diff --git a/lib/didcomm.dart b/lib/didcomm.dart
index b36ad0b..8757d27 100644
--- a/lib/didcomm.dart
+++ b/lib/didcomm.dart
@@ -1,7 +1,9 @@
 library;
 
+export 'src/did_resolver_manager.dart';
 export 'src/errors/errors.dart';
 export 'src/extensions/affinidi_authenticator_extension.dart';
+export 'src/extensions/did_document_extension.dart';
 export 'src/extensions/wallet_extension.dart';
 export 'src/mediator_client.dart';
 export 'src/messages/algorithm_types/algorithms_types.dart';
diff --git a/lib/src/did_resolver_manager.dart b/lib/src/did_resolver_manager.dart
new file mode 100644
index 0000000..7460535
--- /dev/null
+++ b/lib/src/did_resolver_manager.dart
@@ -0,0 +1,23 @@
+import 'package:ssi/ssi.dart';
+
+typedef DIDResolver = Future<DidDocument> Function(
+  String did, {
+  String? resolverAddress,
+});
+
+class DidResolverManager {
+  static DIDResolver _didResolver = UniversalDIDResolver.resolve;
+  static String? _resolverAddress;
+
+  static void setResolver(DIDResolver didResolver) {
+    DidResolverManager._didResolver = didResolver;
+  }
+
+  static void setResolverAddress(String resolverAddress) {
+    _resolverAddress = resolverAddress;
+  }
+
+  static Future<DidDocument> resolve(String did) {
+    return _didResolver(did, resolverAddress: _resolverAddress);
+  }
+}
diff --git a/lib/src/extensions/did_document_extension.dart b/lib/src/extensions/did_document_extension.dart
index f90fd3e..af13b1e 100644
--- a/lib/src/extensions/did_document_extension.dart
+++ b/lib/src/extensions/did_document_extension.dart
@@ -6,6 +6,7 @@ import 'package:web_socket_channel/io.dart';
 import '../common/did.dart';
 import '../common/did_document_service_type.dart';
 import '../curves/curve_type.dart';
+import '../did_resolver_manager.dart';
 import '../jwks/jwk.dart';
 import 'wallet_extension.dart';
 
@@ -128,7 +129,7 @@ extension DidDocumentExtension on DidDocument {
   Future<void> addMediatorsFromResolvedDid(
     String did,
   ) async {
-    final didDocument = await UniversalDIDResolver.resolve(did);
+    final didDocument = await DidResolverManager.resolve(did);
     addMediatorsFromDidDocument(didDocument);
   }
 
diff --git a/lib/src/mediator_client/mediator_client.dart b/lib/src/mediator_client/mediator_client.dart
index 253c079..4f5df61 100644
--- a/lib/src/mediator_client/mediator_client.dart
+++ b/lib/src/mediator_client/mediator_client.dart
@@ -2,6 +2,9 @@ import 'dart:async';
 import 'dart:convert';
 
 import 'package:crypto/crypto.dart';
+import 'package:didcomm/didcomm.dart';
+import 'package:didcomm/src/did_resolver_manager.dart';
+import 'package:didcomm/src/extensions/verification_method_list_extention.dart';
 import 'package:dio/dio.dart';
 import 'package:ssi/ssi.dart';
 import 'package:uuid/uuid.dart';
@@ -68,7 +71,7 @@ class MediatorClient {
     required DidSigner signer,
   }) async {
     return MediatorClient(
-      mediatorDidDocument: await UniversalDIDResolver.resolve(
+      mediatorDidDocument: await DidResolverManager.resolve(
         didDocumentUrl.toString(),
       ),
       keyPair: keyPair,
@@ -109,9 +112,7 @@ class MediatorClient {
   /// [accessToken] - Optional bearer token for authentication.
   ///
   /// Returns a list of message IDs as strings.
-  Future<List<String>> listInboxMessageIds({
-    String? accessToken,
-  }) async {
+  Future<List<String>> listInboxMessageIds({String? accessToken}) async {
     final actorDidDocument = await _getActorDidDocument();
 
     final headers =
@@ -123,9 +124,7 @@ class MediatorClient {
     );
 
     return (response.data!['data'] as List<dynamic>)
-        .map(
-          (item) => (item as Map<String, dynamic>)['msg_id'] as String,
-        )
+        .map((item) => (item as Map<String, dynamic>)['msg_id'] as String)
         .toList();
   }
 
@@ -156,9 +155,8 @@ class MediatorClient {
 
     return (data['success'] as List<dynamic>)
         .map(
-          (item) => jsonDecode(
-            (item as Map<String, dynamic>)['msg'] as String,
-          ) as Map<String, dynamic>,
+          (item) => jsonDecode((item as Map<String, dynamic>)['msg'] as String)
+              as Map<String, dynamic>,
         )
         .toList();
   }
@@ -179,16 +177,12 @@ class MediatorClient {
     bool? cancelOnError,
     String? accessToken,
   }) async {
-    _channel = mediatorDidDocument.toWebSocketChannel(
-      accessToken: accessToken,
-    );
+    _channel = mediatorDidDocument.toWebSocketChannel(accessToken: accessToken);
 
     await _channel!.ready;
 
     final subscription = _channel.stream.listen(
-      (data) => onMessage(
-        jsonDecode(data as String) as Map<String, dynamic>,
-      ),
+      (data) => onMessage(jsonDecode(data as String) as Map<String, dynamic>),
       onError: onError,
       onDone: onDone,
       cancelOnError: cancelOnError,
@@ -239,9 +233,7 @@ class MediatorClient {
   }
 
