diff --git a/src/seedpass/core/encryption.py b/src/seedpass/core/encryption.py
index d063387..1a71ced 100644
--- a/src/seedpass/core/encryption.py
+++ b/src/seedpass/core/encryption.py
@@ -228,6 +228,7 @@ class EncryptionManager:
         relative_path: Optional[Path] = None,
         *,
         strict: bool = True,
+        merge: bool = False,
     ) -> bool:
         """Decrypts data from Nostr and saves it.
 
@@ -249,6 +250,20 @@ class EncryptionManager:
                 data = json_lib.loads(decrypted_data)
             else:
                 data = json_lib.loads(decrypted_data.decode("utf-8"))
+            if merge and (self.fingerprint_dir / relative_path).exists():
+                current = self.load_json_data(relative_path)
+                current_entries = current.get("entries", {})
+                for idx, entry in data.get("entries", {}).items():
+                    cur_ts = current_entries.get(idx, {}).get("modified_ts", 0)
+                    new_ts = entry.get("modified_ts", 0)
+                    if idx not in current_entries or new_ts >= cur_ts:
+                        current_entries[idx] = entry
+                current["entries"] = current_entries
+                if "schema_version" in data:
+                    current["schema_version"] = max(
+                        current.get("schema_version", 0), data.get("schema_version", 0)
+                    )
+                data = current
             self.save_json_data(data, relative_path)  # This always saves in V2 format
             self.update_checksum(relative_path)
             logger.info("Index file from Nostr was processed and saved successfully.")
diff --git a/src/seedpass/core/entry_management.py b/src/seedpass/core/entry_management.py
index 406cfa8..260fe17 100644
--- a/src/seedpass/core/entry_management.py
+++ b/src/seedpass/core/entry_management.py
@@ -27,6 +27,7 @@ import logging
 import hashlib
 import sys
 import shutil
+import time
 from typing import Optional, Tuple, Dict, Any, List
 from pathlib import Path
 
@@ -97,6 +98,7 @@ class EntryManager:
                         entry["word_count"] = entry["words"]
                         entry.pop("words", None)
                     entry.setdefault("tags", [])
+                    entry.setdefault("modified_ts", entry.get("updated", 0))
                 logger.debug("Index loaded successfully.")
                 self._index_cache = data
                 return data
@@ -176,6 +178,7 @@ class EntryManager:
                 "type": EntryType.PASSWORD.value,
                 "kind": EntryType.PASSWORD.value,
                 "notes": notes,
+                "modified_ts": int(time.time()),
                 "custom_fields": custom_fields or [],
                 "tags": tags or [],
             }
@@ -236,6 +239,7 @@ class EntryManager:
                 "type": EntryType.TOTP.value,
                 "kind": EntryType.TOTP.value,
                 "label": label,
+                "modified_ts": int(time.time()),
                 "index": index,
                 "period": period,
                 "digits": digits,
@@ -249,6 +253,7 @@ class EntryManager:
                 "kind": EntryType.TOTP.value,
                 "label": label,
                 "secret": secret,
+                "modified_ts": int(time.time()),
                 "period": period,
                 "digits": digits,
                 "archived": archived,
@@ -294,6 +299,7 @@ class EntryManager:
             "kind": EntryType.SSH.value,
             "index": index,
             "label": label,
+            "modified_ts": int(time.time()),
             "notes": notes,
             "archived": archived,
             "tags": tags or [],
@@ -340,6 +346,7 @@ class EntryManager:
             "kind": EntryType.PGP.value,
             "index": index,
             "label": label,
+            "modified_ts": int(time.time()),
             "key_type": key_type,
             "user_id": user_id,
             "notes": notes,
@@ -392,6 +399,7 @@ class EntryManager:
             "kind": EntryType.NOSTR.value,
             "index": index,
             "label": label,
+            "modified_ts": int(time.time()),
             "notes": notes,
             "archived": archived,
             "tags": tags or [],
@@ -421,6 +429,7 @@ class EntryManager:
             "type": EntryType.KEY_VALUE.value,
             "kind": EntryType.KEY_VALUE.value,
             "label": label,
+            "modified_ts": int(time.time()),
             "value": value,
             "notes": notes,
             "archived": archived,
@@ -480,6 +489,7 @@ class EntryManager:
             "kind": EntryType.SEED.value,
             "index": index,
             "label": label,
+            "modified_ts": int(time.time()),
             "word_count": words_num,
             "notes": notes,
             "archived": archived,
@@ -552,6 +562,7 @@ class EntryManager:
             "kind": EntryType.MANAGED_ACCOUNT.value,
             "index": index,
             "label": label,
+            "modified_ts": int(time.time()),
             "word_count": word_count,
             "notes": notes,
             "fingerprint": fingerprint,
@@ -682,7 +693,8 @@ class EntryManager:
                 ):
                     entry.setdefault("custom_fields", [])
                 logger.debug(f"Retrieved entry at index {index}: {entry}")
-                return entry
+                clean = {k: v for k, v in entry.items() if k != "modified_ts"}
+                return clean
             else:
                 logger.warning(f"No entry found at index {index}.")
                 print(colored(f"Warning: No entry found at index {index}.", "yellow"))
@@ -887,6 +899,8 @@ class EntryManager:
                 entry["tags"] = tags
                 logger.debug(f"Updated tags for index {index}: {tags}")
 
