diff --git a/Back/core/deps.py b/Back/core/deps.py
index 42ec796..9f3048d 100644
--- a/Back/core/deps.py
+++ b/Back/core/deps.py
@@ -51,6 +51,14 @@ async def get_current_user(
             detail="User is inactive",
         )
 
+    # Check token version for remote logout
+    token_version = payload.get("token_version")
+    if token_version != user.token_version:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Token has been invalidated",
+        )
+
     return user
 
 
@@ -61,7 +69,7 @@ async def get_current_admin(
     Ensure the authenticated user is an admin
     """
 
-    if user.role != "admin":
+    if not user.is_admin:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
             detail="Admin privileges required",
diff --git a/Back/core/jwt.py b/Back/core/jwt.py
index c6df1b2..fed860e 100755
--- a/Back/core/jwt.py
+++ b/Back/core/jwt.py
@@ -6,6 +6,7 @@ from core.config import settings
 
 def create_access_token(
     subject: str,
+    token_version: int,
     expires_delta: timedelta | None = None,
 ) -> str:
 
@@ -18,6 +19,7 @@ def create_access_token(
 
     payload = {
         "sub": subject,
+        "token_version": token_version,
         "exp": expire,
     }
 
diff --git a/Back/domains/admin/api.py b/Back/domains/admin/api.py
index 257d278..446a050 100644
--- a/Back/domains/admin/api.py
+++ b/Back/domains/admin/api.py
@@ -38,7 +38,8 @@ async def create_user(
         user, secret = await admin_create_user(
             db,
             payload.username,
-            payload.role
+            payload.phone_number,
+            payload.is_admin
         )
 
     except ValueError as e:
@@ -54,6 +55,22 @@ async def create_user(
     }
 
 
+@router.post("/users/{user_id}/logout")
+async def logout_user(
+    user_id: str,
+    db: AsyncSession = Depends(get_db),
+    admin=Depends(get_current_admin)
+):
+    from domains.admin.service import admin_logout_user
+    user = await admin_logout_user(db, user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+    return {"message": "User logged out successfully"}
+
+
 @router.post("/users/{user_id}/reset-secret",
              response_model=AdminResetSecretResult)
 async def reset_secret(
diff --git a/Back/domains/admin/schemas.py b/Back/domains/admin/schemas.py
index c794317..a0bb7f7 100644
--- a/Back/domains/admin/schemas.py
+++ b/Back/domains/admin/schemas.py
@@ -1,15 +1,16 @@
 import uuid
 from pydantic import BaseModel
-from domains.users.models import UserRole
 
 class AdminCreateUser(BaseModel):
     username: str
-    role: UserRole
+    phone_number: str | None = None
+    is_admin: bool = False
 
 class AdminUserResponse(BaseModel):
     id: uuid.UUID
     username: str
-    role: UserRole
+    phone_number: str | None
+    is_admin: bool
     is_active: bool
 
     class Config:
diff --git a/Back/domains/admin/service.py b/Back/domains/admin/service.py
index eea57c6..1093459 100644
--- a/Back/domains/admin/service.py
+++ b/Back/domains/admin/service.py
@@ -20,7 +20,8 @@ def generate_user_secret():
 async def admin_create_user(
     db: AsyncSession,
     username: str,
-    role: str
+    phone_number: str | None = None,
+    is_admin: bool = False
 ):
 
     existing = await get_user_by_username(db, username)
@@ -32,7 +33,8 @@ async def admin_create_user(
 
     user = User(
         username=username,
-        role=role,
+        phone_number=phone_number,
+        is_admin=is_admin,
         secret_hash=hash_password(secret)
     )
 
@@ -41,6 +43,19 @@ async def admin_create_user(
     return user, secret
 
 
+async def admin_logout_user(
+    db: AsyncSession,
+    user_id: str
+):
+    user = await get_user_by_id(db, user_id)
+    if not user:
+        return None
+    
+    user.token_version += 1
+    await db.commit()
+    return user
+
+
 async def admin_reset_user_secret(
     db: AsyncSession,
     user_id
diff --git a/Back/domains/auth/schemas.py b/Back/domains/auth/schemas.py
index c171682..997fe74 100644
--- a/Back/domains/auth/schemas.py
+++ b/Back/domains/auth/schemas.py
@@ -15,7 +15,7 @@ class TokenResponse(BaseModel):
 class AuthUser(BaseModel):
     id: uuid.UUID
     username: str
-    role: str
+    is_admin: bool
 
