diff --git a/gateway-proxy/oauth_storage.py b/gateway-proxy/oauth_storage.py
new file mode 100644
index 0000000..888846d
--- /dev/null
+++ b/gateway-proxy/oauth_storage.py
@@ -0,0 +1,143 @@
+"""
+Persistent OAuth Client Storage
+Stores OAuth client registrations to disk so they survive gateway restarts.
+"""
+
+import json
+import os
+import logging
+from typing import Dict, Any
+
+logger = logging.getLogger("mcp-gateway.oauth-storage")
+
+# Path to persist OAuth clients
+OAUTH_STORAGE_FILE = os.environ.get("OAUTH_STORAGE_FILE", "/data/oauth_clients.json")
+
+
+def ensure_storage_dir() -> None:
+    """Create storage directory if it doesn't exist"""
+    storage_dir = os.path.dirname(OAUTH_STORAGE_FILE)
+    if storage_dir and not os.path.exists(storage_dir):
+        try:
+            os.makedirs(storage_dir, exist_ok=True)
+            logger.info(f"Created OAuth storage directory: {storage_dir}")
+        except Exception as e:
+            logger.error(f"Failed to create OAuth storage directory: {e}")
+
+
+def load_oauth_clients() -> Dict[str, Dict[str, Any]]:
+    """
+    Load OAuth clients from persistent storage.
+    Returns empty dict if file doesn't exist.
+    """
+    ensure_storage_dir()
+
+    if not os.path.exists(OAUTH_STORAGE_FILE):
+        logger.info(f"OAuth storage file not found: {OAUTH_STORAGE_FILE}")
+        return {}
+
+    try:
+        with open(OAUTH_STORAGE_FILE, 'r') as f:
+            clients = json.load(f)
+            logger.info(f"Loaded {len(clients)} OAuth clients from storage")
+            return clients
+    except json.JSONDecodeError as e:
+        logger.error(f"Failed to parse OAuth storage file: {e}")
+        return {}
+    except Exception as e:
+        logger.error(f"Failed to load OAuth clients: {e}")
+        return {}
+
+
+def save_oauth_clients(clients: Dict[str, Dict[str, Any]]) -> bool:
+    """
+    Save OAuth clients to persistent storage.
+    Returns True if successful, False otherwise.
+    """
+    ensure_storage_dir()
+
+    try:
+        # Write to temp file first, then atomic rename (safer)
+        temp_file = OAUTH_STORAGE_FILE + ".tmp"
+
+        with open(temp_file, 'w') as f:
+            json.dump(clients, f, indent=2)
+
+        # Atomic rename
+        os.replace(temp_file, OAUTH_STORAGE_FILE)
+        logger.debug(f"Saved {len(clients)} OAuth clients to storage")
+        return True
+    except Exception as e:
+        logger.error(f"Failed to save OAuth clients: {e}")
+        # Clean up temp file if it exists
+        try:
+            if os.path.exists(temp_file):
+                os.remove(temp_file)
+        except:
+            pass
+        return False
+
+
+def get_client(client_id: str) -> Dict[str, Any] | None:
+    """Get a specific OAuth client by ID"""
+    clients = load_oauth_clients()
+    return clients.get(client_id)
+
+
+def register_client(client_id: str, client_info: Dict[str, Any]) -> bool:
+    """Register a new OAuth client"""
+    clients = load_oauth_clients()
+    clients[client_id] = client_info
+    success = save_oauth_clients(clients)
+
+    if success:
+        logger.info(f"Registered OAuth client: {client_id} ({client_info.get('client_name', 'Unknown')})")
+    else:
+        logger.error(f"Failed to register OAuth client: {client_id}")
+
+    return success
+
+
+def unregister_client(client_id: str) -> bool:
+    """Unregister an OAuth client"""
+    clients = load_oauth_clients()
+
+    if client_id not in clients:
+        logger.warning(f"Client {client_id} not found for unregistration")
+        return False
+
+    del clients[client_id]
+    success = save_oauth_clients(clients)
+
+    if success:
+        logger.info(f"Unregistered OAuth client: {client_id}")
+    else:
+        logger.error(f"Failed to unregister OAuth client: {client_id}")
+
+    return success
+
+
+def client_exists(client_id: str) -> bool:
+    """Check if a client is registered"""
+    clients = load_oauth_clients()
+    return client_id in clients
+
+
+def get_all_clients() -> Dict[str, Dict[str, Any]]:
+    """Get all registered OAuth clients"""
+    return load_oauth_clients()
+
+
+def clear_all_clients() -> bool:
+    """Clear all OAuth clients (use with caution!)"""
+    logger.warning("Clearing all OAuth clients")
+    return save_oauth_clients({})
+
+
+# Validation helper
+def validate_client_secret(client_id: str, client_secret: str) -> bool:
+    """Validate a client's secret"""
+    client = get_client(client_id)
+    if not client:
+        return False
+    return client.get("client_secret") == client_secret