diff --git a/backend/src/main/java/com/storycove/service/LibraryService.java b/backend/src/main/java/com/storycove/service/LibraryService.java
index 042e0c0..a27b50f 100644
--- a/backend/src/main/java/com/storycove/service/LibraryService.java
+++ b/backend/src/main/java/com/storycove/service/LibraryService.java
@@ -107,13 +107,24 @@ public class LibraryService implements ApplicationContextAware {
     public String authenticateAndGetLibrary(String password) {
         for (Library library : libraries.values()) {
             if (passwordEncoder.matches(password, library.getPasswordHash())) {
-                // Mark as explicitly authenticated for this session
                 explicitlyAuthenticated = true;
                 logger.info("User explicitly authenticated for library: {}", library.getId());
                 return library.getId();
             }
         }
-        return null; // Authentication failed
+
+        // APP_PASSWORD acts as a master override for recovery access.
+        // Grants access to the "main" library, or the first available one.
+        if (appPassword != null && !appPassword.isBlank() && appPassword.equals(password)) {
+            String libraryId = libraries.containsKey("main")
+                    ? "main"
+                    : libraries.keySet().iterator().next();
+            explicitlyAuthenticated = true;
+            logger.warn("Master APP_PASSWORD used for recovery access to library: {}", libraryId);
+            return libraryId;
+        }
+
+        return null;
     }
     
     /**