Add user management system with JWT authentication

- Database schema: users, permissions, client_access tables
- Auth: JWT tokens with Argon2 password hashing
- API: login, user CRUD, permission management
- Dashboard: login required, admin Users tab
- Auto-creates initial admin user on first run

server/migrations/002_user_management.sql

@@ -0,0 +1,44 @@
+-- GuruConnect User Management Schema
+-- User authentication, roles, and per-client access control
+
+-- Users table
+CREATE TABLE users (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    username VARCHAR(64) UNIQUE NOT NULL,
+    password_hash VARCHAR(255) NOT NULL,
+    email VARCHAR(255),
+    role VARCHAR(32) NOT NULL DEFAULT 'viewer',
+    enabled BOOLEAN NOT NULL DEFAULT true,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    last_login TIMESTAMPTZ
+);
+
+-- Granular permissions (what actions a user can perform)
+CREATE TABLE user_permissions (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    permission VARCHAR(64) NOT NULL,
+    UNIQUE(user_id, permission)
+);
+
+-- Per-client access (which machines a user can access)
+-- No entries = access to all clients (for admins)
+CREATE TABLE user_client_access (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    client_id UUID NOT NULL REFERENCES connect_machines(id) ON DELETE CASCADE,
+    UNIQUE(user_id, client_id)
+);
+
+-- Indexes
+CREATE INDEX idx_users_username ON users(username);
+CREATE INDEX idx_users_enabled ON users(enabled);
+CREATE INDEX idx_user_permissions_user ON user_permissions(user_id);
+CREATE INDEX idx_user_client_access_user ON user_client_access(user_id);
+
+-- Trigger for updated_at
+CREATE TRIGGER update_users_updated_at
+    BEFORE UPDATE ON users
+    FOR EACH ROW
+    EXECUTE FUNCTION update_connect_updated_at();

server/src/api/auth.rs

@@ -0,0 +1,317 @@
+//! Authentication API endpoints
+
+use axum::{
+    extract::State,
+    http::StatusCode,
+    Json,
+};
+use serde::{Deserialize, Serialize};
+
+use crate::auth::{
+    verify_password, AuthenticatedUser, JwtConfig,
+};
+use crate::db;
+use crate::AppState;
+
+/// Login request
+#[derive(Debug, Deserialize)]
+pub struct LoginRequest {
+    pub username: String,
+    pub password: String,
+}
+
+/// Login response
+#[derive(Debug, Serialize)]
+pub struct LoginResponse {
+    pub token: String,
+    pub user: UserResponse,
+}
+
+/// User info in response
+#[derive(Debug, Serialize)]
+pub struct UserResponse {
+    pub id: String,
+    pub username: String,
+    pub email: Option<String>,
+    pub role: String,
+    pub permissions: Vec<String>,
+}
+
+/// Error response
+#[derive(Debug, Serialize)]
+pub struct ErrorResponse {
+    pub error: String,
+}
+
+/// POST /api/auth/login
+pub async fn login(
+    State(state): State<AppState>,
+    Json(request): Json<LoginRequest>,
+) -> Result<Json<LoginResponse>, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    // Get user by username
+    let user = db::get_user_by_username(db.pool(), &request.username)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error during login: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Internal server error".to_string(),
+                }),
+            )
+        })?
+        .ok_or_else(|| {
+            (
+                StatusCode::UNAUTHORIZED,
+                Json(ErrorResponse {
+                    error: "Invalid username or password".to_string(),
+                }),
+            )
+        })?;
+
+    // Check if user is enabled
+    if !user.enabled {
+        return Err((
+            StatusCode::UNAUTHORIZED,
+            Json(ErrorResponse {
+                error: "Account is disabled".to_string(),
+            }),
+        ));
+    }
+
+    // Verify password
+    let password_valid = verify_password(&request.password, &user.password_hash)
+        .map_err(|e| {
+            tracing::error!("Password verification error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Internal server error".to_string(),
+                }),
+            )
+        })?;
+
+    if !password_valid {
+        return Err((
+            StatusCode::UNAUTHORIZED,
+            Json(ErrorResponse {
+                error: "Invalid username or password".to_string(),
+            }),
+        ));
+    }
+
+    // Get user permissions
+    let permissions = db::get_user_permissions(db.pool(), user.id)
+        .await
+        .unwrap_or_default();
+
+    // Update last login
+    let _ = db::update_last_login(db.pool(), user.id).await;
+
+    // Create JWT token
+    let token = state.jwt_config.create_token(
+        user.id,
+        &user.username,
+        &user.role,
+        permissions.clone(),
+    )
+    .map_err(|e| {
+        tracing::error!("Token creation error: {}", e);
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            Json(ErrorResponse {
+                error: "Failed to create token".to_string(),
+            }),
+        )
+    })?;
+
+    tracing::info!("User {} logged in successfully", user.username);
+
+    Ok(Json(LoginResponse {
+        token,
+        user: UserResponse {
+            id: user.id.to_string(),
+            username: user.username,
+            email: user.email,
+            role: user.role,
+            permissions,
+        },
+    }))
+}
+
+/// GET /api/auth/me - Get current user info
+pub async fn get_me(
+    State(state): State<AppState>,
+    user: AuthenticatedUser,
+) -> Result<Json<UserResponse>, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = uuid::Uuid::parse_str(&user.user_id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    let db_user = db::get_user_by_id(db.pool(), user_id)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Internal server error".to_string(),
+                }),
+            )
+        })?
+        .ok_or_else(|| {
+            (
+                StatusCode::NOT_FOUND,
+                Json(ErrorResponse {
+                    error: "User not found".to_string(),
+                }),
+            )
+        })?;
+
+    let permissions = db::get_user_permissions(db.pool(), db_user.id)
+        .await
+        .unwrap_or_default();
+
+    Ok(Json(UserResponse {
+        id: db_user.id.to_string(),
+        username: db_user.username,
+        email: db_user.email,
+        role: db_user.role,
+        permissions,
+    }))
+}
+
+/// Change password request
+#[derive(Debug, Deserialize)]
+pub struct ChangePasswordRequest {
+    pub current_password: String,
+    pub new_password: String,
+}
+
+/// POST /api/auth/change-password
+pub async fn change_password(
+    State(state): State<AppState>,
+    user: AuthenticatedUser,
+    Json(request): Json<ChangePasswordRequest>,
+) -> Result<StatusCode, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = uuid::Uuid::parse_str(&user.user_id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    // Get current user
+    let db_user = db::get_user_by_id(db.pool(), user_id)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Internal server error".to_string(),
+                }),
+            )
+        })?
+        .ok_or_else(|| {
+            (
+                StatusCode::NOT_FOUND,
+                Json(ErrorResponse {
+                    error: "User not found".to_string(),
+                }),
+            )
+        })?;
+
+    // Verify current password
+    let password_valid = verify_password(&request.current_password, &db_user.password_hash)
+        .map_err(|e| {
+            tracing::error!("Password verification error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Internal server error".to_string(),
+                }),
+            )
+        })?;
+
+    if !password_valid {
+        return Err((
+            StatusCode::UNAUTHORIZED,
+            Json(ErrorResponse {
+                error: "Current password is incorrect".to_string(),
+            }),
+        ));
+    }
+
+    // Validate new password
+    if request.new_password.len() < 8 {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Password must be at least 8 characters".to_string(),
+            }),
+        ));
+    }
+
+    // Hash new password
+    let new_hash = crate::auth::hash_password(&request.new_password)
+        .map_err(|e| {
+            tracing::error!("Password hashing error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to hash password".to_string(),
+                }),
+            )
+        })?;
+
+    // Update password
+    db::update_user_password(db.pool(), user_id, &new_hash)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to update password".to_string(),
+                }),
+            )
+        })?;
+
+    tracing::info!("User {} changed their password", user.username);
+    Ok(StatusCode::OK)
+}

server/src/api/mod.rs

@@ -1,5 +1,8 @@
 //! REST API endpoints
 
+pub mod auth;
+pub mod users;
+
 use axum::{
     extract::{Path, State, Query},
     Json,

