v0.2.1 - Nip-40 implemented

README.md

@@ -10,20 +10,13 @@ Do NOT modify the formatting, add emojis, or change the text. Keep the simple fo
 
 - [x] NIP-01: Basic protocol flow implementation
 - [x] NIP-09: Event deletion
-- [ ] NIP-11: Relay information document
-- [ ] NIP-12: Generic tag queries
-- [ ] NIP-13: Proof of Work
+- [x] NIP-11: Relay information document
+- [x] NIP-13: Proof of Work
 - [x] NIP-15: End of Stored Events Notice
-- [ ] NIP-16: Event Treatment
 - [x] NIP-20: Command Results
-- [ ] NIP-22: Event `created_at` Limits
-- [ ] NIP-25: Reactions
-- [ ] NIP-26: Delegated Event Signing
-- [ ] NIP-28: Public Chat
-- [ ] NIP-33: Parameterized Replaceable Events
-- [ ] NIP-40: Expiration Timestamp
+- [x] NIP-33: Parameterized Replaceable Events
+- [x] NIP-40: Expiration Timestamp
 - [ ] NIP-42: Authentication of clients to relays
-- [ ] NIP-45: Counting results. [experimental](#count)
-- [ ] NIP-50: Keywords filter. [experimental](#search)
+- [ ] NIP-45: Counting results.
+- [ ] NIP-50: Keywords filter.
 - [ ] NIP-70: Protected Events
-

admin_spec.md

@@ -0,0 +1,387 @@
+# Ginxsom Admin System - Comprehensive Specification
+
+## Overview
+
+The Ginxsom admin system provides both programmatic (API-based) and interactive (web-based) administration capabilities for the Ginxsom Blossom server. The system is designed around Nostr-based authentication and supports multiple administration workflows including first-run setup, ongoing configuration management, and operational monitoring.
+
+## Architecture Components
+
+### 1. Configuration System
+- **File-based configuration**: Signed Nostr events stored as JSON files following XDG Base Directory specification
+- **Database configuration**: Key-value pairs stored in SQLite for runtime configuration
+- **Interactive setup**: Command-line wizard for initial server configuration
+- **Manual setup**: Scripts for generating signed configuration events
+
+### 2. Authentication & Authorization
+- **Nostr-based auth**: All admin operations require valid Nostr event signatures
+- **Admin pubkey verification**: Only configured admin public keys can perform admin operations
+- **Event validation**: Full cryptographic verification of Nostr events including structure, signature, and expiration
+- **Method-specific authorization**: Different event types for different operations (upload, admin, delete, etc.)
+
+### 3. API System
+- **RESTful endpoints**: `/api/*` routes for programmatic administration
+- **Command-line testing**: Complete test suite using `nak` and `curl`
+- **JSON responses**: Structured data for all admin operations
+- **CORS support**: Cross-origin requests for web admin interface
+
+### 4. Web Interface (Future)
+- **Single-page application**: Self-contained HTML file with inline CSS/JS
+- **Real-time monitoring**: Statistics and system health dashboards
+- **Configuration management**: GUI for server settings
+- **File management**: Browse and manage uploaded blobs
+
+## Configuration System Architecture
+
+### File-based Configuration (Priority 1)
+
+**Location**: Follows XDG Base Directory Specification
+- `$XDG_CONFIG_HOME/ginxsom/ginxsom_config_event.json`
+- Falls back to `$HOME/.config/ginxsom/ginxsom_config_event.json`
+
+**Format**: Signed Nostr event containing server configuration
+```json
+{
+  "kind": 33333,
+  "created_at": 1704067200,
+  "tags": [
+    ["server_privkey", "server_private_key_hex"],
+    ["cdn_origin", "https://cdn.example.com"],
+    ["max_file_size", "104857600"],
+    ["nip94_enabled", "true"]
+  ],
+  "content": "Ginxsom server configuration",
+  "pubkey": "admin_public_key_hex",
+  "id": "event_id_hash",
+  "sig": "event_signature"
+}
+```
+
+**Loading Process**:
+1. Check for file-based config at XDG location
+2. Validate Nostr event structure and signature
+3. Extract configuration from event tags
+4. Apply settings to server (database storage)
+5. Fall back to database-only config if file missing/invalid
+
+### Database Configuration (Priority 2)
+
+**Table**: `server_config`
+```sql
+CREATE TABLE server_config (
+    key TEXT PRIMARY KEY,
+    value TEXT NOT NULL,
+    description TEXT,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+```
+
+**Key Configuration Items**:
+- `admin_pubkey`: Authorized admin public key
+- `admin_enabled`: Enable/disable admin interface
+- `cdn_origin`: Base URL for blob access
+- `max_file_size`: Maximum upload size in bytes
+- `nip94_enabled`: Enable NIP-94 metadata emission
+- `auth_rules_enabled`: Enable authentication rules system
+
+### Setup Workflows
+
+#### Interactive Setup (Command Line)
+```bash
+# First-run detection
+if [[ ! -f "$XDG_CONFIG_HOME/ginxsom/ginxsom_config_event.json" ]]; then
+    echo "=== Ginxsom First-Time Setup Required ==="
+    echo "1. Run interactive setup wizard"
+    echo "2. Exit and create config manually"
+    read -p "Choice (1/2): " choice
+    
+    if [[ "$choice" == "1" ]]; then
+        ./scripts/setup.sh
+    else
+        echo "Manual setup: Run ./scripts/generate_config.sh"
+        exit 1
+    fi
+fi
+```
+
+#### Manual Setup (Script-based)
+```bash
+# Generate configuration event
+./scripts/generate_config.sh --admin-key <admin_pubkey> \
+    --server-key <server_privkey> \
+    --cdn-origin "https://cdn.example.com" \
+    --output "$XDG_CONFIG_HOME/ginxsom/ginxsom_config_event.json"
+```
+
+### C Implementation Functions
+
+#### Configuration Loading
+```c
+// Get XDG-compliant config file path
+int get_config_file_path(char* path, size_t path_size);
+
+// Load and validate config event from file
+int load_server_config(const char* config_path);
+
+// Extract config from validated event and apply to server
+int apply_config_from_event(cJSON* event);
+
+// Interactive setup runner for first-run
+int run_interactive_setup(const char* config_path);
+```
+
+#### Security Features
+- Server private key stored only in memory (never in database)
+- Config file must be signed Nostr event
+- Full cryptographic validation of config events
+- Admin pubkey verification for all operations
+
+## Admin API Specification
+
+### Authentication Model
+
+All admin API endpoints (except `/api/health`) require Nostr authentication:
+
+**Authorization Header Format**:
+```
+Authorization: Nostr <base64-encoded-event>
+```
+
+**Required Event Structure**:
+```json
+{
+  "kind": 24242,
+  "created_at": 1704067200,
+  "tags": [
+    ["t", "GET"],
+    ["expiration", "1704070800"]
+  ],
+  "content": "admin_request",
+  "pubkey": "admin_public_key",
+  "id": "event_id",
+  "sig": "event_signature"
+}
+```
+
+### API Endpoints
+
+#### GET /api/health
+**Purpose**: System health check (no authentication required)
+**Response**:
+```json
+{
+  "status": "success",
+  "data": {
+    "database": "connected",
+    "blob_directory": "accessible",
+    "server_time": 1704067200,
+    "uptime": 3600,
+    "disk_usage": {
+      "total_bytes": 1073741824,
+      "used_bytes": 536870912,
+      "available_bytes": 536870912,
+      "usage_percent": 50.0
+    }
+  }
+}
+```
+
+#### GET /api/stats
+**Purpose**: Server statistics and metrics
+**Authentication**: Required (admin pubkey)
+**Response**:
+```json
+{
+  "status": "success",
+  "data": {
+    "total_files": 1234,
+    "total_bytes": 104857600,
+    "total_size_mb": 100.0,
+    "unique_uploaders": 56,
+    "first_upload": 1693929600,
+    "last_upload": 1704067200,
+    "avg_file_size": 85049,
+    "file_types": {
+      "image/png": 45,
+      "image/jpeg": 32,
+      "application/pdf": 12,
+      "other": 8
+    }
+  }
+}
+```
+
+#### GET /api/config
+**Purpose**: Retrieve current server configuration
+**Authentication**: Required (admin pubkey)
+**Response**:
+```json
+{
+  "status": "success",
+  "data": {
+    "cdn_origin": "http://localhost:9001",
+    "max_file_size": "104857600",
+    "nip94_enabled": "true",
+    "auth_rules_enabled": "false",
+    "auth_cache_ttl": "300"
+  }
+}
+```
+
+#### PUT /api/config
+**Purpose**: Update server configuration
+**Authentication**: Required (admin pubkey)
+**Request Body**:
+```json
+{
+  "max_file_size": "209715200",
+  "nip94_enabled": "true",
+  "cdn_origin": "https://cdn.example.com"
+}
+```
+**Response**:
+```json
+{
+  "status": "success",
+  "message": "Configuration updated successfully",
+  "updated_keys": ["max_file_size", "cdn_origin"]
+}
+```
+
+#### GET /api/files
+**Purpose**: List recent files with pagination
+**Authentication**: Required (admin pubkey)
+**Parameters**:
+- `limit` (default: 50): Number of files to return
+- `offset` (default: 0): Pagination offset
+**Response**:
+```json
+{
+  "status": "success",
+  "data": {
+    "files": [
+      {
+        "sha256": "b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553",
+        "size": 184292,
+        "type": "application/pdf",
+        "uploaded_at": 1725105921,
+        "uploader_pubkey": "79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798",
+        "filename": "document.pdf",
+        "url": "http://localhost:9001/b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553.pdf"
+      }
+    ],
+    "total": 1234,
+    "limit": 50,
+    "offset": 0
+  }
+}
+```
+
+## Implementation Status
+
+### ✅ Completed Components
+1. **Database-based configuration loading** - Implemented in main.c
+2. **Admin API authentication system** - Implemented in admin_api.c
+3. **Nostr event validation** - Full cryptographic verification
+4. **Admin pubkey verification** - Database-backed authorization
+5. **Basic API endpoints** - Health, stats, config, files
+
+### ✅ Recently Completed Components
+1. **File-based configuration system** - Fully implemented in main.c with XDG compliance
+2. **Interactive setup wizard** - Complete shell script with guided setup process (`scripts/setup.sh`)
+3. **Manual config generation** - Full-featured command-line config generator (`scripts/generate_config.sh`)
+4. **Testing infrastructure** - Comprehensive admin API test suite (`scripts/test_admin.sh`)
+5. **Documentation system** - Complete setup and usage documentation (`scripts/README.md`)
+
+### 📋 Planned Components
+1. **Web admin interface** - Single-page HTML application
+2. **Enhanced monitoring** - Real-time statistics dashboard
+3. **Bulk operations** - Multi-file management APIs
+4. **Configuration validation** - Advanced config checking
+5. **Audit logging** - Admin action tracking
+
+## Setup Instructions
+
+### 1. Enable Admin Interface
+```bash
+# Configure admin pubkey and enable interface
+sqlite3 db/ginxsom.db << EOF
+INSERT OR REPLACE INTO server_config (key, value, description) VALUES
+    ('admin_pubkey', 'your_admin_public_key_here', 'Authorized admin public key'),
+    ('admin_enabled', 'true', 'Enable admin interface');
+EOF
+```
+
+### 2. Test API Access
+```bash
+# Generate admin authentication event
+ADMIN_PRIVKEY="your_admin_private_key"
+EVENT=$(nak event -k 24242 -c "admin_request" \
+    --tag t="GET" \
+    --tag expiration="$(date -d '+1 hour' +%s)" \
+    --sec "$ADMIN_PRIVKEY")
+
+# Test admin API
+AUTH_HEADER="Nostr $(echo "$EVENT" | base64 -w 0)"
+curl -H "Authorization: $AUTH_HEADER" http://localhost:9001/api/stats
+```
+
+### 3. Configure File-based Setup (Future)
+```bash
+# Create XDG config directory
+mkdir -p "$XDG_CONFIG_HOME/ginxsom"
+
+# Generate signed config event
+./scripts/generate_config.sh \
+    --admin-key "your_admin_pubkey" \
+    --server-key "generated_server_privkey" \
+    --output "$XDG_CONFIG_HOME/ginxsom/ginxsom_config_event.json"
+```
+
+## Security Considerations
+
+### Authentication Security
+- **Event expiration**: All admin events must include expiration timestamps
+- **Signature validation**: Full secp256k1 cryptographic verification
+- **Replay protection**: Event IDs tracked to prevent reuse
+- **Admin key rotation**: Support for updating admin pubkeys
+
+### Configuration Security
+- **File permissions**: Config files should be readable only by server user
+- **Private key handling**: Server private keys never stored in database
+- **Config validation**: All configuration changes validated before application
+- **Backup verification**: Config events cryptographically verifiable
+
+### Operational Security
+- **Access logging**: All admin operations logged with timestamps
+- **Rate limiting**: API endpoints protected against abuse
+- **Input validation**: All user input sanitized and validated
+- **Database security**: Prepared statements prevent SQL injection
+
+## Future Enhancements
+
+### 1. Web Admin Interface
+- Self-contained HTML file with inline CSS/JavaScript
+- Real-time monitoring dashboards
+- Visual configuration management
+- File upload/management interface
+
+### 2. Advanced Monitoring
+- Performance metrics collection
+- Alert system for critical events
+- Historical data trending
+- Resource usage tracking
+
+### 3. Multi-admin Support
+- Multiple authorized admin pubkeys
+- Role-based permissions (read-only vs full admin)
+- Admin action audit trails
+- Delegation capabilities
+
+### 4. Integration Features
+- Nostr relay integration for admin events
+- Webhook notifications for admin actions
+- External authentication providers
+- API key management for programmatic access
+
+This specification represents the current understanding and planned development of the Ginxsom admin system, focusing on security, usability, and maintainability.

