diff --git a/veilid-flutter/example/lib/app.dart b/veilid-flutter/example/lib/app.dart
index 00e6600a..06576424 100644
--- a/veilid-flutter/example/lib/app.dart
+++ b/veilid-flutter/example/lib/app.dart
@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -97,11 +98,11 @@ class _MyAppState extends State<MyApp> with UiLoggy {
         if (update is VeilidLog) {
           await processLog(update);
         } else if (update is VeilidAppMessage) {
-          loggy.info("AppMessage: ${update.json}");
+          loggy.info("AppMessage: ${jsonEncode(update)}");
         } else if (update is VeilidAppCall) {
-          loggy.info("AppCall: ${update.json}");
+          loggy.info("AppCall: ${jsonEncode(update)}");
         } else {
-          loggy.trace("Update: ${update.json}");
+          loggy.trace("Update: ${jsonEncode(update)}");
         }
       }
     }
diff --git a/veilid-flutter/example/lib/veilid_init.dart b/veilid-flutter/example/lib/veilid_init.dart
index 7d0f8fb3..a7d6b5b7 100644
--- a/veilid-flutter/example/lib/veilid_init.dart
+++ b/veilid-flutter/example/lib/veilid_init.dart
@@ -14,7 +14,7 @@ void veilidInit() {
                 logsInConsole: false),
             api: VeilidWASMConfigLoggingApi(
                 enabled: true, level: VeilidConfigLogLevel.info)));
-    Veilid.instance.initializeVeilidCore(platformConfig.json);
+    Veilid.instance.initializeVeilidCore(platformConfig.toJson());
   } else {
     var platformConfig = VeilidFFIConfig(
         logging: VeilidFFIConfigLogging(
@@ -29,6 +29,6 @@ void veilidInit() {
                 serviceName: "VeilidExample"),
             api: VeilidFFIConfigLoggingApi(
                 enabled: true, level: VeilidConfigLogLevel.info)));
-    Veilid.instance.initializeVeilidCore(platformConfig.json);
+    Veilid.instance.initializeVeilidCore(platformConfig.toJson());
   }
 }
diff --git a/veilid-flutter/lib/routing_context.dart b/veilid-flutter/lib/routing_context.dart
index 7fc15526..6d7345b4 100644
--- a/veilid-flutter/lib/routing_context.dart
+++ b/veilid-flutter/lib/routing_context.dart
@@ -33,7 +33,7 @@ abstract class DHTSchema {
         }
     }
   }
-  Map<String, dynamic> get json;
+  Map<String, dynamic> toJson();
 }
 
 class DHTSchemaDFLT implements DHTSchema {
@@ -49,7 +49,7 @@ class DHTSchemaDFLT implements DHTSchema {
   }
 
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'kind': "DFLT",
       'o_cnt': oCnt,
@@ -71,7 +71,7 @@ class DHTSchemaMember {
     }
   }
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'm_key': mKey,
       'm_cnt': mCnt,
@@ -97,11 +97,11 @@ class DHTSchemaSMPL implements DHTSchema {
     }
   }
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'kind': "SMPL",
       'o_cnt': oCnt,
-      'members': members.map((p) => p.json).toList(),
+      'members': members.map((p) => p.toJson()).toList(),
     };
   }
 }
@@ -122,12 +122,12 @@ class DHTRecordDescriptor {
     required this.schema,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'key': key.toString(),
       'owner': owner,
       'owner_secret': ownerSecret,
-      'schema': schema.json,
+      'schema': schema.toJson(),
     };
   }
 
@@ -168,7 +168,7 @@ class ValueSubkeyRange {
     }
   }
 
-  List<dynamic> get json {
+  List<dynamic> toJson() {
     return [low, high];
   }
 }
@@ -192,7 +192,7 @@ class ValueData {
         data = base64UrlNoPadDecode(json['data']),
         writer = json['writer'];
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {'seq': seq, 'data': base64UrlNoPadEncode(data), 'writer': writer};
   }
 }
@@ -205,7 +205,7 @@ enum Stability {
 }
 
 extension StabilityExt on Stability {
-  String get json {
+  String toJson() {
     return name.toPascalCase();
   }
 }
@@ -224,7 +224,7 @@ enum Sequencing {
 }
 
 extension SequencingExt on Sequencing {
-  String get json {
+  String toJson() {
     return name.toPascalCase();
   }
 }
@@ -245,7 +245,7 @@ class RouteBlob {
       : routeId = json['route_id'],
         blob = base64UrlNoPadDecode(json['blob']);
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {'route_id': routeId, 'blob': base64UrlNoPadEncode(blob)};
   }
 }
diff --git a/veilid-flutter/lib/veilid.dart b/veilid-flutter/lib/veilid.dart
index e716b22b..f6e1e78d 100644
--- a/veilid-flutter/lib/veilid.dart
+++ b/veilid-flutter/lib/veilid.dart
@@ -36,16 +36,29 @@ Object? veilidApiToEncodable(Object? value) {
     return value;
   }
   switch (value.runtimeType) {
-    case AttachmentState:
-      return (value as AttachmentState).json;
-    case VeilidLogLevel:
-      return (value as VeilidLogLevel).json;
-    case VeilidConfigLogLevel:
-      return (value as VeilidConfigLogLevel).json;
+    // case KeyPair:
+    //   return (value as KeyPair).json;
   }
   throw UnsupportedError('Cannot convert to JSON: $value');
 }
 
+T? Function(dynamic) optFromJson<T>(T Function(dynamic) jsonConstructor) {
+  return (dynamic j) {
+    if (j == null) {
+      return null;
+    } else {
+      return jsonConstructor(j);
+    }
+  };
+}
+
+List<T> Function(dynamic) jsonListConstructor<T>(
+    T Function(dynamic) jsonConstructor) {
+  return (dynamic j) {
+    return (j as List<dynamic>).map((e) => jsonConstructor(e)).toList();
+  };
+}
+
 //////////////////////////////////////
 /// VeilidVersion
 