server/src/api/users.rs

@@ -0,0 +1,592 @@
+//! User management API endpoints (admin only)
+
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    Json,
+};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::auth::{hash_password, AdminUser};
+use crate::db;
+use crate::AppState;
+
+use super::auth::ErrorResponse;
+
+/// User info response
+#[derive(Debug, Serialize)]
+pub struct UserInfo {
+    pub id: String,
+    pub username: String,
+    pub email: Option<String>,
+    pub role: String,
+    pub enabled: bool,
+    pub created_at: String,
+    pub last_login: Option<String>,
+    pub permissions: Vec<String>,
+}
+
+/// Create user request
+#[derive(Debug, Deserialize)]
+pub struct CreateUserRequest {
+    pub username: String,
+    pub password: String,
+    pub email: Option<String>,
+    pub role: String,
+    pub permissions: Option<Vec<String>>,
+}
+
+/// Update user request
+#[derive(Debug, Deserialize)]
+pub struct UpdateUserRequest {
+    pub email: Option<String>,
+    pub role: String,
+    pub enabled: bool,
+    pub password: Option<String>,
+}
+
+/// Set permissions request
+#[derive(Debug, Deserialize)]
+pub struct SetPermissionsRequest {
+    pub permissions: Vec<String>,
+}
+
+/// Set client access request
+#[derive(Debug, Deserialize)]
+pub struct SetClientAccessRequest {
+    pub client_ids: Vec<String>,
+}
+
+/// GET /api/users - List all users
+pub async fn list_users(
+    State(state): State<AppState>,
+    _admin: AdminUser,
+) -> Result<Json<Vec<UserInfo>>, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let users = db::get_all_users(db.pool())
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to fetch users".to_string(),
+                }),
+            )
+        })?;
+
+    let mut result = Vec::new();
+    for user in users {
+        let permissions = db::get_user_permissions(db.pool(), user.id)
+            .await
+            .unwrap_or_default();
+
+        result.push(UserInfo {
+            id: user.id.to_string(),
+            username: user.username,
+            email: user.email,
+            role: user.role,
+            enabled: user.enabled,
+            created_at: user.created_at.to_rfc3339(),
+            last_login: user.last_login.map(|t| t.to_rfc3339()),
+            permissions,
+        });
+    }
+
+    Ok(Json(result))
+}
+
+/// POST /api/users - Create new user
+pub async fn create_user(
+    State(state): State<AppState>,
+    _admin: AdminUser,
+    Json(request): Json<CreateUserRequest>,
+) -> Result<Json<UserInfo>, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    // Validate role
+    let valid_roles = ["admin", "operator", "viewer"];
+    if !valid_roles.contains(&request.role.as_str()) {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: format!("Invalid role. Must be one of: {:?}", valid_roles),
+            }),
+        ));
+    }
+
+    // Validate password
+    if request.password.len() < 8 {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Password must be at least 8 characters".to_string(),
+            }),
+        ));
+    }
+
+    // Check if username exists
+    if db::get_user_by_username(db.pool(), &request.username)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Database error".to_string(),
+                }),
+            )
+        })?
+        .is_some()
+    {
+        return Err((
+            StatusCode::CONFLICT,
+            Json(ErrorResponse {
+                error: "Username already exists".to_string(),
+            }),
+        ));
+    }
+
+    // Hash password
+    let password_hash = hash_password(&request.password).map_err(|e| {
+        tracing::error!("Password hashing error: {}", e);
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            Json(ErrorResponse {
+                error: "Failed to hash password".to_string(),
+            }),
+        )
+    })?;
+
+    // Create user
+    let user = db::create_user(
+        db.pool(),
+        &request.username,
+        &password_hash,
+        request.email.as_deref(),
+        &request.role,
+    )
+    .await
+    .map_err(|e| {
+        tracing::error!("Failed to create user: {}", e);
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            Json(ErrorResponse {
+                error: "Failed to create user".to_string(),
+            }),
+        )
+    })?;
+
+    // Set initial permissions if provided
+    let permissions = if let Some(perms) = request.permissions {
+        db::set_user_permissions(db.pool(), user.id, &perms)
+            .await
+            .map_err(|e| {
+                tracing::error!("Failed to set permissions: {}", e);
+                (
+                    StatusCode::INTERNAL_SERVER_ERROR,
+                    Json(ErrorResponse {
+                        error: "Failed to set permissions".to_string(),
+                    }),
+                )
+            })?;
+        perms
+    } else {
+        // Default permissions based on role
+        let default_perms = match request.role.as_str() {
+            "admin" => vec!["view", "control", "transfer", "manage_users", "manage_clients"],
+            "operator" => vec!["view", "control", "transfer"],
+            "viewer" => vec!["view"],
+            _ => vec!["view"],
+        };
+        let perms: Vec<String> = default_perms.into_iter().map(String::from).collect();
+        db::set_user_permissions(db.pool(), user.id, &perms)
+            .await
+            .ok();
+        perms
+    };
+
+    tracing::info!("Created user: {} ({})", user.username, user.role);
+
+    Ok(Json(UserInfo {
+        id: user.id.to_string(),
+        username: user.username,
+        email: user.email,
+        role: user.role,
+        enabled: user.enabled,
+        created_at: user.created_at.to_rfc3339(),
+        last_login: None,
+        permissions,
+    }))
+}
+
+/// GET /api/users/:id - Get user details
+pub async fn get_user(
+    State(state): State<AppState>,
+    _admin: AdminUser,
+    Path(id): Path<String>,
+) -> Result<Json<UserInfo>, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = Uuid::parse_str(&id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    let user = db::get_user_by_id(db.pool(), user_id)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Database error".to_string(),
+                }),
+            )
+        })?
+        .ok_or_else(|| {
+            (
+                StatusCode::NOT_FOUND,
+                Json(ErrorResponse {
+                    error: "User not found".to_string(),
+                }),
+            )
+        })?;
+
+    let permissions = db::get_user_permissions(db.pool(), user.id)
+        .await
+        .unwrap_or_default();
+
+    Ok(Json(UserInfo {
+        id: user.id.to_string(),
+        username: user.username,
+        email: user.email,
+        role: user.role,
+        enabled: user.enabled,
+        created_at: user.created_at.to_rfc3339(),
+        last_login: user.last_login.map(|t| t.to_rfc3339()),
+        permissions,
+    }))
+}
+
+/// PUT /api/users/:id - Update user
+pub async fn update_user(
+    State(state): State<AppState>,
+    admin: AdminUser,
+    Path(id): Path<String>,
+    Json(request): Json<UpdateUserRequest>,
+) -> Result<Json<UserInfo>, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = Uuid::parse_str(&id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    // Prevent admin from disabling themselves
+    if user_id.to_string() == admin.0.user_id && !request.enabled {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Cannot disable your own account".to_string(),
+            }),
+        ));
+    }
+
+    // Validate role
+    let valid_roles = ["admin", "operator", "viewer"];
+    if !valid_roles.contains(&request.role.as_str()) {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: format!("Invalid role. Must be one of: {:?}", valid_roles),
+            }),
+        ));
+    }
+
+    // Update user
+    let user = db::update_user(
+        db.pool(),
+        user_id,
+        request.email.as_deref(),
+        &request.role,
+        request.enabled,
+    )
+    .await
+    .map_err(|e| {
+        tracing::error!("Database error: {}", e);
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            Json(ErrorResponse {
+                error: "Failed to update user".to_string(),
+            }),
+        )
+    })?
+    .ok_or_else(|| {
+        (
+            StatusCode::NOT_FOUND,
+            Json(ErrorResponse {
+                error: "User not found".to_string(),
+            }),
+        )
+    })?;
+
+    // Update password if provided
+    if let Some(password) = request.password {
+        if password.len() < 8 {
+            return Err((
+                StatusCode::BAD_REQUEST,
+                Json(ErrorResponse {
+                    error: "Password must be at least 8 characters".to_string(),
+                }),
+            ));
+        }
+
+        let password_hash = hash_password(&password).map_err(|e| {
+            tracing::error!("Password hashing error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to hash password".to_string(),
+                }),
+            )
+        })?;
+
+        db::update_user_password(db.pool(), user_id, &password_hash)
+            .await
+            .map_err(|e| {
+                tracing::error!("Database error: {}", e);
+                (
+                    StatusCode::INTERNAL_SERVER_ERROR,
+                    Json(ErrorResponse {
+                        error: "Failed to update password".to_string(),
+                    }),
+                )
+            })?;
+    }
+
+    let permissions = db::get_user_permissions(db.pool(), user.id)
+        .await
+        .unwrap_or_default();
+
+    tracing::info!("Updated user: {}", user.username);
+
+    Ok(Json(UserInfo {
+        id: user.id.to_string(),
+        username: user.username,
+        email: user.email,
+        role: user.role,
+        enabled: user.enabled,
+        created_at: user.created_at.to_rfc3339(),
+        last_login: user.last_login.map(|t| t.to_rfc3339()),
+        permissions,
+    }))
+}
+
+/// DELETE /api/users/:id - Delete user
+pub async fn delete_user(
+    State(state): State<AppState>,
+    admin: AdminUser,
+    Path(id): Path<String>,
+) -> Result<StatusCode, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = Uuid::parse_str(&id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    // Prevent admin from deleting themselves
+    if user_id.to_string() == admin.0.user_id {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Cannot delete your own account".to_string(),
+            }),
+        ));
+    }
+
+    let deleted = db::delete_user(db.pool(), user_id)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to delete user".to_string(),
+                }),
+            )
+        })?;
+
+    if deleted {
+        tracing::info!("Deleted user: {}", id);
+        Ok(StatusCode::NO_CONTENT)
+    } else {
+        Err((
+            StatusCode::NOT_FOUND,
+            Json(ErrorResponse {
+                error: "User not found".to_string(),
+            }),
+        ))
+    }
+}
+
+/// PUT /api/users/:id/permissions - Set user permissions
+pub async fn set_permissions(
+    State(state): State<AppState>,
+    _admin: AdminUser,
+    Path(id): Path<String>,
+    Json(request): Json<SetPermissionsRequest>,
+) -> Result<StatusCode, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = Uuid::parse_str(&id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    // Validate permissions
+    let valid_permissions = ["view", "control", "transfer", "manage_users", "manage_clients"];
+    for perm in &request.permissions {
+        if !valid_permissions.contains(&perm.as_str()) {
+            return Err((
+                StatusCode::BAD_REQUEST,
+                Json(ErrorResponse {
+                    error: format!("Invalid permission: {}. Valid: {:?}", perm, valid_permissions),
+                }),
+            ));
+        }
+    }
+
+    db::set_user_permissions(db.pool(), user_id, &request.permissions)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to set permissions".to_string(),
+                }),
+            )
+        })?;
+
+    tracing::info!("Updated permissions for user: {}", id);
+    Ok(StatusCode::OK)
+}
+
+/// PUT /api/users/:id/clients - Set user client access
+pub async fn set_client_access(
+    State(state): State<AppState>,
+    _admin: AdminUser,
+    Path(id): Path<String>,
+    Json(request): Json<SetClientAccessRequest>,
+) -> Result<StatusCode, (StatusCode, Json<ErrorResponse>)> {
+    let db = state.db.as_ref().ok_or_else(|| {
+        (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ErrorResponse {
+                error: "Database not available".to_string(),
+            }),
+        )
+    })?;
+
+    let user_id = Uuid::parse_str(&id).map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid user ID".to_string(),
+            }),
+        )
+    })?;
+
+    // Parse client IDs
+    let client_ids: Result<Vec<Uuid>, _> = request
+        .client_ids
+        .iter()
+        .map(|s| Uuid::parse_str(s))
+        .collect();
+
+    let client_ids = client_ids.map_err(|_| {
+        (
+            StatusCode::BAD_REQUEST,
+            Json(ErrorResponse {
+                error: "Invalid client ID format".to_string(),
+            }),
+        )
+    })?;
+
+    db::set_user_client_access(db.pool(), user_id, &client_ids)
+        .await
+        .map_err(|e| {
+            tracing::error!("Database error: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ErrorResponse {
+                    error: "Failed to set client access".to_string(),
+                }),
+            )
+        })?;
+
+    tracing::info!("Updated client access for user: {}", id);
+    Ok(StatusCode::OK)
+}