relay.log

@@ -1,18 +1,35 @@
 === C Nostr Relay Server ===
 [SUCCESS] Database connection established
+[SUCCESS] Relay information initialized with default values
+[INFO] Initializing NIP-13 Proof of Work configuration
+[INFO] PoW Configuration: enabled=true, min_difficulty=0, validation_flags=0x1, mode=full
+[INFO] Initializing NIP-40 Expiration Timestamp configuration
+[INFO] Expiration Configuration: enabled=true, strict_mode=true, filter_responses=true, grace_period=300 seconds
 [INFO] Starting relay server...
 [INFO] Starting libwebsockets-based Nostr relay server...
 [SUCCESS] WebSocket relay started on ws://127.0.0.1:8888
+[INFO] HTTP request received
+[INFO] Handling NIP-11 relay information request
+[SUCCESS] NIP-11 relay information served successfully
+[INFO] HTTP request received
+[INFO] Handling NIP-11 relay information request
+[SUCCESS] NIP-11 relay information served successfully
 [INFO] WebSocket connection established
 [INFO] Received WebSocket message
+[INFO] Handling EVENT message with full NIP-01 validation
+[SUCCESS] Event stored in database
+[SUCCESS] Event validated and stored successfully
+[INFO] WebSocket connection closed
+[INFO] WebSocket connection established
 [INFO] Received WebSocket message
+[INFO] Handling EVENT message with full NIP-01 validation
+[SUCCESS] Event stored in database
+[SUCCESS] Event validated and stored successfully
+[INFO] WebSocket connection closed
+[INFO] WebSocket connection established
 [INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
+[INFO] Handling EVENT message with full NIP-01 validation
+[WARNING] Event rejected: expired timestamp
 [INFO] WebSocket connection closed
 [INFO] WebSocket connection established
 [INFO] Received WebSocket message
@@ -34,98 +51,33 @@
 [INFO] WebSocket connection closed
 [INFO] WebSocket connection established
 [INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[WARNING] Subscription 'exists_1757082297' not found for removal
-[INFO] Closed subscription: exists_1757082297
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[WARNING] Subscription 'exists_1757082298' not found for removal
-[INFO] Closed subscription: exists_1757082298
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
 [INFO] Handling EVENT message with full NIP-01 validation
-[INFO] Event not found for deletion: [INFO] ...
-[INFO] Event not found for deletion: [INFO] ...
-[SUCCESS] Event stored in database
-[INFO] Deletion request processed: 0 events deleted
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[WARNING] Subscription 'exists_1757082301' not found for removal
-[INFO] Closed subscription: exists_1757082301
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[WARNING] Subscription 'exists_1757082301' not found for removal
-[INFO] Closed subscription: exists_1757082301
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[WARNING] Subscription 'exists_1757082301' not found for removal
-[INFO] Closed subscription: exists_1757082301
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[SUCCESS] Event stored in database
-[INFO] Deletion request processed: 0 events deleted
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[WARNING] Subscription 'exists_1757082305' not found for removal
-[INFO] Closed subscription: exists_1757082305
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] Event not found for deletion: ✗ Cou...
-[SUCCESS] Event stored in database
-[INFO] Deletion request processed: 0 events deleted
+[WARNING] Event rejected: expired timestamp
 [INFO] WebSocket connection closed
 [INFO] WebSocket connection established
 [INFO] Received WebSocket message
 [INFO] Handling REQ message for persistent subscription
-[INFO] Added subscription 'exists_1757082309' (total: 1)
-[INFO] Executing SQL: SELECT id, pubkey, created_at, kind, content, sig, tags FROM events WHERE 1=1 ORDER BY created_at DESC LIMIT 500
-[INFO] Query returned 25 rows
-[INFO] Total events sent: 25
+[INFO] Added subscription 'filter_test' (total: 1)
+[INFO] Executing SQL: SELECT id, pubkey, created_at, kind, content, sig, tags FROM events WHERE 1=1 AND kind IN (1) ORDER BY created_at DESC LIMIT 10
+[INFO] Query returned 10 rows
+[INFO] Total events sent: 10
 [INFO] Received WebSocket message
-[INFO] Removed subscription 'exists_1757082309' (total: 0)
-[INFO] Closed subscription: exists_1757082309
+[INFO] Removed subscription 'filter_test' (total: 0)
+[INFO] Closed subscription: filter_test
 [INFO] WebSocket connection closed
-[WARNING] Subscription 'z[<5B><>.Y' not found for removal
+[WARNING] Subscription '<EFBFBD><EFBFBD><15>a' not found for removal
 [INFO] WebSocket connection established
 [INFO] Received WebSocket message
 [INFO] Handling EVENT message with full NIP-01 validation
+[SUCCESS] Event stored in database
+[SUCCESS] Event validated and stored successfully
 [INFO] WebSocket connection closed
 [INFO] WebSocket connection established
 [INFO] Received WebSocket message
-[INFO] Handling REQ message for persistent subscription
-[INFO] Added subscription 'kind5_1757082309' (total: 1)
-[INFO] Executing SQL: SELECT id, pubkey, created_at, kind, content, sig, tags FROM events WHERE 1=1 AND kind IN (5) ORDER BY created_at DESC LIMIT 500
-[INFO] Query returned 3 rows
-[INFO] Total events sent: 3
-[INFO] Received WebSocket message
-[INFO] Removed subscription 'kind5_1757082309' (total: 0)
-[INFO] Closed subscription: kind5_1757082309
+[INFO] Handling EVENT message with full NIP-01 validation
+[SUCCESS] Event stored in database
+[SUCCESS] Event validated and stored successfully
 [INFO] WebSocket connection closed
-[WARNING] Subscription '<27>f<EFBFBD><66>.Y' not found for removal
+[INFO] HTTP request received
+[INFO] Handling NIP-11 relay information request
+[SUCCESS] NIP-11 relay information served successfully

relay.pid

@@ -1 +1 @@
-682319
+743964

src/main.c

@@ -14,6 +14,7 @@
 // Include nostr_core_lib for Nostr functionality
 #include "../nostr_core_lib/cjson/cJSON.h"
 #include "../nostr_core_lib/nostr_core/nostr_core.h"
+#include "../nostr_core_lib/nostr_core/nip013.h"  // NIP-13: Proof of Work
 
 // Server Configuration
 #define DEFAULT_PORT 8888
@@ -28,6 +29,13 @@
 #define SUBSCRIPTION_ID_MAX_LENGTH 64
 #define CLIENT_IP_MAX_LENGTH 64
 
+// NIP-11 relay information configuration
+#define RELAY_NAME_MAX_LENGTH 128
+#define RELAY_DESCRIPTION_MAX_LENGTH 1024
+#define RELAY_URL_MAX_LENGTH 256
+#define RELAY_CONTACT_MAX_LENGTH 128
+#define RELAY_PUBKEY_MAX_LENGTH 65  // 64 hex chars + null terminator
+
 // Color constants for logging
 #define RED     "\033[31m"
 #define GREEN   "\033[32m"
@@ -41,6 +49,72 @@ static sqlite3* g_db = NULL;
 static int g_server_running = 1;
 static struct lws_context *ws_context = NULL;
 
+// NIP-11 relay information structure
+struct relay_info {
+    char name[RELAY_NAME_MAX_LENGTH];
+    char description[RELAY_DESCRIPTION_MAX_LENGTH];
+    char banner[RELAY_URL_MAX_LENGTH];
+    char icon[RELAY_URL_MAX_LENGTH];
+    char pubkey[RELAY_PUBKEY_MAX_LENGTH];
+    char contact[RELAY_CONTACT_MAX_LENGTH];
+    char software[RELAY_URL_MAX_LENGTH];
+    char version[64];
+    char privacy_policy[RELAY_URL_MAX_LENGTH];
+    char terms_of_service[RELAY_URL_MAX_LENGTH];
+    cJSON* supported_nips;      // Array of supported NIP numbers
+    cJSON* limitation;          // Server limitations object
+    cJSON* retention;           // Event retention policies array
+    cJSON* relay_countries;     // Array of country codes
+    cJSON* language_tags;       // Array of language tags
+    cJSON* tags;               // Array of content tags
+    char posting_policy[RELAY_URL_MAX_LENGTH];
+    cJSON* fees;               // Payment fee structure
+    char payments_url[RELAY_URL_MAX_LENGTH];
+};
+
+// Global relay information instance
+static struct relay_info g_relay_info = {0};
+
+// NIP-13 PoW configuration structure
+struct pow_config {
+    int enabled;                    // 0 = disabled, 1 = enabled
+    int min_pow_difficulty;         // Minimum required difficulty (0 = no requirement)
+    int validation_flags;           // Bitflags for validation options
+    int require_nonce_tag;          // 1 = require nonce tag presence
+    int reject_lower_targets;       // 1 = reject if committed < actual difficulty
+    int strict_format;              // 1 = enforce strict nonce tag format
+    int anti_spam_mode;             // 1 = full anti-spam validation
+};
+
+// Global PoW configuration instance
+static struct pow_config g_pow_config = {
+    .enabled = 1,                   // Enable PoW validation by default
+    .min_pow_difficulty = 0,        // No minimum difficulty by default
+    .validation_flags = NOSTR_POW_VALIDATE_BASIC,
+    .require_nonce_tag = 0,         // Don't require nonce tags by default
+    .reject_lower_targets = 0,      // Allow lower committed targets by default
+    .strict_format = 0,             // Relaxed format validation by default
+    .anti_spam_mode = 0            // Basic validation by default
+};
+
+// NIP-40 Expiration configuration structure
+struct expiration_config {
+    int enabled;                    // 0 = disabled, 1 = enabled
+    int strict_mode;                // 1 = reject expired events on submission
+    int filter_responses;           // 1 = filter expired events from responses
+    int delete_expired;             // 1 = delete expired events from DB (future feature)
+    long grace_period;              // Grace period in seconds for clock skew
+};
+
+// Global expiration configuration instance
+static struct expiration_config g_expiration_config = {
+    .enabled = 1,                   // Enable expiration handling by default
+    .strict_mode = 1,               // Reject expired events on submission by default
+    .filter_responses = 1,          // Filter expired events from responses by default
+    .delete_expired = 0,            // Don't delete by default (keep for audit)
+    .grace_period = 300             // 5 minutes grace period for clock skew
+};
+
 
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
@@ -151,6 +225,22 @@ int mark_event_as_deleted(const char* event_id, const char* deletion_event_id, c
 // Forward declaration for database functions
 int store_event(cJSON* event);
 
+// Forward declarations for NIP-11 relay information handling
+void init_relay_info();
+void cleanup_relay_info();
+cJSON* generate_relay_info_json();
+int handle_nip11_http_request(struct lws* wsi, const char* accept_header);
+
+// Forward declarations for NIP-13 PoW validation
+void init_pow_config();
+int validate_event_pow(cJSON* event, char* error_message, size_t error_size);
+
+// Forward declarations for NIP-40 expiration handling
+void init_expiration_config();
+long extract_expiration_timestamp(cJSON* tags);
+int is_event_expired(cJSON* event, time_t current_time);
+int validate_event_expiration(cJSON* event, char* error_message, size_t error_size);
+
 
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
@@ -585,6 +675,19 @@ int broadcast_event_to_subscriptions(cJSON* event) {
         return 0;
     }
     
+    // Check if event is expired and should not be broadcast (NIP-40)
+    if (g_expiration_config.enabled && g_expiration_config.filter_responses) {
+        time_t current_time = time(NULL);
+        if (is_event_expired(event, current_time)) {
+            char debug_msg[256];
+            cJSON* event_id_obj = cJSON_GetObjectItem(event, "id");
+            const char* event_id = event_id_obj ? cJSON_GetStringValue(event_id_obj) : "unknown";
+            snprintf(debug_msg, sizeof(debug_msg), "Skipping broadcast of expired event: %.16s", event_id);
+            log_info(debug_msg);
+            return 0; // Don't broadcast expired events
+        }
+    }
+    
     int broadcasts = 0;
     
     pthread_mutex_lock(&g_subscription_manager.subscriptions_lock);
@@ -922,8 +1025,11 @@ int handle_deletion_request(cJSON* event, char* error_message, size_t error_size
     }
     
     const char* requester_pubkey = cJSON_GetStringValue(pubkey_obj);
+    // Extract deletion event ID and reason (for potential logging)
     const char* deletion_event_id = cJSON_GetStringValue(event_id_obj);
     const char* reason = content_obj ? cJSON_GetStringValue(content_obj) : "";
+    (void)deletion_event_id; // Mark as intentionally unused for now
+    (void)reason;           // Mark as intentionally unused for now
     long deletion_timestamp = (long)cJSON_GetNumberValue(created_at_obj);
     
     if (!cJSON_IsArray(tags_obj)) {
@@ -1011,7 +1117,7 @@ int handle_deletion_request(cJSON* event, char* error_message, size_t error_size
     snprintf(debug_msg, sizeof(debug_msg), "Deletion request processed: %d events deleted", deleted_count);
     log_info(debug_msg);
     