@@ -71,8 +84,7 @@ class Timestamp {
   Timestamp.fromString(String s) : value = BigInt.parse(s);
 
   Timestamp.fromJson(dynamic json) : this.fromString(json as String);
-
-  String get json {
+  String toJson() {
     return toString();
   }
 
@@ -97,8 +109,7 @@ class TimestampDuration {
   TimestampDuration.fromString(String s) : value = BigInt.parse(s);
 
   TimestampDuration.fromJson(dynamic json) : this.fromString(json as String);
-
-  String get json {
+  String toJson() {
     return toString();
   }
 
diff --git a/veilid-flutter/lib/veilid_config.dart b/veilid-flutter/lib/veilid_config.dart
index 7f5d0787..176fe2b3 100644
--- a/veilid-flutter/lib/veilid_config.dart
+++ b/veilid-flutter/lib/veilid_config.dart
@@ -20,7 +20,7 @@ enum VeilidConfigLogLevel {
 }
 
 extension VeilidConfigLogLevelExt on VeilidConfigLogLevel {
-  String get json {
+  String toJson() {
     return name.toPascalCase();
   }
 }
@@ -45,7 +45,7 @@ class VeilidConfigHTTPS {
     this.url,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
       'listen_address': listenAddress,
@@ -76,7 +76,7 @@ class VeilidConfigHTTP {
     this.url,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
       'listen_address': listenAddress,
@@ -103,10 +103,10 @@ class VeilidConfigApplication {
     required this.http,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'https': https.json,
-      'http': http.json,
+      'https': https.toJson(),
+      'http': http.toJson(),
     };
   }
 
@@ -129,7 +129,7 @@ class VeilidConfigUDP {
       required this.listenAddress,
       this.publicAddress});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
       'socket_pool_size': socketPoolSize,
@@ -161,7 +161,7 @@ class VeilidConfigTCP {
       required this.listenAddress,
       this.publicAddress});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'connect': connect,
       'listen': listen,
@@ -197,7 +197,7 @@ class VeilidConfigWS {
       required this.path,
       this.url});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'connect': connect,
       'listen': listen,
@@ -235,7 +235,7 @@ class VeilidConfigWSS {
       required this.path,
       this.url});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'connect': connect,
       'listen': listen,
@@ -270,12 +270,12 @@ class VeilidConfigProtocol {
     required this.wss,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'udp': udp.json,
-      'tcp': tcp.json,
-      'ws': ws.json,
-      'wss': wss.json,
+      'udp': udp.toJson(),
+      'tcp': tcp.toJson(),
+      'ws': ws.toJson(),
+      'wss': wss.toJson(),
     };
   }
 
@@ -299,7 +299,7 @@ class VeilidConfigTLS {
     required this.connectionInitialTimeoutMs,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'certificate_path': certificatePath,
       'private_key_path': privateKeyPath,
@@ -357,7 +357,7 @@ class VeilidConfigDHT {
       required this.remoteMaxSubkeyCacheMemoryMb,
       required this.remoteMaxStorageSpaceMb});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'max_find_node_count': maxFindNodeCount,
       'resolve_node_timeout_ms': resolveNodeTimeoutMs,
@@ -425,7 +425,7 @@ class VeilidConfigRPC {
       required this.maxRouteHopCount,
       required this.defaultRouteHopCount});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'concurrency': concurrency,
       'queue_size': queueSize,
@@ -470,10 +470,10 @@ class VeilidConfigRoutingTable {
     required this.limitAttachedWeak,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'node_id': nodeId.map((p) => p.json).toList(),
-      'node_id_secret': nodeIdSecret.map((p) => p.json).toList(),
+      'node_id': nodeId.map((p) => p.toJson()).toList(),
+      'node_id_secret': nodeIdSecret.map((p) => p.toJson()).toList(),
       'bootstrap': bootstrap.map((p) => p).toList(),
       'limit_over_attached': limitOverAttached,
       'limit_fully_attached': limitFullyAttached,
@@ -539,7 +539,7 @@ class VeilidConfigNetwork {
     required this.protocol,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'connection_initial_timeout_ms': connectionInitialTimeoutMs,
       'connection_inactivity_timeout_ms': connectionInactivityTimeoutMs,
@@ -550,15 +550,15 @@ class VeilidConfigNetwork {
       'client_whitelist_timeout_ms': clientWhitelistTimeoutMs,
       'reverse_connection_receipt_time_ms': reverseConnectionReceiptTimeMs,
       'hole_punch_receipt_time_ms': holePunchReceiptTimeMs,
-      'routing_table': routingTable.json,
-      'rpc': rpc.json,
-      'dht': dht.json,
+      'routing_table': routingTable.toJson(),
+      'rpc': rpc.toJson(),
+      'dht': dht.toJson(),
       'upnp': upnp,
       'detect_address_changes': detectAddressChanges,
       'restricted_nat_retries': restrictedNatRetries,
-      'tls': tls.json,
-      'application': application.json,
-      'protocol': protocol.json,
+      'tls': tls.toJson(),
+      'application': application.toJson(),
+      'protocol': protocol.toJson(),
     };
   }
 
@@ -597,7 +597,7 @@ class VeilidConfigTableStore {
     required this.delete,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {'directory': directory, 'delete': delete};
   }
 
@@ -617,7 +617,7 @@ class VeilidConfigBlockStore {
     required this.delete,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {'directory': directory, 'delete': delete};
   }
 
