
+            return False
+
+        # Compare as naive UTC datetimes (SQLite stores without timezone)
+        now_utc = datetime.now(UTC).replace(tzinfo=None)
+        if invitation.expires_at < now_utc:
+            return False
+
+        # Check if already consumed
+        if invitation.is_consumed:
+            return False
+
+        # Mark as consumed
+        invitation.is_consumed = True
+        invitation.consumed_at = now_utc
+        self.db.commit()
+
+        return True
+
+    def cleanup_expired(self) -> None:
+        """Remove expired invitation tokens from storage."""
+        now_utc = datetime.now(UTC).replace(tzinfo=None)
+        self.db.query(Invitation).filter(Invitation.expires_at < now_utc).delete()
+        self.db.commit()
diff --git a/src/baby_monitor/repositories/user/sqlite_user.py b/src/baby_monitor/repositories/user/sqlite_user.py
index ac7318d..fc64a21 100644
--- a/src/baby_monitor/repositories/user/sqlite_user.py
+++ b/src/baby_monitor/repositories/user/sqlite_user.py
@@ -20,13 +20,18 @@ class SQLiteUserRepository(UserRepositoryInterface):
                 "id": user.id,
                 "username": user.username,
                 "hashed_password": user.hashed_password,
+                "is_admin": user.is_admin,
                 "created_at": user.created_at,
             }
         return None
 
     def create(self, username: str, hashed_password: str) -> dict:
         """Create a new user."""
-        user = User(username=username, hashed_password=hashed_password)
+        user = User(
+            username=username,
+            hashed_password=hashed_password,
+            is_admin=False,
+        )
         self.db.add(user)
         self.db.commit()
         self.db.refresh(user)
@@ -34,6 +39,7 @@ class SQLiteUserRepository(UserRepositoryInterface):
             "id": user.id,
             "username": user.username,
             "hashed_password": user.hashed_password,
+            "is_admin": user.is_admin,
             "created_at": user.created_at,
         }
 
@@ -45,6 +51,7 @@ class SQLiteUserRepository(UserRepositoryInterface):
                 "id": user.id,
                 "username": user.username,
                 "hashed_password": user.hashed_password,
+                "is_admin": user.is_admin,
                 "created_at": user.created_at,
             }
         return None
diff --git a/src/baby_monitor/routers/admin.py b/src/baby_monitor/routers/admin.py
new file mode 100644
index 0000000..2f90071
--- /dev/null
+++ b/src/baby_monitor/routers/admin.py
@@ -0,0 +1,66 @@
+"""Admin router for administrative functions."""
+
+import secrets
+from datetime import datetime, timedelta, UTC
+from typing import Annotated
+from fastapi import APIRouter, Depends
+from pydantic import BaseModel
+
+from baby_monitor.routers.auth import verify_admin
+from baby_monitor.repositories.dependencies.get_invitation_repository import (
+    get_invitation_repository,
+)
+from baby_monitor.repositories.interfaces import (
+    InvitationRepositoryInterface,
+)
+
+router = APIRouter(prefix="/api/admin", tags=["admin"])
+
+
+class InvitationResponse(BaseModel):
+    """Response model for invitation link generation."""
+
+    token: str
+    expires_at: str
+    message: str
+
+
+@router.post("/generate-invitation", response_model=InvitationResponse)
+async def generate_invitation_link(
+    user_id: Annotated[int, Depends(verify_admin)],
+    invitation_repository: Annotated[
+        InvitationRepositoryInterface,
+        Depends(get_invitation_repository),
+    ],
+) -> InvitationResponse:
+    """Generate a new invitation link for user registration.
+
+    The invitation token is valid for 24 hours and can be used once.
+    Requires admin role.
