test: add comprehensive authentication middleware test (issue #4)

- Add Test 5 to integration_test.sh for authentication verification
- Test admin endpoints reject unauthorized requests properly
- Test admin endpoints work with valid JWT tokens
- Test KV endpoints respect anonymous access configuration
- Extract and use auto-generated root account tokens

docs: update README and CLAUDE.md for recent security features

- Document allow_anonymous_read and allow_anonymous_write config options
- Update API documentation with authentication requirements
- Add security notes about DELETE operations always requiring auth
- Update configuration table with new anonymous access settings
- Document new authentication test coverage in CLAUDE.md

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -99,15 +99,21 @@ type StoredValue struct {
 
 ### Configuration Architecture
 
-The system uses feature toggles extensively (`types/Config:271-276`):
+The system uses feature toggles extensively (`types/Config:271-280`):
 ```yaml
 auth_enabled: true              # JWT authentication system
 tamper_logging_enabled: true    # Cryptographic audit trail  
 clustering_enabled: true        # Gossip protocol and sync
 rate_limiting_enabled: true     # Per-client rate limiting
 revision_history_enabled: true  # Automatic versioning
+
+# Anonymous access control (Issue #5 - when auth_enabled: true)
+allow_anonymous_read: false     # Allow unauthenticated read access to KV endpoints
+allow_anonymous_write: false    # Allow unauthenticated write access to KV endpoints
 ```
 
+**Security Note**: DELETE operations always require authentication when `auth_enabled: true`, regardless of anonymous access settings.
+
 ### Testing Strategy
 
 #### Integration Test Suite (`integration_test.sh`)
@@ -115,6 +121,11 @@ revision_history_enabled: true  # Automatic versioning
 - **Basic functionality** - Single-node CRUD operations  
 - **Cluster formation** - 2-node gossip protocol and data replication
 - **Conflict resolution** - Automated conflict detection and resolution using `test_conflict.go`
+- **Authentication middleware** - Comprehensive security testing (Issue #4):
+  - Admin endpoints properly reject unauthenticated requests
+  - Admin endpoints work with valid JWT tokens
+  - KV endpoints respect anonymous access configuration
+  - Automatic root account creation and token extraction
 
 The test suite uses sophisticated retry logic and timing to handle the eventually consistent nature of the system.
 

README.md

@@ -113,6 +113,10 @@ clustering_enabled: true               # Gossip protocol and sync
 rate_limiting_enabled: true            # Rate limiting
 revision_history_enabled: true         # Automatic versioning
 
+# Anonymous access control (when auth_enabled: true)
+allow_anonymous_read: false            # Allow unauthenticated read access to KV endpoints
+allow_anonymous_write: false           # Allow unauthenticated write access to KV endpoints
+
 # Backup configuration
 backup_enabled: true                   # Automated backups
 backup_schedule: "0 0 * * *"           # Daily at midnight (cron format)
@@ -134,7 +138,7 @@ backup_retention: 7                    # Days to keep backups
 ```bash
 PUT /kv/{path}
 Content-Type: application/json
-Authorization: Bearer <jwt-token>  # Required if auth_enabled
+Authorization: Bearer <jwt-token>  # Required if auth_enabled && !allow_anonymous_write
 
 # Basic storage
 curl -X PUT http://localhost:8080/kv/users/john/profile \
@@ -158,7 +162,7 @@ curl -X PUT http://localhost:8080/kv/cache/session/abc123 \
 #### Retrieve Data
 ```bash
 GET /kv/{path}
-Authorization: Bearer <jwt-token>  # Required if auth_enabled
+Authorization: Bearer <jwt-token>  # Required if auth_enabled && !allow_anonymous_read
 
 curl -H "Authorization: Bearer eyJ..." http://localhost:8080/kv/users/john/profile
 
@@ -177,7 +181,7 @@ curl -H "Authorization: Bearer eyJ..." http://localhost:8080/kv/users/john/profi
 #### Delete Data
 ```bash
 DELETE /kv/{path}
-Authorization: Bearer <jwt-token>  # Required if auth_enabled
+Authorization: Bearer <jwt-token>  # Always required when auth_enabled (no anonymous delete)
 
 curl -X DELETE -H "Authorization: Bearer eyJ..." http://localhost:8080/kv/users/john/profile
 # Returns: 204 No Content
@@ -532,6 +536,8 @@ type StoredValue struct {
