diff --git a/gsma_dataset_creation/argilla_cli.py b/gsma_dataset_creation/argilla_cli.py
index 99a3f23..d057caf 100644
--- a/gsma_dataset_creation/argilla_cli.py
+++ b/gsma_dataset_creation/argilla_cli.py
@@ -493,8 +493,8 @@ def delete_workspace(
 
 @app.command(name="add-user")
 def add_user(
-    username: str = typer.Option(..., "--username", "-u", help="Username for the new user"),
-    password: str = typer.Option(..., "--password", "-p", help="Password for the new user"),
+    username: str = typer.Option(..., "--username", "-u", help="Username for the user"),
+    password: str | None = typer.Option(None, "--password", "-p", help="Password for the user (optional for SSO users)"),
     workspaces: list[str] = typer.Option(
         ..., "--workspace", "-w", help="Workspace name(s) to add user to (can be specified multiple times)"
     ),
@@ -515,11 +515,12 @@ def add_user(
     logger_level: str = typer.Option("INFO", "--logger-level", help="Logging level"),
 ) -> None:
     """
-    Create a new user and add them to one or more workspaces.
+    Create a new user or update an existing user's role and workspaces.
 
     This command:
-    1. Creates a new user with specified credentials and role
-    2. Adds the user to all specified workspaces
+    1. If user doesn't exist: Creates a new user with specified credentials and role
+    2. If user exists: Updates their role (if different) and adds them to specified workspaces
+    3. Adds the user to all specified workspaces
 
     Available roles:
     - annotator: Can annotate datasets (default)
@@ -527,19 +528,25 @@ def add_user(
     - owner: Full administrative access
 
     Examples:
-        # Create user and add to single workspace
+        # Create user with password and add to single workspace
         uv run gsma argilla add-user -u john.doe -p mypassword123 -w mantis
 
+        # Create SSO user (no password needed)
+        uv run gsma argilla add-user -u john.doe -w mantis
+
         # Create user and add to multiple workspaces
         uv run gsma argilla add-user -u john.doe -p mypassword123 -w tsg -w fasg -w ng
 
         # Create admin user
         uv run gsma argilla add-user -u admin.user -p securepass -w mantis -r admin
+
+        # Update existing user's role to owner and add to new workspace
+        uv run gsma argilla add-user -u existing.user -w new-workspace -r owner
     """
     logger.remove()
     logger.add(lambda msg: typer.echo(msg, err=False), level=logger_level)
 
-    logger.info("👤 Creating user...")
+    logger.info("👤 Processing user...")
     logger.info(f"   Username: {username}")
     logger.info(f"   Workspaces: {', '.join(workspaces)}")
     logger.info(f"   Role: {role}")
@@ -580,7 +587,7 @@ def add_user(
             ws = client.workspaces(name=ws_name)
             if not ws:
                 logger.error(f"❌ Workspace '{ws_name}' not found")
-                logger.error("   All workspaces must exist before creating user")
+                logger.error("   All workspaces must exist before adding user")
                 raise typer.Exit(code=1)
             workspace_objs.append(ws)
 
@@ -588,34 +595,72 @@ def add_user(
 
         # Check if user already exists
         existing_user = client.users(username=username)
+
         if existing_user:
-            logger.error(f"❌ User '{username}' already exists")
-            logger.error("   Use 'add-to-workspace' command to add existing user to workspaces")
-            raise typer.Exit(code=1)
+            logger.info(f"ℹ️  User '{username}' already exists - updating role and workspaces")
+            user = existing_user
+
+            # Update role if different
+            current_role = str(user.role).replace("Role.", "")
+            if current_role != role:
+                logger.info(f"🔄 Updating role from '{current_role}' to '{role}'")
+                user.role = role
+                try:
+                    user.update()
+                    logger.info(f"✅ Updated user role to: {role}")
+                except AttributeError:
+                    # Try save() if update() doesn't exist
+                    try:
+                        user.save()
+                        logger.info(f"✅ Updated user role to: {role}")
+                    except AttributeError:
+                        logger.warning(f"⚠️  Could not update role - SDK method not available")
+            else:
+                logger.info(f"ℹ️  User already has role '{role}'")
 