+
+    Args:
+        user_id: Admin user ID (from verify_admin)
+        invitation_repository: Invitation storage backend
+
+    Returns:
+        InvitationResponse with token and expiration details
+    """
+
+    # Generate secure random token
+    invitation_token = secrets.token_urlsafe(32)
+
+    # Calculate expiration (24 hours from now)
+    expires_at = datetime.now(UTC) + timedelta(hours=24)
+
+    # Store invitation token in database
+    invitation_repository.create_invitation(
+        token=invitation_token,
+        created_by_user_id=user_id,
+        expires_at=expires_at,
+    )
+
+    return InvitationResponse(
+        token=invitation_token,
+        expires_at=expires_at.isoformat(),
+        message="Invitation link generated successfully. Valid for 24 hours.",
+    )
diff --git a/src/baby_monitor/routers/auth.py b/src/baby_monitor/routers/auth.py
index 30581e4..c81b940 100644
--- a/src/baby_monitor/routers/auth.py
+++ b/src/baby_monitor/routers/auth.py
@@ -4,14 +4,25 @@ import secrets
 from fastapi import APIRouter, HTTPException, Depends, Header
 from typing import Annotated
 
-from baby_monitor.models.auth import LoginRequest, LoginResponse
+from baby_monitor.models.auth import (
+    LoginRequest,
+    LoginResponse,
+    RegisterRequest,
+    RegisterResponse,
+)
 from baby_monitor.repositories import (
     get_token_repository,
     get_credentials_repository,
+    get_user_repository,
+)
+from baby_monitor.repositories.dependencies.get_invitation_repository import (
+    get_invitation_repository,
 )
 from baby_monitor.repositories.interfaces import (
     TokenRepositoryInterface,
     CredentialsRepositoryInterface,
+    UserRepositoryInterface,
+    InvitationRepositoryInterface,
 )
 
 router = APIRouter(prefix="/api", tags=["authentication"])
@@ -39,11 +50,37 @@ def verify_token(
     return user_id
 
 
+def verify_admin(
+    user_id: Annotated[int, Depends(verify_token)],
+    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
+) -> int:
+    """Verify the user is an admin and return user_id."""
+    # First try to get user from database
+    user = user_repo.get_by_id(user_id)
+
+    if user:
+        # Database user - check is_admin field
+        if not user.get("is_admin", False):
+            raise HTTPException(status_code=403, detail="Admin access required")
+        return user_id
+
+    # If not in database but has valid token with user_id=1,
+    # it's the environment-based admin (only assigned during env admin login)
+    if user_id == 1:
+        return user_id
+
+    # User not found and not environment admin
+    raise HTTPException(status_code=401, detail="User not found")
+
+
 @router.post("/login", response_model=LoginResponse)
 def login(
     credentials: LoginRequest,
-    token_repo: TokenRepositoryInterface = Depends(get_token_repository),
-    creds_repo: CredentialsRepositoryInterface = Depends(get_credentials_repository),
+    token_repo: Annotated[TokenRepositoryInterface, Depends(get_token_repository)],
+    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
+    creds_repo: Annotated[
+        CredentialsRepositoryInterface, Depends(get_credentials_repository)
+    ],
 ) -> LoginResponse:
     """
     API endpoint for user authentication.
@@ -51,20 +88,38 @@ def login(
     Returns user info and access token on successful login.
     Raises 401 on invalid credentials.
     """
-    # Verify credentials using repository
+    # First check if it's a database user
+    user = user_repo.get_by_username(credentials.username)
+    if user:
+        # TODO: Use proper password hashing (bcrypt/argon2)
+        # For now, compare plain text (matches registration)
+        if user["hashed_password"] == credentials.password:
+            # Generate a secure random token
+            access_token = secrets.token_urlsafe(32)
+            token_repo.store(access_token, user_id=user["id"], ttl=3600)
+
+            return LoginResponse(
+                message="Login successful",
+                username=credentials.username,
+                access_token=access_token,
+                is_admin=user.get("is_admin", False),
+            )
+
+    # Fallback to admin credentials from environment
     if creds_repo.verify_admin_credentials(credentials.username, credentials.password):
         # Generate a secure random token
         access_token = secrets.token_urlsafe(32)
-        # Store token with user_id (hardcoded 1 for now)
+        # Store token with user_id (hardcoded 1 for admin)
         token_repo.store(access_token, user_id=1, ttl=3600)
 
         return LoginResponse(
             message="Login successful",
             username=credentials.username,
             access_token=access_token,
+            is_admin=True,
         )
-    else:
-        raise HTTPException(status_code=401, detail="Invalid username or password")
+
+    raise HTTPException(status_code=401, detail="Invalid username or password")
 
 
 @router.post("/logout")
@@ -76,3 +131,96 @@ def logout(
     # Note: We'd need to pass the token itself, not user_id
     # This is simplified - in production, extract token from verify_token
     return {"message": "Logged out successfully"}
+
+
+@router.get("/verify-invitation")
+def verify_invitation(
+    token: str,
+    invitation_repo: Annotated[
+        InvitationRepositoryInterface, Depends(get_invitation_repository)
+    ],
+) -> dict[str, bool]:
+    """Verify if an invitation token is valid."""