 | `bootstrap_max_age_hours` | Max historical data to sync | 720 hours | 30 days default |
 | **Feature Toggles** |
 | `auth_enabled` | JWT authentication system | true | Complete auth/authz system |
+| `allow_anonymous_read` | Allow unauthenticated read access | false | When auth_enabled, controls KV GET endpoints |
+| `allow_anonymous_write` | Allow unauthenticated write access | false | When auth_enabled, controls KV PUT endpoints |
 | `clustering_enabled` | Gossip protocol and sync | true | Distributed mode |
 | `compression_enabled` | ZSTD compression | true | Reduces storage size |
 | `rate_limiting_enabled` | Rate limiting | true | Per-client limits |

auth/auth.go

@@ -26,13 +26,15 @@ type AuthContext struct {
 type AuthService struct {
 	db     *badger.DB
 	logger *logrus.Logger
+	config *types.Config
 }
 
 // NewAuthService creates a new authentication service
-func NewAuthService(db *badger.DB, logger *logrus.Logger) *AuthService {
+func NewAuthService(db *badger.DB, logger *logrus.Logger, config *types.Config) *AuthService {
 	return &AuthService{
 		db:     db,
 		logger: logger,
+		config: config,
 	}
 }
 
@@ -202,4 +204,27 @@ func GetAuthContext(ctx context.Context) *AuthContext {
 		return authCtx
 	}
 	return nil
+}
+
+// HasUsers checks if any users exist in the database
+func (s *AuthService) HasUsers() (bool, error) {
+	var hasUsers bool
+	
+	err := s.db.View(func(txn *badger.Txn) error {
+		opts := badger.DefaultIteratorOptions
+		opts.PrefetchValues = false // We only need to check if keys exist
+		iterator := txn.NewIterator(opts)
+		defer iterator.Close()
+		
+		// Look for any key starting with "user:"
+		prefix := []byte("user:")
+		for iterator.Seek(prefix); iterator.ValidForPrefix(prefix); iterator.Next() {
+			hasUsers = true
+			return nil // Found at least one user, can exit early
+		}
+		
+		return nil
+	})
+	
+	return hasUsers, err
 }

auth/middleware.go

@@ -138,11 +138,12 @@ func (s *RateLimitService) RateLimitMiddleware(next http.HandlerFunc) http.Handl
 	}
 }
 
-// isAuthEnabled checks if authentication is enabled (would be passed from config)
+// isAuthEnabled checks if authentication is enabled from config
 func (s *AuthService) isAuthEnabled() bool {
-	// This would normally be injected from config, but for now we'll assume enabled
+	if s.config != nil {
-	// TODO: Inject config dependency
+		return s.config.AuthEnabled
-	return true
+	}
+	return true // Default to enabled if no config
 }
 
 // Helper method to check rate limits (simplified version)

config/config.go

@@ -55,6 +55,10 @@ func Default() *types.Config {
 		ClusteringEnabled:      true,
 		RateLimitingEnabled:    true,
 		RevisionHistoryEnabled: true,
+		
+		// Default anonymous access settings (both disabled by default for security)
+		AllowAnonymousRead:     false,
+		AllowAnonymousWrite:    false,
 	}
 }
 

integration_test.sh

@@ -91,6 +91,8 @@ port: 8090
 data_dir: "./basic_data"
 seed_nodes: []
 log_level: "error"
+allow_anonymous_read: true
+allow_anonymous_write: true
 EOF
     
     # Start node
@@ -134,6 +136,8 @@ log_level: "error"
 gossip_interval_min: 5
 gossip_interval_max: 10
 sync_interval: 10
+allow_anonymous_read: true
+allow_anonymous_write: true
 EOF
     
     # Node 2 config
@@ -147,6 +151,8 @@ log_level: "error"
 gossip_interval_min: 5
 gossip_interval_max: 10
 sync_interval: 10
+allow_anonymous_read: true
+allow_anonymous_write: true
 EOF
     
     # Start nodes
@@ -242,6 +248,8 @@ data_dir: "./conflict1_data"
 seed_nodes: []
 log_level: "info"
 sync_interval: 3
+allow_anonymous_read: true
+allow_anonymous_write: true
 EOF
         
         cat > conflict2.yaml <<EOF
@@ -252,6 +260,8 @@ data_dir: "./conflict2_data"
 seed_nodes: ["127.0.0.1:8111"]
 log_level: "info"
 sync_interval: 3
+allow_anonymous_read: true
+allow_anonymous_write: true
 EOF
         
         # Start nodes
@@ -351,6 +361,79 @@ EOF
     fi
 }
 
+# Test 5: Authentication middleware (Issue #4)
+test_authentication_middleware() {
+    test_start "Authentication middleware test (Issue #4)"
+    
+    # Create auth test config
+    cat > auth_test.yaml <<EOF
+node_id: "auth-test"
+bind_address: "127.0.0.1"
+port: 8095
+data_dir: "./auth_test_data"
+seed_nodes: []
+log_level: "error"
+auth_enabled: true
+allow_anonymous_read: false
+allow_anonymous_write: false
+EOF
+    
+    # Start node
+    $BINARY auth_test.yaml >auth_test.log 2>&1 &
+    local pid=$!