-    snprintf(error_message, error_size, ""); // Success
+    error_message[0] = '\0'; // Success - empty error message
     return 0;
 }
 
@@ -1176,6 +1282,658 @@ int mark_event_as_deleted(const char* event_id, const char* deletion_event_id, c
     return 0;
 }
 
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+//             NIP-11 RELAY INFORMATION DOCUMENT
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+// Initialize relay information with default values
+void init_relay_info() {
+    // Set default relay information
+    strncpy(g_relay_info.name, "C Nostr Relay", sizeof(g_relay_info.name) - 1);
+    strncpy(g_relay_info.description, "A high-performance Nostr relay implemented in C with SQLite storage", sizeof(g_relay_info.description) - 1);
+    strncpy(g_relay_info.software, "https://github.com/teknari/c-relay", sizeof(g_relay_info.software) - 1);
+    strncpy(g_relay_info.version, "0.1.0", sizeof(g_relay_info.version) - 1);
+    
+    // Initialize supported NIPs array
+    g_relay_info.supported_nips = cJSON_CreateArray();
+    if (g_relay_info.supported_nips) {
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(1));   // NIP-01: Basic protocol
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(9));   // NIP-09: Event deletion
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(11));  // NIP-11: Relay information
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(13));  // NIP-13: Proof of Work
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(15));  // NIP-15: EOSE
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(20));  // NIP-20: Command results
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(40));  // NIP-40: Expiration Timestamp
+    }
+    
+    // Initialize server limitations
+    g_relay_info.limitation = cJSON_CreateObject();
+    if (g_relay_info.limitation) {
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_message_length", 16384);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_subscriptions", MAX_SUBSCRIPTIONS_PER_CLIENT);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_limit", 5000);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_subid_length", SUBSCRIPTION_ID_MAX_LENGTH);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_event_tags", 100);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_content_length", 8196);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "min_pow_difficulty", g_pow_config.min_pow_difficulty);
+        cJSON_AddBoolToObject(g_relay_info.limitation, "auth_required", cJSON_False);
+        cJSON_AddBoolToObject(g_relay_info.limitation, "payment_required", cJSON_False);
+        cJSON_AddBoolToObject(g_relay_info.limitation, "restricted_writes", cJSON_False);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "created_at_lower_limit", 0);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "created_at_upper_limit", 2147483647);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "default_limit", 500);
+    }
+    
+    // Initialize empty retention policies (can be configured later)
+    g_relay_info.retention = cJSON_CreateArray();
+    
+    // Initialize language tags - set to global for now
+    g_relay_info.language_tags = cJSON_CreateArray();
+    if (g_relay_info.language_tags) {
+        cJSON_AddItemToArray(g_relay_info.language_tags, cJSON_CreateString("*"));
+    }
+    
+    // Initialize relay countries - set to global for now
+    g_relay_info.relay_countries = cJSON_CreateArray();
+    if (g_relay_info.relay_countries) {
+        cJSON_AddItemToArray(g_relay_info.relay_countries, cJSON_CreateString("*"));
+    }
+    
+    // Initialize content tags as empty array
+    g_relay_info.tags = cJSON_CreateArray();
+    
+    // Initialize fees as empty object (no payment required by default)
+    g_relay_info.fees = cJSON_CreateObject();
+    
+    log_success("Relay information initialized with default values");
+}
+
+// Clean up relay information JSON objects
+void cleanup_relay_info() {
+    if (g_relay_info.supported_nips) {
+        cJSON_Delete(g_relay_info.supported_nips);
+        g_relay_info.supported_nips = NULL;
+    }
+    if (g_relay_info.limitation) {
+        cJSON_Delete(g_relay_info.limitation);
+        g_relay_info.limitation = NULL;
+    }
+    if (g_relay_info.retention) {
+        cJSON_Delete(g_relay_info.retention);
+        g_relay_info.retention = NULL;
+    }
+    if (g_relay_info.language_tags) {
+        cJSON_Delete(g_relay_info.language_tags);
+        g_relay_info.language_tags = NULL;
+    }
+    if (g_relay_info.relay_countries) {
+        cJSON_Delete(g_relay_info.relay_countries);
+        g_relay_info.relay_countries = NULL;
+    }
+    if (g_relay_info.tags) {
+        cJSON_Delete(g_relay_info.tags);
+        g_relay_info.tags = NULL;
+    }
+    if (g_relay_info.fees) {
+        cJSON_Delete(g_relay_info.fees);
+        g_relay_info.fees = NULL;
+    }
+}
+
+// Generate NIP-11 compliant JSON document
+cJSON* generate_relay_info_json() {
+    cJSON* info = cJSON_CreateObject();
+    if (!info) {
+        log_error("Failed to create relay info JSON object");
+        return NULL;
+    }
+    
+    // Add basic relay information
+    if (strlen(g_relay_info.name) > 0) {
+        cJSON_AddStringToObject(info, "name", g_relay_info.name);
+    }
+    if (strlen(g_relay_info.description) > 0) {
+        cJSON_AddStringToObject(info, "description", g_relay_info.description);
+    }
+    if (strlen(g_relay_info.banner) > 0) {
+        cJSON_AddStringToObject(info, "banner", g_relay_info.banner);
+    }
+    if (strlen(g_relay_info.icon) > 0) {
+        cJSON_AddStringToObject(info, "icon", g_relay_info.icon);
+    }
+    if (strlen(g_relay_info.pubkey) > 0) {
+        cJSON_AddStringToObject(info, "pubkey", g_relay_info.pubkey);
+    }
+    if (strlen(g_relay_info.contact) > 0) {
+        cJSON_AddStringToObject(info, "contact", g_relay_info.contact);
+    }
+    
+    // Add supported NIPs
+    if (g_relay_info.supported_nips) {
+        cJSON_AddItemToObject(info, "supported_nips", cJSON_Duplicate(g_relay_info.supported_nips, 1));
+    }
+    
+    // Add software information
+    if (strlen(g_relay_info.software) > 0) {
+        cJSON_AddStringToObject(info, "software", g_relay_info.software);
+    }
+    if (strlen(g_relay_info.version) > 0) {
+        cJSON_AddStringToObject(info, "version", g_relay_info.version);
+    }
+    
+    // Add policies
+    if (strlen(g_relay_info.privacy_policy) > 0) {
+        cJSON_AddStringToObject(info, "privacy_policy", g_relay_info.privacy_policy);
+    }
+    if (strlen(g_relay_info.terms_of_service) > 0) {
+        cJSON_AddStringToObject(info, "terms_of_service", g_relay_info.terms_of_service);
+    }
+    if (strlen(g_relay_info.posting_policy) > 0) {
+        cJSON_AddStringToObject(info, "posting_policy", g_relay_info.posting_policy);
+    }
+    
+    // Add server limitations
+    if (g_relay_info.limitation) {
+        cJSON_AddItemToObject(info, "limitation", cJSON_Duplicate(g_relay_info.limitation, 1));
+    }
+    
+    // Add retention policies if configured
+    if (g_relay_info.retention && cJSON_GetArraySize(g_relay_info.retention) > 0) {
+        cJSON_AddItemToObject(info, "retention", cJSON_Duplicate(g_relay_info.retention, 1));
+    }
+    
+    // Add geographical and language information
+    if (g_relay_info.relay_countries) {
+        cJSON_AddItemToObject(info, "relay_countries", cJSON_Duplicate(g_relay_info.relay_countries, 1));
+    }
+    if (g_relay_info.language_tags) {
+        cJSON_AddItemToObject(info, "language_tags", cJSON_Duplicate(g_relay_info.language_tags, 1));
+    }
+    if (g_relay_info.tags && cJSON_GetArraySize(g_relay_info.tags) > 0) {
+        cJSON_AddItemToObject(info, "tags", cJSON_Duplicate(g_relay_info.tags, 1));
+    }
+    
+    // Add payment information if configured
+    if (strlen(g_relay_info.payments_url) > 0) {
+        cJSON_AddStringToObject(info, "payments_url", g_relay_info.payments_url);
+    }
+    if (g_relay_info.fees && cJSON_GetObjectItem(g_relay_info.fees, "admission")) {
+        cJSON_AddItemToObject(info, "fees", cJSON_Duplicate(g_relay_info.fees, 1));
+    }
+    
+    return info;
+}
+
+// Handle NIP-11 HTTP request
+int handle_nip11_http_request(struct lws* wsi, const char* accept_header) {
+    log_info("Handling NIP-11 relay information request");
+    
+    // Check if client accepts application/nostr+json
+    int accepts_nostr_json = 0;
+    if (accept_header) {
+        if (strstr(accept_header, "application/nostr+json") != NULL) {
+            accepts_nostr_json = 1;
+        }
+    }
+    
+    if (!accepts_nostr_json) {
+        log_warning("HTTP request without proper Accept header for NIP-11");
+        // Return 406 Not Acceptable
+        unsigned char buf[LWS_PRE + 256];
+        unsigned char *p = &buf[LWS_PRE];
+        unsigned char *start = p;
+        unsigned char *end = &buf[sizeof(buf) - 1];
+
+        if (lws_add_http_header_status(wsi, HTTP_STATUS_NOT_ACCEPTABLE, &p, end)) {
+            return -1;
+        }
+        if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)"text/plain", 10, &p, end)) {
+            return -1;
+        }
+        if (lws_add_http_header_content_length(wsi, 0, &p, end)) {
+            return -1;
+        }
+        if (lws_finalize_http_header(wsi, &p, end)) {
+            return -1;
+        }
+        lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
+        return -1; // Close connection
+    }
+    
+    // Generate relay information JSON
+    cJSON* info_json = generate_relay_info_json();
+    if (!info_json) {
+        log_error("Failed to generate relay info JSON");
+        unsigned char buf[LWS_PRE + 256];
+        unsigned char *p = &buf[LWS_PRE];
+        unsigned char *start = p;
+        unsigned char *end = &buf[sizeof(buf) - 1];
+
+        if (lws_add_http_header_status(wsi, HTTP_STATUS_INTERNAL_SERVER_ERROR, &p, end)) {
+            return -1;
+        }
+        if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)"text/plain", 10, &p, end)) {
+            return -1;
+        }
+        if (lws_add_http_header_content_length(wsi, 0, &p, end)) {
+            return -1;
+        }
+        if (lws_finalize_http_header(wsi, &p, end)) {
+            return -1;
+        }
+        lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
+        return -1;
+    }
+    
+    char* json_string = cJSON_Print(info_json);
+    cJSON_Delete(info_json);
+    
+    if (!json_string) {
+        log_error("Failed to serialize relay info JSON");
+        unsigned char buf[LWS_PRE + 256];
+        unsigned char *p = &buf[LWS_PRE];
+        unsigned char *start = p;
+        unsigned char *end = &buf[sizeof(buf) - 1];
+
+        if (lws_add_http_header_status(wsi, HTTP_STATUS_INTERNAL_SERVER_ERROR, &p, end)) {
+            return -1;
+        }
+        if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)"text/plain", 10, &p, end)) {
+            return -1;
+        }
+        if (lws_add_http_header_content_length(wsi, 0, &p, end)) {
+            return -1;
+        }
+        if (lws_finalize_http_header(wsi, &p, end)) {
+            return -1;
+        }
+        lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
+        return -1;
+    }
+    
+    size_t json_len = strlen(json_string);
+    
+    // Prepare HTTP response with CORS headers
+    unsigned char buf[LWS_PRE + 1024];
+    unsigned char *p = &buf[LWS_PRE];
+    unsigned char *start = p;
+    unsigned char *end = &buf[sizeof(buf) - 1];
+    
+    // Add status
+    if (lws_add_http_header_status(wsi, HTTP_STATUS_OK, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    
+    // Add content type
+    if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
+                                     (unsigned char*)"application/nostr+json", 22, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    
+    // Add content length
+    if (lws_add_http_header_content_length(wsi, json_len, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    
+    // Add CORS headers as required by NIP-11
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-origin:",
+                                    (unsigned char*)"*", 1, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-headers:",
+                                    (unsigned char*)"content-type, accept", 20, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-methods:",
+                                    (unsigned char*)"GET, OPTIONS", 12, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    
+    // Finalize headers
+    if (lws_finalize_http_header(wsi, &p, end)) {
+        free(json_string);
+        return -1;
+    }
+    
+    // Write headers
+    if (lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS) < 0) {
+        free(json_string);
+        return -1;
+    }
+    
+    // Write JSON body
+    unsigned char *json_buf = malloc(LWS_PRE + json_len);
+    if (!json_buf) {
+        free(json_string);
+        return -1;
+    }
+    
+    memcpy(json_buf + LWS_PRE, json_string, json_len);
+    if (lws_write(wsi, json_buf + LWS_PRE, json_len, LWS_WRITE_HTTP) < 0) {
+        free(json_string);
+        free(json_buf);
+        return -1;
+    }
+    
+    free(json_buf);
+    
+    free(json_string);
+    log_success("NIP-11 relay information served successfully");
+    return 0;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+//             NIP-13 PROOF OF WORK VALIDATION
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+// Initialize PoW configuration with environment variables and defaults