+    is_valid = invitation_repo.verify_invitation(token)
+    if not is_valid:
+        raise HTTPException(status_code=400, detail="Invalid or expired invitation")
+    return {"valid": True}
+
+
+@router.post("/register", response_model=RegisterResponse)
+def register(
+    request: RegisterRequest,
+    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
+    invitation_repo: Annotated[
+        InvitationRepositoryInterface, Depends(get_invitation_repository)
+    ],
+    token_repo: Annotated[TokenRepositoryInterface, Depends(get_token_repository)],
+) -> RegisterResponse:
+    """
+    Register a new user with an invitation token.
+
+    Verifies the invitation, creates the user, consumes the invitation,
+    and returns an authentication token.
+    """
+    # Verify invitation token
+    if not invitation_repo.verify_invitation(request.invitation_token):
+        raise HTTPException(
+            status_code=400,
+            detail="Invalid or expired invitation token",
+        )
+
+    # Check if username already exists
+    existing_user = user_repo.get_by_username(request.username)
+    if existing_user:
+        raise HTTPException(
+            status_code=400,
+            detail="Username already exists",
+        )
+
+    # Create the new user
+    # TODO: Hash password before storing (currently plain text)
+    user = user_repo.create(
+        username=request.username,
+        hashed_password=request.password,
+    )
+
+    # Consume the invitation token
+    invitation_repo.consume_invitation(request.invitation_token)
+
+    # Generate authentication token
+    access_token = secrets.token_urlsafe(32)
+    token_repo.store(access_token, user_id=user["id"], ttl=3600)
+
+    return RegisterResponse(
+        message="Registration successful",
+        username=user["username"],
+        access_token=access_token,
+        is_admin=user.get("is_admin", False),
+    )
+
+
+@router.get("/me")
+def get_current_user(
+    user_id: Annotated[int, Depends(verify_token)],
+    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
+    creds_repo: Annotated[
+        CredentialsRepositoryInterface, Depends(get_credentials_repository)
+    ],
+) -> dict:
+    """Get current user info including admin status."""
+    user = user_repo.get_by_id(user_id)
+
+    # If user not found in DB, might be env-based admin
+    if not user:
+        # Return admin info from environment
+        return {
+            "id": user_id,
+            "username": creds_repo.get_admin_username(),
+            "is_admin": True,  # Env-based admin is always admin
+        }
+
+    return {
+        "id": user["id"],
+        "username": user["username"],
+        "is_admin": user.get("is_admin", False),
+    }
diff --git a/src/baby_monitor/static/admin.html b/src/baby_monitor/static/admin.html
new file mode 100644
index 0000000..e27d0c9
--- /dev/null
+++ b/src/baby_monitor/static/admin.html
@@ -0,0 +1,319 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Baby Monitor - Admin</title>
+    <style>
+      * {
+        margin: 0;
+        padding: 0;
+        box-sizing: border-box;
+      }
+
+      body {
+        font-family:
+          -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
+          Cantarell, sans-serif;
+        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        min-height: 100vh;
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        padding: 20px;
+      }
+
+      .container {
+        background: white;
+        border-radius: 12px;
+        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+        padding: 40px;
+        max-width: 600px;
+        width: 100%;
+      }
+
+      h1 {
+        color: #333;
+        margin-bottom: 10px;
+        font-size: 28px;
+      }
+
+      .subtitle {
+        color: #666;
+        margin-bottom: 30px;
+        font-size: 14px;
+      }
+
+      .section {
+        margin-bottom: 30px;
+      }
+
+      .section h2 {
+        color: #444;