   Future<DidDocument> _getActorDidDocument() async {
-    return DidKey.generateDocument(
-      keyPair.publicKey,
-    );
+    return DidKey.generateDocument(keyPair.publicKey);
   }
 
   Future<DidcommMessage> _packMessage(
@@ -251,10 +243,7 @@ class MediatorClient {
     DidcommMessage messageToSend = message;
 
     if (messageOptions.shouldSign) {
-      messageToSend = await SignedMessage.pack(
-        message,
-        signer: signer,
-      );
+      messageToSend = await SignedMessage.pack(message, signer: signer);
     }
 
     if (messageOptions.shouldEncrypt) {
@@ -278,8 +267,6 @@ class MediatorClient {
       );
     }
 
-    _channel.sink.add(
-      jsonEncode(message),
-    );
+    _channel.sink.add(jsonEncode(message));
   }
 }
diff --git a/lib/src/messages/core/encrypted_message/encrypted_message.dart b/lib/src/messages/core/encrypted_message/encrypted_message.dart
index 2abd262..38bb4cb 100644
--- a/lib/src/messages/core/encrypted_message/encrypted_message.dart
+++ b/lib/src/messages/core/encrypted_message/encrypted_message.dart
@@ -1,6 +1,11 @@
 import 'dart:convert';
 import 'dart:typed_data';
 
+import 'package:didcomm/src/did_resolver_manager.dart';
+import 'package:didcomm/src/errors/missing_authentication_tag_error.dart';
+import 'package:didcomm/src/errors/missing_initialization_vector_error.dart';
+import 'package:didcomm/src/errors/missing_key_agreement_error.dart';
+import 'package:json_annotation/json_annotation.dart';
 import 'package:crypto_keys_plus/crypto_keys.dart' as ck;
 import 'package:json_annotation/json_annotation.dart';
 import 'package:ssi/ssi.dart' hide Jwk;
@@ -165,12 +170,14 @@ class EncryptedMessage extends DidcommMessage {
 
     if (encryptedInnerMessage.initializationVector == null) {
       throw MissingInitializationVectorError(
-          'Initialization vector not set after encryption');
+        'Initialization vector not set after encryption',
+      );
     }
 
     if (encryptedInnerMessage.authenticationTag == null) {
       throw MissingAuthenticationTag(
-          'Authentication tag not set after encryption');
+        'Authentication tag not set after encryption',
+      );
     }
 
     final recipients = await _createRecipients(
@@ -201,9 +208,7 @@ class EncryptedMessage extends DidcommMessage {
   /// [recipientWallet]: The wallet to use for decryption.
   ///
   /// Returns the decrypted inner message as a JSON map.
-  Future<Map<String, dynamic>> unpack({
-    required Wallet recipientWallet,
-  }) async {
+  Future<Map<String, dynamic>> unpack({required Wallet recipientWallet}) async {
     final self = await _findSelfAsRecipient(recipientWallet);
     final jweHeader = _jweHeaderConverter.fromJson(protected);
 
@@ -237,9 +242,7 @@ class EncryptedMessage extends DidcommMessage {
         cipherText,
         initializationVector: initializationVector,
         authenticationTag: authenticationTag,
-        additionalAuthenticatedData: ascii.encode(
-          protected,
-        ),
+        additionalAuthenticatedData: ascii.encode(protected),
       ),
     );
 
@@ -249,17 +252,16 @@ class EncryptedMessage extends DidcommMessage {
 
   Future<Jwk> _getSenderJwk(String subjectKeyId) async {
     final senderDid = subjectKeyId.split('#').first;
-    final senderDidDocument = await UniversalDIDResolver.resolve(senderDid);
+    final senderDidDocument = await DidResolverManager.resolve(senderDid);
 
     final keyAgreement = senderDidDocument.keyAgreement.firstWhere(
       (keyAgreement) => keyAgreement.id == subjectKeyId,
       orElse: () => throw MissingKeyAgreementError(
-          'Can not find a key agreement for subject ID'),
+        'Can not find a key agreement for subject ID',
+      ),
     );
 
-    final senderJwk = Jwk.fromJson(
-      keyAgreement.asJwk().toJson(),
-    );
+    final senderJwk = Jwk.fromJson(keyAgreement.asJwk().toJson());
 
     return senderJwk;
   }
@@ -298,8 +300,9 @@ class EncryptedMessage extends DidcommMessage {
     EncryptionAlgorithm encryptionAlgorithm,
   ) {
     // TODO: clarify why 512 for a256cbc
-    final keySize =
-        encryptionAlgorithm == EncryptionAlgorithm.a256cbc ? 512 : 256;
+    final keySize = encryptionAlgorithm == EncryptionAlgorithm.a256cbc
+        ? 512
+        : 256;
     return ck.SymmetricKey.generate(keySize);
   }