server/src/auth/jwt.rs

@@ -0,0 +1,140 @@
+//! JWT token handling
+
+use anyhow::{anyhow, Result};
+use chrono::{Duration, Utc};
+use jsonwebtoken::{decode, encode, DecodingKey, EncodingKey, Header, Validation};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+/// JWT claims
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct Claims {
+    /// Subject (user ID)
+    pub sub: String,
+    /// Username
+    pub username: String,
+    /// Role (admin, operator, viewer)
+    pub role: String,
+    /// Permissions list
+    pub permissions: Vec<String>,
+    /// Expiration time (unix timestamp)
+    pub exp: i64,
+    /// Issued at (unix timestamp)
+    pub iat: i64,
+}
+
+impl Claims {
+    /// Check if user has a specific permission
+    pub fn has_permission(&self, permission: &str) -> bool {
+        // Admins have all permissions
+        if self.role == "admin" {
+            return true;
+        }
+        self.permissions.contains(&permission.to_string())
+    }
+
+    /// Check if user is admin
+    pub fn is_admin(&self) -> bool {
+        self.role == "admin"
+    }
+
+    /// Get user ID as UUID
+    pub fn user_id(&self) -> Result<Uuid> {
+        Uuid::parse_str(&self.sub).map_err(|e| anyhow!("Invalid user ID in token: {}", e))
+    }
+}
+
+/// JWT configuration
+#[derive(Clone)]
+pub struct JwtConfig {
+    secret: String,
+    expiry_hours: i64,
+}
+
+impl JwtConfig {
+    /// Create new JWT config
+    pub fn new(secret: String, expiry_hours: i64) -> Self {
+        Self { secret, expiry_hours }
+    }
+
+    /// Create a JWT token for a user
+    pub fn create_token(
+        &self,
+        user_id: Uuid,
+        username: &str,
+        role: &str,
+        permissions: Vec<String>,
+    ) -> Result<String> {
+        let now = Utc::now();
+        let exp = now + Duration::hours(self.expiry_hours);
+
+        let claims = Claims {
+            sub: user_id.to_string(),
+            username: username.to_string(),
+            role: role.to_string(),
+            permissions,
+            exp: exp.timestamp(),
+            iat: now.timestamp(),
+        };
+
+        let token = encode(
+            &Header::default(),
+            &claims,
+            &EncodingKey::from_secret(self.secret.as_bytes()),
+        )
+        .map_err(|e| anyhow!("Failed to create token: {}", e))?;
+
+        Ok(token)
+    }
+
+    /// Validate and decode a JWT token
+    pub fn validate_token(&self, token: &str) -> Result<Claims> {
+        let token_data = decode::<Claims>(
+            token,
+            &DecodingKey::from_secret(self.secret.as_bytes()),
+            &Validation::default(),
+        )
+        .map_err(|e| anyhow!("Invalid token: {}", e))?;
+
+        Ok(token_data.claims)
+    }
+}
+
+/// Default JWT secret if not configured (NOT for production!)
+pub fn default_jwt_secret() -> String {
+    // In production, this should come from environment variable
+    std::env::var("JWT_SECRET").unwrap_or_else(|_| {
+        tracing::warn!("JWT_SECRET not set, using default (INSECURE!)");
+        "guruconnect-dev-secret-change-me-in-production".to_string()
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_create_and_validate_token() {
+        let config = JwtConfig::new("test-secret".to_string(), 24);
+        let user_id = Uuid::new_v4();
+
+        let token = config.create_token(
+            user_id,
+            "testuser",
+            "admin",
+            vec!["view".to_string(), "control".to_string()],
+        ).unwrap();
+
+        let claims = config.validate_token(&token).unwrap();
+        assert_eq!(claims.username, "testuser");
+        assert_eq!(claims.role, "admin");
+        assert!(claims.has_permission("view"));
+        assert!(claims.has_permission("manage_users")); // admin has all
+    }
+
+    #[test]
+    fn test_invalid_token() {
+        let config = JwtConfig::new("test-secret".to_string(), 24);
+        assert!(config.validate_token("invalid.token.here").is_err());
+    }
+}

server/src/auth/mod.rs

@@ -3,17 +3,51 @@
 //! Handles JWT validation for dashboard users and API key
 //! validation for agents.
 
+pub mod jwt;
+pub mod password;
+
+pub use jwt::{Claims, JwtConfig};
+pub use password::{hash_password, verify_password, generate_random_password};
+
 use axum::{
     extract::FromRequestParts,
     http::{request::Parts, StatusCode},
 };
+use std::sync::Arc;
 
 /// Authenticated user from JWT
 #[derive(Debug, Clone)]
 pub struct AuthenticatedUser {
     pub user_id: String,
-    pub email: String,
-    pub roles: Vec<String>,
+    pub username: String,
+    pub role: String,
+    pub permissions: Vec<String>,
+}
+
+impl AuthenticatedUser {
+    /// Check if user has a specific permission
+    pub fn has_permission(&self, permission: &str) -> bool {
+        if self.role == "admin" {
+            return true;
+        }
+        self.permissions.contains(&permission.to_string())
+    }
+
+    /// Check if user is admin
+    pub fn is_admin(&self) -> bool {
+        self.role == "admin"
+    }
+}
+
+impl From<Claims> for AuthenticatedUser {
+    fn from(claims: Claims) -> Self {
+        Self {
+            user_id: claims.sub,
+            username: claims.username,
+            role: claims.role,
+            permissions: claims.permissions,
+        }
+    }
 }
 
 /// Authenticated agent from API key
@@ -23,7 +57,21 @@ pub struct AuthenticatedAgent {
     pub org_id: String,
 }
 
-/// Extract authenticated user from request (placeholder for MVP)
+/// JWT configuration stored in app state
+#[derive(Clone)]
+pub struct AuthState {
+    pub jwt_config: Arc<JwtConfig>,
+}
+
+impl AuthState {
+    pub fn new(jwt_secret: String, expiry_hours: i64) -> Self {
+        Self {
+            jwt_config: Arc::new(JwtConfig::new(jwt_secret, expiry_hours)),
+        }
+    }
+}
+
+/// Extract authenticated user from request
 #[axum::async_trait]
 impl<S> FromRequestParts<S> for AuthenticatedUser
 where
@@ -32,28 +80,77 @@ where
     type Rejection = (StatusCode, &'static str);
 
     async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
-        // TODO: Implement JWT validation
-        // For MVP, accept any request
-
-        // Look for Authorization header
-        let _auth_header = parts
+        // Get Authorization header
+        let auth_header = parts
             .headers
             .get("Authorization")
-            .and_then(|v| v.to_str().ok());
+            .and_then(|v| v.to_str().ok())
+            .ok_or((StatusCode::UNAUTHORIZED, "Missing Authorization header"))?;
 