@@ -641,7 +641,7 @@ class VeilidConfigProtectedStore {
     required this.delete,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'allow_insecure_fallback': allowInsecureFallback,
       'always_use_insecure_storage': alwaysUseInsecureStorage,
@@ -678,7 +678,7 @@ class VeilidConfigCapabilities {
     required this.protocolAcceptWSS,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'protocol_udp': protocolUDP,
       'protocol_connect_tcp': protocolConnectTCP,
@@ -721,15 +721,15 @@ class VeilidConfig {
     required this.network,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'program_name': programName,
       'namespace': namespace,
-      'capabilities': capabilities.json,
-      'protected_store': protectedStore.json,
-      'table_store': tableStore.json,
-      'block_store': blockStore.json,
-      'network': network.json
+      'capabilities': capabilities.toJson(),
+      'protected_store': protectedStore.toJson(),
+      'table_store': tableStore.toJson(),
+      'block_store': blockStore.toJson(),
+      'network': network.toJson()
     };
   }
 
diff --git a/veilid-flutter/lib/veilid_crypto.dart b/veilid-flutter/lib/veilid_crypto.dart
index 40be7f74..9f90ed39 100644
--- a/veilid-flutter/lib/veilid_crypto.dart
+++ b/veilid-flutter/lib/veilid_crypto.dart
@@ -55,7 +55,7 @@ class Typed<V extends EncodedString> {
     value = EncodedString.fromString<V>(parts.sublist(1).join(":"));
   }
 
-  String get json {
+  String toJson() {
     return toString();
   }
 
@@ -83,7 +83,7 @@ class KeyPair {
     secret = PublicKey(parts[1]);
   }
 
-  String get json {
+  String toJson() {
     return toString();
   }
 
@@ -114,7 +114,7 @@ class TypedKeyPair {
     secret = PublicKey(parts[2]);
   }
 
-  String get json {
+  String toJson() {
     return toString();
   }
 
diff --git a/veilid-flutter/lib/veilid_encoding.dart b/veilid-flutter/lib/veilid_encoding.dart
index f2746da9..9d56b58d 100644
--- a/veilid-flutter/lib/veilid_encoding.dart
+++ b/veilid-flutter/lib/veilid_encoding.dart
@@ -70,7 +70,7 @@ class FixedEncodedString32 extends EncodedString {
     return 24;
   }
 
-  String get json {
+  String toJson() {
     return toString();
   }
 
@@ -89,7 +89,7 @@ class FixedEncodedString43 extends EncodedString {
     return 32;
   }
 
-  String get json {
+  String toJson() {
     return toString();
   }
 
@@ -108,7 +108,7 @@ class FixedEncodedString86 extends EncodedString {
     return 64;
   }
 
-  String get json {
+  String toJson() {
     return toString();
   }
 
diff --git a/veilid-flutter/lib/veilid_ffi.dart b/veilid-flutter/lib/veilid_ffi.dart
index a1c352ca..1ad56fa4 100644
--- a/veilid-flutter/lib/veilid_ffi.dart
+++ b/veilid-flutter/lib/veilid_ffi.dart
@@ -22,10 +22,10 @@ class VeilidFFIConfigLoggingTerminal {
     required this.level,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
-      'level': level.json,
+      'level': level.toJson(),
     };
   }
 
@@ -47,10 +47,10 @@ class VeilidFFIConfigLoggingOtlp {
     required this.serviceName,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
-      'level': level.json,
+      'level': level.toJson(),
       'grpc_endpoint': grpcEndpoint,
       'service_name': serviceName,
     };
@@ -72,10 +72,10 @@ class VeilidFFIConfigLoggingApi {
     required this.level,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
-      'level': level.json,
+      'level': level.toJson(),
     };
   }
 
@@ -92,11 +92,11 @@ class VeilidFFIConfigLogging {
   VeilidFFIConfigLogging(
       {required this.terminal, required this.otlp, required this.api});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'terminal': terminal.json,
-      'otlp': otlp.json,
-      'api': api.json,
+      'terminal': terminal.toJson(),
+      'otlp': otlp.toJson(),
+      'api': api.toJson(),
     };
   }
 
@@ -113,9 +113,9 @@ class VeilidFFIConfig {
     required this.logging,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'logging': logging.json,
+      'logging': logging.toJson(),
     };
   }
 
@@ -221,9 +221,9 @@ typedef _RoutingContextSetDHTValueDart = void Function(
     int, int, Pointer<Utf8>, int, Pointer<Utf8>);
 // fn routing_context_watch_dht_values(port: i64, id: u32, key: FfiStr, subkeys: FfiStr, expiration: FfiStr, count: u32)
 typedef _RoutingContextWatchDHTValuesC = Void Function(
-    Int64, Uint32, Pointer<Utf8>, Pointer<Utf8>, Pointer<Utf8>, Uint32);
+    Int64, Uint32, Pointer<Utf8>, Pointer<Utf8>, Uint64, Uint32);
 typedef _RoutingContextWatchDHTValuesDart = void Function(
-    int, int, Pointer<Utf8>, Pointer<Utf8>, Pointer<Utf8>, int);
+    int, int, Pointer<Utf8>, Pointer<Utf8>, int, int);
 // fn routing_context_cancel_dht_watch(port: i64, id: u32, key: FfiStr, subkeys: FfiStr)
 typedef _RoutingContextCancelDHTWatchC = Void Function(
     Int64, Uint32, Pointer<Utf8>, Pointer<Utf8>);
@@ -652,14 +652,14 @@ class VeilidRoutingContextFFI implements VeilidRoutingContext {
   @override
   VeilidRoutingContextFFI withCustomPrivacy(Stability stability) {
     final newId = _ctx.ffi._routingContextWithCustomPrivacy(
-        _ctx.id, stability.json.toNativeUtf8());
+        _ctx.id, jsonEncode(stability).toNativeUtf8());
     return VeilidRoutingContextFFI._(_Ctx(newId, _ctx.ffi));
   }
 
   @override
   VeilidRoutingContextFFI withSequencing(Sequencing sequencing) {
-    final newId = _ctx.ffi
-        ._routingContextWithSequencing(_ctx.id, sequencing.json.toNativeUtf8());
+    final newId = _ctx.ffi._routingContextWithSequencing(
+        _ctx.id, jsonEncode(sequencing).toNativeUtf8());
     return VeilidRoutingContextFFI._(_Ctx(newId, _ctx.ffi));
   }
 
@@ -677,7 +677,7 @@ class VeilidRoutingContextFFI implements VeilidRoutingContext {
   }
 