+void init_pow_config() {
+    log_info("Initializing NIP-13 Proof of Work configuration");
+    
+    // Initialize with defaults (already set in struct initialization)
+    
+    // Check environment variables for configuration
+    const char* pow_enabled_env = getenv("RELAY_POW_ENABLED");
+    if (pow_enabled_env) {
+        g_pow_config.enabled = (strcmp(pow_enabled_env, "1") == 0 ||
+                               strcmp(pow_enabled_env, "true") == 0 ||
+                               strcmp(pow_enabled_env, "yes") == 0);
+    }
+    
+    const char* min_diff_env = getenv("RELAY_MIN_POW_DIFFICULTY");
+    if (min_diff_env) {
+        int min_diff = atoi(min_diff_env);
+        if (min_diff >= 0 && min_diff <= 64) {  // Reasonable bounds
+            g_pow_config.min_pow_difficulty = min_diff;
+        }
+    }
+    
+    const char* pow_mode_env = getenv("RELAY_POW_MODE");
+    if (pow_mode_env) {
+        if (strcmp(pow_mode_env, "strict") == 0) {
+            g_pow_config.validation_flags = NOSTR_POW_VALIDATE_ANTI_SPAM | NOSTR_POW_STRICT_FORMAT;
+            g_pow_config.require_nonce_tag = 1;
+            g_pow_config.reject_lower_targets = 1;
+            g_pow_config.strict_format = 1;
+            g_pow_config.anti_spam_mode = 1;
+            log_info("PoW configured in strict anti-spam mode");
+        } else if (strcmp(pow_mode_env, "full") == 0) {
+            g_pow_config.validation_flags = NOSTR_POW_VALIDATE_FULL;
+            g_pow_config.require_nonce_tag = 1;
+            log_info("PoW configured in full validation mode");
+        } else if (strcmp(pow_mode_env, "basic") == 0) {
+            g_pow_config.validation_flags = NOSTR_POW_VALIDATE_BASIC;
+            log_info("PoW configured in basic validation mode");
+        } else if (strcmp(pow_mode_env, "disabled") == 0) {
+            g_pow_config.enabled = 0;
+            log_info("PoW validation disabled via RELAY_POW_MODE");
+        }
+    }
+    
+    // Log final configuration
+    char config_msg[512];
+    snprintf(config_msg, sizeof(config_msg),
+             "PoW Configuration: enabled=%s, min_difficulty=%d, validation_flags=0x%x, mode=%s",
+             g_pow_config.enabled ? "true" : "false",
+             g_pow_config.min_pow_difficulty,
+             g_pow_config.validation_flags,
+             g_pow_config.anti_spam_mode ? "anti-spam" :
+             (g_pow_config.validation_flags & NOSTR_POW_VALIDATE_FULL) ? "full" : "basic");
+    log_info(config_msg);
+}
+
+// Validate event Proof of Work according to NIP-13
+int validate_event_pow(cJSON* event, char* error_message, size_t error_size) {
+    if (!g_pow_config.enabled) {
+        return 0; // PoW validation disabled
+    }
+    
+    if (!event) {
+        snprintf(error_message, error_size, "pow: null event");
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    
+    // If min_pow_difficulty is 0, only validate events that have nonce tags
+    // This allows events without PoW when difficulty requirement is 0
+    if (g_pow_config.min_pow_difficulty == 0) {
+        cJSON* tags = cJSON_GetObjectItem(event, "tags");
+        int has_nonce_tag = 0;
+        
+        if (tags && cJSON_IsArray(tags)) {
+            cJSON* tag = NULL;
+            cJSON_ArrayForEach(tag, tags) {
+                if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
+                    cJSON* tag_name = cJSON_GetArrayItem(tag, 0);
+                    if (cJSON_IsString(tag_name)) {
+                        const char* name = cJSON_GetStringValue(tag_name);
+                        if (name && strcmp(name, "nonce") == 0) {
+                            has_nonce_tag = 1;
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+        
+        // If no minimum difficulty required and no nonce tag, skip PoW validation
+        if (!has_nonce_tag) {
+            return 0; // Accept event without PoW when min_difficulty=0
+        }
+    }
+    
+    // Perform PoW validation using nostr_core_lib
+    nostr_pow_result_t pow_result;
+    int validation_result = nostr_validate_pow(event, g_pow_config.min_pow_difficulty,
+                                             g_pow_config.validation_flags, &pow_result);
+    
+    if (validation_result != NOSTR_SUCCESS) {
+        // Handle specific error cases with appropriate messages
+        switch (validation_result) {
+            case NOSTR_ERROR_NIP13_INSUFFICIENT:
+                snprintf(error_message, error_size,
+                        "pow: insufficient difficulty: %d < %d",
+                        pow_result.actual_difficulty, g_pow_config.min_pow_difficulty);
+                log_warning("Event rejected: insufficient PoW difficulty");
+                break;
+            case NOSTR_ERROR_NIP13_NO_NONCE_TAG:
+                // This should not happen with min_difficulty=0 after our check above
+                if (g_pow_config.min_pow_difficulty > 0) {
+                    snprintf(error_message, error_size, "pow: missing required nonce tag");
+                    log_warning("Event rejected: missing nonce tag");
+                } else {
+                    return 0; // Allow when min_difficulty=0
+                }
+                break;
+            case NOSTR_ERROR_NIP13_INVALID_NONCE_TAG:
+                snprintf(error_message, error_size, "pow: invalid nonce tag format");
+                log_warning("Event rejected: invalid nonce tag format");
+                break;
+            case NOSTR_ERROR_NIP13_TARGET_MISMATCH:
+                snprintf(error_message, error_size,
+                        "pow: committed target (%d) lower than minimum (%d)",
+                        pow_result.committed_target, g_pow_config.min_pow_difficulty);
+                log_warning("Event rejected: committed target too low (anti-spam protection)");
+                break;
+            case NOSTR_ERROR_NIP13_CALCULATION:
+                snprintf(error_message, error_size, "pow: difficulty calculation failed");
+                log_error("PoW difficulty calculation error");
+                break;
+            case NOSTR_ERROR_EVENT_INVALID_ID:
+                snprintf(error_message, error_size, "pow: invalid event ID format");
+                log_warning("Event rejected: invalid event ID for PoW calculation");
+                break;
+            default:
+                snprintf(error_message, error_size, "pow: validation failed - %s",
+                        strlen(pow_result.error_detail) > 0 ? pow_result.error_detail : "unknown error");
+                log_warning("Event rejected: PoW validation failed");
+        }
+        return validation_result;
+    }
+    
+    // Log successful PoW validation (only if minimum difficulty is required)
+    if (g_pow_config.min_pow_difficulty > 0 || pow_result.has_nonce_tag) {
+        char debug_msg[256];
+        snprintf(debug_msg, sizeof(debug_msg),
+                "PoW validated: difficulty=%d, target=%d, nonce=%llu%s",
+                pow_result.actual_difficulty,
+                pow_result.committed_target,
+                (unsigned long long)pow_result.nonce_value,
+                pow_result.has_nonce_tag ? "" : " (no nonce tag)");
+        log_info(debug_msg);
+    }
+    
+    return 0;  // Success
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+//             NIP-40 EXPIRATION TIMESTAMP HANDLING
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+// Initialize expiration configuration with environment variables and defaults
+void init_expiration_config() {
+    log_info("Initializing NIP-40 Expiration Timestamp configuration");
+    
+    // Check environment variables for configuration
+    const char* exp_enabled_env = getenv("RELAY_EXPIRATION_ENABLED");
+    if (exp_enabled_env) {
+        g_expiration_config.enabled = (strcmp(exp_enabled_env, "1") == 0 ||
+                                      strcmp(exp_enabled_env, "true") == 0 ||
+                                      strcmp(exp_enabled_env, "yes") == 0);
+    }
+    
+    const char* exp_strict_env = getenv("RELAY_EXPIRATION_STRICT");
+    if (exp_strict_env) {
+        g_expiration_config.strict_mode = (strcmp(exp_strict_env, "1") == 0 ||
+                                          strcmp(exp_strict_env, "true") == 0 ||
+                                          strcmp(exp_strict_env, "yes") == 0);
+    }
+    
+    const char* exp_filter_env = getenv("RELAY_EXPIRATION_FILTER");
+    if (exp_filter_env) {
+        g_expiration_config.filter_responses = (strcmp(exp_filter_env, "1") == 0 ||
+                                               strcmp(exp_filter_env, "true") == 0 ||
+                                               strcmp(exp_filter_env, "yes") == 0);
+    }
+    
+    const char* exp_delete_env = getenv("RELAY_EXPIRATION_DELETE");
+    if (exp_delete_env) {
+        g_expiration_config.delete_expired = (strcmp(exp_delete_env, "1") == 0 ||
+                                             strcmp(exp_delete_env, "true") == 0 ||
+                                             strcmp(exp_delete_env, "yes") == 0);
+    }
+    
+    const char* exp_grace_env = getenv("RELAY_EXPIRATION_GRACE_PERIOD");
+    if (exp_grace_env) {
+        long grace_period = atol(exp_grace_env);
+        if (grace_period >= 0 && grace_period <= 86400) {  // Max 24 hours
+            g_expiration_config.grace_period = grace_period;
+        }
+    }
+    
+    // Log final configuration
+    char config_msg[512];
+    snprintf(config_msg, sizeof(config_msg),
+             "Expiration Configuration: enabled=%s, strict_mode=%s, filter_responses=%s, grace_period=%ld seconds",
+             g_expiration_config.enabled ? "true" : "false",
+             g_expiration_config.strict_mode ? "true" : "false",
+             g_expiration_config.filter_responses ? "true" : "false",
+             g_expiration_config.grace_period);
+    log_info(config_msg);
+}
+
+// Extract expiration timestamp from event tags
+long extract_expiration_timestamp(cJSON* tags) {
+    if (!tags || !cJSON_IsArray(tags)) {
+        return 0; // No expiration
+    }
+    
+    cJSON* tag = NULL;
+    cJSON_ArrayForEach(tag, tags) {
+        if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
+            cJSON* tag_name = cJSON_GetArrayItem(tag, 0);
+            cJSON* tag_value = cJSON_GetArrayItem(tag, 1);
+            
+            if (cJSON_IsString(tag_name) && cJSON_IsString(tag_value)) {
+                const char* name = cJSON_GetStringValue(tag_name);
+                const char* value = cJSON_GetStringValue(tag_value);
+                
+                if (name && value && strcmp(name, "expiration") == 0) {
+                    long expiration_ts = atol(value);
+                    if (expiration_ts > 0) {
+                        return expiration_ts;
+                    }
+                }
+            }
+        }
+    }
+    
+    return 0; // No valid expiration tag found
+}
+
+// Check if event is currently expired
+int is_event_expired(cJSON* event, time_t current_time) {
+    if (!event) {
+        return 0; // Invalid event, not expired
+    }
+    
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    long expiration_ts = extract_expiration_timestamp(tags);
+    
+    if (expiration_ts == 0) {
+        return 0; // No expiration timestamp, not expired
+    }
+    
+    // Check if current time exceeds expiration + grace period
+    return (current_time > (expiration_ts + g_expiration_config.grace_period));
+}
+
+// Validate event expiration according to NIP-40
+int validate_event_expiration(cJSON* event, char* error_message, size_t error_size) {
+    if (!g_expiration_config.enabled) {
+        return 0; // Expiration validation disabled
+    }
+    
+    if (!event) {
+        snprintf(error_message, error_size, "expiration: null event");
+        return -1;
+    }
+    
+    // Check if event is expired
+    time_t current_time = time(NULL);
+    if (is_event_expired(event, current_time)) {
+        if (g_expiration_config.strict_mode) {
+            cJSON* tags = cJSON_GetObjectItem(event, "tags");
+            long expiration_ts = extract_expiration_timestamp(tags);
+            
+            snprintf(error_message, error_size,
+                    "invalid: event expired (expiration=%ld, current=%ld, grace=%ld)",
+                    expiration_ts, (long)current_time, g_expiration_config.grace_period);
+            log_warning("Event rejected: expired timestamp");
+            return -1;
+        } else {
+            // In non-strict mode, log but allow expired events
+            char debug_msg[256];
+            snprintf(debug_msg, sizeof(debug_msg),
+                    "Accepting expired event (strict_mode disabled)");
+            log_info(debug_msg);
+        }
+    }
+    
+    return 0; // Success
+}
+
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
 //             DATABASE FUNCTIONS
@@ -1584,6 +2342,9 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
         char* sql_ptr = sql + strlen(sql);
         int remaining = sizeof(sql) - strlen(sql);
         
+        // Note: Expiration filtering will be done at application level
+        // after retrieving events to ensure compatibility with all SQLite versions
+        
         // Handle kinds filter
         cJSON* kinds = cJSON_GetObjectItem(filter, "kinds");
         if (kinds && cJSON_IsArray(kinds)) {
@@ -1712,6 +2473,16 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
             }
             cJSON_AddItemToObject(event, "tags", tags);
             