-        // Placeholder - in production, validate JWT
-        Ok(AuthenticatedUser {
-            user_id: "mvp-user".to_string(),
-            email: "mvp@example.com".to_string(),
-            roles: vec!["admin".to_string()],
-        })
+        // Extract Bearer token
+        let token = auth_header
+            .strip_prefix("Bearer ")
+            .ok_or((StatusCode::UNAUTHORIZED, "Invalid Authorization format"))?;
+
+        // Get JWT config from extensions (set by middleware)
+        let jwt_config = parts
+            .extensions
+            .get::<Arc<JwtConfig>>()
+            .ok_or((StatusCode::INTERNAL_SERVER_ERROR, "Auth not configured"))?;
+
+        // Validate token
+        let claims = jwt_config
+            .validate_token(token)
+            .map_err(|_| (StatusCode::UNAUTHORIZED, "Invalid or expired token"))?;
+
+        Ok(AuthenticatedUser::from(claims))
+    }
+}
+
+/// Optional authenticated user (doesn't reject if not authenticated)
+#[derive(Debug, Clone)]
+pub struct OptionalUser(pub Option<AuthenticatedUser>);
+
+#[axum::async_trait]
+impl<S> FromRequestParts<S> for OptionalUser
+where
+    S: Send + Sync,
+{
+    type Rejection = (StatusCode, &'static str);
+
+    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
+        match AuthenticatedUser::from_request_parts(parts, state).await {
+            Ok(user) => Ok(OptionalUser(Some(user))),
+            Err(_) => Ok(OptionalUser(None)),
+        }
+    }
+}
+
+/// Require admin role
+#[derive(Debug, Clone)]
+pub struct AdminUser(pub AuthenticatedUser);
+
+#[axum::async_trait]
+impl<S> FromRequestParts<S> for AdminUser
+where
+    S: Send + Sync,
+{
+    type Rejection = (StatusCode, &'static str);
+
+    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
+        let user = AuthenticatedUser::from_request_parts(parts, state).await?;
+        if user.is_admin() {
+            Ok(AdminUser(user))
+        } else {
+            Err((StatusCode::FORBIDDEN, "Admin access required"))
+        }
     }
 }
 
 /// Validate an agent API key (placeholder for MVP)
 pub fn validate_agent_key(_api_key: &str) -> Option<AuthenticatedAgent> {
-    // TODO: Implement actual API key validation
-    // For MVP, accept any key
+    // TODO: Implement actual API key validation against database
+    // For now, accept any key for agent connections
     Some(AuthenticatedAgent {
         agent_id: "mvp-agent".to_string(),
         org_id: "mvp-org".to_string(),

server/src/auth/password.rs

@@ -0,0 +1,57 @@
+//! Password hashing using Argon2id
+
+use anyhow::{anyhow, Result};
+use argon2::{
+    password_hash::{rand_core::OsRng, PasswordHash, PasswordHasher, PasswordVerifier, SaltString},
+    Argon2,
+};
+
+/// Hash a password using Argon2id
+pub fn hash_password(password: &str) -> Result<String> {
+    let salt = SaltString::generate(&mut OsRng);
+    let argon2 = Argon2::default();
+    let hash = argon2
+        .hash_password(password.as_bytes(), &salt)
+        .map_err(|e| anyhow!("Failed to hash password: {}", e))?;
+    Ok(hash.to_string())
+}
+
+/// Verify a password against a stored hash
+pub fn verify_password(password: &str, hash: &str) -> Result<bool> {
+    let parsed_hash = PasswordHash::new(hash)
+        .map_err(|e| anyhow!("Invalid password hash format: {}", e))?;
+    let argon2 = Argon2::default();
+    Ok(argon2.verify_password(password.as_bytes(), &parsed_hash).is_ok())
+}
+
+/// Generate a random password (for initial admin)
+pub fn generate_random_password(length: usize) -> String {
+    use rand::Rng;
+    const CHARSET: &[u8] = b"ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz23456789!@#$%";
+    let mut rng = rand::thread_rng();
+    (0..length)
+        .map(|_| {
+            let idx = rng.gen_range(0..CHARSET.len());
+            CHARSET[idx] as char
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_hash_and_verify() {
+        let password = "test_password_123";
+        let hash = hash_password(password).unwrap();
+        assert!(verify_password(password, &hash).unwrap());
+        assert!(!verify_password("wrong_password", &hash).unwrap());
+    }
+
+    #[test]
+    fn test_random_password() {
+        let password = generate_random_password(16);
+        assert_eq!(password.len(), 16);
+    }
+}

server/src/db/mod.rs

@@ -7,6 +7,7 @@ pub mod machines;
 pub mod sessions;
 pub mod events;
 pub mod support_codes;
+pub mod users;
 
 use anyhow::Result;
 use sqlx::postgres::PgPoolOptions;
@@ -17,6 +18,7 @@ pub use machines::*;
 pub use sessions::*;
 pub use events::*;
 pub use support_codes::*;
+pub use users::*;
 
 /// Database connection pool wrapper
 #[derive(Clone)]

server/src/db/users.rs

@@ -0,0 +1,283 @@
+//! User database operations
+
+use anyhow::Result;
+use chrono::{DateTime, Utc};
+use sqlx::PgPool;
+use uuid::Uuid;
+
+/// User record from database
+#[derive(Debug, Clone, sqlx::FromRow)]
+pub struct User {
+    pub id: Uuid,
+    pub username: String,
+    pub password_hash: String,
+    pub email: Option<String>,
+    pub role: String,
+    pub enabled: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    pub last_login: Option<DateTime<Utc>>,
+}
+
+/// User without password hash (for API responses)
+#[derive(Debug, Clone, serde::Serialize)]
+pub struct UserInfo {
+    pub id: Uuid,
+    pub username: String,
+    pub email: Option<String>,
+    pub role: String,
+    pub enabled: bool,
+    pub created_at: DateTime<Utc>,
+    pub last_login: Option<DateTime<Utc>>,
+    pub permissions: Vec<String>,
+}
+
+impl From<User> for UserInfo {
+    fn from(u: User) -> Self {
+        Self {
+            id: u.id,
+            username: u.username,
+            email: u.email,
+            role: u.role,
+            enabled: u.enabled,
+            created_at: u.created_at,
+            last_login: u.last_login,
+            permissions: Vec::new(), // Filled in by caller
+        }
+    }
+}
+
+/// Get user by username
+pub async fn get_user_by_username(pool: &PgPool, username: &str) -> Result<Option<User>> {
+    let user = sqlx::query_as::<_, User>(
+        "SELECT * FROM users WHERE username = $1"
+    )
+    .bind(username)
+    .fetch_optional(pool)
+    .await?;
+    Ok(user)
+}
+
+/// Get user by ID
+pub async fn get_user_by_id(pool: &PgPool, id: Uuid) -> Result<Option<User>> {
+    let user = sqlx::query_as::<_, User>(
+        "SELECT * FROM users WHERE id = $1"
+    )
+    .bind(id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(user)
+}
+
+/// Get all users
+pub async fn get_all_users(pool: &PgPool) -> Result<Vec<User>> {
+    let users = sqlx::query_as::<_, User>(
+        "SELECT * FROM users ORDER BY username"
+    )
+    .fetch_all(pool)
+    .await?;
+    Ok(users)
+}
+
+/// Create a new user
+pub async fn create_user(
+    pool: &PgPool,
+    username: &str,
+    password_hash: &str,
+    email: Option<&str>,
+    role: &str,
+) -> Result<User> {
+    let user = sqlx::query_as::<_, User>(
+        r#"
+        INSERT INTO users (username, password_hash, email, role)
+        VALUES ($1, $2, $3, $4)
+        RETURNING *
+        "#
+    )
+    .bind(username)
+    .bind(password_hash)
+    .bind(email)
+    .bind(role)
+    .fetch_one(pool)
+    .await?;
+    Ok(user)
+}
+
+/// Update user
+pub async fn update_user(
+    pool: &PgPool,
+    id: Uuid,
+    email: Option<&str>,
+    role: &str,
+    enabled: bool,
+) -> Result<Option<User>> {
+    let user = sqlx::query_as::<_, User>(
+        r#"
+        UPDATE users
+        SET email = $2, role = $3, enabled = $4, updated_at = NOW()
+        WHERE id = $1
+        RETURNING *
+        "#
+    )
+    .bind(id)
+    .bind(email)
+    .bind(role)
+    .bind(enabled)
+    .fetch_optional(pool)
+    .await?;
+    Ok(user)
+}
+
+/// Update user password
+pub async fn update_user_password(
+    pool: &PgPool,
+    id: Uuid,
+    password_hash: &str,
+) -> Result<bool> {
+    let result = sqlx::query(
+        "UPDATE users SET password_hash = $2, updated_at = NOW() WHERE id = $1"
+    )
+    .bind(id)
+    .bind(password_hash)
+    .execute(pool)
+    .await?;
+    Ok(result.rows_affected() > 0)
+}
+
+/// Update last login timestamp
+pub async fn update_last_login(pool: &PgPool, id: Uuid) -> Result<()> {
+    sqlx::query("UPDATE users SET last_login = NOW() WHERE id = $1")
+        .bind(id)
+        .execute(pool)
+        .await?;
+    Ok(())
+}
+
+/// Delete user
+pub async fn delete_user(pool: &PgPool, id: Uuid) -> Result<bool> {
+    let result = sqlx::query("DELETE FROM users WHERE id = $1")
+        .bind(id)
+        .execute(pool)
+        .await?;
+    Ok(result.rows_affected() > 0)
+}
+
+/// Count users (for initial admin check)
+pub async fn count_users(pool: &PgPool) -> Result<i64> {
+    let count: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM users")
+        .fetch_one(pool)
+        .await?;
+    Ok(count.0)
+}
+
+/// Get user permissions
+pub async fn get_user_permissions(pool: &PgPool, user_id: Uuid) -> Result<Vec<String>> {
+    let perms: Vec<(String,)> = sqlx::query_as(
+        "SELECT permission FROM user_permissions WHERE user_id = $1"
+    )
+    .bind(user_id)
+    .fetch_all(pool)
+    .await?;
+    Ok(perms.into_iter().map(|p| p.0).collect())
+}
+
+/// Set user permissions (replaces all)
+pub async fn set_user_permissions(
+    pool: &PgPool,
+    user_id: Uuid,
+    permissions: &[String],
+) -> Result<()> {
+    // Delete existing
+    sqlx::query("DELETE FROM user_permissions WHERE user_id = $1")
+        .bind(user_id)
+        .execute(pool)
+        .await?;
+
+    // Insert new
+    for perm in permissions {
+        sqlx::query(
+            "INSERT INTO user_permissions (user_id, permission) VALUES ($1, $2)"
+        )
+        .bind(user_id)
+        .bind(perm)
+        .execute(pool)
+        .await?;
+    }
+    Ok(())
+}
+
+/// Get user's accessible client IDs (empty = all access)
+pub async fn get_user_client_access(pool: &PgPool, user_id: Uuid) -> Result<Vec<Uuid>> {
+    let clients: Vec<(Uuid,)> = sqlx::query_as(
+        "SELECT client_id FROM user_client_access WHERE user_id = $1"
+    )
+    .bind(user_id)
+    .fetch_all(pool)
+    .await?;
+    Ok(clients.into_iter().map(|c| c.0).collect())
+}
+
+/// Set user's client access (replaces all)
+pub async fn set_user_client_access(
+    pool: &PgPool,
+    user_id: Uuid,
+    client_ids: &[Uuid],
+) -> Result<()> {
+    // Delete existing
+    sqlx::query("DELETE FROM user_client_access WHERE user_id = $1")
+        .bind(user_id)
+        .execute(pool)
+        .await?;
+
+    // Insert new
+    for client_id in client_ids {
+        sqlx::query(
+            "INSERT INTO user_client_access (user_id, client_id) VALUES ($1, $2)"
+        )
+        .bind(user_id)
+        .bind(client_id)
+        .execute(pool)
+        .await?;
+    }
+    Ok(())
+}
+
+/// Check if user has access to a specific client
+pub async fn user_has_client_access(
+    pool: &PgPool,
+    user_id: Uuid,
+    client_id: Uuid,
+) -> Result<bool> {
+    // Admins have access to all
+    let user = get_user_by_id(pool, user_id).await?;
+    if let Some(u) = user {
+        if u.role == "admin" {
+            return Ok(true);
+        }
+    }
+
+    // Check explicit access
+    let access: Option<(Uuid,)> = sqlx::query_as(
+        "SELECT client_id FROM user_client_access WHERE user_id = $1 AND client_id = $2"
+    )
+    .bind(user_id)
+    .bind(client_id)
+    .fetch_optional(pool)
+    .await?;
+
+    // If no explicit access entries exist, user has access to all (legacy behavior)
+    if access.is_some() {
+        return Ok(true);
+    }
+
+    // Check if user has ANY access restrictions
+    let count: (i64,) = sqlx::query_as(
+        "SELECT COUNT(*) FROM user_client_access WHERE user_id = $1"
+    )
+    .bind(user_id)
+    .fetch_one(pool)
+    .await?;
+
+    // No restrictions means access to all
+    Ok(count.0 == 0)
+}