     class Config:
         from_attributes = True
\ No newline at end of file
diff --git a/Back/domains/auth/service.py b/Back/domains/auth/service.py
index 42d0f05..35de957 100644
--- a/Back/domains/auth/service.py
+++ b/Back/domains/auth/service.py
@@ -44,7 +44,8 @@ async def login_user(
         return None
 
     token = create_access_token(
-        subject=str(user.id)
+        subject=str(user.id),
+        token_version=user.token_version
     )
 
     return {
diff --git a/Back/domains/groups/api.py b/Back/domains/groups/api.py
index 56c58f9..be8b8a2 100644
--- a/Back/domains/groups/api.py
+++ b/Back/domains/groups/api.py
@@ -2,17 +2,22 @@ from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from db.session import get_db
-from core.deps import get_current_admin
+from core.deps import get_current_admin, get_current_user
 
 from domains.groups.schemas import (
     GroupCreate,
     GroupResponse,
-    AddMemberRequest
+    AddMemberRequest,
+    GroupMemberResponse
 )
 
 from domains.groups.service import (
     create_new_group,
-    add_member_to_group,
+    list_user_groups,
+    list_all_groups_admin,
+    list_group_members_api,
+    invite_member_to_group,
+    remove_member_from_group
 )
 
 
@@ -29,35 +34,100 @@ router = APIRouter(
 async def create_group(
     payload: GroupCreate,
     db: AsyncSession = Depends(get_db),
-    admin=Depends(get_current_admin)
+    user=Depends(get_current_user)
 ):
-
+    """
+    Admin creates Public groups, Regular users create Private groups.
+    """
     group = await create_new_group(
         db,
-        payload.name
+        payload.name,
+        user.id,
+        user.is_admin
     )
 
     return group
 
 
-@router.post("/{group_id}/members")
-async def add_member(
-    group_id: str,
-    payload: AddMemberRequest,
+@router.get("/my", response_model=list[GroupResponse])
+async def my_groups(
+    db: AsyncSession = Depends(get_db),
+    user=Depends(get_current_user)
+):
+    """
+    List groups the user is a member of.
+    """
+    return await list_user_groups(db, user.id)
+
+
+@router.get("/admin/all", response_model=list[GroupResponse])
+async def list_all_groups(
     db: AsyncSession = Depends(get_db),
     admin=Depends(get_current_admin)
 ):
+    """
+    Admin can see all groups.
+    """
+    return await list_all_groups_admin(db)
 
+
+@router.get("/{group_id}/members", response_model=list[GroupMemberResponse])
+async def group_members(
+    group_id: str,
+    db: AsyncSession = Depends(get_db),
+    user=Depends(get_current_user)
+):
+    """
+    List group members with username and online status.
+    """
+    return await list_group_members_api(db, group_id)
+
+
+@router.post("/{group_id}/invite")
+async def invite_member(
+    group_id: str,
+    payload: AddMemberRequest,
+    db: AsyncSession = Depends(get_db),
+    user=Depends(get_current_user)
+):
+    """
+    Invite a user by username. Sends a notification.
+    """
     try:
-        membership = await add_member_to_group(
+        notification = await invite_member_to_group(
             db,
             group_id,
-            payload.user_id,
+            user.id,
+            payload.username
         )
+        return {"message": "Invitation sent", "notification_id": notification.id}
     except ValueError as e:
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
             detail=str(e)
         )
 
-    return membership
\ No newline at end of file
+
+@router.delete("/{group_id}/members/{user_id}")
+async def remove_member(
+    group_id: str,
+    user_id: str,
+    db: AsyncSession = Depends(get_db),
+    user=Depends(get_current_user)
+):
+    """
+    Admin or Group Manager can remove a member.
+    """
+    try:
+        await remove_member_from_group(
+            db,
+            group_id,
+            user_id,
+            user
+        )
+        return {"message": "Member removed successfully"}
+    except ValueError as e:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail=str(e)
+        )
\ No newline at end of file
diff --git a/Back/domains/groups/models.py b/Back/domains/groups/models.py
index 8ecd293..688e397 100644
--- a/Back/domains/groups/models.py
+++ b/Back/domains/groups/models.py
@@ -3,14 +3,20 @@ from enum import Enum
 
 from sqlalchemy import String, Boolean, ForeignKey, Enum as SQLEnum
 from sqlalchemy.orm import Mapped, mapped_column, relationship
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from domains.users.models import User
 
 from db.base import Base
 
 class GroupType(str, Enum):
-    GROUP = "group"
-    DIRECT = "direct"
-
+    PUBLIC = "public"
+    PRIVATE = "private"
 