+            // Check expiration filtering (NIP-40) at application level
+            if (g_expiration_config.enabled && g_expiration_config.filter_responses) {
+                time_t current_time = time(NULL);
+                if (is_event_expired(event, current_time)) {
+                    // Skip this expired event
+                    cJSON_Delete(event);
+                    continue;
+                }
+            }
+            
             // Send EVENT message
             cJSON* event_msg = cJSON_CreateArray();
             cJSON_AddItemToArray(event_msg, cJSON_CreateString("EVENT"));
@@ -1801,14 +2572,26 @@ int handle_event_message(cJSON* event, char* error_message, size_t error_size) {
         return signature_result;
     }
     
-    // Step 3: Complete event validation (combines structure + signature + additional checks)
+    // Step 3: Validate Proof of Work (NIP-13) if enabled
+    int pow_result = validate_event_pow(event, error_message, error_size);
+    if (pow_result != 0) {
+        return pow_result;  // PoW validation failed, error message already set
+    }
+    
+    // Step 4: Validate expiration timestamp (NIP-40) if enabled
+    int expiration_result = validate_event_expiration(event, error_message, error_size);
+    if (expiration_result != 0) {
+        return expiration_result;  // Expiration validation failed, error message already set
+    }
+    
+    // Step 5: Complete event validation (combines structure + signature + additional checks)
     int validation_result = nostr_validate_event(event);
     if (validation_result != NOSTR_SUCCESS) {
         snprintf(error_message, error_size, "invalid: complete event validation failed");
         return validation_result;
     }
     
-    // Step 4: Check for special event types and handle accordingly
+    // Step 6: Check for special event types and handle accordingly
     cJSON* kind_obj = cJSON_GetObjectItem(event, "kind");
     cJSON* pubkey_obj = cJSON_GetObjectItem(event, "pubkey");
     cJSON* created_at_obj = cJSON_GetObjectItem(event, "created_at");
@@ -1843,14 +2626,14 @@ int handle_event_message(cJSON* event, char* error_message, size_t error_size) {
             }
         } else if (event_type == EVENT_TYPE_EPHEMERAL) {
             // Ephemeral events should not be stored
-            snprintf(error_message, error_size, "");  // Success but no storage
+            error_message[0] = '\0';  // Success but no storage - empty error message
             return 0;  // Accept but don't store
         }
     }
     
-    // Step 5: Store event in database
+    // Step 7: Store event in database
     if (store_event(event) == 0) {
-        snprintf(error_message, error_size, "");  // Success
+        error_message[0] = '\0';  // Success - empty error message
         log_success("Event validated and stored successfully");
         return 0;
     }
@@ -1873,6 +2656,43 @@ static int nostr_relay_callback(struct lws *wsi, enum lws_callback_reasons reaso
     struct per_session_data *pss = (struct per_session_data *)user;
     
     switch (reason) {
+        case LWS_CALLBACK_HTTP:
+            // Handle NIP-11 relay information requests (HTTP GET to root path)
+            {
+                char *requested_uri = (char *)in;
+                log_info("HTTP request received");
+                
+                // Check if this is a GET request to the root path
+                if (strcmp(requested_uri, "/") == 0) {
+                    // Get Accept header
+                    char accept_header[256] = {0};
+                    int header_len = lws_hdr_copy(wsi, accept_header, sizeof(accept_header) - 1, WSI_TOKEN_HTTP_ACCEPT);
+                    
+                    if (header_len > 0) {
+                        accept_header[header_len] = '\0';
+                        
+                        // Handle NIP-11 request
+                        if (handle_nip11_http_request(wsi, accept_header) == 0) {
+                            return 0; // Successfully handled
+                        }
+                    } else {
+                        log_warning("HTTP request without Accept header");
+                    }
+                    
+                    // Return 404 for other requests
+                    lws_return_http_status(wsi, HTTP_STATUS_NOT_FOUND, NULL);
+                    return -1;
+                }
+                
+                // Return 404 for non-root paths
+                lws_return_http_status(wsi, HTTP_STATUS_NOT_FOUND, NULL);
+                return -1;
+            }
+            
+        case LWS_CALLBACK_HTTP_WRITEABLE:
+            // HTTP response continuation if needed
+            break;
+            
         case LWS_CALLBACK_ESTABLISHED:
             log_info("WebSocket connection established");
             memset(pss, 0, sizeof(*pss));
@@ -2175,12 +2995,22 @@ int main(int argc, char* argv[]) {
         return 1;
     }
     
+    // Initialize NIP-11 relay information
+    init_relay_info();
+    
+    // Initialize NIP-13 PoW configuration
+    init_pow_config();
+    
+    // Initialize NIP-40 expiration configuration
+    init_expiration_config();
+    
     log_info("Starting relay server...");
     
     // Start WebSocket Nostr relay server
     int result = start_websocket_relay();
     
     // Cleanup
+    cleanup_relay_info();
     nostr_cleanup();
     close_database();
     

tests/11_nip_information.sh

@@ -0,0 +1,432 @@
+#!/bin/bash
+
+# NIP-11 Relay Information Document Test
+# Tests HTTP endpoint for relay information according to NIP-11 specification
+
+set -e  # Exit on any error
+
+# Color constants
+RED='\033[31m'
+GREEN='\033[32m'
+YELLOW='\033[33m'
+BLUE='\033[34m'
+BOLD='\033[1m'
+RESET='\033[0m'
+
+# Test configuration
+RELAY_URL="http://127.0.0.1:8888"
+RELAY_WS_URL="ws://127.0.0.1:8888"
+
+# Print functions
+print_header() {
+    echo -e "${BLUE}${BOLD}=== $1 ===${RESET}"
+}
+
+print_step() {
+    echo -e "${YELLOW}[STEP]${RESET} $1"
+}
+
+print_success() {
+    echo -e "${GREEN}✓${RESET} $1"
+}
+
+print_error() {
+    echo -e "${RED}✗${RESET} $1"
+}
+
+print_info() {
+    echo -e "${BLUE}[INFO]${RESET} $1"
+}
+
+print_warning() {
+    echo -e "${YELLOW}[WARNING]${RESET} $1"
+}
+
+# Test functions
+test_http_with_correct_header() {
+    print_step "Testing HTTP request with correct Accept header"
+    
+    local response=""
+    local http_code=""
+    
+    if command -v curl &> /dev/null; then
+        # Use curl to test with proper Accept header
+        response=$(curl -s -H "Accept: application/nostr+json" "$RELAY_URL/" 2>/dev/null || echo "")
+        http_code=$(curl -s -o /dev/null -w "%{http_code}" -H "Accept: application/nostr+json" "$RELAY_URL/" 2>/dev/null || echo "000")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    if [[ "$http_code" == "200" ]]; then
+        print_success "HTTP 200 OK received with correct Accept header"
+        
+        # Validate JSON response
+        if echo "$response" | jq . >/dev/null 2>&1; then
+            print_success "Response is valid JSON"
+            return 0
+        else
+            print_error "Response is not valid JSON"
+            return 1
+        fi
+    else
+        print_error "Expected HTTP 200, got HTTP $http_code"
+        return 1
+    fi
+}
+
+test_http_without_header() {
+    print_step "Testing HTTP request without Accept header (should return 406)"
+    
+    local http_code=""
+    
+    if command -v curl &> /dev/null; then
+        http_code=$(curl -s -o /dev/null -w "%{http_code}" "$RELAY_URL/" 2>/dev/null || echo "000")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    if [[ "$http_code" == "406" ]]; then
+        print_success "HTTP 406 Not Acceptable received without proper Accept header"
+        return 0
+    else
+        print_error "Expected HTTP 406, got HTTP $http_code"
+        return 1
+    fi
+}
+
+test_http_with_wrong_header() {
+    print_step "Testing HTTP request with wrong Accept header (should return 406)"
+    
+    local http_code=""
+    
+    if command -v curl &> /dev/null; then
+        http_code=$(curl -s -o /dev/null -w "%{http_code}" -H "Accept: application/json" "$RELAY_URL/" 2>/dev/null || echo "000")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    if [[ "$http_code" == "406" ]]; then
+        print_success "HTTP 406 Not Acceptable received with wrong Accept header"
+        return 0
+    else
+        print_error "Expected HTTP 406, got HTTP $http_code"
+        return 1
+    fi
+}
+
+test_cors_headers() {
+    print_step "Testing CORS headers presence"
+    
+    local headers=""
+    
+    if command -v curl &> /dev/null; then
+        headers=$(curl -s -I -H "Accept: application/nostr+json" "$RELAY_URL/" 2>/dev/null || echo "")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    local cors_origin_found=false
+    local cors_headers_found=false
+    local cors_methods_found=false
+    
+    if echo "$headers" | grep -qi "access-control-allow-origin"; then
+        cors_origin_found=true
+        print_success "Access-Control-Allow-Origin header found"
+    fi
+    
+    if echo "$headers" | grep -qi "access-control-allow-headers"; then
+        cors_headers_found=true
+        print_success "Access-Control-Allow-Headers header found"
+    fi
+    
+    if echo "$headers" | grep -qi "access-control-allow-methods"; then
+        cors_methods_found=true
+        print_success "Access-Control-Allow-Methods header found"
+    fi
+    
+    if [[ "$cors_origin_found" == true && "$cors_headers_found" == true && "$cors_methods_found" == true ]]; then
+        print_success "All required CORS headers present"
+        return 0
+    else
+        print_error "Missing CORS headers"
+        return 1
+    fi
+}
+
+test_json_structure() {
+    print_step "Testing NIP-11 JSON structure and required fields"
+    
+    local response=""
+    
+    if command -v curl &> /dev/null; then
+        response=$(curl -s -H "Accept: application/nostr+json" "$RELAY_URL/" 2>/dev/null || echo "")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    if [[ -z "$response" ]]; then
+        print_error "Empty response received"
+        return 1
+    fi
+    
+    # Validate JSON structure using jq
+    if ! echo "$response" | jq . >/dev/null 2>&1; then
+        print_error "Response is not valid JSON"
+        return 1
+    fi
+    
+    print_success "Valid JSON structure confirmed"
+    
+    # Check for required fields
+    local required_checks=0
+    local total_checks=0
+    
+    # Test name field
+    ((total_checks++))
+    if echo "$response" | jq -e '.name' >/dev/null 2>&1; then
+        local name=$(echo "$response" | jq -r '.name')
+        print_success "Name field present: $name"
+        ((required_checks++))
+    else
+        print_warning "Name field missing (optional)"
+    fi
+    
+    # Test supported_nips field (required)
+    ((total_checks++))
+    if echo "$response" | jq -e '.supported_nips' >/dev/null 2>&1; then
+        local nips=$(echo "$response" | jq -r '.supported_nips | @json')
+        print_success "Supported NIPs field present: $nips"
+        ((required_checks++))
+        
+        # Verify NIP-11 is in the supported list
+        if echo "$response" | jq -e '.supported_nips | contains([11])' >/dev/null 2>&1; then
+            print_success "NIP-11 correctly listed in supported NIPs"
+        else
+            print_warning "NIP-11 not found in supported NIPs list"
+        fi
+    else
+        print_error "Supported NIPs field missing (should be present)"
+    fi
+    
+    # Test software field
+    ((total_checks++))
+    if echo "$response" | jq -e '.software' >/dev/null 2>&1; then
+        local software=$(echo "$response" | jq -r '.software')
+        print_success "Software field present: $software"
+        ((required_checks++))
+    else
+        print_warning "Software field missing (optional)"
+    fi
+    
+    # Test version field
+    ((total_checks++))
+    if echo "$response" | jq -e '.version' >/dev/null 2>&1; then
+        local version=$(echo "$response" | jq -r '.version')
+        print_success "Version field present: $version"
+        ((required_checks++))
+    else
+        print_warning "Version field missing (optional)"
+    fi
+    
+    # Test limitation object
+    ((total_checks++))
+    if echo "$response" | jq -e '.limitation' >/dev/null 2>&1; then
+        print_success "Limitation object present"
+        ((required_checks++))
+        
+        # Check some common limitation fields
+        if echo "$response" | jq -e '.limitation.max_message_length' >/dev/null 2>&1; then
+            local max_msg=$(echo "$response" | jq -r '.limitation.max_message_length')
+            print_info "  max_message_length: $max_msg"
+        fi
+        
+        if echo "$response" | jq -e '.limitation.max_subscriptions' >/dev/null 2>&1; then
+            local max_subs=$(echo "$response" | jq -r '.limitation.max_subscriptions')
+            print_info "  max_subscriptions: $max_subs"
+        fi
+    else
+        print_warning "Limitation object missing (recommended)"
+    fi
+    
+    # Test description field
+    if echo "$response" | jq -e '.description' >/dev/null 2>&1; then
+        local description=$(echo "$response" | jq -r '.description')
+        print_success "Description field present: ${description:0:50}..."
+    else
+        print_warning "Description field missing (optional)"
+    fi
+    
+    print_info "JSON structure validation: $required_checks/$total_checks core fields present"
+    return 0
+}
+
+test_content_type_header() {
+    print_step "Testing Content-Type header"
+    
+    local headers=""
+    
+    if command -v curl &> /dev/null; then
+        headers=$(curl -s -I -H "Accept: application/nostr+json" "$RELAY_URL/" 2>/dev/null || echo "")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    if echo "$headers" | grep -qi "content-type.*application/nostr+json"; then
+        print_success "Correct Content-Type header: application/nostr+json"
+        return 0
+    else
+        print_warning "Content-Type header not exactly 'application/nostr+json'"
+        echo "$headers" | grep -i "content-type" | head -1
+        return 1
+    fi
+}
+
+test_non_root_path() {
+    print_step "Testing non-root path (should return 404)"
+    
+    local http_code=""
+    
+    if command -v curl &> /dev/null; then
+        http_code=$(curl -s -o /dev/null -w "%{http_code}" -H "Accept: application/nostr+json" "$RELAY_URL/nonexistent" 2>/dev/null || echo "000")
+    else
+        print_error "curl command not found - required for NIP-11 testing"
+        return 1
+    fi
+    
+    if [[ "$http_code" == "404" ]]; then
+        print_success "HTTP 404 Not Found received for non-root path"
+        return 0
+    else
+        print_error "Expected HTTP 404 for non-root path, got HTTP $http_code"
+        return 1
+    fi
+}
+
+test_websocket_still_works() {
+    print_step "Testing that WebSocket functionality still works on same port"
+    
+    if ! command -v websocat &> /dev/null; then
+        print_warning "websocat not available - skipping WebSocket test"
+        return 0
+    fi
+    
+    # Try to connect to WebSocket and send a simple REQ
+    local response=""
+    response=$(echo '["REQ","test_ws_nip11",{}]' | timeout 3s websocat "$RELAY_WS_URL" 2>/dev/null || echo "Connection failed")
+    
+    if [[ "$response" == *"Connection failed"* ]]; then
+        print_error "WebSocket connection failed"
+        return 1
+    elif [[ "$response" == *"EOSE"* ]]; then
+        print_success "WebSocket still functional - received EOSE response"
+        return 0
+    else
+        print_warning "WebSocket response unclear, but connection succeeded"
+        return 0
+    fi
+}
+
+# Main test function
+run_nip11_tests() {
+    print_header "NIP-11 Relay Information Document Tests"
+    
+    # Check dependencies
+    print_step "Checking dependencies..."
+    if ! command -v curl &> /dev/null; then
+        print_error "curl command not found - required for NIP-11 HTTP testing"
+        return 1
+    fi
+    if ! command -v jq &> /dev/null; then
+        print_error "jq command not found - required for JSON validation"
+        return 1
+    fi
+    print_success "All dependencies found"
+    
+    print_header "PHASE 1: Basic HTTP Functionality"
+    
+    # Test 1: Correct Accept header
+    if ! test_http_with_correct_header; then
+        return 1
+    fi
+    
+    # Test 2: Missing Accept header
+    if ! test_http_without_header; then
+        return 1
+    fi
+    
+    # Test 3: Wrong Accept header
+    if ! test_http_with_wrong_header; then
+        return 1
+    fi
+    
+    print_header "PHASE 2: HTTP Headers Validation"
+    
+    # Test 4: CORS headers
+    if ! test_cors_headers; then
+        return 1
+    fi
+    
+    # Test 5: Content-Type header
+    if ! test_content_type_header; then
+        return 1
+    fi
+    
+    print_header "PHASE 3: JSON Structure Validation"
+    
+    # Test 6: JSON structure and required fields
+    if ! test_json_structure; then
+        return 1
+    fi
+    
+    print_header "PHASE 4: Additional Endpoint Behavior"
+    
+    # Test 7: Non-root paths
+    if ! test_non_root_path; then
+        return 1
+    fi
+    
+    # Test 8: WebSocket compatibility
+    if ! test_websocket_still_works; then
+        return 1
+    fi
+    
+    print_header "PHASE 5: NIP-11 Compliance Summary"
+    
+    # Final validation - get the actual response and display it
+    print_step "Displaying complete NIP-11 response..."
+    local response=""
+    if command -v curl &> /dev/null; then
+        response=$(curl -s -H "Accept: application/nostr+json" "$RELAY_URL/" 2>/dev/null || echo "")
+        if [[ -n "$response" ]] && echo "$response" | jq . >/dev/null 2>&1; then
+            echo "$response" | jq .
+        else
+            print_error "Failed to retrieve or parse final response"
+        fi
+    fi
+    
+    print_success "All NIP-11 tests passed!"
+    return 0
+}
+
+# Main execution
+print_header "Starting NIP-11 Relay Information Document Test Suite"
+echo
+
+if run_nip11_tests; then
+    echo
+    print_success "All NIP-11 tests completed successfully!"
+    print_info "The C-Relay NIP-11 implementation is fully compliant"
+    print_info "✅ HTTP endpoint, Accept header validation, CORS, and JSON structure all working"
+    echo
+    exit 0
+else
+    echo
+    print_error "Some NIP-11 tests failed"
+    exit 1
+fi