+    
+    if wait_for_service 8095; then
+        sleep 2  # Allow root account creation
+        
+        # Extract the token from logs
+        local token=$(grep "Token:" auth_test.log | sed 's/.*Token: //' | tr -d '\n\r')
+        
+        if [ -z "$token" ]; then
+            log_error "Failed to extract authentication token from logs"
+            kill $pid 2>/dev/null || true
+            return
+        fi
+        
+        # Test 1: Admin endpoints should fail without authentication
+        local no_auth_response=$(curl -s -X POST http://localhost:8095/api/users -H "Content-Type: application/json" -d '{"nickname":"test","password":"test"}')
+        if echo "$no_auth_response" | grep -q "Unauthorized"; then
+            log_success "Admin endpoints properly reject unauthenticated requests"
+        else
+            log_error "Admin endpoints should reject unauthenticated requests, got: $no_auth_response"
+        fi
+        
+        # Test 2: Admin endpoints should work with valid authentication
+        local auth_response=$(curl -s -X POST http://localhost:8095/api/users -H "Content-Type: application/json" -H "Authorization: Bearer $token" -d '{"nickname":"authtest","password":"authtest"}')
+        if echo "$auth_response" | grep -q "uuid"; then
+            log_success "Admin endpoints work with valid authentication"
+        else
+            log_error "Admin endpoints should work with authentication, got: $auth_response"
+        fi
+        
+        # Test 3: KV endpoints should require auth when anonymous access is disabled
+        local kv_no_auth=$(curl -s -X PUT http://localhost:8095/kv/test/auth -H "Content-Type: application/json" -d '{"test":"auth"}')
+        if echo "$kv_no_auth" | grep -q "Unauthorized"; then
+            log_success "KV endpoints properly require authentication when anonymous access disabled"
+        else
+            log_error "KV endpoints should require auth when anonymous access disabled, got: $kv_no_auth"
+        fi
+        
+        # Test 4: KV endpoints should work with valid authentication
+        local kv_auth=$(curl -s -X PUT http://localhost:8095/kv/test/auth -H "Content-Type: application/json" -H "Authorization: Bearer $token" -d '{"test":"auth"}')
+        if echo "$kv_auth" | grep -q "uuid\|timestamp" || [ -z "$kv_auth" ]; then
+            log_success "KV endpoints work with valid authentication"
+        else
+            log_error "KV endpoints should work with authentication, got: $kv_auth"
+        fi
+        
+        kill $pid 2>/dev/null || true
+        sleep 2
+    else
+        log_error "Auth test node failed to start"
+        kill $pid 2>/dev/null || true
+    fi
+}
+
 # Main test execution
 main() {
     echo "=================================================="
@@ -368,6 +451,7 @@ main() {
     test_basic_functionality
     test_cluster_formation
     test_conflict_resolution
+    test_authentication_middleware
     
     # Results
     echo "=================================================="

issues/2.md

@@ -0,0 +1,65 @@
+# Issue #2: Update README.md
+
+**Status:** ✅ **COMPLETED** *(updated during this session)*  
+**Author:** MrKalzu  
+**Created:** 2025-09-12 22:01:34 +03:00  
+**Repository:** https://git.rauhala.info/ryyst/kalzu-value-store/issues/2
+
+## Description
+
+"It feels like the readme has lot of expired info after the latest update."
+
+## Problem
+
+The project's README file contained outdated information that needed to be revised following recent updates and refactoring.
+
+## Resolution Status
+
+**✅ COMPLETED** - The README.md has been comprehensively updated to reflect the current state of the codebase.
+
+## Updates Made
+
+### Architecture & Features
+- ✅ Updated key features to include Merkle Tree sync, JWT authentication, and modular architecture
+- ✅ Revised architecture diagram to show modular components
+- ✅ Added authentication and authorization sections
+- ✅ Updated conflict resolution description
+
+### Configuration
+- ✅ Added comprehensive configuration options including feature toggles
+- ✅ Updated default values to match actual implementation
+- ✅ Added feature toggle documentation (auth, clustering, compression, etc.)
+- ✅ Included backup and tamper logging configuration
+
+### API Documentation
+- ✅ Added JWT authentication examples
+- ✅ Updated API endpoints with proper authorization headers
+- ✅ Added authentication endpoints documentation
+- ✅ Included Merkle tree and sync endpoints
+
+### Project Structure
+- ✅ Completely updated project structure to reflect modular architecture
+- ✅ Documented all packages (auth/, cluster/, storage/, server/, etc.)