+class GroupMemberRole(str, Enum):
+    MANAGER = "manager"
+    MEMBER = "member"
 
 class Group(Base):
     __tablename__ = "groups" # type: ignore
@@ -23,7 +29,7 @@ class Group(Base):
 
     type: Mapped[GroupType] = mapped_column(
         SQLEnum(GroupType, name="group_type"),
-        default=GroupType.GROUP,
+        default=GroupType.PUBLIC,
         nullable=False
     )
 
@@ -33,6 +39,9 @@ class Group(Base):
         index=True
     )
 
+    # Relationship to members
+    members: Mapped[list["GroupMember"]] = relationship(back_populates="group", cascade="all, delete-orphan")
+
 
 class GroupMember(Base):
     __tablename__ = "group_members" # type: ignore
@@ -45,4 +54,14 @@ class GroupMember(Base):
     group_id: Mapped[uuid.UUID] = mapped_column(
         ForeignKey("groups.id", ondelete="CASCADE"),
         index=True
-    )
\ No newline at end of file
+    )
+
+    role: Mapped[GroupMemberRole] = mapped_column(
+        SQLEnum(GroupMemberRole, name="group_member_role"),
+        default=GroupMemberRole.MEMBER,
+        nullable=False
+    )
+
+    # Relationships
+    group: Mapped["Group"] = relationship(back_populates="members")
+    user: Mapped["User"] = relationship()
\ No newline at end of file
diff --git a/Back/domains/groups/repo.py b/Back/domains/groups/repo.py
index 177bd55..c159701 100644
--- a/Back/domains/groups/repo.py
+++ b/Back/domains/groups/repo.py
@@ -1,4 +1,5 @@
 from sqlalchemy import select
+import uuid
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from domains.groups.models import Group, GroupMember
@@ -31,6 +32,42 @@ async def get_user_groups(db: AsyncSession, user_id):
     return result.scalars().all()
 
 
+async def get_groups_by_type(db: AsyncSession, group_type):
+    result = await db.execute(
+        select(Group).where(Group.type == group_type)
+    )
+    return result.scalars().all()
+
+
 async def get_all_groups(db: AsyncSession):
     result = await db.execute(select(Group))
-    return result.scalars().all()
\ No newline at end of file
+    return result.scalars().all()
+
+
+async def get_group_members_with_details(db: AsyncSession, group_id: uuid.UUID):
+    from domains.users.models import User
+    result = await db.execute(
+        select(GroupMember, User.username)
+        .join(User, GroupMember.user_id == User.id)
+        .where(GroupMember.group_id == group_id)
+    )
+    return result.all()
+
+
+async def get_group_member(db: AsyncSession, group_id: uuid.UUID, user_id: uuid.UUID):
+    result = await db.execute(
+        select(GroupMember)
+        .where(GroupMember.group_id == group_id)
+        .where(GroupMember.user_id == user_id)
+    )
+    return result.scalar_one_or_none()
+
+
+async def delete_group_member(db: AsyncSession, group_id: uuid.UUID, user_id: uuid.UUID):
+    from sqlalchemy import delete
+    await db.execute(
+        delete(GroupMember)
+        .where(GroupMember.group_id == group_id)
+        .where(GroupMember.user_id == user_id)
+    )
+    await db.commit()
\ No newline at end of file
diff --git a/Back/domains/groups/schemas.py b/Back/domains/groups/schemas.py
index 2ba8963..b68cdfe 100644
--- a/Back/domains/groups/schemas.py
+++ b/Back/domains/groups/schemas.py
@@ -1,7 +1,7 @@
 import uuid
 from pydantic import BaseModel
 