+        font-size: 18px;
+        margin-bottom: 15px;
+        display: flex;
+        align-items: center;
+      }
+
+      .section h2::before {
+        content: "🔗";
+        margin-right: 8px;
+      }
+
+      .button {
+        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        color: white;
+        border: none;
+        padding: 12px 24px;
+        border-radius: 6px;
+        font-size: 16px;
+        font-weight: 600;
+        cursor: pointer;
+        transition:
+          transform 0.2s,
+          box-shadow 0.2s;
+        width: 100%;
+      }
+
+      .button:hover {
+        transform: translateY(-2px);
+        box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
+      }
+
+      .button:active {
+        transform: translateY(0);
+      }
+
+      .button:disabled {
+        opacity: 0.6;
+        cursor: not-allowed;
+        transform: none;
+      }
+
+      .link-container {
+        display: none;
+        margin-top: 20px;
+        padding: 15px;
+        background: #f8f9fa;
+        border-radius: 8px;
+        border: 2px solid #667eea;
+      }
+
+      .link-container.show {
+        display: block;
+      }
+
+      .link-label {
+        font-size: 12px;
+        color: #666;
+        margin-bottom: 8px;
+        font-weight: 600;
+        text-transform: uppercase;
+      }
+
+      .link-display {
+        display: flex;
+        gap: 10px;
+        align-items: center;
+      }
+
+      .link-text {
+        flex: 1;
+        padding: 10px;
+        background: white;
+        border: 1px solid #ddd;
+        border-radius: 4px;
+        font-family: "Courier New", monospace;
+        font-size: 13px;
+        word-break: break-all;
+        color: #333;
+      }
+
+      .copy-button {
+        padding: 10px 16px;
+        background: #28a745;
+        color: white;
+        border: none;
+        border-radius: 4px;
+        cursor: pointer;
+        font-weight: 600;
+        transition: background 0.2s;
+        white-space: nowrap;
+      }
+
+      .copy-button:hover {
+        background: #218838;
+      }
+
+      .copy-button.copied {
+        background: #155724;
+      }
+
+      .info-box {
+        background: #e7f3ff;
+        border-left: 4px solid #2196f3;
+        padding: 12px;
+        border-radius: 4px;
+        margin-top: 15px;
+        font-size: 14px;
+        color: #555;
+      }
+
+      .error {
+        background: #ffebee;
+        border-left: 4px solid #f44336;
+        color: #c62828;
+        padding: 12px;
+        border-radius: 4px;
+        margin-top: 15px;
+        display: none;
+      }
+
+      .error.show {
+        display: block;
+      }
+
+      .logout-button {
+        background: #dc3545;
+        padding: 8px 16px;
+        font-size: 14px;
+        margin-top: 20px;
+      }
+
+      .logout-button:hover {
+        background: #c82333;
+        box-shadow: 0 4px 12px rgba(220, 53, 69, 0.4);
+      }
+    </style>
+  </head>
+  <body>
+    <div class="container">
+      <h1>👨‍💼 Admin Dashboard</h1>
+      <p class="subtitle">Manage user invitations and settings</p>
+
+      <div class="section">
+        <h2>Generate Invitation Link</h2>
+        <p style="color: #666; margin-bottom: 15px; font-size: 14px">
+          Create a secure one-time link to invite a new user to register.
+        </p>
+        <button class="button" id="generateBtn" onclick="generateLink()">
+          Generate New Invitation Link
+        </button>
+
+        <div id="linkContainer" class="link-container">
+          <div class="link-label">Invitation Link</div>
+          <div class="link-display">
+            <div class="link-text" id="linkText"></div>
+            <button class="copy-button" id="copyBtn" onclick="copyLink()">
+              Copy
+            </button>
+          </div>
+          <div class="info-box">
+            ℹ️ This link expires in 24 hours and can only be used once. Share it
+            securely with the intended user.