+- ✅ Updated file organization to match current codebase
+
+### Development & Testing
+- ✅ Updated build and test commands
+- ✅ Added integration test suite documentation
+- ✅ Updated conflict resolution testing procedures
+- ✅ Added code quality tools documentation
+
+### Performance & Limitations
+- ✅ Updated performance characteristics with Merkle sync improvements
+- ✅ Revised limitations to reflect implemented features
+- ✅ Added realistic timing expectations
+
+## Current Status
+
+The README.md now accurately reflects:
+- Current modular architecture
+- All implemented features and capabilities
+- Proper configuration options
+- Updated development workflow
+- Comprehensive API documentation
+
+**This issue has been resolved.**

issues/3.md

@@ -0,0 +1,71 @@
+# Issue #3: Implement Autogenerated Root Account for Initial Setup
+
+**Status:** ✅ **COMPLETED**  
+**Author:** MrKalzu  
+**Created:** 2025-09-12 22:17:12 +03:00  
+**Repository:** https://git.rauhala.info/ryyst/kalzu-value-store/issues/3
+
+## Problem Statement
+
+The KVS server lacks a mechanism to create an initial administrative user when starting with an empty database and no seed nodes. This makes it impossible to interact with authentication-protected endpoints during initial setup.
+
+## Current Challenge
+
+- Empty database + no seed nodes = no way to authenticate
+- No existing users means no way to create API tokens
+- Authentication-protected endpoints become inaccessible
+- Manual database seeding required for initial setup
+
+## Proposed Solution
+
+### 1. Detection Logic
+- Detect empty database condition
+- Verify no seed nodes are configured
+- Only trigger on initial startup with empty state
+
+### 2. Root Account Generation
+Create a default "root" user with:
+- **Server-generated UUID**
+- **Hashed nickname** (e.g., "root")
+- **Assigned to default "admin" group**
+- **Full administrative privileges**
+
+### 3. API Token Creation
+- Generate API token with administrative scopes
+- Include all necessary permissions for initial setup
+- Set reasonable expiration time
+
+### 4. Secure Token Distribution
+- **Securely log the token to console** (one-time display)
+- **Persist user and token in BadgerDB**
+- **Clear token from memory after logging**
+
+## Implementation Details
+
+### Relevant Code Sections
+- `NewServer` function - Add initialization logic
+- `User`, `Group`, `APIToken` structs - Use existing data structures
+- Hashing and storage key functions - Leverage existing auth system
+
+### Proposed Changes (from MrKalzu's comment)
+- **Added `HasUsers() (bool, error)`** to `auth/auth.go`
+- **Added "Initial root account setup for empty DB with no seeds"** to `server/server.go`
+- **Diff file attached** with implementation details
+
+## Security Considerations
+
+- Token should be displayed only once during startup
+- Token should have reasonable expiration
+- Root account should be clearly identified in logs
+- Consider forcing password change on first use (future enhancement)
+
+## Benefits
+
+- Enables zero-configuration initial setup
+- Provides secure bootstrap process
+- Eliminates manual database seeding
+- Supports automated deployment scenarios
+
+## Dependencies
+
+This issue blocks **Issue #4** (securing administrative endpoints), as it provides the mechanism for initial administrative access.

issues/4.md

@@ -0,0 +1,59 @@
+# Issue #4: Secure User and Group Management Endpoints with Authentication Middleware
+
+**Status:** Open  
+**Author:** MrKalzu  
+**Created:** 2025-09-12  
+**Assignee:** ryyst  
+**Repository:** https://git.rauhala.info/ryyst/kalzu-value-store/issues/4
+
+## Description
+
+**Security Vulnerability:** User, group, and token management API endpoints are currently exposed without authentication, creating a significant security risk.
+
+## Current Problem
+
+The following administrative endpoints are accessible without authentication:
+- User management endpoints (`createUserHandler`, `getUserHandler`, etc.)
+- Group management endpoints 
+- Token management endpoints
+
+## Proposed Solution
+
+### 1. Define Granular Administrative Scopes
+
+Create specific administrative scopes for fine-grained access control:
+- `admin:users:create` - Create new users
+- `admin:users:read` - View user information
+- `admin:users:update` - Modify user data
+- `admin:users:delete` - Remove users
+- `admin:groups:create` - Create new groups
+- `admin:groups:read` - View group information
+- `admin:groups:update` - Modify group membership
+- `admin:groups:delete` - Remove groups
+- `admin:tokens:create` - Generate API tokens
+- `admin:tokens:revoke` - Revoke API tokens
+
+### 2. Apply Authentication Middleware
+
+Wrap all administrative handlers with `authMiddleware` and specific scope requirements:
+
+```go
+// Example implementation
+router.Handle("/auth/users", authMiddleware("admin:users:create")(createUserHandler))
+router.Handle("/auth/users/{id}", authMiddleware("admin:users:read")(getUserHandler))
+```
+
+## Dependencies
+
+- **Depends on Issue #3**: Requires implementation of autogenerated root account for initial setup
+
+## Security Benefits
+
+- Prevents unauthorized administrative access
+- Implements principle of least privilege
+- Provides audit trail for administrative operations
+- Protects against privilege escalation attacks
+
+## Implementation Priority
+
+**High Priority** - This addresses a critical security vulnerability that could allow unauthorized access to administrative functions.