-        # Create user
-        user = client.users.add(
-            rg.User(
-                username=username,
-                password=password,
-                first_name=first_name or username,
-                last_name=last_name or "",
-                role=role,
+            if password:
+                logger.warning(f"⚠️  Password parameter ignored for existing user '{username}'")
+                logger.warning(f"    Passwords can only be set during user creation")
+        else:
+            # Create new user
+            logger.info(f"📝 Creating new user: {username}")
+
+            # Password is required for new users (unless SSO is configured)
+            if not password:
+                logger.warning(f"⚠️  No password provided for new user")
+                logger.warning(f"    This will only work if SSO (e.g., Hugging Face) is enabled")
+                logger.warning(f"    Otherwise, user creation will fail")
+
+            user = client.users.add(
+                rg.User(
+                    username=username,
+                    password=password or "",  # Use empty string if no password
+                    first_name=first_name or username,
+                    last_name=last_name or "",
+                    role=role,
+                )
             )
-        )
-        logger.info(f"✅ Created user: {username}")
+            logger.info(f"✅ Created user: {username}")
 
         # Add user to all workspaces
         for ws in workspace_objs:
-            ws.add_user(user)
-            logger.info(f"✅ Added {username} to workspace {ws.name}")
+            # Check if user is already in workspace
+            existing_users = [u.username for u in ws.users]
+            if user.username in existing_users:
+                logger.info(f"ℹ️  {username} already in workspace {ws.name}")
+            else:
+                ws.add_user(user)
+                logger.info(f"✅ Added {username} to workspace {ws.name}")
 
-        logger.info(f"🎉 Successfully created user and added to {len(workspaces)} workspace(s)")
+        if existing_user:
+            logger.info(f"🎉 Successfully updated user and ensured membership in {len(workspaces)} workspace(s)")
+        else:
+            logger.info(f"🎉 Successfully created user and added to {len(workspaces)} workspace(s)")
 
     except typer.Exit:
         raise
     except Exception as e:
-        logger.error(f"❌ User creation failed: {e}")
+        logger.error(f"❌ User operation failed: {e}")
         raise typer.Exit(code=1) from e
 
 
@@ -860,8 +905,8 @@ def add_users(
 
 @app.command(name="list-users")
 def list_users(
-    workspace: str = typer.Option(
-        ..., "--workspace", "-w", help="Workspace name to list users for"
+    workspace: str | None = typer.Option(
+        None, "--workspace", "-w", help="Workspace name to list users for (if not provided, lists all users)"
     ),
     output_csv: Path = typer.Option(
         None, "--output-csv", "-o", help="Path to save CSV file with user credentials"
@@ -875,12 +920,16 @@ def list_users(
     logger_level: str = typer.Option("INFO", "--logger-level", help="Logging level"),
 ) -> None:
     """
-    List all users for a given workspace.
+    List users and their roles.
 
-    This command retrieves all users associated with a workspace and displays their usernames.
+    If --workspace is provided, lists users in that workspace with their roles.
+    If --workspace is not provided, lists ALL users in Argilla with their roles.
     Note: Passwords cannot be retrieved from Argilla as they are hashed.
 
     Examples:
+        # List all users with roles
+        uv run gsma argilla list-users
+
         # List users for TSG workspace
         uv run gsma argilla list-users -w tsg-wg -o data/tsg_users.csv
 
@@ -890,8 +939,12 @@ def list_users(
     logger.remove()
     logger.add(lambda msg: typer.echo(msg, err=False), level=logger_level)
 
-    logger.info("📋 Listing workspace users...")
-    logger.info(f"   Workspace: {workspace}")
+    if workspace:
+        logger.info("📋 Listing workspace users...")
+        logger.info(f"   Workspace: {workspace}")
+    else:
+        logger.info("📋 Listing all users...")
+
     logger.debug(f"Logger level set to: {logger_level}")
 
     # Import here to provide better error message if argilla not installed
@@ -916,44 +969,90 @@ def list_users(
         # Create client
         client = rg.Argilla(api_url=api_url, api_key=api_key)
 
-        # Get workspace
-        workspace_obj = client.workspaces(name=workspace)
-        if not workspace_obj:
-            logger.error(f"❌ Workspace '{workspace}' not found")
-            raise typer.Exit(code=1)
+        if workspace:
+            # Get workspace-specific users
+            workspace_obj = client.workspaces(name=workspace)
+            if not workspace_obj:
+                logger.error(f"❌ Workspace '{workspace}' not found")
+                raise typer.Exit(code=1)
 