+          </div>
+        </div>
+
+        <div id="error" class="error"></div>
+      </div>
+
+      <button class="button logout-button" onclick="logout()">Logout</button>
+    </div>
+
+    <script>
+      // Check if user is authenticated and is admin
+      const token = localStorage.getItem("access_token");
+      if (!token) {
+        window.location.href = "/login.html";
+      }
+
+      // Verify user is admin
+      fetch("/api/me", {
+        headers: {
+          Authorization: `Bearer ${token}`,
+        },
+      })
+        .then((response) => response.json())
+        .then((user) => {
+          if (!user.is_admin) {
+            alert("Access denied. Admin privileges required.");
+            window.location.href = "/";
+          }
+        })
+        .catch((error) => {
+          console.error("Error verifying admin status:", error);
+          window.location.href = "/login.html";
+        });
+
+      async function generateLink() {
+        const btn = document.getElementById("generateBtn");
+        const linkContainer = document.getElementById("linkContainer");
+        const linkText = document.getElementById("linkText");
+        const errorDiv = document.getElementById("error");
+
+        // Disable button and show loading state
+        btn.disabled = true;
+        btn.textContent = "Generating...";
+        errorDiv.classList.remove("show");
+
+        try {
+          const response = await fetch("/api/admin/generate-invitation", {
+            method: "POST",
+            headers: {
+              Authorization: `Bearer ${token}`,
+              "Content-Type": "application/json",
+            },
+          });
+
+          if (!response.ok) {
+            throw new Error(`Failed to generate link: ${response.statusText}`);
+          }
+
+          const data = await response.json();
+
+          // Build the full URL
+          const baseUrl = window.location.origin;
+          const inviteUrl = `${baseUrl}/register.html?token=${data.token}`;
+
+          // Display the link
+          linkText.textContent = inviteUrl;
+          linkContainer.classList.add("show");
+        } catch (error) {
+          errorDiv.textContent = `Error: ${error.message}`;
+          errorDiv.classList.add("show");
+        } finally {
+          btn.disabled = false;
+          btn.textContent = "Generate New Invitation Link";
+        }
+      }
+
+      function copyLink() {
+        const linkText = document.getElementById("linkText").textContent;
+        const copyBtn = document.getElementById("copyBtn");
+
+        navigator.clipboard
+          .writeText(linkText)
+          .then(() => {
+            // Show success state
+            copyBtn.textContent = "✓ Copied!";
+            copyBtn.classList.add("copied");
+
+            // Reset after 2 seconds
+            setTimeout(() => {
+              copyBtn.textContent = "Copy";
+              copyBtn.classList.remove("copied");
+            }, 2000);
+          })
+          .catch((err) => {
+            alert("Failed to copy link: " + err);
+          });
+      }
+
+      function logout() {
+        localStorage.removeItem("access_token");
+        window.location.href = "/login.html";
+      }
+    </script>
+  </body>
+</html>
diff --git a/src/baby_monitor/static/index.html b/src/baby_monitor/static/index.html
index 1880344..da17c70 100644
--- a/src/baby_monitor/static/index.html
+++ b/src/baby_monitor/static/index.html
@@ -3,7 +3,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>Baby Monitor - Home</title>
+    <title>Baby Monitor</title>
     <style>
       body {
         font-family: Arial, sans-serif;
@@ -12,6 +12,69 @@
         padding: 0 1rem;
         background-color: #f0f0f0;
       }
+      .burger-menu {
+        position: fixed;
+        top: 1rem;
+        left: 1rem;
+        cursor: pointer;
+        z-index: 1000;
+        background: white;
+        padding: 0.5rem;
+        border-radius: 4px;
+        box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
+      }
+      .burger-menu div {
+        width: 25px;
+        height: 3px;
+        background-color: #333;
+        margin: 5px 0;
+        transition: 0.3s;
+      }
+      .menu-overlay {
+        position: fixed;
+        top: 0;
+        left: -250px;
+        width: 250px;
+        height: 100vh;
+        background: white;
+        box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
+        transition: left 0.3s;
+        z-index: 999;
+        padding: 4rem 1rem 1rem 1rem;
+      }
+      .menu-overlay.open {
+        left: 0;
+      }
+      .menu-backdrop {
+        position: fixed;
+        top: 0;
+        left: 0;
+        width: 100%;
+        height: 100vh;
+        background: rgba(0, 0, 0, 0.5);
+        display: none;
+        z-index: 998;
+      }
+      .menu-backdrop.open {
+        display: block;
+      }
+      .menu-item {
+        padding: 1rem;
+        border-bottom: 1px solid #eee;
+        cursor: pointer;
+        transition: background 0.2s;
+      }
+      .menu-item:hover {
+        background: #f5f5f5;
+      }
+      .menu-item.admin {
+        color: #667eea;
+        font-weight: 600;
+      }
+      .menu-item.logout {
+        color: #dc3545;
+        font-weight: 600;
+      }
       .container {
         background: white;
         padding: 2rem;
@@ -36,10 +99,20 @@
         border-radius: 4px;
         cursor: pointer;
         font-size: 1rem;
+        margin-right: 0.5rem;
       }
       button:hover {
         background-color: #c82333;
       }
+      .admin-button {
+        background-color: #667eea;
+      }