   @override
-  Future<void> appMessage(String target, Uint8List message) async {
+  Future<void> appMessage(String target, Uint8List message) {
     final nativeEncodedTarget = target.toNativeUtf8();
     final nativeEncodedMessage = base64UrlNoPadEncode(message).toNativeUtf8();
 
@@ -687,6 +687,111 @@ class VeilidRoutingContextFFI implements VeilidRoutingContext {
         nativeEncodedTarget, nativeEncodedMessage);
     return processFutureVoid(recvPort.first);
   }
+
+  @override
+  Future<DHTRecordDescriptor> createDHTRecord(
+      CryptoKind kind, DHTSchema schema) async {
+    final nativeSchema = jsonEncode(schema).toNativeUtf8();
+    final recvPort = ReceivePort("routing_context_create_dht_record");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextCreateDHTRecord(
+        sendPort.nativePort, _ctx.id, kind, nativeSchema);
+    final dhtRecordDescriptor =
+        await processFutureJson(DHTRecordDescriptor.fromJson, recvPort.first);
+    return dhtRecordDescriptor;
+  }
+
+  @override
+  Future<DHTRecordDescriptor> openDHTRecord(
+      TypedKey key, KeyPair? writer) async {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final nativeWriter =
+        writer != null ? jsonEncode(key).toNativeUtf8() : nullptr;
+    final recvPort = ReceivePort("routing_context_open_dht_record");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextOpenDHTRecord(
+        sendPort.nativePort, _ctx.id, nativeKey, nativeWriter);
+    final dhtRecordDescriptor =
+        await processFutureJson(DHTRecordDescriptor.fromJson, recvPort.first);
+    return dhtRecordDescriptor;
+  }
+
+  @override
+  Future<void> closeDHTRecord(TypedKey key) {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final recvPort = ReceivePort("routing_context_close_dht_record");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi
+        ._routingContextCloseDHTRecord(sendPort.nativePort, _ctx.id, nativeKey);
+    return processFutureVoid(recvPort.first);
+  }
+
+  @override
+  Future<void> deleteDHTRecord(TypedKey key) {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final recvPort = ReceivePort("routing_context_delete_dht_record");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextDeleteDHTRecord(
+        sendPort.nativePort, _ctx.id, nativeKey);
+    return processFutureVoid(recvPort.first);
+  }
+
+  @override
+  Future<ValueData?> getDHTValue(
+      TypedKey key, int subkey, bool forceRefresh) async {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final recvPort = ReceivePort("routing_context_get_dht_value");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextGetDHTValue(
+        sendPort.nativePort, _ctx.id, nativeKey, subkey, forceRefresh);
+    final valueData = await processFutureJson(
+        optFromJson(ValueData.fromJson), recvPort.first);
+    return valueData;
+  }
+
+  @override
+  Future<ValueData?> setDHTValue(
+      TypedKey key, int subkey, Uint8List data) async {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final nativeData = base64UrlNoPadEncode(data).toNativeUtf8();
+
+    final recvPort = ReceivePort("routing_context_set_dht_value");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextSetDHTValue(
+        sendPort.nativePort, _ctx.id, nativeKey, subkey, nativeData);
+    final valueData = await processFutureJson(
+        optFromJson(ValueData.fromJson), recvPort.first);
+    return valueData;
+  }
+
+  @override
+  Future<Timestamp> watchDHTValues(TypedKey key, ValueSubkeyRange subkeys,
+      Timestamp expiration, int count) async {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final nativeSubkeys = jsonEncode(subkeys).toNativeUtf8();
+    final nativeExpiration = expiration.value.toInt();
+
+    final recvPort = ReceivePort("routing_context_watch_dht_values");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextWatchDHTValues(sendPort.nativePort, _ctx.id,
+        nativeKey, nativeSubkeys, nativeExpiration, count);
+    final actualExpiration = Timestamp(
+        value: BigInt.from(await processFuturePlain<int>(recvPort.first)));
+    return actualExpiration;
+  }
+
+  @override
+  Future<bool> cancelDHTWatch(TypedKey key, ValueSubkeyRange subkeys) async {
+    final nativeKey = jsonEncode(key).toNativeUtf8();
+    final nativeSubkeys = jsonEncode(subkeys).toNativeUtf8();
+
+    final recvPort = ReceivePort("routing_context_cancel_dht_watch");
+    final sendPort = recvPort.sendPort;
+    _ctx.ffi._routingContextCancelDHTWatch(
+        sendPort.nativePort, _ctx.id, nativeKey, nativeSubkeys);
+    final cancelled = await processFuturePlain<bool>(recvPort.first);
+    return cancelled;
+  }
 }
 
 class _TDBT {
@@ -853,6 +958,56 @@ class VeilidTableDBFFI extends VeilidTableDB {
   }
 }
 