tests/13_nip_test.sh

@@ -0,0 +1,384 @@
+#!/bin/bash
+
+# NIP-13 Proof of Work Validation Test Suite for C Nostr Relay
+# Tests PoW validation in the relay's event processing pipeline
+# Based on nostr_core_lib/tests/nip13_test.c
+
+set -e  # Exit on error
+
+# Color constants
+RED='\033[31m'
+GREEN='\033[32m'
+YELLOW='\033[33m'
+BLUE='\033[34m'
+BOLD='\033[1m'
+RESET='\033[0m'
+
+# Test configuration
+RELAY_URL="ws://127.0.0.1:8888"
+HTTP_URL="http://127.0.0.1:8888"
+TEST_COUNT=0
+PASSED_COUNT=0
+FAILED_COUNT=0
+
+# Test results tracking
+declare -a TEST_RESULTS=()
+
+print_info() {
+    echo -e "${BLUE}[INFO]${RESET} $1"
+}
+
+print_success() {
+    echo -e "${GREEN}${BOLD}[SUCCESS]${RESET} $1"
+}
+
+print_warning() {
+    echo -e "${YELLOW}[WARNING]${RESET} $1"
+}
+
+print_error() {
+    echo -e "${RED}${BOLD}[ERROR]${RESET} $1"
+}
+
+print_test_header() {
+    TEST_COUNT=$((TEST_COUNT + 1))
+    echo ""
+    echo -e "${BOLD}=== TEST $TEST_COUNT: $1 ===${RESET}"
+}
+
+record_test_result() {
+    local test_name="$1"
+    local result="$2"
+    local details="$3"
+    
+    TEST_RESULTS+=("$test_name|$result|$details")
+    
+    if [ "$result" = "PASS" ]; then
+        PASSED_COUNT=$((PASSED_COUNT + 1))
+        print_success "PASS: $test_name"
+    else
+        FAILED_COUNT=$((FAILED_COUNT + 1))
+        print_error "FAIL: $test_name"
+        if [ -n "$details" ]; then
+            echo "       Details: $details"
+        fi
+    fi
+}
+
+# Check if relay is running
+check_relay_running() {
+    print_info "Checking if relay is running..."
+    
+    if ! curl -s -H "Accept: application/nostr+json" "$HTTP_URL/" >/dev/null 2>&1; then
+        print_error "Relay is not running or not accessible at $HTTP_URL"
+        print_info "Please start the relay with: ./make_and_restart_relay.sh"
+        exit 1
+    fi
+    
+    print_success "Relay is running and accessible"
+}
+
+# Test NIP-11 relay information includes NIP-13
+test_nip11_pow_support() {
+    print_test_header "NIP-11 PoW Support Advertisement"
+    
+    print_info "Fetching relay information..."
+    RELAY_INFO=$(curl -s -H "Accept: application/nostr+json" "$HTTP_URL/")
+    
+    echo "Relay Info Response:"
+    echo "$RELAY_INFO" | jq '.'
+    echo ""
+    
+    # Check if NIP-13 is in supported_nips
+    if echo "$RELAY_INFO" | jq -e '.supported_nips | index(13)' >/dev/null 2>&1; then
+        print_success "✓ NIP-13 found in supported_nips array"
+        NIP13_SUPPORTED=true
+    else
+        print_error "✗ NIP-13 not found in supported_nips array"
+        NIP13_SUPPORTED=false
+    fi
+    
+    # Check if min_pow_difficulty is present
+    MIN_POW_DIFF=$(echo "$RELAY_INFO" | jq -r '.limitation.min_pow_difficulty // "missing"')
+    if [ "$MIN_POW_DIFF" != "missing" ]; then
+        print_success "✓ min_pow_difficulty found: $MIN_POW_DIFF"
+        MIN_POW_PRESENT=true
+    else
+        print_error "✗ min_pow_difficulty not found in limitations"
+        MIN_POW_PRESENT=false
+    fi
+    
+    if [ "$NIP13_SUPPORTED" = true ] && [ "$MIN_POW_PRESENT" = true ]; then
+        record_test_result "NIP-11 PoW Support Advertisement" "PASS" "NIP-13 supported, min_pow_difficulty=$MIN_POW_DIFF"
+        return 0
+    else
+        record_test_result "NIP-11 PoW Support Advertisement" "FAIL" "Missing NIP-13 support or min_pow_difficulty"
+        return 1
+    fi
+}
+
+# Test event submission without PoW (should be accepted when min_difficulty=0)
+test_event_without_pow() {
+    print_test_header "Event Submission Without PoW (min_difficulty=0)"
+    
+    # Create a simple event without PoW
+    print_info "Generating test event without PoW..."
+    
+    # Use nak to generate a simple event
+    if ! command -v nak &> /dev/null; then
+        print_warning "nak command not found - skipping PoW generation tests"
+        record_test_result "Event Submission Without PoW" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    # Generate event without PoW using direct private key
+    PRIVATE_KEY="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    EVENT_JSON=$(nak event --sec "$PRIVATE_KEY" -c "Test event without PoW" --ts $(date +%s))
+    
+    print_info "Generated event:"
+    echo "$EVENT_JSON" | jq '.'
+    echo ""
+    
+    # Send event to relay via WebSocket using websocat
+    print_info "Sending event to relay..."
+    
+    # Create EVENT message in Nostr format
+    EVENT_MESSAGE="[\"EVENT\",$EVENT_JSON]"
+    
+    # Send to relay and capture response
+    if command -v websocat &> /dev/null; then
+        RESPONSE=$(echo "$EVENT_MESSAGE" | timeout 5s websocat "$RELAY_URL" 2>&1 || echo "Connection failed")
+        
+        print_info "Relay response: $RESPONSE"
+        
+        if [[ "$RESPONSE" == *"Connection failed"* ]]; then
+            print_error "✗ Failed to connect to relay"
+            record_test_result "Event Submission Without PoW" "FAIL" "Connection failed"
+            return 1
+        elif [[ "$RESPONSE" == *"true"* ]]; then
+            print_success "✓ Event without PoW accepted (expected when min_difficulty=0)"
+            record_test_result "Event Submission Without PoW" "PASS" "Event accepted as expected"
+            return 0
+        else
+            print_error "✗ Event without PoW rejected (unexpected when min_difficulty=0)"
+            record_test_result "Event Submission Without PoW" "FAIL" "Event rejected: $RESPONSE"
+            return 1
+        fi
+    else
+        print_error "websocat not found - required for testing"
+        record_test_result "Event Submission Without PoW" "SKIP" "websocat not available"
+        return 0
+    fi
+}
+
+# Test event with valid PoW
+test_event_with_pow() {
+    print_test_header "Event Submission With Valid PoW"
+    
+    if ! command -v nak &> /dev/null; then
+        print_warning "nak command not found - skipping PoW validation tests"
+        record_test_result "Event Submission With Valid PoW" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Generating event with PoW difficulty 8..."
+    
+    # Generate event with PoW (difficulty 8 for reasonable test time) using direct private key
+    PRIVATE_KEY="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    POW_EVENT_JSON=$(nak event --sec "$PRIVATE_KEY" -c "Test event with PoW difficulty 8" --pow 8 --ts $(date +%s))
+    
+    if [ -z "$POW_EVENT_JSON" ]; then
+        print_error "Failed to generate PoW event"
+        record_test_result "Event Submission With Valid PoW" "FAIL" "PoW event generation failed"
+        return 1
+    fi
+    
+    print_info "Generated PoW event:"
+    echo "$POW_EVENT_JSON" | jq '.'
+    echo ""
+    
+    # Extract nonce info for verification
+    NONCE_TAG=$(echo "$POW_EVENT_JSON" | jq -r '.tags[] | select(.[0] == "nonce") | .[1]' 2>/dev/null || echo "")
+    TARGET_DIFF=$(echo "$POW_EVENT_JSON" | jq -r '.tags[] | select(.[0] == "nonce") | .[2]' 2>/dev/null || echo "")
+    
+    if [ -n "$NONCE_TAG" ] && [ -n "$TARGET_DIFF" ]; then
+        print_info "PoW details: nonce=$NONCE_TAG, target_difficulty=$TARGET_DIFF"
+    fi
+    
+    # Send event to relay via WebSocket using websocat
+    print_info "Sending PoW event to relay..."
+    
+    # Create EVENT message in Nostr format
+    POW_EVENT_MESSAGE="[\"EVENT\",$POW_EVENT_JSON]"
+    
+    # Send to relay and capture response
+    if command -v websocat &> /dev/null; then
+        RESPONSE=$(echo "$POW_EVENT_MESSAGE" | timeout 10s websocat "$RELAY_URL" 2>&1 || echo "Connection failed")
+        
+        print_info "Relay response: $RESPONSE"
+        
+        if [[ "$RESPONSE" == *"Connection failed"* ]]; then
+            print_error "✗ Failed to connect to relay"
+            record_test_result "Event Submission With Valid PoW" "FAIL" "Connection failed"
+            return 1
+        elif [[ "$RESPONSE" == *"true"* ]]; then
+            print_success "✓ Event with valid PoW accepted"
+            record_test_result "Event Submission With Valid PoW" "PASS" "PoW event accepted"
+            return 0
+        else
+            print_error "✗ Event with valid PoW rejected"
+            record_test_result "Event Submission With Valid PoW" "FAIL" "PoW event rejected: $RESPONSE"
+            return 1
+        fi
+    else
+        print_error "websocat not found - required for testing"
+        record_test_result "Event Submission With Valid PoW" "SKIP" "websocat not available"
+        return 0
+    fi
+}
+
+# Test relay configuration with environment variables
+test_pow_configuration() {
+    print_test_header "PoW Configuration Via Environment Variables"
+    
+    print_info "Testing different PoW configurations requires relay restart"
+    print_info "Current configuration from logs:"
+    
+    if [ -f "relay.log" ]; then
+        grep "PoW Configuration:" relay.log | tail -1
+    else
+        print_warning "No relay.log found"
+    fi
+    
+    # Test current configuration values
+    RELAY_INFO=$(curl -s -H "Accept: application/nostr+json" "$HTTP_URL/")
+    MIN_POW_DIFF=$(echo "$RELAY_INFO" | jq -r '.limitation.min_pow_difficulty')
+    
+    print_info "Current min_pow_difficulty from NIP-11: $MIN_POW_DIFF"
+    
+    # For now, just verify the configuration is readable
+    if [ "$MIN_POW_DIFF" != "null" ] && [ "$MIN_POW_DIFF" != "missing" ]; then
+        print_success "✓ PoW configuration is accessible via NIP-11"
+        record_test_result "PoW Configuration Via Environment Variables" "PASS" "min_pow_difficulty=$MIN_POW_DIFF"
+        return 0
+    else
+        print_error "✗ PoW configuration not accessible"
+        record_test_result "PoW Configuration Via Environment Variables" "FAIL" "Cannot read min_pow_difficulty"
+        return 1
+    fi
+}
+
+# Test NIP-13 reference event validation
+test_nip13_reference_event() {
+    print_test_header "NIP-13 Reference Event Validation"
+    
+    # This is the official NIP-13 reference event
+    NIP13_REF_EVENT='{"id":"000006d8c378af1779d2feebc7603a125d99eca0ccf1085959b307f64e5dd358","pubkey":"a48380f4cfcc1ad5378294fcac36439770f9c878dd880ffa94bb74ea54a6f243","created_at":1651794653,"kind":1,"tags":[["nonce","776797","20"]],"content":"It'\''s just me mining my own business","sig":"284622fc0a3f4f1303455d5175f7ba962a3300d136085b9566801bc2e0699de0c7e31e44c81fb40ad9049173742e904713c3594a1da0fc5d2382a25c11aba977"}'
+    
+    print_info "Testing NIP-13 reference event from specification:"
+    echo "$NIP13_REF_EVENT" | jq '.'
+    echo ""
+    
+    # Send reference event to relay via WebSocket using websocat
+    print_info "Sending NIP-13 reference event to relay..."
+    
+    # Create EVENT message in Nostr format
+    REF_EVENT_MESSAGE="[\"EVENT\",$NIP13_REF_EVENT]"
+    
+    # Send to relay and capture response
+    if command -v websocat &> /dev/null; then
+        RESPONSE=$(echo "$REF_EVENT_MESSAGE" | timeout 10s websocat "$RELAY_URL" 2>&1 || echo "Connection failed")
+        
+        print_info "Relay response: $RESPONSE"
+        
+        if [[ "$RESPONSE" == *"Connection failed"* ]] || [[ -z "$RESPONSE" ]]; then
+            print_error "✗ Failed to connect to relay or no response"
+            record_test_result "NIP-13 Reference Event Validation" "FAIL" "Connection failed or timeout"
+            return 1
+        elif [[ "$RESPONSE" == *"true"* ]]; then
+            print_success "✓ NIP-13 reference event accepted"
+            record_test_result "NIP-13 Reference Event Validation" "PASS" "Reference event accepted"
+            return 0
+        else
+            print_error "✗ NIP-13 reference event rejected"
+            record_test_result "NIP-13 Reference Event Validation" "FAIL" "Reference event rejected: $RESPONSE"
+            return 1
+        fi
+    else
+        print_error "websocat not found - required for testing"
+        record_test_result "NIP-13 Reference Event Validation" "SKIP" "websocat not available"
+        return 0
+    fi
+}
+
+# Print test summary
+print_test_summary() {
+    echo ""
+    echo -e "${BOLD}=== TEST SUMMARY ===${RESET}"
+    echo "Total tests run: $TEST_COUNT"
+    echo -e "${GREEN}Passed: $PASSED_COUNT${RESET}"
+    echo -e "${RED}Failed: $FAILED_COUNT${RESET}"
+    
+    if [ $FAILED_COUNT -gt 0 ]; then
+        echo ""
+        echo -e "${RED}${BOLD}Failed tests:${RESET}"
+        for result in "${TEST_RESULTS[@]}"; do
+            IFS='|' read -r name status details <<< "$result"
+            if [ "$status" = "FAIL" ]; then
+                echo -e "  ${RED}✗ $name${RESET}"
+                if [ -n "$details" ]; then
+                    echo "    $details"
+                fi
+            fi
+        done
+    fi
+    
+    echo ""
+    if [ $FAILED_COUNT -eq 0 ]; then
+        echo -e "${GREEN}${BOLD}🎉 ALL TESTS PASSED!${RESET}"
+        echo -e "${GREEN}✅ NIP-13 PoW validation is working correctly in the relay${RESET}"
+        return 0
+    else
+        echo -e "${RED}${BOLD}❌ SOME TESTS FAILED${RESET}"
+        echo "Please review the output above and check relay logs for more details."
+        return 1
+    fi
+}
+
+# Main test execution
+main() {
+    echo -e "${BOLD}=== NIP-13 Proof of Work Relay Test Suite ===${RESET}"
+    echo "Testing NIP-13 PoW validation in the C Nostr Relay"
+    echo "Relay URL: $RELAY_URL"
+    echo ""
+    
+    # Check prerequisites
+    if ! command -v curl &> /dev/null; then
+        print_error "curl is required but not installed"
+        exit 1
+    fi
+    
+    if ! command -v jq &> /dev/null; then
+        print_error "jq is required but not installed"
+        exit 1
+    fi
+    
+    if ! command -v websocat &> /dev/null; then
+        print_warning "websocat not found - WebSocket tests will be skipped"
+    fi
+    
+    # Run tests
+    check_relay_running
+    test_nip11_pow_support
+    test_event_without_pow
+    test_event_with_pow  
+    test_pow_configuration
+    test_nip13_reference_event
+    
+    # Print summary
+    print_test_summary
+    exit $?
+}
+
+# Run main function
+main "$@"

