diff --git a/at_commons/lib/src/at_constants.dart b/at_commons/lib/src/at_constants.dart
index defba095..700bae07 100644
--- a/at_commons/lib/src/at_constants.dart
+++ b/at_commons/lib/src/at_constants.dart
@@ -71,3 +71,4 @@ const String statsNotificationId = '_latestNotificationIdv2';
 const String ENCODING = 'encoding';
 const String CLIENT_CONFIG = 'clientConfig';
 const String VERSION = 'version';
+const String IS_LOCAL = 'isLocal';
diff --git a/at_commons/lib/src/keystore/at_key.dart b/at_commons/lib/src/keystore/at_key.dart
index 28003cea..0ce57377 100644
--- a/at_commons/lib/src/keystore/at_key.dart
+++ b/at_commons/lib/src/keystore/at_key.dart
@@ -10,6 +10,10 @@ class AtKey {
   Metadata? metadata;
   bool isRef = false;
 
+  /// When set to true, represents the [LocalKey]
+  /// These keys will never be synced between the client and secondary server.
+  bool _isLocal = false;
+
   String? get sharedBy => _sharedBy;
 
   set sharedBy(String? atSign) {
@@ -24,6 +28,16 @@ class AtKey {
     _sharedWith = atSign;
   }
 
+  bool get isLocal => _isLocal;
+
+  set isLocal(bool isLocal) {
+    if (isLocal == true && sharedWith != null) {
+      throw InvalidAtKeyException(
+          'sharedWith should be empty when isLocal is set to true');
+    }
+    _isLocal = isLocal;
+  }
+
   String _dotNamespaceIfPresent() {
     if (namespace != null && namespace!.isNotEmpty) {
       return '.$namespace';
@@ -62,6 +76,14 @@ class AtKey {
     if (_sharedWith != null && _sharedWith!.isNotEmpty) {
       return '$_sharedWith:$key${_dotNamespaceIfPresent()}$_sharedBy';
     }
+    // if key starts with local: or isLocal set to true, return local key
+    if (isLocal == true) {
+      String localKey = '$key${_dotNamespaceIfPresent()}$sharedBy';
+      if (localKey.startsWith('local:')) {
+        return localKey;
+      }
+      return 'local:$localKey';
+    }
     // Defaults to return a self key.
     return '$key${_dotNamespaceIfPresent()}$_sharedBy';
   }
@@ -151,6 +173,23 @@ class AtKey {
       ..namespace(namespace);
   }
 
+  /// Local key are confined to the client(device)/server it is created.
+  /// The key does not sync between the local-secondary and the cloud-secondary.
+  ///
+  /// Builds a local key and return a [LocalKeyBuilder].
+  ///
+  /// Example: local:phone.wavi@alice
+  /// ```dart
+  /// AtKey localKey = AtKey.local('phone',namespace:'wavi').build();
+  /// ```
+  static LocalKeyBuilder local(String key, String sharedBy,
+      {String? namespace}) {
+    return LocalKeyBuilder()
+      ..key(key)
+      ..namespace(namespace)
+      ..sharedBy(sharedBy);
+  }
+
   static AtKey fromString(String key) {
     var atKey = AtKey();
     var metaData = Metadata();
@@ -180,6 +219,9 @@ class AtKey {
       if (keyParts[0] == 'public') {
         metaData.isPublic = true;
       }
+      if (keyParts[0] == 'local') {
+        atKey.isLocal = true;
+      }
       // Example key: cached:@alice:phone@bob
       else if (keyParts[0] == CACHED) {
         metaData.isCached = true;
@@ -281,6 +323,21 @@ class PrivateKey extends AtKey {
   }
 }
 