+// FFI implementation of VeilidCryptoSystem
+class VeilidCryptoSystemFFI implements VeilidCryptoSystem {
+  final CryptoKind _kind;
+
+  VeilidCryptoSystemFFI._(this._kind);
+
+  @override
+  CryptoKind kind() {
+    return _kind;
+  }
+
+  @override
+  Future<SharedSecret> cachedDH(PublicKey key, SecretKey secret) {}
+  @override
+  Future<SharedSecret> computeDH(PublicKey key, SecretKey secret) {}
+  @override
+  Future<Nonce> randomNonce() {}
+  @override
+  Future<SharedSecret> randomSharedSecret() {}
+  @override
+  Future<KeyPair> generateKeyPair() {}
+  @override
+  Future<HashDigest> generateHash(Uint8List data) {}
+  @override
+  Future<HashDigest> generateHashReader(Stream<List<int>> reader) {}
+  @override
+  Future<bool> validateKeyPair(PublicKey key, SecretKey secret) {}
+  @override
+  Future<bool> validateHash(Uint8List data, HashDigest hash) {}
+  @override
+  Future<bool> validateHashReader(Stream<List<int>> reader, HashDigest hash) {}
+  @override
+  Future<CryptoKeyDistance> distance(CryptoKey key1, CryptoKey key2) {}
+  @override
+  Future<Signature> sign(PublicKey key, SecretKey secret, Uint8List data) {}
+  @override
+  Future<void> verify(PublicKey key, Uint8List data, Signature signature) {}
+  @override
+  Future<int> aeadOverhead() {}
+  @override
+  Future<Uint8List> decryptAead(Uint8List body, Nonce nonce,
+      SharedSecret sharedSecret, Uint8List? associatedData) {}
+  @override
+  Future<Uint8List> encryptAead(Uint8List body, Nonce nonce,
+      SharedSecret sharedSecret, Uint8List? associatedData) {}
+  @override
+  Future<Uint8List> cryptNoAuth(
+      Uint8List body, Nonce nonce, SharedSecret sharedSecret) {}
+}
+
 // FFI implementation of high level Veilid API
 class VeilidFFI implements Veilid {
   // veilid_core shared library
@@ -1054,31 +1209,63 @@ class VeilidFFI implements Veilid {
         _tableDbTransactionDelete = dylib.lookupFunction<
             _TableDbTransactionDeleteC,
             _TableDbTransactionDeleteDart>('table_db_transaction_delete'),
-
-xxx
-  final _ValidCryptoKindsDart _validCryptoKinds;
-  final _BestCryptoKindDart _bestCryptoKind;
-  final _VerifySignaturesDart _verifySignatures;
-  final _GenerateSignaturesDart _generateSignatures;
-  final _GenerateKeyPairDart _generateKeyPair;
-
-  final _CryptoCachedDHDart _cryptoCachedDH;
-  final _CryptoComputeDHDart _cryptoComputeDH;
-  final _CryptoRandomNonceDart _cryptoRandomNonce;
-  final _CryptoRandomSharedSecretDart _cryptoRandomSharedSecret;
-  final _CryptoGenerateKeyPairDart _cryptoGenerateKeyPair;
-  final _CryptoGenerateHashDart _cryptoGenerateHash;
-  final _CryptoValidateKeyPairDart _cryptoValidateKeyPair;
-  final _CryptoValidateHashDart _cryptoValidateHash;
-  final _CryptoDistanceDart _cryptoDistance;
-  final _CryptoSignDart _cryptoSign;
-  final _CryptoVerifyDart _cryptoVerify;
-  final _CryptoAeadOverheadDart _cryptoAeadOverhead;
-  final _CryptoDecryptAeadDart _cryptoDecryptAead;
-  final _CryptoEncryptAeadDart _cryptoEncryptAead;
-  final _CryptoCryptNoAuthDart _cryptoCryptNoAuth;
-
-
+        _validCryptoKinds =
+            dylib.lookupFunction<_ValidCryptoKindsC, _ValidCryptoKindsDart>(
+                'valid_crypto_kinds'),
+        _bestCryptoKind =
+            dylib.lookupFunction<_BestCryptoKindC, _BestCryptoKindDart>(
+                'best_crypto_kind'),
+        _verifySignatures =
+            dylib.lookupFunction<_VerifySignaturesC, _VerifySignaturesDart>(
+                'verify_signatures'),
+        _generateSignatures =
+            dylib.lookupFunction<_GenerateSignaturesC, _GenerateSignaturesDart>(
+                'generate_signatures'),
+        _generateKeyPair =
+            dylib.lookupFunction<_GenerateKeyPairC, _GenerateKeyPairDart>(
+                'generate_key_pair'),
+        _cryptoCachedDH =
+            dylib.lookupFunction<_CryptoCachedDHC, _CryptoCachedDHDart>(
+                'crypto_cached_dh'),
+        _cryptoComputeDH =
+            dylib.lookupFunction<_CryptoComputeDHC, _CryptoComputeDHDart>(
+                'crypto_compute_dh'),
+        _cryptoRandomNonce =
+            dylib.lookupFunction<_CryptoRandomNonceC, _CryptoRandomNonceDart>(
+                'crypto_random_nonce'),
+        _cryptoRandomSharedSecret = dylib.lookupFunction<
+            _CryptoRandomSharedSecretC,
+            _CryptoRandomSharedSecretDart>('crypto_random_shared_secret'),
+        _cryptoGenerateKeyPair = dylib.lookupFunction<_CryptoGenerateKeyPairC,
+            _CryptoGenerateKeyPairDart>('crypto_generate_key_pair'),
+        _cryptoGenerateHash =
+            dylib.lookupFunction<_CryptoGenerateHashC, _CryptoGenerateHashDart>(
+                'crypto_generate_hash'),
+        _cryptoValidateKeyPair = dylib.lookupFunction<_CryptoValidateKeyPairC,
+            _CryptoValidateKeyPairDart>('crypto_validate_key_pair'),
+        _cryptoValidateHash =
+            dylib.lookupFunction<_CryptoValidateHashC, _CryptoValidateHashDart>(
+                'crypto_validate_hash'),
+        _cryptoDistance =
+            dylib.lookupFunction<_CryptoDistanceC, _CryptoDistanceDart>(
+                'crypto_distance'),
+        _cryptoSign =
+            dylib.lookupFunction<_CryptoSignC, _CryptoSignDart>('crypto_sign'),
+        _cryptoVerify = dylib
+            .lookupFunction<_CryptoVerifyC, _CryptoVerifyDart>('crypto_verify'),
+        _cryptoAeadOverhead =
+            dylib.lookupFunction<_CryptoAeadOverheadC, _CryptoAeadOverheadDart>(
+                'crypto_aead_overhead'),
+        _cryptoDecryptAead =
+            dylib.lookupFunction<_CryptoDecryptAeadC, _CryptoDecryptAeadDart>(
+                'crypto_decrypt_aead'),
+        _cryptoEncryptAead =
+            dylib.lookupFunction<_CryptoEncryptAeadC, _CryptoEncryptAeadDart>(
+                'crypto_encrypt_aead'),
+        _cryptoCryptNoAuth =
+            dylib.lookupFunction<_CryptoCryptNoAuthC, _CryptoCryptNoAuthDart>(
+                'crypto_crypt_no_auth'),
+        _now = dylib.lookupFunction<_NowC, _NowDart>('now'),
         _debug = dylib.lookupFunction<_DebugC, _DebugDart>('debug'),
         _veilidVersionString = dylib.lookupFunction<_VeilidVersionStringC,
             _VeilidVersionStringDart>('veilid_version_string'),
@@ -1094,9 +1281,7 @@ xxx
 