server/src/main.rs

@@ -18,12 +18,14 @@ pub mod proto {
 use anyhow::Result;
 use axum::{
     Router,
-    routing::{get, post, delete},
-    extract::{Path, State, Json, Query},
+    routing::{get, post, put, delete},
+    extract::{Path, State, Json, Query, Request},
     response::{Html, IntoResponse},
     http::StatusCode,
+    middleware::{self, Next},
 };
 use std::net::SocketAddr;
+use std::sync::Arc;
 use tower_http::cors::{Any, CorsLayer};
 use tower_http::trace::TraceLayer;
 use tower_http::services::ServeDir;
@@ -32,6 +34,7 @@ use tracing_subscriber::FmtSubscriber;
 use serde::Deserialize;
 
 use support_codes::{SupportCodeManager, CreateCodeRequest, SupportCode, CodeValidation};
+use auth::{JwtConfig, hash_password, generate_random_password};
 
 /// Application state
 #[derive(Clone)]
@@ -39,6 +42,17 @@ pub struct AppState {
     sessions: session::SessionManager,
     support_codes: SupportCodeManager,
     db: Option<db::Database>,
+    pub jwt_config: Arc<JwtConfig>,
+}
+
+/// Middleware to inject JWT config into request extensions
+async fn auth_layer(
+    State(state): State<AppState>,
+    mut request: Request,
+    next: Next,
+) -> impl IntoResponse {
+    request.extensions_mut().insert(state.jwt_config.clone());
+    next.run(request).await
 }
 
 #[tokio::main]
@@ -58,6 +72,17 @@ async fn main() -> Result<()> {
     let listen_addr = std::env::var("LISTEN_ADDR").unwrap_or_else(|_| "0.0.0.0:3002".to_string());
     info!("Loaded configuration, listening on {}", listen_addr);
 
+    // JWT configuration
+    let jwt_secret = std::env::var("JWT_SECRET").unwrap_or_else(|_| {
+        tracing::warn!("JWT_SECRET not set, using default (INSECURE for production!)");
+        "guruconnect-dev-secret-change-me-in-production".to_string()
+    });
+    let jwt_expiry_hours = std::env::var("JWT_EXPIRY_HOURS")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(24i64);
+    let jwt_config = Arc::new(JwtConfig::new(jwt_secret, jwt_expiry_hours));
+
     // Initialize database if configured
     let database = if let Some(ref db_url) = config.database_url {
         match db::Database::connect(db_url, config.database_max_connections).await {
@@ -79,6 +104,47 @@ async fn main() -> Result<()> {
         None
     };
 
+    // Create initial admin user if no users exist
+    if let Some(ref db) = database {
+        match db::count_users(db.pool()).await {
+            Ok(0) => {
+                info!("No users found, creating initial admin user...");
+                let password = generate_random_password(16);
+                let password_hash = hash_password(&password)?;
+
+                match db::create_user(db.pool(), "admin", &password_hash, None, "admin").await {
+                    Ok(user) => {
+                        // Set admin permissions
+                        let perms = vec![
+                            "view".to_string(),
+                            "control".to_string(),
+                            "transfer".to_string(),
+                            "manage_users".to_string(),
+                            "manage_clients".to_string(),
+                        ];
+                        let _ = db::set_user_permissions(db.pool(), user.id, &perms).await;
+
+                        info!("========================================");
+                        info!("  INITIAL ADMIN USER CREATED");
+                        info!("  Username: admin");
+                        info!("  Password: {}", password);
+                        info!("  (Change this password after first login!)");
+                        info!("========================================");
+                    }
+                    Err(e) => {
+                        tracing::error!("Failed to create initial admin user: {}", e);
+                    }
+                }
+            }
+            Ok(count) => {
+                info!("{} user(s) in database", count);
+            }
+            Err(e) => {
+                tracing::warn!("Could not check user count: {}", e);
+            }
+        }
+    }
+
     // Create session manager
     let sessions = session::SessionManager::new();
 
@@ -102,23 +168,40 @@ async fn main() -> Result<()> {
         sessions,
         support_codes: SupportCodeManager::new(),
         db: database,
+        jwt_config,
     };
 
     // Build router
     let app = Router::new()
-        // Health check
+        // Health check (no auth required)
         .route("/health", get(health))
-        
+
+        // Auth endpoints (no auth required for login)
+        .route("/api/auth/login", post(api::auth::login))
+
+        // Auth endpoints (auth required)
+        .route("/api/auth/me", get(api::auth::get_me))
+        .route("/api/auth/change-password", post(api::auth::change_password))
+
+        // User management (admin only)
+        .route("/api/users", get(api::users::list_users))
+        .route("/api/users", post(api::users::create_user))
+        .route("/api/users/:id", get(api::users::get_user))
+        .route("/api/users/:id", put(api::users::update_user))
+        .route("/api/users/:id", delete(api::users::delete_user))
+        .route("/api/users/:id/permissions", put(api::users::set_permissions))
+        .route("/api/users/:id/clients", put(api::users::set_client_access))
+
         // Portal API - Support codes
         .route("/api/codes", post(create_code))
         .route("/api/codes", get(list_codes))
         .route("/api/codes/:code/validate", get(validate_code))
         .route("/api/codes/:code/cancel", post(cancel_code))
-        
+
         // WebSocket endpoints
         .route("/ws/agent", get(relay::agent_ws_handler))
         .route("/ws/viewer", get(relay::viewer_ws_handler))
-        
+
         // REST API - Sessions
         .route("/api/sessions", get(list_sessions))
         .route("/api/sessions/:id", get(get_session))
@@ -129,17 +212,19 @@ async fn main() -> Result<()> {
         .route("/api/machines/:agent_id", get(get_machine))
         .route("/api/machines/:agent_id", delete(delete_machine))
         .route("/api/machines/:agent_id/history", get(get_machine_history))
-        
+
         // HTML page routes (clean URLs)
         .route("/login", get(serve_login))
         .route("/dashboard", get(serve_dashboard))
+        .route("/users", get(serve_users))
+
+        // State and middleware
+        .with_state(state.clone())
+        .layer(middleware::from_fn_with_state(state, auth_layer))
 