+      .admin-button:hover {
+        background-color: #5568d3;
+      }
+      .hidden {
+        display: none;
+      }
       .loading {
         text-align: center;
         padding: 2rem;
@@ -47,6 +120,18 @@
     </style>
   </head>
   <body>
+    <div class="burger-menu" id="burgerMenu">
+      <div></div>
+      <div></div>
+      <div></div>
+    </div>
+
+    <div class="menu-backdrop" id="menuBackdrop"></div>
+
+    <div class="menu-overlay" id="menuOverlay">
+      <div class="menu-item logout" id="menuLogout">🚪 Logout</div>
+    </div>
+
     <div class="container">
       <div id="content" class="loading">
         <p>Loading...</p>
@@ -57,12 +142,35 @@
       const token = localStorage.getItem("access_token");
       const username = localStorage.getItem("username");
 
+      // Burger menu functionality
+      const burgerMenu = document.getElementById("burgerMenu");
+      const menuOverlay = document.getElementById("menuOverlay");
+      const menuBackdrop = document.getElementById("menuBackdrop");
+
+      function toggleMenu() {
+        menuOverlay.classList.toggle("open");
+        menuBackdrop.classList.toggle("open");
+      }
+
+      function closeMenu() {
+        menuOverlay.classList.remove("open");
+        menuBackdrop.classList.remove("open");
+      }
+
+      burgerMenu.addEventListener("click", toggleMenu);
+      menuBackdrop.addEventListener("click", closeMenu);
+
+      document.getElementById("menuLogout").addEventListener("click", () => {
+        closeMenu();
+        logout();
+      });
+
       // Check if user is logged in
       if (!token) {
-        window.location.href = "/static/login.html";
+        window.location.href = "/login.html";
       } else {
-        // Verify token by making an authenticated request
-        fetch("/api/", {
+        // Fetch current user info including admin status
+        fetch("/api/me", {
           headers: {
             Authorization: `Bearer ${token}`,
           },
@@ -74,25 +182,19 @@
               // Token invalid, redirect to login
               localStorage.removeItem("access_token");
               localStorage.removeItem("username");
-              window.location.href = "/static/login.html";
+              window.location.href = "/login.html";
               throw new Error("Authentication failed");
             }
           })
-          .then((data) => {
+          .then((user) => {
             // Show authenticated content
             document.getElementById("content").innerHTML = `
                     <h1>Welcome to Baby Monitor!</h1>
                     <div class="user-info">
                         <p><strong>Logged in as:</strong> ${username}</p>
                     </div>
-                    <p>${data.message}</p>
-                    <button id="logoutBtn">Logout</button>
+                    <p>Your session is active.</p>
                 `;
-
-            // Add logout handler
-            document
-              .getElementById("logoutBtn")
-              .addEventListener("click", logout);
           })
           .catch((error) => {
             console.error("Error:", error);
@@ -115,7 +217,7 @@
           // Clear local storage and redirect
           localStorage.removeItem("access_token");
           localStorage.removeItem("username");
-          window.location.href = "/static/login.html";
+          window.location.href = "/login.html";
         }
       }
     </script>
diff --git a/src/baby_monitor/static/login.html b/src/baby_monitor/static/login.html
index 11b96e0..eea5bc6 100644
--- a/src/baby_monitor/static/login.html
+++ b/src/baby_monitor/static/login.html
@@ -3,7 +3,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>Baby Monitor - Login</title>
+    <title>Baby Monitor</title>
     <style>
       body {
         font-family: Arial, sans-serif;
@@ -112,9 +112,14 @@
             // Store token in localStorage
             localStorage.setItem("access_token", data.access_token);
             localStorage.setItem("username", data.username);
-            // Redirect to home page
+
+            // Redirect based on is_admin from login response
             setTimeout(() => {
-              window.location.href = "/";
+              if (data.is_admin === true) {
+                window.location.href = "/admin.html";
+              } else {
+                window.location.href = "/";
+              }
             }, 1000);
           } else {
             showMessage(data.detail || "Login failed", "error");
diff --git a/src/baby_monitor/static/register.html b/src/baby_monitor/static/register.html
new file mode 100644
index 0000000..8e3aea0
--- /dev/null
+++ b/src/baby_monitor/static/register.html
@@ -0,0 +1,383 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Baby Monitor - Register</title>
+    <style>
+      * {
+        margin: 0;
+        padding: 0;
+        box-sizing: border-box;
+      }
+
+      body {
+        font-family:
+          -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
+          Cantarell, sans-serif;
+        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        min-height: 100vh;
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        padding: 20px;
+      }
+
+      .container {
+        background: white;
+        border-radius: 12px;
+        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+        padding: 40px;
+        max-width: 450px;
+        width: 100%;
+      }
+
+      h1 {
+        color: #333;
+        margin-bottom: 10px;
+        font-size: 28px;
+        text-align: center;
+      }
+
+      .subtitle {
+        color: #666;
+        margin-bottom: 30px;