tests/40_nip_test.sh

@@ -0,0 +1,539 @@
+#!/bin/bash
+
+# NIP-40 Expiration Timestamp Test Suite for C Nostr Relay
+# Tests expiration timestamp handling in the relay's event processing pipeline
+
+set -e  # Exit on error
+
+# Color constants
+RED='\033[31m'
+GREEN='\033[32m'
+YELLOW='\033[33m'
+BLUE='\033[34m'
+BOLD='\033[1m'
+RESET='\033[0m'
+
+# Test configuration
+RELAY_URL="ws://127.0.0.1:8888"
+HTTP_URL="http://127.0.0.1:8888"
+TEST_COUNT=0
+PASSED_COUNT=0
+FAILED_COUNT=0
+
+# Test results tracking
+declare -a TEST_RESULTS=()
+
+print_info() {
+    echo -e "${BLUE}[INFO]${RESET} $1"
+}
+
+print_success() {
+    echo -e "${GREEN}${BOLD}[SUCCESS]${RESET} $1"
+}
+
+print_warning() {
+    echo -e "${YELLOW}[WARNING]${RESET} $1"
+}
+
+print_error() {
+    echo -e "${RED}${BOLD}[ERROR]${RESET} $1"
+}
+
+print_test_header() {
+    TEST_COUNT=$((TEST_COUNT + 1))
+    echo ""
+    echo -e "${BOLD}=== TEST $TEST_COUNT: $1 ===${RESET}"
+}
+
+record_test_result() {
+    local test_name="$1"
+    local result="$2"
+    local details="$3"
+    
+    TEST_RESULTS+=("$test_name|$result|$details")
+    
+    if [ "$result" = "PASS" ]; then
+        PASSED_COUNT=$((PASSED_COUNT + 1))
+        print_success "PASS: $test_name"
+    else
+        FAILED_COUNT=$((FAILED_COUNT + 1))
+        print_error "FAIL: $test_name"
+        if [ -n "$details" ]; then
+            echo "       Details: $details"
+        fi
+    fi
+}
+
+# Check if relay is running
+check_relay_running() {
+    print_info "Checking if relay is running..."
+    
+    if ! curl -s -H "Accept: application/nostr+json" "$HTTP_URL/" >/dev/null 2>&1; then
+        print_error "Relay is not running or not accessible at $HTTP_URL"
+        print_info "Please start the relay with: ./make_and_restart_relay.sh"
+        exit 1
+    fi
+    
+    print_success "Relay is running and accessible"
+}
+
+# Test NIP-11 relay information includes NIP-40
+test_nip11_expiration_support() {
+    print_test_header "NIP-11 Expiration Support Advertisement"
+    
+    print_info "Fetching relay information..."
+    RELAY_INFO=$(curl -s -H "Accept: application/nostr+json" "$HTTP_URL/")
+    
+    echo "Relay Info Response:"
+    echo "$RELAY_INFO" | jq '.'
+    echo ""
+    
+    # Check if NIP-40 is in supported_nips
+    if echo "$RELAY_INFO" | jq -e '.supported_nips | index(40)' >/dev/null 2>&1; then
+        print_success "✓ NIP-40 found in supported_nips array"
+        NIP40_SUPPORTED=true
+    else
+        print_error "✗ NIP-40 not found in supported_nips array"
+        NIP40_SUPPORTED=false
+    fi
+    
+    if [ "$NIP40_SUPPORTED" = true ]; then
+        record_test_result "NIP-11 Expiration Support Advertisement" "PASS" "NIP-40 advertised in relay info"
+        return 0
+    else
+        record_test_result "NIP-11 Expiration Support Advertisement" "FAIL" "NIP-40 not advertised"
+        return 1
+    fi
+}
+
+# Helper function to create event with expiration tag
+create_event_with_expiration() {
+    local content="$1"
+    local expiration_timestamp="$2"
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    
+    if ! command -v nak &> /dev/null; then
+        echo ""
+        return 1
+    fi
+    
+    # Create event with expiration tag
+    nak event --sec "$private_key" -c "$content" -t "expiration=$expiration_timestamp" --ts $(date +%s)
+}
+
+# Helper function to send event and check response
+send_event_and_check() {
+    local event_json="$1"
+    local expected_result="$2"  # "accept" or "reject"
+    local description="$3"
+    
+    if [ -z "$event_json" ]; then
+        return 1
+    fi
+    
+    # Create EVENT message
+    local event_message="[\"EVENT\",$event_json]"
+    
+    # Send to relay
+    if command -v websocat &> /dev/null; then
+        local response=$(echo "$event_message" | timeout 5s websocat "$RELAY_URL" 2>&1 || echo "Connection failed")
+        
+        print_info "Relay response: $response"
+        
+        if [[ "$response" == *"Connection failed"* ]]; then
+            print_error "✗ Failed to connect to relay"
+            return 1
+        elif [[ "$expected_result" == "accept" && "$response" == *"true"* ]]; then
+            print_success "✓ $description accepted as expected"
+            return 0
+        elif [[ "$expected_result" == "reject" && "$response" == *"false"* ]]; then
+            print_success "✓ $description rejected as expected"
+            return 0
+        elif [[ "$expected_result" == "accept" && "$response" == *"false"* ]]; then
+            print_error "✗ $description unexpectedly rejected: $response"
+            return 1
+        elif [[ "$expected_result" == "reject" && "$response" == *"true"* ]]; then
+            print_error "✗ $description unexpectedly accepted: $response"
+            return 1
+        else
+            print_warning "? Unclear response for $description: $response"
+            return 1
+        fi
+    else
+        print_error "websocat not found - required for testing"
+        return 1
+    fi
+}
+
+# Test event without expiration tag
+test_event_without_expiration() {
+    print_test_header "Event Submission Without Expiration Tag"
+    
+    if ! command -v nak &> /dev/null; then
+        print_warning "nak command not found - skipping expiration tests"
+        record_test_result "Event Submission Without Expiration Tag" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event without expiration tag..."
+    
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    local event_json=$(nak event --sec "$private_key" -c "Test event without expiration" --ts $(date +%s))
+    
+    print_info "Generated event:"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    if send_event_and_check "$event_json" "accept" "Event without expiration tag"; then
+        record_test_result "Event Submission Without Expiration Tag" "PASS" "Non-expiring event accepted"
+        return 0
+    else
+        record_test_result "Event Submission Without Expiration Tag" "FAIL" "Non-expiring event handling failed"
+        return 1
+    fi
+}
+
+# Test event with future expiration (should be accepted)
+test_event_with_future_expiration() {
+    print_test_header "Event Submission With Future Expiration"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Event Submission With Future Expiration" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event with future expiration (1 hour from now)..."
+    
+    local future_timestamp=$(($(date +%s) + 3600))  # 1 hour from now
+    local event_json=$(create_event_with_expiration "Test event expiring in 1 hour" "$future_timestamp")
+    
+    if [ -z "$event_json" ]; then
+        record_test_result "Event Submission With Future Expiration" "FAIL" "Failed to create event"
+        return 1
+    fi
+    
+    print_info "Generated event (expires at $future_timestamp):"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    if send_event_and_check "$event_json" "accept" "Event with future expiration"; then
+        record_test_result "Event Submission With Future Expiration" "PASS" "Future-expiring event accepted"
+        return 0
+    else
+        record_test_result "Event Submission With Future Expiration" "FAIL" "Future-expiring event rejected"
+        return 1
+    fi
+}
+
+# Test event with past expiration (should be rejected in strict mode)
+test_event_with_past_expiration() {
+    print_test_header "Event Submission With Past Expiration"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Event Submission With Past Expiration" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event with past expiration (1 hour ago)..."
+    
+    local past_timestamp=$(($(date +%s) - 3600))  # 1 hour ago
+    local event_json=$(create_event_with_expiration "Test event expired 1 hour ago" "$past_timestamp")
+    
+    if [ -z "$event_json" ]; then
+        record_test_result "Event Submission With Past Expiration" "FAIL" "Failed to create event"
+        return 1
+    fi
+    
+    print_info "Generated event (expired at $past_timestamp):"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    # In strict mode (default), this should be rejected
+    if send_event_and_check "$event_json" "reject" "Event with past expiration"; then
+        record_test_result "Event Submission With Past Expiration" "PASS" "Expired event correctly rejected in strict mode"
+        return 0
+    else
+        record_test_result "Event Submission With Past Expiration" "FAIL" "Expired event handling failed"
+        return 1
+    fi
+}
+
+# Test event with expiration within grace period
+test_event_within_grace_period() {
+    print_test_header "Event Submission Within Grace Period"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Event Submission Within Grace Period" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event with expiration within grace period (2 minutes ago, grace period is 5 minutes)..."
+    
+    local grace_timestamp=$(($(date +%s) - 120))  # 2 minutes ago (within 5 minute grace period)
+    local event_json=$(create_event_with_expiration "Test event within grace period" "$grace_timestamp")
+    
+    if [ -z "$event_json" ]; then
+        record_test_result "Event Submission Within Grace Period" "FAIL" "Failed to create event"
+        return 1
+    fi
+    
+    print_info "Generated event (expired at $grace_timestamp, within grace period):"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    # Should be accepted due to grace period
+    if send_event_and_check "$event_json" "accept" "Event within grace period"; then
+        record_test_result "Event Submission Within Grace Period" "PASS" "Event within grace period accepted"
+        return 0
+    else
+        record_test_result "Event Submission Within Grace Period" "FAIL" "Grace period handling failed"
+        return 1
+    fi
+}
+
+# Test event filtering in subscriptions