-
+from domains.groups.models import GroupType, GroupMemberRole
 
 class GroupCreate(BaseModel):
     name: str
@@ -9,17 +9,20 @@ class GroupCreate(BaseModel):
 class GroupResponse(BaseModel):
     id: uuid.UUID
     name: str
+    type: GroupType
     is_active: bool
 
     class Config:
         from_attributes = True
 
 class AddMemberRequest(BaseModel):
-    user_id: uuid.UUID
+    username: str # Req 12 says user enters username
 
 class GroupMemberResponse(BaseModel):
     user_id: uuid.UUID
-    group_id: uuid.UUID
+    username: str
+    role: GroupMemberRole
+    is_online: bool = False
 
     class Config:
         from_attributes = True
\ No newline at end of file
diff --git a/Back/domains/groups/service.py b/Back/domains/groups/service.py
index ff03b84..f851a28 100644
--- a/Back/domains/groups/service.py
+++ b/Back/domains/groups/service.py
@@ -1,46 +1,86 @@
 from sqlalchemy.ext.asyncio import AsyncSession
+import uuid
 
 from domains.users.repo import get_user_by_id
-from domains.groups.models import Group, GroupMember
+from domains.groups.models import Group, GroupMember, GroupType, GroupMemberRole
 from domains.groups.repo import (
     create_group,
     get_group_by_id,
     add_group_member,
-    get_user_groups
+    get_user_groups,
+    get_group_members_with_details,
+    delete_group_member,
+    get_all_groups as repo_get_all_groups
 )
+from domains.realtime.presence_service import list_online_users
 
 
 async def create_new_group(
     db: AsyncSession,
     name: str,
+    creator_id,
+    is_admin: bool
 ):
-
+    group_type = GroupType.PUBLIC if is_admin else GroupType.PRIVATE
+    
     group = Group(
         name=name,
+        type=group_type
     )
 
-    return await create_group(db, group)
+    await create_group(db, group)
 
-async def add_member_to_group(
+    # Creator becomes Manager
+    membership = GroupMember(
+        group_id=group.id,
+        user_id=creator_id,
+        role=GroupMemberRole.MANAGER
+    )
+    await add_group_member(db, membership)
+    
+    return group
+
+
+async def invite_member_to_group(
     db: AsyncSession,
     group_id,
-    user_id,
+    sender_id,
+    target_username: str
 ):
+    from domains.users.repo import get_user_by_username
+    from domains.notifications.service import send_join_request
+
     # 1. Check if group exists
     group = await get_group_by_id(db, group_id)
     if not group:
         raise ValueError("Group not found")
 
-    # 2. Check if user exists
-    user = await get_user_by_id(db, user_id)
-    if not user:
+    # 2. Check if target user exists
+    target_user = await get_user_by_username(db, target_username)
+    if not target_user:
         raise ValueError("User not found")
 
-    # TODO: Check if already a member to avoid duplicate constraint if any (optional)
+    # 3. Send notification (Req 12)
+    return await send_join_request(
+        db,
+        sender_id=str(sender_id),
+        receiver_id=str(target_user.id),
+        group_id=str(group.id),
+        title="Group Invitation",
+        description=f"You have been invited to join group {group.name}"
+    )
 
+
+async def add_member_to_group(
+    db: AsyncSession,
+    group_id,
+    user_id,
+    role: GroupMemberRole = GroupMemberRole.MEMBER
+):
     membership = GroupMember(
         group_id=group_id,
         user_id=user_id,
+        role=role
     )
     return await add_group_member(db, membership)
 