-        // State
-        .with_state(state)
-        
         // Serve static files for portal (fallback)
         .fallback_service(ServeDir::new("static").append_index_html_on_directories(true))
-        
+
         // Middleware
         .layer(TraceLayer::new_for_http())
         .layer(
@@ -380,3 +465,10 @@ async fn serve_dashboard() -> impl IntoResponse {
         Err(_) => (StatusCode::NOT_FOUND, "Page not found").into_response(),
     }
 }
+
+async fn serve_users() -> impl IntoResponse {
+    match tokio::fs::read_to_string("static/users.html").await {
+        Ok(content) => Html(content).into_response(),
+        Err(_) => (StatusCode::NOT_FOUND, "Page not found").into_response(),
+    }
+}

server/static/dashboard.html

@@ -348,6 +348,7 @@
         <button class="tab" data-tab="access">Access</button>
         <button class="tab" data-tab="build">Build</button>
         <button class="tab" data-tab="settings">Settings</button>
+        <button class="tab admin-only" data-tab="users" style="display: none;">Users</button>
     </nav>
 
     <main class="content">
@@ -510,6 +511,21 @@
                 </p>
             </div>
         </div>
+
+        <!-- Users Tab (Admin Only) -->
+        <div class="tab-panel" id="users-panel">
+            <div class="card">
+                <div class="card-header">
+                    <div>
+                        <h2 class="card-title">User Management</h2>
+                        <p class="card-description">Manage user accounts and permissions</p>
+                    </div>
+                </div>
+                <p style="color: hsl(var(--muted-foreground));">
+                    <a href="/users" style="color: hsl(var(--primary));">Open User Management</a>
+                </p>
+            </div>
+        </div>
     </main>
 
     <!-- Chat Modal -->
@@ -546,19 +562,59 @@
         });
 
         // Check auth
-        const token = localStorage.getItem("token");
-        const user = JSON.parse(localStorage.getItem("user") || "null");
+        const token = localStorage.getItem("guruconnect_token");
+        const user = JSON.parse(localStorage.getItem("guruconnect_user") || "null");
 
-        if (!token) {
-            document.getElementById("userInfo").textContent = "Demo Mode";
-        } else if (user) {
-            document.getElementById("userInfo").textContent = user.email || user.name || "Technician";
+        // Verify authentication
+        async function checkAuth() {
+            if (!token) {
+                window.location.href = "/login";
+                return;
+            }
+
+            try {
+                const response = await fetch("/api/auth/me", {
+                    headers: { "Authorization": `Bearer ${token}` }
+                });
+
+                if (!response.ok) {
+                    localStorage.removeItem("guruconnect_token");
+                    localStorage.removeItem("guruconnect_user");
+                    window.location.href = "/login";
+                    return;
+                }
+
+                const userData = await response.json();
+
+                // Update user display
+                document.getElementById("userInfo").textContent = userData.username + " (" + userData.role + ")";
+
+                // Show admin-only elements
+                if (userData.role === "admin") {
+                    document.querySelectorAll(".admin-only").forEach(el => {
+                        el.style.display = "";
+                    });
+                }
+            } catch (err) {
+                console.error("Auth check failed:", err);
+                // Don't redirect on network error, just show what we have
+                if (user) {
+                    document.getElementById("userInfo").textContent = user.username || "User";
+                    if (user.role === "admin") {
+                        document.querySelectorAll(".admin-only").forEach(el => {
+                            el.style.display = "";
+                        });
+                    }
+                }
+            }
         }
 
+        checkAuth();
+
         // Logout
         document.getElementById("logoutBtn").addEventListener("click", () => {
-            localStorage.removeItem("token");
-            localStorage.removeItem("user");
+            localStorage.removeItem("guruconnect_token");
+            localStorage.removeItem("guruconnect_user");
             window.location.href = "/login";
         });
 

server/static/login.html

@@ -3,7 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>GuruConnect - Technician Login</title>
+    <title>GuruConnect - Login</title>
     <style>
         :root {
             --background: 222.2 84% 4.9%;
@@ -53,7 +53,7 @@
 
         label { font-size: 14px; font-weight: 500; color: hsl(var(--foreground)); }
 
-        input[type="email"], input[type="password"] {
+        input[type="text"], input[type="password"] {
             width: 100%;
             padding: 12px 16px;
             font-size: 14px;
@@ -119,40 +119,24 @@
 
         @keyframes spin { to { transform: rotate(360deg); } }
         .loading .spinner { display: inline-block; }
-
-        .demo-hint {
-            margin-top: 16px;
-            padding: 12px;
-            background: hsla(var(--primary), 0.1);
-            border-radius: 8px;
-            font-size: 13px;
-            color: hsl(var(--muted-foreground));
-            text-align: center;
-        }
-
-        .demo-hint a {
-            color: hsl(var(--primary));
-            text-decoration: none;
-            font-weight: 500;
-        }
     </style>
 </head>
 <body>
     <div class="container">
         <div class="logo">
             <h1>GuruConnect</h1>
-            <p>Technician Login</p>
+            <p>Sign in to your account</p>
         </div>
 
         <form class="login-form" id="loginForm">
             <div class="form-group">
-                <label for="email">Email</label>
-                <input type="email" id="email" placeholder="you@company.com" required>
+                <label for="username">Username</label>
+                <input type="text" id="username" placeholder="Enter your username" autocomplete="username" required>
             </div>
 
             <div class="form-group">
                 <label for="password">Password</label>
-                <input type="password" id="password" placeholder="Enter your password" required>
+                <input type="password" id="password" placeholder="Enter your password" autocomplete="current-password" required>
             </div>
 
             <div class="error-message" id="errorMessage"></div>
@@ -163,10 +147,6 @@
             </button>
         </form>
 
-        <div class="demo-hint">
-            <p>Auth not yet configured. <a href="/dashboard">Skip to Dashboard</a></p>
-        </div>
-
         <div class="footer">
             <p><a href="/">Back to Support Portal</a></p>
         </div>
@@ -177,10 +157,29 @@
         const loginBtn = document.getElementById("loginBtn");
         const errorMessage = document.getElementById("errorMessage");
 
+        // Check if already logged in
+        const token = localStorage.getItem("guruconnect_token");
+        if (token) {
+            // Verify token is still valid
+            fetch('/api/auth/me', {
+                headers: { 'Authorization': `Bearer ${token}` }
+            }).then(res => {
+                if (res.ok) {
+                    window.location.href = '/dashboard';
+                } else {
+                    localStorage.removeItem('guruconnect_token');
+                    localStorage.removeItem('guruconnect_user');
+                }
+            }).catch(() => {
+                localStorage.removeItem('guruconnect_token');
+                localStorage.removeItem('guruconnect_user');
+            });
+        }
+
         form.addEventListener("submit", async (e) => {
             e.preventDefault();
 
-            const email = document.getElementById("email").value;
+            const username = document.getElementById("username").value;
             const password = document.getElementById("password").value;
 
             setLoading(true);
@@ -190,7 +189,7 @@
                 const response = await fetch("/api/auth/login", {
                     method: "POST",
                     headers: { "Content-Type": "application/json" },
-                    body: JSON.stringify({ email, password })
+                    body: JSON.stringify({ username, password })
                 });
 
                 const data = await response.json();
@@ -201,12 +200,13 @@
                     return;
                 }
 
-                localStorage.setItem("token", data.token);
-                localStorage.setItem("user", JSON.stringify(data.user));
+                // Store token and user info
+                localStorage.setItem("guruconnect_token", data.token);
+                localStorage.setItem("guruconnect_user", JSON.stringify(data.user));
                 window.location.href = "/dashboard";
 
             } catch (err) {
-                showError("Auth not configured yet. Use the demo link below.");
+                showError("Connection error. Please try again.");
                 setLoading(false);
             }
         });
@@ -222,9 +222,8 @@
             loginBtn.querySelector(".btn-text").textContent = loading ? "Signing in..." : "Sign In";
         }
 