+/// Represents a local key
+/// Local key are confined to the client(device)/server it is created.
+/// The key does not sync between the local-secondary and the cloud-secondary.
+class LocalKey extends AtKey {
+  LocalKey() {
+    isLocal = true;
+    super.metadata = Metadata();
+  }
+
+  @override
+  String toString() {
+    return 'local:$key${_dotNamespaceIfPresent()}$sharedBy';
+  }
+}
+
 class Metadata {
   /// Represents the time in milliseconds beyond which the key expires
   int? ttl;
diff --git a/at_commons/lib/src/keystore/at_key_builder_impl.dart b/at_commons/lib/src/keystore/at_key_builder_impl.dart
index fe7df1f4..639d1929 100644
--- a/at_commons/lib/src/keystore/at_key_builder_impl.dart
+++ b/at_commons/lib/src/keystore/at_key_builder_impl.dart
@@ -131,3 +131,11 @@ class PrivateKeyBuilder extends AbstractKeyBuilder {
     _meta.isPublic = false;
   }
 }
+
+/// Builder to build the local keys
+class LocalKeyBuilder extends AbstractKeyBuilder {
+  LocalKeyBuilder() : super() {
+    _atKey = LocalKey();
+    _atKey.isLocal = true;
+  }
+}
diff --git a/at_commons/lib/src/keystore/key_type.dart b/at_commons/lib/src/keystore/key_type.dart
index 58742c29..51afe55f 100644
--- a/at_commons/lib/src/keystore/key_type.dart
+++ b/at_commons/lib/src/keystore/key_type.dart
@@ -6,6 +6,7 @@ enum KeyType {
   cachedPublicKey,
   cachedSharedKey,
   reservedKey,
+  localKey,
   invalidKey
 }
 
diff --git a/at_commons/lib/src/utils/at_key_regex_utils.dart b/at_commons/lib/src/utils/at_key_regex_utils.dart
index 3c3da035..e6b32ccb 100644
--- a/at_commons/lib/src/utils/at_key_regex_utils.dart
+++ b/at_commons/lib/src/utils/at_key_regex_utils.dart
@@ -34,6 +34,8 @@ abstract class Regexes {
       '''(?<visibility>(cached:public:){1})((@$sharedWithFragment)?$entityFragment''';
   static const String reservedKeyFragment =
       '''(((@(?<sharedWith>($charsInAtSign|$allowedEmoji){1,55}))|public|privatekey):)?(?<atKey>$_charsInReservedKey)(@(?<owner>($charsInAtSign|$allowedEmoji){1,55}))?''';
+  static const String localKeyFragment =
+      '''(?<visibility>(local:){1})$entityFragment''';
 
   String get publicKey;
   String get privateKey;
@@ -42,6 +44,7 @@ abstract class Regexes {
   String get cachedSharedKey;
   String get cachedPublicKey;
   String get reservedKey;
+  String get localKey;
 
   static final Regexes _regexesWithMandatoryNamespace =
       RegexesWithMandatoryNamespace();
@@ -71,6 +74,8 @@ class RegexesWithMandatoryNamespace implements Regexes {
       '''${Regexes.cachedSharedKeyStartFragment}${Regexes.namespaceFragment}${Regexes.ownershipFragment}''';
   static const String _cachedPublicKey =
       '''${Regexes.cachedPublicKeyStartFragment}${Regexes.namespaceFragment}${Regexes.ownershipFragment}''';
+  static const String _localKey =
+      '''${Regexes.localKeyFragment}${Regexes.namespaceFragment}${Regexes.ownershipFragment}''';
 
   @override
   String get publicKey => _publicKey;
@@ -92,6 +97,9 @@ class RegexesWithMandatoryNamespace implements Regexes {
 
   @override
   String get reservedKey => Regexes.reservedKeyFragment;
+
+  @override
+  String get localKey => _localKey;
 }
 
 class RegexesNonMandatoryNamespace implements Regexes {
@@ -108,6 +116,8 @@ class RegexesNonMandatoryNamespace implements Regexes {
       '''${Regexes.cachedSharedKeyStartFragment}${Regexes.ownershipFragment}''';
   static const String _cachedPublicKey =
       '''${Regexes.cachedPublicKeyStartFragment}${Regexes.ownershipFragment}''';
+  static const String _localkey =
+      '''${Regexes.localKeyFragment}${Regexes.ownershipFragment}''';
 