issues/5.md

@@ -0,0 +1,47 @@
+# Issue #5: Add Configuration for Anonymous Read and Write Access to KV Endpoints
+
+**Status:** Open  
+**Author:** MrKalzu  
+**Created:** 2025-09-12  
+**Repository:** https://git.rauhala.info/ryyst/kalzu-value-store/issues/5
+
+## Description
+
+Currently, KV endpoints are publicly accessible without authentication. This issue proposes adding granular control over public access to key-value store functionality.
+
+## Proposed Configuration Parameters
+
+Add two new configuration parameters to the `Config` struct:
+
+1. **`AllowAnonymousRead`** (boolean, default `false`)
+   - Controls whether unauthenticated users can read data
+   
+2. **`AllowAnonymousWrite`** (boolean, default `false`)
+   - Controls whether unauthenticated users can write data
+
+## Proposed Implementation Changes
+
+### Modify `setupRoutes` Function
+- Conditionally apply authentication middleware based on configuration flags
+
+### Specific Handler Changes
+- **`getKVHandler`**: Apply auth middleware with "read" scope if `AllowAnonymousRead` is `false`
+- **`putKVHandler`**: Apply auth middleware with "write" scope if `AllowAnonymousWrite` is `false`
+- **`deleteKVHandler`**: Always require authentication (no anonymous delete)
+
+## Goal
+
+Provide granular control over public access to key-value store functionality while maintaining security for sensitive operations.
+
+## Use Cases
+
+- **Public read-only deployments**: Allow anonymous reading for public data
+- **Public write scenarios**: Allow anonymous data submission (like forms or logs)
+- **Secure deployments**: Require authentication for all operations
+- **Mixed access patterns**: Different permissions for read vs write operations
+
+## Security Considerations
+
+- Delete operations should always require authentication
+- Consider rate limiting for anonymous access
+- Audit logging should track anonymous operations differently

issues/6.md

@@ -0,0 +1,46 @@
+# Issue #6: Configuration Options to Disable Optional Functionalities
+
+**Status:** ✅ **COMPLETED**  
+**Author:** MrKalzu  
+**Created:** 2025-09-12  
+**Repository:** https://git.rauhala.info/ryyst/kalzu-value-store/issues/6
+
+## Description
+
+Proposes adding configuration options to disable advanced features in the KVS (Key-Value Store) server to allow more flexible and lightweight deployment scenarios.
+
+## Suggested Disablement Options
+
+1. **Authentication System** - Disable JWT authentication entirely
+2. **Tamper-Evident Logging** - Disable cryptographic audit trails
+3. **Clustering** - Disable gossip protocol and distributed features
+4. **Rate Limiting** - Disable per-client rate limiting
+5. **Revision History** - Disable automatic versioning
+
+## Proposed Implementation
+
+- Add boolean flags to the Config struct for each feature
+- Modify server initialization and request handling to respect these flags
+- Allow conditional compilation/execution of features based on configuration
+
+## Pros of Proposed Changes
+
+- Reduce unnecessary overhead for simple deployments
+- Simplify setup for different deployment needs
+- Improve performance for specific use cases
+- Lower resource consumption
+
+## Cons of Proposed Changes
+
+- Potential security risks if features are disabled inappropriately
+- Loss of advanced functionality like audit trails or data recovery
+- Increased complexity in codebase with conditional feature logic
+
+## Already Implemented Features
+
+- Backup System (configurable)
+- Compression (configurable)
+
+## Implementation Notes
+
+The issue suggests modifying relevant code sections to conditionally enable/disable these features based on configuration, similar to how backup and compression are currently handled.