-        if (localStorage.getItem("token")) {
-            window.location.href = "/dashboard";
-        }
+        // Focus username field
+        document.getElementById("username").focus();
     </script>
 </body>
 </html>

server/static/users.html

@@ -0,0 +1,602 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>GuruConnect - User Management</title>
+    <style>
+        :root {
+            --background: 222.2 84% 4.9%;
+            --foreground: 210 40% 98%;
+            --card: 222.2 84% 4.9%;
+            --card-foreground: 210 40% 98%;
+            --primary: 217.2 91.2% 59.8%;
+            --primary-foreground: 222.2 47.4% 11.2%;
+            --muted: 217.2 32.6% 17.5%;
+            --muted-foreground: 215 20.2% 65.1%;
+            --border: 217.2 32.6% 17.5%;
+            --input: 217.2 32.6% 17.5%;
+            --ring: 224.3 76.3% 48%;
+            --accent: 217.2 32.6% 17.5%;
+            --destructive: 0 62.8% 30.6%;
+        }
+
+        * { margin: 0; padding: 0; box-sizing: border-box; }
+
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
+            background-color: hsl(var(--background));
+            color: hsl(var(--foreground));
+            min-height: 100vh;
+        }
+
+        .header {
+            display: flex;
+            align-items: center;
+            justify-content: space-between;
+            padding: 16px 24px;
+            border-bottom: 1px solid hsl(var(--border));
+            background: hsl(var(--card));
+        }
+
+        .header-left { display: flex; align-items: center; gap: 24px; }
+        .logo { font-size: 20px; font-weight: 700; color: hsl(var(--foreground)); }
+        .back-link { color: hsl(var(--muted-foreground)); text-decoration: none; font-size: 14px; }
+        .back-link:hover { color: hsl(var(--foreground)); }
+
+        .content { padding: 24px; max-width: 1200px; margin: 0 auto; }
+
+        .card {
+            background: hsl(var(--card));
+            border: 1px solid hsl(var(--border));
+            border-radius: 8px;
+            padding: 24px;
+            margin-bottom: 16px;
+        }
+
+        .card-header {
+            display: flex;
+            align-items: center;
+            justify-content: space-between;
+            margin-bottom: 16px;
+        }
+
+        .card-title { font-size: 18px; font-weight: 600; }
+        .card-description { color: hsl(var(--muted-foreground)); font-size: 14px; margin-top: 4px; }
+
+        .btn {
+            padding: 10px 20px;
+            font-size: 14px;
+            font-weight: 500;
+            border-radius: 6px;
+            cursor: pointer;
+            transition: all 0.2s;
+            border: none;
+        }
+
+        .btn-primary { background: hsl(var(--primary)); color: hsl(var(--primary-foreground)); }
+        .btn-primary:hover { opacity: 0.9; }
+        .btn-outline { background: transparent; color: hsl(var(--foreground)); border: 1px solid hsl(var(--border)); }
+        .btn-outline:hover { background: hsl(var(--accent)); }
+        .btn-danger { background: hsl(var(--destructive)); color: white; }
+        .btn-danger:hover { opacity: 0.9; }
+        .btn-sm { padding: 6px 12px; font-size: 12px; }
+
+        table { width: 100%; border-collapse: collapse; }
+        th, td { padding: 12px 16px; text-align: left; border-bottom: 1px solid hsl(var(--border)); }
+        th { font-size: 12px; font-weight: 600; text-transform: uppercase; color: hsl(var(--muted-foreground)); }
+        td { font-size: 14px; }
+        tr:hover { background: hsla(var(--muted), 0.3); }
+
+        .badge { display: inline-block; padding: 4px 10px; font-size: 12px; font-weight: 500; border-radius: 9999px; }
+        .badge-admin { background: hsla(270, 76%, 50%, 0.2); color: hsl(270, 76%, 60%); }
+        .badge-operator { background: hsla(45, 93%, 47%, 0.2); color: hsl(45, 93%, 55%); }
+        .badge-viewer { background: hsl(var(--muted)); color: hsl(var(--muted-foreground)); }
+        .badge-enabled { background: hsla(142, 76%, 36%, 0.2); color: hsl(142, 76%, 50%); }
+        .badge-disabled { background: hsla(0, 70%, 50%, 0.2); color: hsl(0, 70%, 60%); }
+
+        .empty-state { text-align: center; padding: 48px 24px; color: hsl(var(--muted-foreground)); }
+        .empty-state h3 { font-size: 16px; margin-bottom: 8px; color: hsl(var(--foreground)); }
+
+        /* Modal */
+        .modal-overlay {
+            display: none;
+            position: fixed;
+            top: 0;
+            left: 0;
+            right: 0;
+            bottom: 0;
+            background: rgba(0, 0, 0, 0.7);
+            z-index: 1000;
+            justify-content: center;
+            align-items: center;
+        }
+        .modal-overlay.active { display: flex; }
+
+        .modal {
+            background: hsl(var(--card));
+            border: 1px solid hsl(var(--border));
+            border-radius: 12px;
+            width: 90%;
+            max-width: 500px;
+            max-height: 90vh;
+            overflow-y: auto;
+        }
+
+        .modal-header {
+            display: flex;
+            justify-content: space-between;
+            align-items: center;
+            padding: 16px 20px;
+            border-bottom: 1px solid hsl(var(--border));
+        }
+
+        .modal-title { font-size: 18px; font-weight: 600; }
+
+        .modal-close {
+            background: transparent;
+            border: none;
+            color: hsl(var(--muted-foreground));
+            font-size: 24px;
+            cursor: pointer;
+            padding: 4px;
+        }
+        .modal-close:hover { color: hsl(var(--foreground)); }
+
+        .modal-body { padding: 20px; }
+        .modal-footer { padding: 16px 20px; border-top: 1px solid hsl(var(--border)); display: flex; gap: 12px; justify-content: flex-end; }
+
+        .form-group { margin-bottom: 16px; }
+        .form-group label { display: block; font-size: 14px; font-weight: 500; margin-bottom: 8px; }
+        .form-group input, .form-group select {
+            width: 100%;
+            padding: 10px 14px;
+            font-size: 14px;
+            background: hsl(var(--input));
+            border: 1px solid hsl(var(--border));
+            border-radius: 6px;
+            color: hsl(var(--foreground));
+            outline: none;
+        }
+        .form-group input:focus, .form-group select:focus {
+            border-color: hsl(var(--ring));
+            box-shadow: 0 0 0 3px hsla(var(--ring), 0.3);
+        }
+
+        .permissions-grid {
+            display: grid;
+            grid-template-columns: repeat(2, 1fr);
+            gap: 8px;
+        }
+        .permission-item {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            padding: 8px;
+            background: hsl(var(--muted));
+            border-radius: 6px;
+            font-size: 13px;
+        }
+        .permission-item input[type="checkbox"] {
+            width: auto;
+        }
+
+        .error-message {
+            background: hsla(0, 70%, 50%, 0.1);
+            border: 1px solid hsla(0, 70%, 50%, 0.3);
+            color: hsl(0, 70%, 70%);
+            padding: 12px 16px;
+            border-radius: 8px;
+            font-size: 14px;
+            margin-bottom: 16px;
+            display: none;
+        }
+        .error-message.visible { display: block; }
+
+        .loading-overlay {
+            position: fixed;
+            top: 0;
+            left: 0;
+            right: 0;
+            bottom: 0;
+            background: rgba(0, 0, 0, 0.5);
+            display: none;
+            justify-content: center;
+            align-items: center;
+            z-index: 2000;
+        }
+        .loading-overlay.active { display: flex; }
+        .spinner {
+            width: 40px;
+            height: 40px;
+            border: 3px solid hsl(var(--muted));
+            border-top-color: hsl(var(--primary));
+            border-radius: 50%;
+            animation: spin 0.8s linear infinite;
+        }
+        @keyframes spin { to { transform: rotate(360deg); } }
+    </style>
+</head>
+<body>
+    <header class="header">
+        <div class="header-left">
+            <div class="logo">GuruConnect</div>
+            <a href="/dashboard" class="back-link">&larr; Back to Dashboard</a>
+        </div>
+    </header>
+
+    <main class="content">
+        <div class="card">
+            <div class="card-header">
+                <div>
+                    <h2 class="card-title">User Management</h2>
+                    <p class="card-description">Create and manage user accounts</p>
+                </div>
+                <button class="btn btn-primary" onclick="openCreateModal()">Create User</button>
+            </div>
+
+            <div class="error-message" id="errorMessage"></div>
+
+            <table>
+                <thead>
+                    <tr>
+                        <th>Username</th>
+                        <th>Email</th>
+                        <th>Role</th>
+                        <th>Status</th>
+                        <th>Last Login</th>
+                        <th>Actions</th>
+                    </tr>
+                </thead>
+                <tbody id="usersTable">
+                    <tr>
+                        <td colspan="6">
+                            <div class="empty-state">
+                                <h3>Loading users...</h3>
+                            </div>
+                        </td>
+                    </tr>
+                </tbody>
+            </table>
+        </div>
+    </main>
+
+    <!-- Create/Edit User Modal -->
+    <div class="modal-overlay" id="userModal">
+        <div class="modal">
+            <div class="modal-header">
+                <div class="modal-title" id="modalTitle">Create User</div>
+                <button class="modal-close" onclick="closeModal()">&times;</button>
+            </div>
+            <div class="modal-body">
+                <form id="userForm">
+                    <input type="hidden" id="userId">
+
+                    <div class="form-group">
+                        <label for="username">Username</label>
+                        <input type="text" id="username" required minlength="3">
+                    </div>
+
+                    <div class="form-group" id="passwordGroup">
+                        <label for="password">Password</label>
+                        <input type="password" id="password" minlength="8">
+                        <small style="color: hsl(var(--muted-foreground)); font-size: 12px;">Minimum 8 characters. Leave blank to keep existing password.</small>
+                    </div>
+
+                    <div class="form-group">
+                        <label for="email">Email (optional)</label>
+                        <input type="email" id="email">
+                    </div>
+
+                    <div class="form-group">
+                        <label for="role">Role</label>
+                        <select id="role">
+                            <option value="viewer">Viewer - View only access</option>
+                            <option value="operator">Operator - Can control machines</option>
+                            <option value="admin">Admin - Full access</option>
+                        </select>
+                    </div>
+
+                    <div class="form-group">
+                        <label>
+                            <input type="checkbox" id="enabled" checked style="width: auto; margin-right: 8px;">
+                            Account Enabled
+                        </label>
+                    </div>
+
+                    <div class="form-group">
+                        <label>Permissions</label>