+        font-size: 14px;
+        text-align: center;
+      }
+
+      .form-group {
+        margin-bottom: 20px;
+      }
+
+      label {
+        display: block;
+        margin-bottom: 8px;
+        color: #444;
+        font-weight: 600;
+        font-size: 14px;
+      }
+
+      input {
+        width: 100%;
+        padding: 12px;
+        border: 2px solid #e0e0e0;
+        border-radius: 6px;
+        font-size: 16px;
+        transition: border-color 0.3s;
+      }
+
+      input:focus {
+        outline: none;
+        border-color: #667eea;
+      }
+
+      .button {
+        width: 100%;
+        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        color: white;
+        border: none;
+        padding: 14px;
+        border-radius: 6px;
+        font-size: 16px;
+        font-weight: 600;
+        cursor: pointer;
+        transition:
+          transform 0.2s,
+          box-shadow 0.2s;
+        margin-top: 10px;
+      }
+
+      .button:hover {
+        transform: translateY(-2px);
+        box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
+      }
+
+      .button:active {
+        transform: translateY(0);
+      }
+
+      .button:disabled {
+        opacity: 0.6;
+        cursor: not-allowed;
+        transform: none;
+      }
+
+      .error {
+        background: #ffebee;
+        border-left: 4px solid #f44336;
+        color: #c62828;
+        padding: 12px;
+        border-radius: 4px;
+        margin-bottom: 20px;
+        display: none;
+        font-size: 14px;
+      }
+
+      .error.show {
+        display: block;
+      }
+
+      .success {
+        background: #e8f5e9;
+        border-left: 4px solid #4caf50;
+        color: #2e7d32;
+        padding: 12px;
+        border-radius: 4px;
+        margin-bottom: 20px;
+        display: none;
+        font-size: 14px;
+      }
+
+      .success.show {
+        display: block;
+      }
+
+      .loading-container {
+        text-align: center;
+        padding: 40px;
+      }
+
+      .spinner {
+        border: 3px solid #f3f3f3;
+        border-top: 3px solid #667eea;
+        border-radius: 50%;
+        width: 40px;
+        height: 40px;
+        animation: spin 1s linear infinite;
+        margin: 0 auto 20px;
+      }
+
+      @keyframes spin {
+        0% {
+          transform: rotate(0deg);
+        }
+        100% {
+          transform: rotate(360deg);
+        }
+      }
+
+      .info-box {
+        background: #e7f3ff;
+        border-left: 4px solid #2196f3;
+        padding: 12px;
+        border-radius: 4px;
+        margin-bottom: 20px;
+        font-size: 14px;
+        color: #555;
+      }
+
+      .hidden {
+        display: none;
+      }
+
+      .password-requirements {
+        font-size: 12px;
+        color: #666;
+        margin-top: 5px;
+      }
+
+      .password-requirements ul {
+        margin: 5px 0 0 20px;
+      }
+    </style>
+  </head>
+  <body>
+    <div class="container">
+      <div id="loadingContainer" class="loading-container">
+        <div class="spinner"></div>
+        <p style="color: #666">Validating invitation...</p>
+      </div>
+
+      <div id="registerContainer" class="hidden">
+        <h1>🎉 Create Your Account</h1>
+        <p class="subtitle">Complete the registration to get started</p>
+
+        <div id="error" class="error"></div>
+        <div id="success" class="success"></div>
+
+        <form id="registerForm" onsubmit="handleRegister(event)">
+          <div class="form-group">
+            <label for="username">Username</label>
+            <input
+              type="text"
+              id="username"
+              name="username"
+              required
+              minlength="3"
+              autocomplete="username"
+              placeholder="Choose a username"
+            />
+          </div>
+
+          <div class="form-group">
+            <label for="password">Password</label>
+            <input
+              type="password"
+              id="password"
+              name="password"
+              required
+              minlength="8"
+              autocomplete="new-password"
+              placeholder="Choose a strong password"
+            />
+            <div class="password-requirements">
+              <ul>
+                <li>At least 8 characters long</li>
+                <li>Mix of letters, numbers recommended</li>
+              </ul>
+            </div>
+          </div>
+
+          <div class="form-group">
+            <label for="confirmPassword">Confirm Password</label>
+            <input
+              type="password"
+              id="confirmPassword"
+              name="confirmPassword"
+              required
+              minlength="8"
+              autocomplete="new-password"
+              placeholder="Re-enter your password"
+            />
+          </div>
+
+          <button type="submit" class="button" id="submitBtn">
+            Create Account
+          </button>
+        </form>
+      </div>
+
+      <div id="invalidTokenContainer" class="hidden">
+        <h1>⚠️ Invalid Invitation</h1>
+        <p class="subtitle">This invitation link is invalid or has expired</p>
+        <div class="info-box">
+          This could mean:
+          <ul style="margin: 10px 0 0 20px; color: #555">
+            <li>The invitation has already been used</li>
+            <li>The invitation has expired (24 hours)</li>
+            <li>The invitation link is incorrect</li>
+          </ul>
+        </div>
+        <p style="text-align: center; color: #666; margin-top: 20px">
+          Please contact an administrator for a new invitation link.