@@ -49,4 +89,46 @@ async def list_user_groups(
     db: AsyncSession,
     user_id
 ):
-    return await get_user_groups(db, user_id)
\ No newline at end of file
+    return await get_user_groups(db, user_id)
+
+
+async def list_all_groups_admin(db: AsyncSession):
+    return await repo_get_all_groups(db)
+
+
+async def list_group_members_api(db: AsyncSession, group_id: str):
+    group_id_uuid = uuid.UUID(group_id)
+    members_data = await get_group_members_with_details(db, group_id_uuid)
+    online_users = await list_online_users(str(group_id))
+    
+    result = []
+    for member_info in members_data:
+        member, username = member_info
+        result.append({
+            "user_id": member.user_id,
+            "username": username,
+            "role": member.role,
+            "is_online": str(member.user_id) in online_users
+        })
+    return result
+
+
+async def remove_member_from_group(
+    db: AsyncSession,
+    group_id,
+    target_user_id,
+    requesting_user
+):
+    group_id_uuid = group_id if isinstance(group_id, uuid.UUID) else uuid.UUID(group_id)
+    target_user_id_uuid = target_user_id if isinstance(target_user_id, uuid.UUID) else uuid.UUID(target_user_id)
+
+    # Req 13: Admin or Group Manager can remove
+    if not requesting_user.is_admin:
+        # Check if requesting user is manager of this group
+        from domains.groups.repo import get_group_member
+        membership = await get_group_member(db, group_id_uuid, requesting_user.id)
+        if not membership or membership.role != GroupMemberRole.MANAGER:
+            raise ValueError("Permission denied. Only admin or group manager can remove members.")
+
+    # For now, let's assume we implement the check here or in repo.
+    await delete_group_member(db, group_id_uuid, target_user_id_uuid)
\ No newline at end of file
diff --git a/Back/domains/notifications/__init__.py b/Back/domains/notifications/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/Back/domains/notifications/api.py b/Back/domains/notifications/api.py
new file mode 100644
index 0000000..aa8a09a
--- /dev/null
+++ b/Back/domains/notifications/api.py
@@ -0,0 +1,64 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from db.session import get_db
+from core.deps import get_current_user, get_current_admin
+from domains.notifications.schemas import (
+    NotificationResponse, 
+    NotificationAction, 
+    NotificationCreate
+)
+from domains.notifications.service import (
+    list_my_notifications, 
+    respond_to_notification,
+    send_public_notification
+)
+from domains.users.repo import get_all_users
+
+router = APIRouter(
+    prefix="/notifications",
+    tags=["notifications"]
+)
+
+@router.get("/", response_model=list[NotificationResponse])
+async def my_notifications(
+    db: AsyncSession = Depends(get_db),
+    user=Depends(get_current_user)
+):
+    return await list_my_notifications(db, user.id)
+
+@router.post("/{notification_id}/respond", response_model=NotificationResponse)
+async def respond_notification(
+    notification_id: str,
+    payload: NotificationAction,
+    db: AsyncSession = Depends(get_db),
+    user=Depends(get_current_user)
+):
+    try:
+        return await respond_to_notification(
+            db, 
+            notification_id, 
+            user.id, 
+            payload.is_accepted
+        )
+    except ValueError as e:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=str(e)
+        )
+
+@router.post("/public")
+async def broadcast_notification(
+    title: str,
+    description: str,
+    db: AsyncSession = Depends(get_db),
+    admin=Depends(get_current_admin)
+):
+    users = await get_all_users(db)
+    user_ids = [str(u.id) for u in users]
+    return await send_public_notification(
+        db, 
+        title, 
+        description, 
+        admin.id, 
+        user_ids
+    )
diff --git a/Back/domains/notifications/models.py b/Back/domains/notifications/models.py
new file mode 100644
index 0000000..0e38033
--- /dev/null
+++ b/Back/domains/notifications/models.py
@@ -0,0 +1,42 @@
+import uuid
+from enum import Enum
+from sqlalchemy import String, Boolean, ForeignKey, Enum as SQLEnum, Text
+from sqlalchemy.orm import Mapped, mapped_column
+from db.base import Base
+
+class NotificationType(str, Enum):
+    PUBLIC = "public"
+    JOIN_REQUEST = "join_request"
+
+class Notification(Base):
+    __tablename__ = "notifications" # type: ignore
+
+    title: Mapped[str] = mapped_column(String(200), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    
+    type: Mapped[NotificationType] = mapped_column(
+        SQLEnum(NotificationType, name="notification_type"),
+        nullable=False
+    )
+    
+    is_accepted: Mapped[bool | None] = mapped_column(
+        Boolean, 
+        nullable=True, 
+        default=None
+    )
+
+    receiver_id: Mapped[uuid.UUID] = mapped_column(
+        ForeignKey("users.id", ondelete="CASCADE"),
+        index=True,
+        nullable=False
+    )
+
+    sender_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True
+    )
+    