+                        <div class="permissions-grid">
+                            <label class="permission-item">
+                                <input type="checkbox" id="perm-view" checked>
+                                View
+                            </label>
+                            <label class="permission-item">
+                                <input type="checkbox" id="perm-control">
+                                Control
+                            </label>
+                            <label class="permission-item">
+                                <input type="checkbox" id="perm-transfer">
+                                Transfer
+                            </label>
+                            <label class="permission-item">
+                                <input type="checkbox" id="perm-manage_users">
+                                Manage Users
+                            </label>
+                            <label class="permission-item">
+                                <input type="checkbox" id="perm-manage_clients">
+                                Manage Clients
+                            </label>
+                        </div>
+                    </div>
+
+                    <div class="error-message" id="formError"></div>
+                </form>
+            </div>
+            <div class="modal-footer">
+                <button class="btn btn-outline" onclick="closeModal()">Cancel</button>
+                <button class="btn btn-primary" onclick="saveUser()">Save</button>
+            </div>
+        </div>
+    </div>
+
+    <div class="loading-overlay" id="loadingOverlay">
+        <div class="spinner"></div>
+    </div>
+
+    <script>
+        const token = localStorage.getItem("guruconnect_token");
+        let users = [];
+        let editingUser = null;
+
+        // Check auth
+        if (!token) {
+            window.location.href = "/login";
+        }
+
+        // Verify admin access
+        async function checkAdmin() {
+            try {
+                const response = await fetch("/api/auth/me", {
+                    headers: { "Authorization": `Bearer ${token}` }
+                });
+
+                if (!response.ok) {
+                    window.location.href = "/login";
+                    return;
+                }
+
+                const user = await response.json();
+                if (user.role !== "admin") {
+                    alert("Admin access required");
+                    window.location.href = "/dashboard";
+                    return;
+                }
+
+                loadUsers();
+            } catch (err) {
+                console.error("Auth check failed:", err);
+                window.location.href = "/login";
+            }
+        }
+
+        checkAdmin();
+
+        async function loadUsers() {
+            try {
+                const response = await fetch("/api/users", {
+                    headers: { "Authorization": `Bearer ${token}` }
+                });
+
+                if (!response.ok) {
+                    throw new Error("Failed to load users");
+                }
+
+                users = await response.json();
+                renderUsers();
+            } catch (err) {
+                showError(err.message);
+            }
+        }
+
+        function renderUsers() {
+            const tbody = document.getElementById("usersTable");
+
+            if (users.length === 0) {
+                tbody.innerHTML = '<tr><td colspan="6"><div class="empty-state"><h3>No users found</h3></div></td></tr>';
+                return;
+            }
+
+            tbody.innerHTML = users.map(user => {
+                const roleClass = user.role === "admin" ? "badge-admin" :
+                                 user.role === "operator" ? "badge-operator" : "badge-viewer";
+                const statusClass = user.enabled ? "badge-enabled" : "badge-disabled";
+                const lastLogin = user.last_login ? new Date(user.last_login).toLocaleString() : "Never";
+
+                return `<tr>
+                    <td><strong>${escapeHtml(user.username)}</strong></td>
+                    <td>${escapeHtml(user.email || "-")}</td>
+                    <td><span class="badge ${roleClass}">${user.role}</span></td>
+                    <td><span class="badge ${statusClass}">${user.enabled ? "Enabled" : "Disabled"}</span></td>
+                    <td>${lastLogin}</td>
+                    <td>
+                        <button class="btn btn-outline btn-sm" onclick="editUser('${user.id}')">Edit</button>
+                        <button class="btn btn-danger btn-sm" onclick="deleteUser('${user.id}', '${escapeHtml(user.username)}')" style="margin-left: 4px;">Delete</button>
+                    </td>
+                </tr>`;
+            }).join("");
+        }
+
+        function openCreateModal() {
+            editingUser = null;
+            document.getElementById("modalTitle").textContent = "Create User";
+            document.getElementById("userForm").reset();
+            document.getElementById("userId").value = "";
+            document.getElementById("username").disabled = false;
+            document.getElementById("password").required = true;
+            document.getElementById("perm-view").checked = true;
+            document.getElementById("formError").classList.remove("visible");
+            document.getElementById("userModal").classList.add("active");
+        }
+
+        function editUser(id) {
+            editingUser = users.find(u => u.id === id);
+            if (!editingUser) return;
+
+            document.getElementById("modalTitle").textContent = "Edit User";
+            document.getElementById("userId").value = editingUser.id;
+            document.getElementById("username").value = editingUser.username;
+            document.getElementById("username").disabled = true;
+            document.getElementById("password").value = "";
+            document.getElementById("password").required = false;
+            document.getElementById("email").value = editingUser.email || "";
+            document.getElementById("role").value = editingUser.role;
+            document.getElementById("enabled").checked = editingUser.enabled;
+
+            // Set permissions
+            ["view", "control", "transfer", "manage_users", "manage_clients"].forEach(perm => {
+                document.getElementById("perm-" + perm).checked = editingUser.permissions.includes(perm);
+            });
+
+            document.getElementById("formError").classList.remove("visible");
+            document.getElementById("userModal").classList.add("active");
+        }
+
+        function closeModal() {
+            document.getElementById("userModal").classList.remove("active");
+            editingUser = null;
+        }
+
+        async function saveUser() {
+            const userId = document.getElementById("userId").value;
+            const username = document.getElementById("username").value;
+            const password = document.getElementById("password").value;
+            const email = document.getElementById("email").value || null;
+            const role = document.getElementById("role").value;
+            const enabled = document.getElementById("enabled").checked;
+
+            const permissions = [];
+            ["view", "control", "transfer", "manage_users", "manage_clients"].forEach(perm => {
+                if (document.getElementById("perm-" + perm).checked) {
+                    permissions.push(perm);
+                }
+            });
+
+            // Validation
+            if (!username || username.length < 3) {
+                showFormError("Username must be at least 3 characters");
+                return;
+            }
+
+            if (!userId && (!password || password.length < 8)) {
+                showFormError("Password must be at least 8 characters");
+                return;
+            }
+
+            showLoading(true);
+
+            try {
+                let response;
+
+                if (userId) {
+                    // Update existing user
+                    const updateData = { email, role, enabled };
+                    if (password) updateData.password = password;
+
+                    response = await fetch("/api/users/" + userId, {
+                        method: "PUT",
+                        headers: {
+                            "Authorization": `Bearer ${token}`,
+                            "Content-Type": "application/json"
+                        },
+                        body: JSON.stringify(updateData)
+                    });
+
+                    if (response.ok && permissions.length > 0) {
+                        // Update permissions separately
+                        await fetch("/api/users/" + userId + "/permissions", {
+                            method: "PUT",
+                            headers: {
+                                "Authorization": `Bearer ${token}`,
+                                "Content-Type": "application/json"
+                            },
+                            body: JSON.stringify({ permissions })
+                        });
+                    }
+                } else {
+                    // Create new user
+                    response = await fetch("/api/users", {
+                        method: "POST",
+                        headers: {
+                            "Authorization": `Bearer ${token}`,
+                            "Content-Type": "application/json"
+                        },
+                        body: JSON.stringify({ username, password, email, role, permissions })
+                    });
+                }
+
+                if (!response.ok) {
+                    const data = await response.json();
+                    throw new Error(data.error || "Operation failed");
+                }
+
+                closeModal();
+                loadUsers();
+            } catch (err) {
+                showFormError(err.message);
+            } finally {
+                showLoading(false);
+            }
+        }
+
+        async function deleteUser(id, username) {
+            if (!confirm(`Delete user "${username}"?\n\nThis action cannot be undone.`)) {
+                return;
+            }
+
+            showLoading(true);
+
+            try {
+                const response = await fetch("/api/users/" + id, {
+                    method: "DELETE",
+                    headers: { "Authorization": `Bearer ${token}` }
+                });
+
+                if (!response.ok) {
+                    const data = await response.json();
+                    throw new Error(data.error || "Delete failed");
+                }
+
+                loadUsers();
+            } catch (err) {
+                showError(err.message);
+            } finally {
+                showLoading(false);
+            }
+        }
+
+        function showError(message) {
+            const el = document.getElementById("errorMessage");
+            el.textContent = message;
+            el.classList.add("visible");
+        }
+
+        function showFormError(message) {
+            const el = document.getElementById("formError");
+            el.textContent = message;
+            el.classList.add("visible");
+        }
+
+        function showLoading(show) {
+            document.getElementById("loadingOverlay").classList.toggle("active", show);
+        }
+
+        function escapeHtml(text) {
+            if (!text) return "";
+            const div = document.createElement("div");
+            div.textContent = text;
+            return div.innerHTML;
+        }
+    </script>
+</body>
+</html>