   @override
   String get publicKey => _publicKey;
@@ -129,6 +139,9 @@ class RegexesNonMandatoryNamespace implements Regexes {
 
   @override
   String get reservedKey => Regexes.reservedKeyFragment;
+
+  @override
+  String get localKey => _localkey;
 }
 
 class RegexUtil {
@@ -168,6 +181,9 @@ class RegexUtil {
     if (matchAll(regexes.cachedSharedKey, key)) {
       return KeyType.cachedSharedKey;
     }
+    if (matchAll(regexes.localKey, key)) {
+      return KeyType.localKey;
+    }
     return KeyType.invalidKey;
   }
 
diff --git a/at_commons/lib/src/validators/at_key_validation_impl.dart b/at_commons/lib/src/validators/at_key_validation_impl.dart
index b6652a3b..87b35595 100644
--- a/at_commons/lib/src/validators/at_key_validation_impl.dart
+++ b/at_commons/lib/src/validators/at_key_validation_impl.dart
@@ -82,6 +82,9 @@ class _AtKeyValidatorImpl extends AtKeyValidator {
       case KeyType.reservedKey:
         _regex = regexes.reservedKey;
         break;
+      case KeyType.localKey:
+        _regex = regexes.localKey;
+        break;
       case KeyType.invalidKey:
         _regex = '';
         break;
diff --git a/at_commons/test/at_key_regex_test.dart b/at_commons/test/at_key_regex_test.dart
index f44421aa..a82b396f 100644
--- a/at_commons/test/at_key_regex_test.dart
+++ b/at_commons/test/at_key_regex_test.dart
@@ -411,4 +411,28 @@ void main() {
       });
     });
   });
+
+  group('A group of test to validate local keys', () {
+    test('Test to validate local keys with enforcing namespaces', () {
+      var keyTypeList = [];
+      keyTypeList.add('local:phone.buzz@alice');
+      keyTypeList.add('local:pho_-n________e.b@alice');
+      keyTypeList.add('local:phone😀.buzz@alice💙');
+      for (var key in keyTypeList) {
+        var type = RegexUtil.keyType(key, true);
+        expect(type == KeyType.localKey, true);
+      }
+    });
+
+    test('Test to validate local keys without enforcing namespaces', () {
+      var keyTypeList = [];
+      keyTypeList.add('local:phone@alice');
+      keyTypeList.add('local:pho_-n________e@alice');
+      keyTypeList.add('local:phone😀@alice💙');
+      for (var key in keyTypeList) {
+        var type = RegexUtil.keyType(key, false);
+        expect(type == KeyType.localKey, true);
+      }
+    });
+  });
 }
diff --git a/at_commons/test/at_key_test.dart b/at_commons/test/at_key_test.dart
index 6f00e7cd..078cefd7 100644
--- a/at_commons/test/at_key_test.dart
+++ b/at_commons/test/at_key_test.dart
@@ -513,4 +513,102 @@ void main() {
       expect('privatekey:at_secret', atKey.toString());
     });
   });
+
+  group('A group of tests to validate local key', () {
+    test('A test to verify toString on AtKey', () {
+      var atKey = AtKey()
+        ..key = 'phone'
+        ..sharedBy = '@alice'
+        ..namespace = 'wavi'
+        ..isLocal = true;
+      expect(atKey.toString(), 'local:phone.wavi@alice');
+    });
+
+    test('A test to verify toString on AtKey with local: in atKey', () {
+      var atKey = AtKey()
+        ..key = 'local:phone'
+        ..sharedBy = '@alice'
+        ..namespace = 'wavi'
+        ..isLocal = true;
+      expect(atKey.toString(), 'local:phone.wavi@alice');
+    });
+
+    test('A test to verify fromString on AtKey', () {
+      var atKey = AtKey.fromString('local:phone.wavi@alice');
+      expect(atKey.key, 'phone');
+      expect(atKey.namespace, 'wavi');
+      expect(atKey.sharedBy, '@alice');
+      expect(atKey.isLocal, true);
+    });
+
+    test('A test to validate the creation of local key using static method',
+        () {
+      var atKey = AtKey.local('phone', '@alice', namespace: 'wavi').build();