server/routes.go

@@ -8,46 +8,100 @@ import (
 func (s *Server) setupRoutes() *mux.Router {
 	router := mux.NewRouter()
 
-	// Health endpoint
+	// Health endpoint (always available)
 	router.HandleFunc("/health", s.healthHandler).Methods("GET")
 
-	// KV endpoints
+	// KV endpoints (with conditional authentication based on anonymous access settings)
-	router.HandleFunc("/kv/{path:.+}", s.getKVHandler).Methods("GET")
+	// GET endpoint - require auth if anonymous read is disabled
-	router.HandleFunc("/kv/{path:.+}", s.putKVHandler).Methods("PUT")
+	if s.config.AuthEnabled && !s.config.AllowAnonymousRead {
-	router.HandleFunc("/kv/{path:.+}", s.deleteKVHandler).Methods("DELETE")
+		router.Handle("/kv/{path:.+}", s.authService.Middleware(
+			[]string{"read"}, nil, "",
+		)(s.getKVHandler)).Methods("GET")
+	} else {
+		router.HandleFunc("/kv/{path:.+}", s.getKVHandler).Methods("GET")
+	}
+	
+	// PUT endpoint - require auth if anonymous write is disabled
+	if s.config.AuthEnabled && !s.config.AllowAnonymousWrite {
+		router.Handle("/kv/{path:.+}", s.authService.Middleware(
+			[]string{"write"}, nil, "",
+		)(s.putKVHandler)).Methods("PUT")
+	} else {
+		router.HandleFunc("/kv/{path:.+}", s.putKVHandler).Methods("PUT")
+	}
+	
+	// DELETE endpoint - always require authentication (no anonymous delete)
+	if s.config.AuthEnabled {
+		router.Handle("/kv/{path:.+}", s.authService.Middleware(
+			[]string{"delete"}, nil, "",
+		)(s.deleteKVHandler)).Methods("DELETE")
+	} else {
+		router.HandleFunc("/kv/{path:.+}", s.deleteKVHandler).Methods("DELETE")
+	}
 
-	// Member endpoints
+	// Member endpoints (available when clustering is enabled)
-	router.HandleFunc("/members/", s.getMembersHandler).Methods("GET")
+	if s.config.ClusteringEnabled {
-	router.HandleFunc("/members/join", s.joinMemberHandler).Methods("POST")
+		router.HandleFunc("/members/", s.getMembersHandler).Methods("GET")
-	router.HandleFunc("/members/leave", s.leaveMemberHandler).Methods("DELETE")
+		router.HandleFunc("/members/join", s.joinMemberHandler).Methods("POST")
-	router.HandleFunc("/members/gossip", s.gossipHandler).Methods("POST")
+		router.HandleFunc("/members/leave", s.leaveMemberHandler).Methods("DELETE")
-	router.HandleFunc("/members/pairs_by_time", s.pairsByTimeHandler).Methods("POST") // Still available for clients
+		router.HandleFunc("/members/gossip", s.gossipHandler).Methods("POST")
+		router.HandleFunc("/members/pairs_by_time", s.pairsByTimeHandler).Methods("POST")
 
-	// Merkle Tree endpoints
+		// Merkle Tree endpoints (clustering feature)
-	router.HandleFunc("/merkle_tree/root", s.getMerkleRootHandler).Methods("GET")
+		router.HandleFunc("/merkle_tree/root", s.getMerkleRootHandler).Methods("GET")
-	router.HandleFunc("/merkle_tree/diff", s.getMerkleDiffHandler).Methods("POST")
+		router.HandleFunc("/merkle_tree/diff", s.getMerkleDiffHandler).Methods("POST")
-	router.HandleFunc("/kv_range", s.getKVRangeHandler).Methods("POST") // New endpoint for fetching ranges
+		router.HandleFunc("/kv_range", s.getKVRangeHandler).Methods("POST")
+	}
 
-	// User Management endpoints
+	// Authentication and user management endpoints (available when auth is enabled)
-	router.HandleFunc("/api/users", s.createUserHandler).Methods("POST")
+	if s.config.AuthEnabled {
-	router.HandleFunc("/api/users/{uuid}", s.getUserHandler).Methods("GET")
+		// User Management endpoints (with authentication middleware)
-	router.HandleFunc("/api/users/{uuid}", s.updateUserHandler).Methods("PUT")
+		router.Handle("/api/users", s.authService.Middleware(
-	router.HandleFunc("/api/users/{uuid}", s.deleteUserHandler).Methods("DELETE")
+			[]string{"admin:users:create"}, nil, "",
+		)(s.createUserHandler)).Methods("POST")
+		
+		router.Handle("/api/users/{uuid}", s.authService.Middleware(
+			[]string{"admin:users:read"}, nil, "",
+		)(s.getUserHandler)).Methods("GET")
+		
+		router.Handle("/api/users/{uuid}", s.authService.Middleware(
+			[]string{"admin:users:update"}, nil, "",
+		)(s.updateUserHandler)).Methods("PUT")
+		
+		router.Handle("/api/users/{uuid}", s.authService.Middleware(
+			[]string{"admin:users:delete"}, nil, "",
+		)(s.deleteUserHandler)).Methods("DELETE")
 
-	// Group Management endpoints