-        logger.info(f"✅ Workspace '{workspace}' found")
+            logger.info(f"✅ Workspace '{workspace}' found")
 
-        # Get all users in the workspace
-        users_in_workspace = list(workspace_obj.users)
+            # Get all users in the workspace
+            users_list = list(workspace_obj.users)
 
-        if not users_in_workspace:
-            logger.warning(f"⚠️  No users found in workspace '{workspace}'")
-            logger.info("📄 No CSV file written (no users)")
-            raise typer.Exit(code=0)
+            if not users_list:
+                logger.warning(f"⚠️  No users found in workspace '{workspace}'")
+                logger.info("📄 No CSV file written (no users)")
+                raise typer.Exit(code=0)
 
-        logger.info(f"✅ Found {len(users_in_workspace)} users in workspace")
+            logger.info(f"✅ Found {len(users_list)} users in workspace")
 
-        # Collect usernames (passwords are hashed in Argilla and cannot be retrieved)
-        usernames = [user.username for user in users_in_workspace]
+            # Print to console in table format
+            print(f"\n👥 Users in workspace '{workspace}' ({len(users_list)} users)\n")
 
-        # Print to console in table format
-        print(f"\n👥 Users in workspace '{workspace}' ({len(usernames)} users)\n")
+        else:
+            # Get all users in Argilla
+            users_list = list(client.users)
+
+            if not users_list:
+                logger.warning("⚠️  No users found")
+                logger.info("📄 No CSV file written (no users)")
+                raise typer.Exit(code=0)
+
+            logger.info(f"✅ Found {len(users_list)} users")
+
+            # Print to console in table format
+            print(f"\n👥 All users ({len(users_list)} users)\n")
+
+        # Prepare data with role information
+        user_data = []
+        for user in users_list:
+            role_str = str(user.role).replace("Role.", "")
+            user_data.append({
+                "username": user.username,
+                "role": role_str,
+            })
+
+        # Sort by role (owner, admin, annotator) then by username
+        role_order = {"owner": 0, "admin": 1, "annotator": 2}
+        user_data_sorted = sorted(
+            user_data,
+            key=lambda u: (role_order.get(u["role"], 999), u["username"])
+        )
 
         try:
             from tabulate import tabulate
 
             # Prepare data for table
-            table_data = [[i+1, username] for i, username in enumerate(usernames)]
-            print(tabulate(table_data, headers=["#", "Username"], tablefmt="simple_grid"))
+            table_data = [
+                [i+1, u["username"], u["role"]]
+                for i, u in enumerate(user_data_sorted)
+            ]
+            print(tabulate(
+                table_data,
+                headers=["#", "Username", "Role"],
+                tablefmt="simple_grid"
+            ))
             print()
 
         except ImportError:
             # Fallback to simple format
-            for i, username in enumerate(usernames, 1):
-                print(f"  {i}. {username}")
+            for i, u in enumerate(user_data_sorted, 1):
+                print(f"  {i}. {u['username']:<30} {u['role']:<15}")
             print()
 
+        # Print summary by role
+        role_counts = {}
+        for u in user_data:
+            role_counts[u["role"]] = role_counts.get(u["role"], 0) + 1
+
+        print("📊 Summary by role:")
+        for role in ["owner", "admin", "annotator"]:
+            if role in role_counts:
+                print(f"  {role}: {role_counts[role]}")
+        print()
+
         # Write CSV output if requested
         if output_csv:
             output_csv = Path(output_csv)
@@ -961,12 +1060,12 @@ def list_users(
 
             with open(output_csv, "w", newline="") as f:
                 writer = csv.writer(f)
-                writer.writerow(["username"])
-                for username in usernames:
-                    writer.writerow([username])
+                writer.writerow(["username", "role"])
+                for u in user_data_sorted:
+                    writer.writerow([u["username"], u["role"]])
 
-            logger.info(f"✅ Successfully exported {len(usernames)} usernames")
-            logger.info(f"📄 Usernames saved to: {output_csv}")
+            logger.info(f"✅ Successfully exported {len(user_data)} users")
+            logger.info(f"📄 Users saved to: {output_csv}")
 
         logger.info(f"ℹ️  Note: Passwords are only available during user creation (add-users command)")
         logger.info(f"ℹ️  Save the CSV when creating users to share passwords with annotators")