+            entry["modified_ts"] = int(time.time())
+
             data["entries"][str(index)] = entry
             logger.debug(f"Modified entry at index {index}: {entry}")
 
diff --git a/src/seedpass/core/manager.py b/src/seedpass/core/manager.py
index bd844f6..ec7d8d3 100644
--- a/src/seedpass/core/manager.py
+++ b/src/seedpass/core/manager.py
@@ -1179,7 +1179,7 @@ class PasswordManager:
             updated = False
             if current != encrypted:
                 if self.vault.decrypt_and_save_index_from_nostr(
-                    encrypted, strict=False
+                    encrypted, strict=False, merge=False
                 ):
                     updated = True
                     current = encrypted
@@ -1189,7 +1189,7 @@ class PasswordManager:
                 for delta in deltas:
                     if current != delta:
                         if self.vault.decrypt_and_save_index_from_nostr(
-                            delta, strict=False
+                            delta, strict=False, merge=True
                         ):
                             updated = True
                             current = delta
@@ -1314,7 +1314,7 @@ class PasswordManager:
                 manifest, chunks = result
                 encrypted = gzip.decompress(b"".join(chunks))
                 success = self.vault.decrypt_and_save_index_from_nostr(
-                    encrypted, strict=False
+                    encrypted, strict=False, merge=False
                 )
                 if success:
                     have_data = True
@@ -1325,7 +1325,7 @@ class PasswordManager:
                         for delta in deltas:
                             if current != delta:
                                 if self.vault.decrypt_and_save_index_from_nostr(
-                                    delta, strict=False
+                                    delta, strict=False, merge=True
                                 ):
                                     current = delta
                     logger.info("Initialized local database from Nostr.")
@@ -3641,7 +3641,7 @@ class PasswordManager:
         :param encrypted_data: The encrypted data retrieved from Nostr.
         """
         try:
-            self.vault.decrypt_and_save_index_from_nostr(encrypted_data)
+            self.vault.decrypt_and_save_index_from_nostr(encrypted_data, merge=True)
             logging.info("Index file updated from Nostr successfully.")
             print(colored("Index file updated from Nostr successfully.", "green"))
         except Exception as e:
diff --git a/src/seedpass/core/vault.py b/src/seedpass/core/vault.py
index 93667c1..e1a6fbc 100644
--- a/src/seedpass/core/vault.py
+++ b/src/seedpass/core/vault.py
@@ -61,11 +61,11 @@ class Vault:
         return self.encryption_manager.get_encrypted_index()
 
     def decrypt_and_save_index_from_nostr(
-        self, encrypted_data: bytes, *, strict: bool = True
+        self, encrypted_data: bytes, *, strict: bool = True, merge: bool = False
     ) -> bool:
-        """Decrypt Nostr payload and overwrite the local index."""
+        """Decrypt Nostr payload and update the local index."""
         return self.encryption_manager.decrypt_and_save_index_from_nostr(
-            encrypted_data, strict=strict
+            encrypted_data, strict=strict, merge=merge
         )
 
     # ----- Config helpers -----
diff --git a/src/tests/test_delta_merge.py b/src/tests/test_delta_merge.py
new file mode 100644
index 0000000..c6b2866
--- /dev/null
+++ b/src/tests/test_delta_merge.py
@@ -0,0 +1,49 @@
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+import pytest
+
+from helpers import create_vault
+from seedpass.core.entry_management import EntryManager
+from seedpass.core.backup import BackupManager
+from seedpass.core.config_manager import ConfigManager
+
+
+def _setup_mgr(path: Path):
+    vault, _ = create_vault(path)
+    cfg = ConfigManager(vault, path)
+    backup = BackupManager(path, cfg)
+    return vault, EntryManager(vault, backup)
+
+
+def test_merge_modified_ts():
+    with TemporaryDirectory() as tmpdir:
+        base = Path(tmpdir)
+        va, ema = _setup_mgr(base / "A")
+        vb, emb = _setup_mgr(base / "B")
+
+        idx0 = ema.add_entry("a", 8)
+        idx1 = ema.add_entry("b", 8)
+
+        # B starts from A's snapshot
+        enc = va.get_encrypted_index() or b""
+        vb.decrypt_and_save_index_from_nostr(enc, merge=False)
+        emb.clear_cache()
+        assert emb.retrieve_entry(idx0)["username"] == ""
+
+        ema.modify_entry(idx0, username="ua")
+        delta_a = va.get_encrypted_index() or b""
+        vb.decrypt_and_save_index_from_nostr(delta_a, merge=True)
+        emb.clear_cache()
+        assert emb.retrieve_entry(idx0)["username"] == "ua"
+
+        emb.modify_entry(idx1, username="ub")
+        delta_b = vb.get_encrypted_index() or b""
+        va.decrypt_and_save_index_from_nostr(delta_b, merge=True)
+        ema.clear_cache()
+        assert ema.retrieve_entry(idx1)["username"] == "ub"
+
+        assert ema.retrieve_entry(idx0)["username"] == "ua"
+        assert ema.retrieve_entry(idx1)["username"] == "ub"
+        assert emb.retrieve_entry(idx0)["username"] == "ua"
+        assert emb.retrieve_entry(idx1)["username"] == "ub"
diff --git a/src/tests/test_entry_add.py b/src/tests/test_entry_add.py
index 07344bb..c7a966a 100644
--- a/src/tests/test_entry_add.py
+++ b/src/tests/test_entry_add.py
@@ -44,7 +44,9 @@ def test_add_and_retrieve_entry():
 
         data = enc_mgr.load_json_data(entry_mgr.index_file)
         assert str(index) in data.get("entries", {})
-        assert data["entries"][str(index)] == entry
+        stored = data["entries"][str(index)]
+        stored.pop("modified_ts", None)
+        assert stored == entry
 
 
 @pytest.mark.parametrize(