+    group_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("groups.id", ondelete="CASCADE"),
+        nullable=True
+    )
diff --git a/Back/domains/notifications/repo.py b/Back/domains/notifications/repo.py
new file mode 100644
index 0000000..e50b464
--- /dev/null
+++ b/Back/domains/notifications/repo.py
@@ -0,0 +1,28 @@
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from domains.notifications.models import Notification
+
+async def create_notification(db: AsyncSession, notification: Notification):
+    db.add(notification)
+    await db.commit()
+    await db.refresh(notification)
+    return notification
+
+async def get_notification_by_id(db: AsyncSession, notification_id):
+    result = await db.execute(
+        select(Notification).where(Notification.id == notification_id)
+    )
+    return result.scalar_one_or_none()
+
+async def get_user_notifications(db: AsyncSession, user_id):
+    result = await db.execute(
+        select(Notification)
+        .where(Notification.receiver_id == user_id)
+        .order_by(Notification.created_at.desc())
+    )
+    return result.scalars().all()
+
+async def update_notification(db: AsyncSession, notification: Notification):
+    await db.commit()
+    await db.refresh(notification)
+    return notification
diff --git a/Back/domains/notifications/schemas.py b/Back/domains/notifications/schemas.py
new file mode 100644
index 0000000..1f81efc
--- /dev/null
+++ b/Back/domains/notifications/schemas.py
@@ -0,0 +1,25 @@
+import uuid
+from pydantic import BaseModel
+from domains.notifications.models import NotificationType
+
+class NotificationBase(BaseModel):
+    title: str
+    description: str | None = None
+    type: NotificationType
+    group_id: uuid.UUID | None = None
+
+class NotificationCreate(NotificationBase):
+    receiver_id: uuid.UUID
+    sender_id: uuid.UUID | None = None
+
+class NotificationResponse(NotificationBase):
+    id: uuid.UUID
+    is_accepted: bool | None
+    receiver_id: uuid.UUID
+    sender_id: uuid.UUID | None
+    
+    class Config:
+        from_attributes = True
+
+class NotificationAction(BaseModel):
+    is_accepted: bool
diff --git a/Back/domains/notifications/service.py b/Back/domains/notifications/service.py
new file mode 100644
index 0000000..bfbfeea
--- /dev/null
+++ b/Back/domains/notifications/service.py
@@ -0,0 +1,74 @@
+from sqlalchemy.ext.asyncio import AsyncSession
+from domains.notifications.models import Notification, NotificationType
+from domains.notifications.repo import (
+    create_notification,
+    get_user_notifications,
+    get_notification_by_id,
+    update_notification
+)
+
+async def send_public_notification(
+    db: AsyncSession,
+    title: str,
+    description: str,
+    sender_id: str,
+    receiver_ids: list[str]
+):
+    notifications = []
+    for receiver_id in receiver_ids:
+        notification = Notification(
+            title=title,
+            description=description,
+            type=NotificationType.PUBLIC,
+            sender_id=sender_id,
+            receiver_id=receiver_id
+        )
+        db.add(notification)
+        notifications.append(notification)
+    
+    await db.commit()
+    return notifications
+
+async def send_join_request(
+    db: AsyncSession,
+    sender_id: str,
+    receiver_id: str,
+    group_id: str,
+    title: str,
+    description: str | None = None
+):
+    notification = Notification(
+        title=title,
+        description=description,
+        type=NotificationType.JOIN_REQUEST,
+        sender_id=sender_id,
+        receiver_id=receiver_id,
+        group_id=group_id
+    )
+    return await create_notification(db, notification)
+
+async def list_my_notifications(db: AsyncSession, user_id):
+    return await get_user_notifications(db, user_id)
+
+async def respond_to_notification(
+    db: AsyncSession,
+    notification_id: str,
+    user_id: str,
+    is_accepted: bool
+):
+    notification = await get_notification_by_id(db, notification_id)
+    if not notification:
+        raise ValueError("Notification not found")
+    
+    if str(notification.receiver_id) != str(user_id):
+        raise ValueError("Permission denied")
+    
+    notification.is_accepted = is_accepted
+    await update_notification(db, notification)
+    
+    # If it's a join request and accepted, add user to group
+    if notification.type == NotificationType.JOIN_REQUEST and is_accepted:
+        from domains.groups.service import add_member_to_group
+        await add_member_to_group(db, notification.group_id, user_id)
+        
+    return notification
diff --git a/Back/domains/users/api.py b/Back/domains/users/api.py
index b76c9d1..a244395 100644
--- a/Back/domains/users/api.py
+++ b/Back/domains/users/api.py
@@ -2,11 +2,10 @@ from fastapi import APIRouter, Depends
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from db.session import get_db
-from core.deps import get_current_admin, get_current_user
-
-from domains.groups.schemas import GroupResponse
-from domains.groups.service import list_user_groups
+from core.deps import get_current_user
 