   @override
   void initializeVeilidCore(Map<String, dynamic> platformConfigJson) {
-    var nativePlatformConfig =
-        jsonEncode(platformConfigJson, toEncodable: veilidApiToEncodable)
-            .toNativeUtf8();
+    var nativePlatformConfig = jsonEncode(platformConfigJson).toNativeUtf8();
 
     _initializeVeilidCore(nativePlatformConfig);
 
@@ -1105,9 +1290,7 @@ xxx
 
   @override
   void changeLogLevel(String layer, VeilidConfigLogLevel logLevel) {
-    var nativeLogLevel =
-        jsonEncode(logLevel.json, toEncodable: veilidApiToEncodable)
-            .toNativeUtf8();
+    var nativeLogLevel = jsonEncode(logLevel).toNativeUtf8();
     var nativeLayer = layer.toNativeUtf8();
     _changeLogLevel(nativeLayer, nativeLogLevel);
     malloc.free(nativeLayer);
@@ -1116,9 +1299,7 @@ xxx
 
   @override
   Future<Stream<VeilidUpdate>> startupVeilidCore(VeilidConfig config) {
-    var nativeConfig =
-        jsonEncode(config.json, toEncodable: veilidApiToEncodable)
-            .toNativeUtf8();
+    var nativeConfig = jsonEncode(config).toNativeUtf8();
     final recvStreamPort = ReceivePort("veilid_api_stream");
     final sendStreamPort = recvStreamPort.sendPort;
     final recvPort = ReceivePort("startup_veilid_core");
@@ -1185,8 +1366,10 @@ xxx
       Stability stability, Sequencing sequencing) async {
     final recvPort = ReceivePort("new_custom_private_route");
     final sendPort = recvPort.sendPort;
-    _newCustomPrivateRoute(sendPort.nativePort, stability.json.toNativeUtf8(),
-        sequencing.json.toNativeUtf8());
+    _newCustomPrivateRoute(
+        sendPort.nativePort,
+        jsonEncode(stability).toNativeUtf8(),
+        jsonEncode(sequencing).toNativeUtf8());
     final routeBlob =
         await processFutureJson(RouteBlob.fromJson, recvPort.first);
     return routeBlob;
@@ -1240,6 +1423,48 @@ xxx
     return deleted;
   }
 
+  @override
+  List<CryptoKind> validCryptoKinds() {
+    final vckString = _validCryptoKinds();
+    final vck = jsonDecode(vckString.toDartString());
+    _freeString(vckString);
+    return vck;
+  }
+
+  @override
+  Future<VeilidCryptoSystem> getCryptoSystem(CryptoKind kind) async {
+    if (!validCryptoKinds().contains(kind)) {
+      throw VeilidAPIExceptionGeneric("unsupported cryptosystem");
+    }
+    return VeilidCryptoSystemFFI._(kind);
+  }
+
+  @override
+  Future<VeilidCryptoSystem> bestCryptoSystem() async {
+    return VeilidCryptoSystemFFI._(_bestCryptoKind());
+  }
+
+  @override
+  Future<List<TypedKey>> verifySignatures(
+      List<TypedKey> nodeIds, Uint8List data, List<TypedSignature> signatures) {
+    final nativeNodeIds = jsonEncode(nodeIds).toNativeUtf8();
+    final nativeData = base64UrlNoPadEncode(data).toNativeUtf8();
+    final nativeSignatures = jsonEncode(signatures).toNativeUtf8();
+
+    final recvPort = ReceivePort("app_call_reply");
+    final sendPort = recvPort.sendPort;
+    _verifySignatures(
+        sendPort.nativePort, nativeNodeIds, nativeData, nativeSignatures);
+    return processFutureJson(
+        jsonListConstructor<TypedKey>(TypedKey.fromJson), recvPort.first);
+  }
+xxx
+  @override
+  Future<List<TypedSignature>> generateSignatures(
+      Uint8List data, List<TypedKeyPair> keyPairs) {}
+  @override
+  Future<TypedKeyPair> generateKeyPair(CryptoKind kind) {}
+
   @override
   Future<String> debug(String command) async {
     var nativeCommand = command.toNativeUtf8();
diff --git a/veilid-flutter/lib/veilid_js.dart b/veilid-flutter/lib/veilid_js.dart
index 0125236a..3cc9efc1 100644
--- a/veilid-flutter/lib/veilid_js.dart
+++ b/veilid-flutter/lib/veilid_js.dart
@@ -25,10 +25,10 @@ class VeilidWASMConfigLoggingPerformance {
     required this.logsInConsole,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
-      'level': level.json,
+      'level': level.toJson(),
       'logs_in_timings': logsInTimings,
       'logs_in_console': logsInConsole,
     };
@@ -50,10 +50,10 @@ class VeilidWASMConfigLoggingApi {
     required this.level,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'enabled': enabled,
-      'level': level.json,
+      'level': level.toJson(),
     };
   }
 
@@ -68,10 +68,10 @@ class VeilidWASMConfigLogging {
 
   VeilidWASMConfigLogging({required this.performance, required this.api});
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'performance': performance.json,
-      'api': api.json,
+      'performance': performance.toJson(),
+      'api': api.toJson(),
     };
   }
 
@@ -88,9 +88,9 @@ class VeilidWASMConfig {
     required this.logging,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'logging': logging.json,
+      'logging': logging.toJson(),
     };
   }
 