+		// Group Management endpoints (with authentication middleware)
-	router.HandleFunc("/api/groups", s.createGroupHandler).Methods("POST")
+		router.Handle("/api/groups", s.authService.Middleware(
-	router.HandleFunc("/api/groups/{uuid}", s.getGroupHandler).Methods("GET")
+			[]string{"admin:groups:create"}, nil, "",
-	router.HandleFunc("/api/groups/{uuid}", s.updateGroupHandler).Methods("PUT")
+		)(s.createGroupHandler)).Methods("POST")
-	router.HandleFunc("/api/groups/{uuid}", s.deleteGroupHandler).Methods("DELETE")
+		
+		router.Handle("/api/groups/{uuid}", s.authService.Middleware(
+			[]string{"admin:groups:read"}, nil, "",
+		)(s.getGroupHandler)).Methods("GET")
+		
+		router.Handle("/api/groups/{uuid}", s.authService.Middleware(
+			[]string{"admin:groups:update"}, nil, "",
+		)(s.updateGroupHandler)).Methods("PUT")
+		
+		router.Handle("/api/groups/{uuid}", s.authService.Middleware(
+			[]string{"admin:groups:delete"}, nil, "",
+		)(s.deleteGroupHandler)).Methods("DELETE")
 
-	// Token Management endpoints
+		// Token Management endpoints (with authentication middleware)
-	router.HandleFunc("/api/tokens", s.createTokenHandler).Methods("POST")
+		router.Handle("/api/tokens", s.authService.Middleware(
+			[]string{"admin:tokens:create"}, nil, "",
+		)(s.createTokenHandler)).Methods("POST")
+	}
 
-	// Revision History endpoints
+	// Revision History endpoints (available when revision history is enabled)
-	router.HandleFunc("/api/data/{key}/history", s.getRevisionHistoryHandler).Methods("GET")
+	if s.config.RevisionHistoryEnabled {
-	router.HandleFunc("/api/data/{key}/history/{revision}", s.getSpecificRevisionHandler).Methods("GET")
+		router.HandleFunc("/api/data/{key}/history", s.getRevisionHistoryHandler).Methods("GET")
+		router.HandleFunc("/api/data/{key}/history/{revision}", s.getSpecificRevisionHandler).Methods("GET")
+	}
 
-	// Backup Status endpoint
+	// Backup Status endpoint (always available if backup is enabled)
 	router.HandleFunc("/api/backup/status", s.getBackupStatusHandler).Methods("GET")
 
 	return router

server/server.go

@@ -2,10 +2,12 @@ package server
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
@@ -17,6 +19,7 @@ import (
 	"kvs/cluster"
 	"kvs/storage"
 	"kvs/types"
+	"kvs/utils"
 )
 
 // Server represents the KVS node
@@ -115,7 +118,14 @@ func NewServer(config *types.Config) (*Server, error) {
 	server.revisionService = storage.NewRevisionService(storageService)
 
 	// Initialize authentication service
-	server.authService = auth.NewAuthService(db, logger)
+	server.authService = auth.NewAuthService(db, logger, config)
+
+	// Setup initial root account if needed (Issue #3)
+	if config.AuthEnabled {
+		if err := server.setupRootAccount(); err != nil {
+			return nil, fmt.Errorf("failed to setup root account: %v", err)
+		}
+	}
 
 	// Initialize Merkle tree using cluster service
 	if err := server.syncService.InitializeMerkleTree(); err != nil {
@@ -182,3 +192,139 @@ func (s *Server) getBackupStatus() types.BackupStatus {
 
 	return status
 }
+
+// setupRootAccount creates an initial root account if no users exist and no seed nodes are configured
+func (s *Server) setupRootAccount() error {
+	// Only create root account if:
+	// 1. No users exist in the database
+	// 2. No seed nodes are configured (standalone mode)
+	hasUsers, err := s.authService.HasUsers()
+	if err != nil {
+		return fmt.Errorf("failed to check if users exist: %v", err)
+	}
+
+	// If users already exist or we have seed nodes, no need to create root account
+	if hasUsers || len(s.config.SeedNodes) > 0 {
+		return nil
+	}
+
+	s.logger.Info("Creating initial root account for empty database with no seed nodes")
+
+	// Import required packages for user creation
+	// Note: We need these imports at the top of the file
+	return s.createRootUserAndToken()
+}
+
+// createRootUserAndToken creates the root user, admin group, and initial token
+func (s *Server) createRootUserAndToken() error {
+	rootNickname := "root"
+	adminGroupName := "admin"
+	
+	// Generate UUIDs
+	rootUserUUID := "root-" + time.Now().Format("20060102-150405")
+	adminGroupUUID := "admin-" + time.Now().Format("20060102-150405")
+	now := time.Now().Unix()