+test_expiration_filtering_in_subscriptions() {
+    print_test_header "Expiration Filtering in Subscriptions"
+    
+    if ! command -v nak &> /dev/null || ! command -v websocat &> /dev/null; then
+        record_test_result "Expiration Filtering in Subscriptions" "SKIP" "Required tools not available"
+        return 0
+    fi
+    
+    print_info "Setting up test events for subscription filtering..."
+    
+    # First, create a few events with different expiration times
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    
+    # Event 1: No expiration (should be returned)
+    local event1=$(nak event --sec "$private_key" -c "Event without expiration for filtering test" --ts $(date +%s))
+    
+    # Event 2: Future expiration (should be returned)
+    local future_timestamp=$(($(date +%s) + 1800))  # 30 minutes from now
+    local event2=$(create_event_with_expiration "Event with future expiration for filtering test" "$future_timestamp")
+    
+    # Event 3: Past expiration (should NOT be returned if filtering is enabled)
+    local past_timestamp=$(($(date +%s) - 3600))  # 1 hour ago
+    local event3=$(create_event_with_expiration "Event with past expiration for filtering test" "$past_timestamp")
+    
+    print_info "Publishing test events..."
+    
+    # Note: We expect event3 to be rejected on submission in strict mode,
+    # so we'll create it with a slightly more recent expiration that might get through
+    local recent_past=$(($(date +%s) - 600))  # 10 minutes ago (outside grace period)
+    local event3_recent=$(create_event_with_expiration "Recently expired event for filtering test" "$recent_past")
+    
+    # Try to submit all events (some may be rejected)
+    echo "[\"EVENT\",$event1]" | timeout 3s websocat "$RELAY_URL" >/dev/null 2>&1 || true
+    echo "[\"EVENT\",$event2]" | timeout 3s websocat "$RELAY_URL" >/dev/null 2>&1 || true
+    echo "[\"EVENT\",$event3_recent]" | timeout 3s websocat "$RELAY_URL" >/dev/null 2>&1 || true
+    
+    sleep 2  # Let events settle
+    
+    print_info "Testing subscription filtering..."
+    
+    # Create subscription for recent events
+    local req_message='["REQ","filter_test",{"kinds":[1],"limit":10}]'
+    local response=$(echo -e "$req_message\n[\"CLOSE\",\"filter_test\"]" | timeout 5s websocat "$RELAY_URL" 2>/dev/null || echo "")
+    
+    print_info "Subscription response:"
+    echo "$response"
+    echo ""
+    
+    # Count events that contain our test content
+    local no_exp_count=0
+    local future_exp_count=0  
+    local past_exp_count=0
+    
+    if echo "$response" | grep -q "Event without expiration for filtering test"; then
+        no_exp_count=1
+        print_success "✓ Event without expiration found in subscription results"
+    fi
+    
+    if echo "$response" | grep -q "Event with future expiration for filtering test"; then
+        future_exp_count=1
+        print_success "✓ Event with future expiration found in subscription results"
+    fi
+    
+    if echo "$response" | grep -q "Recently expired event for filtering test"; then
+        past_exp_count=1
+        print_warning "✗ Recently expired event found in subscription results (should be filtered)"
+    else
+        print_success "✓ Recently expired event properly filtered from subscription results"
+    fi
+    
+    # Evaluate results
+    local expected_events=$((no_exp_count + future_exp_count))
+    if [ $expected_events -ge 1 ] && [ $past_exp_count -eq 0 ]; then
+        record_test_result "Expiration Filtering in Subscriptions" "PASS" "Expired events properly filtered from subscriptions"
+        return 0
+    else
+        record_test_result "Expiration Filtering in Subscriptions" "FAIL" "Expiration filtering not working properly in subscriptions"
+        return 1
+    fi
+}
+
+# Test malformed expiration tags
+test_malformed_expiration_tags() {
+    print_test_header "Handling of Malformed Expiration Tags"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Handling of Malformed Expiration Tags" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Testing events with malformed expiration tags..."
+    
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    
+    # Test 1: Non-numeric expiration value
+    local event1=$(nak event --sec "$private_key" -c "Event with non-numeric expiration" -t "expiration=not_a_number" --ts $(date +%s))
+    
+    # Test 2: Empty expiration value  
+    local event2=$(nak event --sec "$private_key" -c "Event with empty expiration" -t "expiration=" --ts $(date +%s))
+    
+    print_info "Testing non-numeric expiration value..."
+    if send_event_and_check "$event1" "accept" "Event with non-numeric expiration (should be treated as no expiration)"; then
+        print_success "✓ Non-numeric expiration handled gracefully"
+        malformed_test1=true
+    else
+        malformed_test1=false
+    fi
+    
+    print_info "Testing empty expiration value..."
+    if send_event_and_check "$event2" "accept" "Event with empty expiration (should be treated as no expiration)"; then
+        print_success "✓ Empty expiration handled gracefully"
+        malformed_test2=true
+    else
+        malformed_test2=false
+    fi
+    
+    if [ "$malformed_test1" = true ] && [ "$malformed_test2" = true ]; then
+        record_test_result "Handling of Malformed Expiration Tags" "PASS" "Malformed expiration tags handled gracefully"
+        return 0
+    else
+        record_test_result "Handling of Malformed Expiration Tags" "FAIL" "Malformed expiration tag handling failed"
+        return 1
+    fi
+}
+
+# Test configuration via environment variables
+test_expiration_configuration() {
+    print_test_header "Expiration Configuration Via Environment Variables"
+    
+    print_info "Testing expiration configuration from relay logs..."
+    
+    if [ -f "relay.log" ]; then
+        print_info "Current configuration from logs:"
+        grep "Expiration Configuration:" relay.log | tail -1 || print_warning "No expiration configuration found in logs"
+    else
+        print_warning "No relay.log found"
+    fi
+    
+    # The relay should be running with default configuration
+    print_info "Default configuration should be:"
+    print_info "  enabled=true"
+    print_info "  strict_mode=true (rejects expired events on submission)"
+    print_info "  filter_responses=true (filters expired events from responses)"
+    print_info "  grace_period=300 seconds (5 minutes)"
+    
+    # Test current behavior matches expected default configuration
+    print_info "Configuration test based on observed behavior:"
+    
+    # Check if NIP-40 is advertised (indicates enabled=true)
+    if curl -s -H "Accept: application/nostr+json" "$HTTP_URL/" | jq -e '.supported_nips | index(40)' >/dev/null 2>&1; then
+        print_success "✓ NIP-40 support advertised (enabled=true)"
+        config_test=true
+    else
+        print_error "✗ NIP-40 not advertised (may be disabled)"
+        config_test=false
+    fi
+    
+    if [ "$config_test" = true ]; then
+        record_test_result "Expiration Configuration Via Environment Variables" "PASS" "Expiration configuration is accessible and working"
+        return 0
+    else
+        record_test_result "Expiration Configuration Via Environment Variables" "FAIL" "Expiration configuration issues detected"
+        return 1
+    fi
+}
+
+# Print test summary
+print_test_summary() {
+    echo ""
+    echo -e "${BOLD}=== TEST SUMMARY ===${RESET}"
+    echo "Total tests run: $TEST_COUNT"
+    echo -e "${GREEN}Passed: $PASSED_COUNT${RESET}"
+    echo -e "${RED}Failed: $FAILED_COUNT${RESET}"
+    
+    if [ $FAILED_COUNT -gt 0 ]; then
+        echo ""
+        echo -e "${RED}${BOLD}Failed tests:${RESET}"
+        for result in "${TEST_RESULTS[@]}"; do
+            IFS='|' read -r name status details <<< "$result"
+            if [ "$status" = "FAIL" ]; then
+                echo -e "  ${RED}✗ $name${RESET}"
+                if [ -n "$details" ]; then
+                    echo "    $details"
+                fi
+            fi
+        done
+    fi
+    
+    echo ""
+    if [ $FAILED_COUNT -eq 0 ]; then
+        echo -e "${GREEN}${BOLD}🎉 ALL TESTS PASSED!${RESET}"
+        echo -e "${GREEN}✅ NIP-40 Expiration Timestamp support is working correctly in the relay${RESET}"
+        return 0
+    else
+        echo -e "${RED}${BOLD}❌ SOME TESTS FAILED${RESET}"
+        echo "Please review the output above and check relay logs for more details."
+        return 1
+    fi
+}
+
+# Main test execution
+main() {
+    echo -e "${BOLD}=== NIP-40 Expiration Timestamp Relay Test Suite ===${RESET}"
+    echo "Testing NIP-40 Expiration Timestamp support in the C Nostr Relay"
+    echo "Relay URL: $RELAY_URL"
+    echo ""
+    
+    # Check prerequisites
+    if ! command -v curl &> /dev/null; then
+        print_error "curl is required but not installed"
+        exit 1
+    fi
+    
+    if ! command -v jq &> /dev/null; then
+        print_error "jq is required but not installed"
+        exit 1
+    fi
+    
+    if ! command -v websocat &> /dev/null; then
+        print_warning "websocat not found - WebSocket tests will be skipped"
+    fi
+    
+    if ! command -v nak &> /dev/null; then
+        print_warning "nak not found - Event generation tests will be skipped"
+        print_info "Install with: go install github.com/fiatjaf/nak@latest"
+    fi
+    
+    # Run tests
+    check_relay_running
+    test_nip11_expiration_support
+    test_event_without_expiration
+    test_event_with_future_expiration
+    test_event_with_past_expiration
+    test_event_within_grace_period
+    test_expiration_filtering_in_subscriptions
+    test_malformed_expiration_tags
+    test_expiration_configuration
+    
+    # Print summary
+    print_test_summary
+    exit $?
+}
+
+# Run main function
+main "$@"