+      expect(atKey.key, 'phone');
+      expect(atKey.namespace, 'wavi');
+      expect(atKey.sharedBy, '@alice');
+      expect(atKey.isLocal, true);
+    });
+
+    test(
+        'A test to verify InvalidAtKey exception is thrown when sharedWith and isLocal are populated',
+        () {
+      expect(
+          () => AtKey()
+            ..key = 'phone'
+            ..namespace = 'wavi'
+            ..sharedWith = '@bob'
+            ..sharedBy = '@alice'
+            ..isLocal = true,
+          throwsA(predicate((dynamic e) =>
+              e is InvalidAtKeyException &&
+              e.message ==
+                  'sharedWith should be empty when isLocal is set to true')));
+    });
+
+    test('A test to verify local key builder', () {
+      var localKey = (LocalKeyBuilder()
+            ..key('phone')
+            ..sharedBy('@alice'))
+          .build();
+      expect(localKey, isA<LocalKey>());
+      expect(localKey.isLocal, true);
+      expect(localKey.toString(), 'local:phone@alice');
+    });
+
+    test('validate a local key with sharedBy populated', () {
+      var localKey = (LocalKeyBuilder()
+            ..key('phone')
+            ..sharedBy('@alice'))
+          .build();
+      var validationResult = AtKeyValidators.get().validate(
+          localKey.toString(), ValidationContext()..atSign = '@alice');
+      expect(validationResult.isValid, true);
+    });
+
+    test('validate a local key with sharedBy not populated', () {
+      var localKey = (LocalKeyBuilder()
+            ..key('phone')
+            ..sharedBy(''))
+          .build();
+      var validationResult = AtKeyValidators.get().validate(
+          localKey.toString(), ValidationContext()..atSign = '@alice');
+      expect(validationResult.isValid, false);
+      expect(validationResult.failureReason, 'local:phone is not a valid key');
+    });
+
+    test('validate a local key with namespace not populated', () {
+      var localKey = (LocalKeyBuilder()
+            ..key('phone')
+            ..sharedBy('@alice'))
+          .build();
+      var validationResult = AtKeyValidators.get().validate(
+          localKey.toString(),
+          ValidationContext()
+            ..atSign = '@alice'
+            ..enforceNamespace = true);
+      expect(validationResult.isValid, false);
+      expect(validationResult.failureReason, 'local:phone@alice is not a valid key');
+    });
+  });
 }
diff --git a/at_commons/test/at_key_type_test.dart b/at_commons/test/at_key_type_test.dart
index 45a72ba5..09e4da12 100644
--- a/at_commons/test/at_key_type_test.dart
+++ b/at_commons/test/at_key_type_test.dart
@@ -27,6 +27,11 @@ void main() {
       var keyType = AtKey.getKeyType('@bob:phone.buzz@bob');
       expect(keyType, equals(KeyType.selfKey));
     });
+
+    test('Test to verify local key type with namespace', () {
+      var keyType = AtKey.getKeyType('local:latestNotification.wavi@bob', enforceNameSpace: true);
+      expect(keyType, equals(KeyType.localKey));
+    });
   });
   group('A group of tests to check invalid key types', () {
     test('Test public key type without namespace', () {
@@ -62,6 +67,10 @@ void main() {
       var keyType = AtKey.getKeyType('@bob:phone@bob', enforceNameSpace: true);
       expect(keyType, equals(KeyType.invalidKey));
     });
+    test('Test local key type with atsign and without namespace', () {
+      var keyType = AtKey.getKeyType('local:phone@bob', enforceNameSpace: true);
+      expect(keyType, equals(KeyType.invalidKey));
+    });
   });
 
   group('A group of tests to check reserved key types', () {