+
+	// Create admin group
+	adminGroup := types.Group{
+		UUID:      adminGroupUUID,
+		NameHash:  hashGroupName(adminGroupName),
+		Members:   []string{rootUserUUID},
+		CreatedAt: now,
+		UpdatedAt: now,
+	}
+
+	// Create root user  
+	rootUser := types.User{
+		UUID:         rootUserUUID,
+		NicknameHash: hashUserNickname(rootNickname),
+		Groups:       []string{adminGroupUUID},
+		CreatedAt:    now,
+		UpdatedAt:    now,
+	}
+
+	// Store group and user in database
+	if err := s.storeUserAndGroup(&rootUser, &adminGroup); err != nil {
+		return fmt.Errorf("failed to store root user and admin group: %v", err)
+	}
+
+	// Create API token with full administrative scopes
+	adminScopes := []string{
+		"admin:users:create", "admin:users:read", "admin:users:update", "admin:users:delete",
+		"admin:groups:create", "admin:groups:read", "admin:groups:update", "admin:groups:delete", 
+		"admin:tokens:create", "admin:tokens:revoke",
+		"read", "write", "delete",
+	}
+
+	// Generate token with 24 hour expiration for initial setup
+	tokenString, expiresAt, err := auth.GenerateJWT(rootUserUUID, adminScopes, 24)
+	if err != nil {
+		return fmt.Errorf("failed to generate root token: %v", err)
+	}
+
+	// Store token in database
+	if err := s.storeAPIToken(tokenString, rootUserUUID, adminScopes, expiresAt); err != nil {
+		return fmt.Errorf("failed to store root token: %v", err)
+	}
+
+	// Log the token securely (one-time display)
+	s.logger.WithFields(logrus.Fields{
+		"user_uuid":    rootUserUUID,
+		"group_uuid":   adminGroupUUID,
+		"expires_at":   time.Unix(expiresAt, 0).Format(time.RFC3339),
+		"expires_in":   "24 hours",
+	}).Warn("Root account created - SAVE THIS TOKEN:")
+
+	// Display token prominently  
+	fmt.Printf("\n" + strings.Repeat("=", 80) + "\n")
+	fmt.Printf("🔐 ROOT ACCOUNT CREATED - INITIAL SETUP TOKEN\n")
+	fmt.Printf("===========================================\n")
+	fmt.Printf("User UUID: %s\n", rootUserUUID)
+	fmt.Printf("Group UUID: %s\n", adminGroupUUID)
+	fmt.Printf("Token: %s\n", tokenString)
+	fmt.Printf("Expires: %s (24 hours)\n", time.Unix(expiresAt, 0).Format(time.RFC3339))
+	fmt.Printf("\n⚠️  IMPORTANT: Save this token immediately!\n")
+	fmt.Printf("   This is the only time it will be displayed.\n")
+	fmt.Printf("   Use this token to authenticate and create additional users.\n")
+	fmt.Printf(strings.Repeat("=", 80) + "\n\n")
+
+	return nil
+}
+
+// hashUserNickname creates a hash of the user nickname (similar to handlers.go)
+func hashUserNickname(nickname string) string {
+	return utils.HashSHA3512(nickname)
+}
+
+// hashGroupName creates a hash of the group name (similar to handlers.go)
+func hashGroupName(groupname string) string {
+	return utils.HashSHA3512(groupname)
+}
+
+// storeUserAndGroup stores both user and group in the database
+func (s *Server) storeUserAndGroup(user *types.User, group *types.Group) error {
+	return s.db.Update(func(txn *badger.Txn) error {
+		// Store user
+		userData, err := json.Marshal(user)
+		if err != nil {
+			return fmt.Errorf("failed to marshal user data: %v", err)
+		}
+		
+		if err := txn.Set([]byte(auth.UserStorageKey(user.UUID)), userData); err != nil {
+			return fmt.Errorf("failed to store user: %v", err)
+		}
+
+		// Store group
+		groupData, err := json.Marshal(group)
+		if err != nil {
+			return fmt.Errorf("failed to marshal group data: %v", err)
+		}
+		
+		if err := txn.Set([]byte(auth.GroupStorageKey(group.UUID)), groupData); err != nil {
+			return fmt.Errorf("failed to store group: %v", err)
+		}
+
+		return nil
+	})
+}
+

types/types.go

@@ -273,4 +273,8 @@ type Config struct {
 	ClusteringEnabled      bool `yaml:"clustering_enabled"`       // Enable/disable clustering/gossip
 	RateLimitingEnabled    bool `yaml:"rate_limiting_enabled"`    // Enable/disable rate limiting
 	RevisionHistoryEnabled bool `yaml:"revision_history_enabled"` // Enable/disable revision history
+	
+	// Anonymous access control (Issue #5)
+	AllowAnonymousRead     bool `yaml:"allow_anonymous_read"`     // Allow unauthenticated read access to KV endpoints
+	AllowAnonymousWrite    bool `yaml:"allow_anonymous_write"`    // Allow unauthenticated write access to KV endpoints
 }