@@ -137,15 +137,17 @@ class VeilidRoutingContextJS implements VeilidRoutingContext {
   @override
   VeilidRoutingContextJS withCustomPrivacy(Stability stability) {
     final newId = js_util.callMethod(
-        wasm, "routing_context_with_custom_privacy", [_ctx.id, stability.json]);
+        wasm,
+        "routing_context_with_custom_privacy",
+        [_ctx.id, jsonEncode(stability)]);
 
     return VeilidRoutingContextJS._(_Ctx(newId, _ctx.js));
   }
 
   @override
   VeilidRoutingContextJS withSequencing(Sequencing sequencing) {
-    final newId = js_util.callMethod(
-        wasm, "routing_context_with_sequencing", [_ctx.id, sequencing.json]);
+    final newId = js_util.callMethod(wasm, "routing_context_with_sequencing",
+        [_ctx.id, jsonEncode(sequencing)]);
     return VeilidRoutingContextJS._(_Ctx(newId, _ctx.js));
   }
 
@@ -292,16 +294,14 @@ class VeilidTableDBJS extends VeilidTableDB {
 class VeilidJS implements Veilid {
   @override
   void initializeVeilidCore(Map<String, dynamic> platformConfigJson) {
-    var platformConfigJsonString =
-        jsonEncode(platformConfigJson, toEncodable: veilidApiToEncodable);
+    var platformConfigJsonString = jsonEncode(platformConfigJson);
     js_util
         .callMethod(wasm, "initialize_veilid_core", [platformConfigJsonString]);
   }
 
   @override
   void changeLogLevel(String layer, VeilidConfigLogLevel logLevel) {
-    var logLevelJsonString =
-        jsonEncode(logLevel.json, toEncodable: veilidApiToEncodable);
+    var logLevelJsonString = jsonEncode(logLevel);
     js_util.callMethod(wasm, "change_log_level", [layer, logLevelJsonString]);
   }
 
@@ -318,10 +318,8 @@ class VeilidJS implements Veilid {
       }
     }
 
-    await _wrapApiPromise(js_util.callMethod(wasm, "startup_veilid_core", [
-      js.allowInterop(updateCallback),
-      jsonEncode(config.json, toEncodable: veilidApiToEncodable)
-    ]));
+    await _wrapApiPromise(js_util.callMethod(wasm, "startup_veilid_core",
+        [js.allowInterop(updateCallback), jsonEncode(config)]));
 
     return streamController.stream;
   }
@@ -365,10 +363,8 @@ class VeilidJS implements Veilid {
   @override
   Future<RouteBlob> newCustomPrivateRoute(
       Stability stability, Sequencing sequencing) async {
-    var stabilityString =
-        jsonEncode(stability, toEncodable: veilidApiToEncodable);
-    var sequencingString =
-        jsonEncode(sequencing, toEncodable: veilidApiToEncodable);
+    var stabilityString = jsonEncode(stability);
+    var sequencingString = jsonEncode(sequencing);
 
     Map<String, dynamic> blobJson = jsonDecode(await _wrapApiPromise(js_util
         .callMethod(
diff --git a/veilid-flutter/lib/veilid_state.dart b/veilid-flutter/lib/veilid_state.dart
index a1248f3f..39142d20 100644
--- a/veilid-flutter/lib/veilid_state.dart
+++ b/veilid-flutter/lib/veilid_state.dart
@@ -20,7 +20,7 @@ enum AttachmentState {
 }
 
 extension AttachmentStateExt on AttachmentState {
-  String get json {
+  String toJson() {
     return name.toPascalCase();
   }
 }
@@ -41,7 +41,7 @@ enum VeilidLogLevel {
 }
 
 extension VeilidLogLevelExt on VeilidLogLevel {
-  String get json {
+  String toJson() {
     return name.toPascalCase();
   }
 }
@@ -63,11 +63,11 @@ class LatencyStats {
     required this.slowest,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'fastest': fastest.json,
-      'average': average.json,
-      'slowest': slowest.json,
+      'fastest': fastest.toJson(),
+      'average': average.toJson(),
+      'slowest': slowest.toJson(),
     };
   }
 
@@ -92,7 +92,7 @@ class TransferStats {
     required this.minimum,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'total': total.toString(),
       'maximum': maximum.toString(),
@@ -119,10 +119,10 @@ class TransferStatsDownUp {
     required this.up,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'down': down.json,
-      'up': up.json,
+      'down': down.toJson(),
+      'up': up.toJson(),
     };
   }
 
@@ -154,14 +154,14 @@ class RPCStats {
     required this.failedToSend,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'messages_sent': messagesSent,
       'messages_rcvd': messagesRcvd,
       'questions_in_flight': questionsInFlight,
-      'last_question': lastQuestion?.json,
-      'last_seen_ts': lastSeenTs?.json,
-      'first_consecutive_seen_ts': firstConsecutiveSeenTs?.json,
+      'last_question': lastQuestion?.toJson(),
+      'last_seen_ts': lastSeenTs?.toJson(),
+      'first_consecutive_seen_ts': firstConsecutiveSeenTs?.toJson(),
       'recent_lost_answers': recentLostAnswers,
       'failed_to_send': failedToSend,
     };
@@ -199,12 +199,12 @@ class PeerStats {
     required this.transfer,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'time_added': timeAdded.json,
-      'rpc_stats': rpcStats.json,
-      'latency': latency?.json,
-      'transfer': transfer.json,
+      'time_added': timeAdded.toJson(),
+      'rpc_stats': rpcStats.toJson(),
+      'latency': latency?.toJson(),
+      'transfer': transfer.toJson(),
     };
   }
 
@@ -230,11 +230,11 @@ class PeerTableData {
     required this.peerStats,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'node_ids': nodeIds.map((p) => p.json).toList(),
-      'peer_address': peerAddress.json,
-      'peer_stats': peerStats.json,
+      'node_ids': nodeIds.map((p) => p.toJson()).toList(),
+      'peer_address': peerAddress.toJson(),
+      'peer_stats': peerStats.toJson(),
     };
   }
 