+from domains.users.schemas import UserResponse
+from domains.users.repo import get_all_users
 
 router = APIRouter(
     prefix="/users",
@@ -14,9 +13,12 @@ router = APIRouter(
 )
 
 
-@router.get("/me/groups", response_model=list[GroupResponse])
-async def my_groups(
+@router.get("/", response_model=list[UserResponse])
+async def list_users(
     db: AsyncSession = Depends(get_db),
     user=Depends(get_current_user)
 ):
-    return await list_user_groups(db, user.id)
\ No newline at end of file
+    """
+    List all users. Regular users can use this to find people to invite to groups.
+    """
+    return await get_all_users(db)
diff --git a/Back/domains/users/models.py b/Back/domains/users/models.py
index 6c929dd..0e180a7 100644
--- a/Back/domains/users/models.py
+++ b/Back/domains/users/models.py
@@ -1,15 +1,9 @@
 from enum import Enum
-
-from sqlalchemy import String, Boolean, Enum as SQLEnum
+from sqlalchemy import String, Boolean, Integer
 from sqlalchemy.orm import Mapped, mapped_column
 
 from db.base import Base
 
-class UserRole(str, Enum):
-    ADMIN = "admin"
-    GROUP_MANAGER = "group_manager"
-    MEMBER = "member"
-
 class User(Base):
     username: Mapped[str] = mapped_column(
         String(50),
@@ -23,13 +17,26 @@ class User(Base):
         nullable=False,
     )
 
-    role: Mapped[UserRole] = mapped_column(
-        SQLEnum(UserRole, name="user_role"),
-        default=UserRole.MEMBER,
+    is_admin: Mapped[bool] = mapped_column(
+        Boolean,
+        default=False,
         index=True,
         nullable=False,
     )
 
+    phone_number: Mapped[str | None] = mapped_column(
+        String(11),
+        unique=True,
+        index=True,
+        nullable=True,
+    )
+
+    token_version: Mapped[int] = mapped_column(
+        Integer,
+        default=1,
+        nullable=False,
+    )
+
     is_active: Mapped[bool] = mapped_column(
         Boolean,
         default=True,
diff --git a/Back/domains/users/schemas.py b/Back/domains/users/schemas.py
index 41e1fe7..ffdc732 100644
--- a/Back/domains/users/schemas.py
+++ b/Back/domains/users/schemas.py
@@ -1,15 +1,27 @@
 import uuid
 from pydantic import BaseModel
-from domains.users.models import UserRole
+from pydantic import BaseModel, Field, field_validator
+import re
 
 class UserCreate(BaseModel):
     username: str
-    role: UserRole
+    phone_number: str | None = Field(None, description="11 digit phone number")
+    is_admin: bool = False
+
+    @field_validator("phone_number")
+    @classmethod
+    def validate_phone_number(cls, v: str | None) -> str | None:
+        if v is None:
+            return v
+        if not re.match(r"^\d{11}$", v):
+            raise ValueError("Phone number must be exactly 11 digits")
+        return v
 
 class UserResponse(BaseModel):
     id: uuid.UUID
     username: str
-    role: str
+    phone_number: str | None
+    is_admin: bool
     is_active: bool
 
     class Config:
diff --git a/Back/domains/users/service.py b/Back/domains/users/service.py
index 042f2dc..4f5f00b 100644
--- a/Back/domains/users/service.py
+++ b/Back/domains/users/service.py
@@ -1,44 +1,6 @@
-import secrets
 from sqlalchemy.ext.asyncio import AsyncSession
-from core.security import hash_password
-from domains.users.models import User
-from domains.users.repo import create_user
-from core.config import settings
+from domains.users.repo import get_user_by_id
 
 
-def generate_user_secret():
-    # return secrets.token_urlsafe(settings.SECRET_PASS_LENGTH)
-    return "1234"
-
-async def create_user_by_admin(
-    db: AsyncSession,
-    username: str,
-    role: str
-):
-
-    secret = generate_user_secret()
-
-    user = User(
-        username=username,
-        role=role,
-        secret_hash=hash_password(secret)
-    )
-
-    await create_user(db, user)
-
-    return user, secret
-
 async def get_user(db: AsyncSession, user_id):
-    from domains.users.repo import get_user_by_id
-
-    return await get_user_by_id(db, user_id)
-
-async def reset_user_secret(db: AsyncSession, user: User):
-
-    new_secret = generate_user_secret()
-
-    user.secret_hash = hash_password(new_secret)
-
-    await db.commit()
-
-    return new_secret
\ No newline at end of file
+    return await get_user_by_id(db, user_id)
\ No newline at end of file