+        </p>
+      </div>
+    </div>
+
+    <script>
+      let invitationToken = null;
+
+      // Extract token from URL query parameters
+      const urlParams = new URLSearchParams(window.location.search);
+      invitationToken = urlParams.get("token");
+
+      // Validate token on page load
+      window.addEventListener("DOMContentLoaded", async () => {
+        if (!invitationToken) {
+          showInvalidToken();
+          return;
+        }
+
+        try {
+          // Verify the invitation token
+          const response = await fetch(
+            `/api/verify-invitation?token=${encodeURIComponent(invitationToken)}`,
+          );
+
+          if (response.ok) {
+            showRegisterForm();
+          } else {
+            showInvalidToken();
+          }
+        } catch (error) {
+          console.error("Error validating invitation:", error);
+          showInvalidToken();
+        }
+      });
+
+      function showRegisterForm() {
+        document.getElementById("loadingContainer").classList.add("hidden");
+        document.getElementById("registerContainer").classList.remove("hidden");
+      }
+
+      function showInvalidToken() {
+        document.getElementById("loadingContainer").classList.add("hidden");
+        document
+          .getElementById("invalidTokenContainer")
+          .classList.remove("hidden");
+      }
+
+      async function handleRegister(event) {
+        event.preventDefault();
+
+        const username = document.getElementById("username").value;
+        const password = document.getElementById("password").value;
+        const confirmPassword =
+          document.getElementById("confirmPassword").value;
+        const errorDiv = document.getElementById("error");
+        const successDiv = document.getElementById("success");
+        const submitBtn = document.getElementById("submitBtn");
+
+        // Clear previous messages
+        errorDiv.classList.remove("show");
+        successDiv.classList.remove("show");
+
+        // Validate passwords match
+        if (password !== confirmPassword) {
+          errorDiv.textContent = "Passwords do not match!";
+          errorDiv.classList.add("show");
+          return;
+        }
+
+        // Disable submit button
+        submitBtn.disabled = true;
+        submitBtn.textContent = "Creating Account...";
+
+        try {
+          const response = await fetch("/api/register", {
+            method: "POST",
+            headers: {
+              "Content-Type": "application/json",
+            },
+            body: JSON.stringify({
+              username: username,
+              password: password,
+              invitation_token: invitationToken,
+            }),
+          });
+
+          const data = await response.json();
+
+          if (response.ok) {
+            // Store the access token and username
+            localStorage.setItem("access_token", data.access_token);
+            localStorage.setItem("username", data.username);
+
+            // Show success message
+            successDiv.textContent =
+              "Account created successfully! Redirecting...";
+            successDiv.classList.add("show");
+
+            // Redirect to home page after a brief delay
+            setTimeout(() => {
+              window.location.href = "/";
+            }, 1500);
+          } else {
+            errorDiv.textContent =
+              data.detail || "Registration failed. Please try again.";
+            errorDiv.classList.add("show");
+            submitBtn.disabled = false;
+            submitBtn.textContent = "Create Account";
+          }
+        } catch (error) {
+          console.error("Registration error:", error);
+          errorDiv.textContent = "An error occurred. Please try again.";
+          errorDiv.classList.add("show");
+          submitBtn.disabled = false;
+          submitBtn.textContent = "Create Account";
+        }
+      }
+    </script>
+  </body>
+</html>