@@ -256,7 +256,7 @@ enum ProtocolType {
 }
 
 extension ProtocolTypeExt on ProtocolType {
-  String get json {
+  String toJson() {
     return name.toUpperCase();
   }
 }
@@ -276,9 +276,9 @@ class PeerAddress {
     required this.socketAddress,
   });
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'protocol_type': protocolType.json,
+      'protocol_type': protocolType.toJson(),
       'socket_address': socketAddress,
     };
   }
@@ -347,7 +347,7 @@ abstract class VeilidUpdate {
         }
     }
   }
-  Map<String, dynamic> get json;
+  Map<String, dynamic> toJson();
 }
 
 class VeilidLog implements VeilidUpdate {
@@ -362,10 +362,10 @@ class VeilidLog implements VeilidUpdate {
   });
 
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'kind': "Log",
-      'log_level': logLevel.json,
+      'log_level': logLevel.toJson(),
       'message': message,
       'backtrace': backtrace
     };
@@ -383,7 +383,7 @@ class VeilidAppMessage implements VeilidUpdate {
   });
 
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'kind': "AppMessage",
       'sender': sender,
@@ -405,7 +405,7 @@ class VeilidAppCall implements VeilidUpdate {
   });
 
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'kind': "AppMessage",
       'sender': sender,
@@ -421,8 +421,8 @@ class VeilidUpdateAttachment implements VeilidUpdate {
   VeilidUpdateAttachment({required this.state});
 
   @override
-  Map<String, dynamic> get json {
-    var jsonRep = state.json;
+  Map<String, dynamic> toJson() {
+    var jsonRep = state.toJson();
     jsonRep['kind'] = "Attachment";
     return jsonRep;
   }
@@ -434,8 +434,8 @@ class VeilidUpdateNetwork implements VeilidUpdate {
   VeilidUpdateNetwork({required this.state});
 
   @override
-  Map<String, dynamic> get json {
-    var jsonRep = state.json;
+  Map<String, dynamic> toJson() {
+    var jsonRep = state.toJson();
     jsonRep['kind'] = "Network";
     return jsonRep;
   }
@@ -447,8 +447,8 @@ class VeilidUpdateConfig implements VeilidUpdate {
   VeilidUpdateConfig({required this.state});
 
   @override
-  Map<String, dynamic> get json {
-    var jsonRep = state.json;
+  Map<String, dynamic> toJson() {
+    var jsonRep = state.toJson();
     jsonRep['kind'] = "Config";
     return jsonRep;
   }
@@ -464,7 +464,7 @@ class VeilidUpdateRouteChange implements VeilidUpdate {
   });
 
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'dead_routes': deadRoutes.map((p) => p).toList(),
       'dead_remote_routes': deadRemoteRoutes.map((p) => p).toList()
@@ -487,12 +487,12 @@ class VeilidUpdateValueChange implements VeilidUpdate {
   });
 
   @override
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'key': key.json,
-      'subkeys': subkeys.map((p) => p.json).toList(),
+      'key': key.toJson(),
+      'subkeys': subkeys.map((p) => p.toJson()).toList(),
       'count': count,
-      'value_data': valueData.json,
+      'value_data': valueData.toJson(),
     };
   }
 }
@@ -513,9 +513,9 @@ class VeilidStateAttachment {
         publicInternetReady = json['public_internet_ready'],
         localNetworkReady = json['local_network_ready'];
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'state': state.json,
+      'state': state.toJson(),
       'public_internet_ready': publicInternetReady,
       'local_network_ready': localNetworkReady,
     };
@@ -544,12 +544,12 @@ class VeilidStateNetwork {
         peers = List<PeerTableData>.from(
             json['peers'].map((j) => PeerTableData.fromJson(j)));
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
       'started': started,
       'bps_down': bpsDown.toString(),
       'bps_up': bpsUp.toString(),
-      'peers': peers.map((p) => p.json).toList(),
+      'peers': peers.map((p) => p.toJson()).toList(),
     };
   }
 }
@@ -566,7 +566,7 @@ class VeilidStateConfig {
 
   VeilidStateConfig.fromJson(dynamic json) : config = json['config'];
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {'config': config};
   }
 }
@@ -584,11 +584,11 @@ class VeilidState {
         network = VeilidStateNetwork.fromJson(json['network']),
         config = VeilidStateConfig.fromJson(json['config']);
 
-  Map<String, dynamic> get json {
+  Map<String, dynamic> toJson() {
     return {
-      'attachment': attachment.json,
-      'network': network.json,
-      'config': config.json
+      'attachment': attachment.toJson(),
+      'network': network.toJson(),
+      'config': config.toJson()
     };
   }
 }
diff --git a/veilid-flutter/rust/src/dart_ffi.rs b/veilid-flutter/rust/src/dart_ffi.rs
index 3f341912..cd44552d 100644
--- a/veilid-flutter/rust/src/dart_ffi.rs
+++ b/veilid-flutter/rust/src/dart_ffi.rs
@@ -606,10 +606,10 @@ pub extern "C" fn routing_context_set_dht_value(port: i64, id: u32, key: FfiStr,
 
 
 #[no_mangle]
-pub extern "C" fn routing_context_watch_dht_values(port: i64, id: u32, key: FfiStr, subkeys: FfiStr, expiration: FfiStr, count: u32) {
+pub extern "C" fn routing_context_watch_dht_values(port: i64, id: u32, key: FfiStr, subkeys: FfiStr, expiration: u64, count: u32) {
     let key: veilid_core::TypedKey = veilid_core::deserialize_opt_json(key.into_opt_string()).unwrap();
     let subkeys: veilid_core::ValueSubkeyRangeSet = veilid_core::deserialize_opt_json(subkeys.into_opt_string()).unwrap();
-    let expiration = veilid_core::Timestamp::from_str(expiration.as_opt_str().unwrap()).unwrap();
+    let expiration = veilid_core::Timestamp::from(expiration);
 
     DartIsolateWrapper::new(port).spawn_result(async move {        
         let routing_context = {
@@ -620,7 +620,7 @@ pub extern "C" fn routing_context_watch_dht_values(port: i64, id: u32, key: FfiS
             routing_context.clone()
         };
         let res = routing_context.watch_dht_values(key, subkeys, expiration, count).await?;
-        APIResult::Ok(res.to_string())
+        APIResult::Ok(res.as_u64())
     });
 }