diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b8471f7..1aaea93 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     name: Flutter version ${{ matrix.flutter_version }}
     strategy:
       matrix:
-        flutter_version: ['2.0.5', '1.20.4', '2.5.1']
+        flutter_version: ['2.0.6', '2.2.3', '2.5.3', '2.8.0']
     
     steps:
     - uses: actions/checkout@v2
@@ -91,7 +91,7 @@ jobs:
     name: Flutter version ${{ matrix.flutter_version }} (iOS)
     strategy:
       matrix:
-        flutter_version: ['1.20.4', '2.5.1']
+        flutter_version: ['2.0.6', '2.2.3', '2.5.3', '2.8.0']
     
     steps:
     - uses: actions/checkout@v2
diff --git a/.gitignore b/.gitignore
index ba114aa..0135026 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 local.properties
 **/pana-report
 **/.pubignore
+
+**/.DS_Store
diff --git a/analysis_options.yaml b/analysis_options.yaml
deleted file mode 100644
index dd816eb..0000000
--- a/analysis_options.yaml
+++ /dev/null
@@ -1,14 +0,0 @@
-# Defines a default set of lint rules enforced for
-# projects at Google. For details and rationale,
-# see https://github.com/dart-lang/pedantic#enabled-lints.
-include: package:pedantic/analysis_options.yaml
-
-# For lint rules and documentation, see http://dart-lang.github.io/linter/lints.
-# Uncomment to specify additional rules.
-# linter:
-#   rules:
-#     - camel_case_types
-
-analyzer:
-  exclude:
-    - 'example/**'
diff --git a/rollbar_dart/CHANGELOG.md b/rollbar_dart/CHANGELOG.md
index c14078a..a3fc616 100644
--- a/rollbar_dart/CHANGELOG.md
+++ b/rollbar_dart/CHANGELOG.md
@@ -1,3 +1,5 @@
-## 0.1.0-beta
+## 0.2.0-beta
+- Added null-safety.
 
+## 0.1.0-beta
 - Initial version of rollbar-dart.
diff --git a/rollbar_dart/analysis_options.yaml b/rollbar_dart/analysis_options.yaml
deleted file mode 120000
index c9e0d9f..0000000
--- a/rollbar_dart/analysis_options.yaml
+++ /dev/null
@@ -1 +0,0 @@
-../analysis_options.yaml
\ No newline at end of file
diff --git a/rollbar_dart/analysis_options.yaml b/rollbar_dart/analysis_options.yaml
new file mode 100644
index 0000000..e7f6299
--- /dev/null
+++ b/rollbar_dart/analysis_options.yaml
@@ -0,0 +1,32 @@
+# Defines a default set of lint rules enforced for
+# projects at Google. For details and rationale,
+# see https://github.com/dart-lang/pedantic#enabled-lints.
+
+# include: package:lints/core.yaml
+include: package:lints/recommended.yaml
+
+# For lint rules and documentation, see http://dart-lang.github.io/linter/lints.
+# Uncomment to specify additional rules.
+# linter:
+#   rules:
+#     - camel_case_types
+
+linter:
+  rules:
+    - always_declare_return_types
+    - prefer_single_quotes
+    - sort_child_properties_last
+    - unawaited_futures
+    - unsafe_html
+    - use_full_hex_values_for_flutter_colors
+    # - cancel_subscriptions
+    # - close_sinks
+    # - comment_references
+    # - one_member_abstracts
+    # - only_throw_errors
+    # - package_api_docs
+    # - prefer_final_in_for_each
+
+analyzer:
+  exclude:
+    - 'example/**'
diff --git a/rollbar_dart/lib/rollbar.dart b/rollbar_dart/lib/rollbar.dart
index d1555f4..f9841be 100644
--- a/rollbar_dart/lib/rollbar.dart
+++ b/rollbar_dart/lib/rollbar.dart
@@ -1,5 +1,6 @@
 library rollbar;
 
+export 'src/logging.dart';
 export 'src/rollbar.dart';
 export 'src/config.dart';
 export 'src/sender.dart';
diff --git a/rollbar_dart/lib/src/api/payload/body.dart b/rollbar_dart/lib/src/api/payload/body.dart
index 6727a14..12f9b67 100644
--- a/rollbar_dart/lib/src/api/payload/body.dart
+++ b/rollbar_dart/lib/src/api/payload/body.dart
@@ -4,13 +4,13 @@ import 'frame.dart';
 /// Container class with the error or message to be sent to Rollbar.
 abstract class Body {
   Map<String, dynamic> toJson();
-  List<TraceInfo> getTraces();
+  List<TraceInfo?>? getTraces();
 
   static Body empty() {
     return Message()..body = '';
   }
 
-  static Body fromMap(Map attributes) {
+  static Body? fromMap(Map attributes) {
     if (attributes.containsKey('trace')) {
       return TraceInfo.fromMap(attributes);
     } else if (attributes.containsKey('message')) {
@@ -23,9 +23,9 @@ abstract class Body {
 
 /// An individual error with its corresponding stack trace if available.
 class TraceInfo implements Body {
-  List<Frame> frames;
-  ExceptionInfo exception;
-  String rawTrace;
+  late List<Frame> frames;
+  ExceptionInfo? exception;
+  String? rawTrace;
 
   TraceInfo() {
     frames = [];
@@ -45,7 +45,7 @@ class TraceInfo implements Body {
     };
 
     if (exception != null) {
-      traceInfo['trace']['exception'] = exception.toJson();
+      traceInfo['trace']['exception'] = exception!.toJson();
     }
 
     if (rawTrace != null) {
@@ -55,7 +55,7 @@ class TraceInfo implements Body {
     return traceInfo;
   }
 
-  static TraceInfo fromMap(Map attributes) {
+  static TraceInfo? fromMap(Map attributes) {
     if (!attributes.containsKey('trace')) {
       return null;
     }
@@ -87,13 +87,13 @@ class TraceInfo implements Body {
 /// A chain of multiple errors, where the first one on the list represents the
 /// root cause of the error.
 class TraceChain implements Body {
-  List<TraceInfo> traces;
+  List<TraceInfo?>? traces;
 
   @override
   Map<String, dynamic> toJson() {
     return {
-      'trace_chain': traces.map((v) {
-        return v.toJson()['trace'];
+      'trace_chain': traces!.map((v) {
+        return v!.toJson()['trace'];
       }).toList()
     };
   }
@@ -107,21 +107,21 @@ class TraceChain implements Body {
   }
 
   @override
-  List<TraceInfo> getTraces() {
+  List<TraceInfo?>? getTraces() {
     return traces;
   }
 }
 
 /// A text message to be sent to Rollbar.
 class Message implements Body {
-  String body;
+  String? body;
 
   @override
   List<TraceInfo> getTraces() {
     return [];
   }
 
-  static Message fromMap(Map attributes) {
+  static Message? fromMap(Map attributes) {
     if (!attributes.containsKey('message')) {
       return null;
     }
diff --git a/rollbar_dart/lib/src/api/payload/client.dart b/rollbar_dart/lib/src/api/payload/client.dart
index e9fa30c..2c248ff 100644
--- a/rollbar_dart/lib/src/api/payload/client.dart
+++ b/rollbar_dart/lib/src/api/payload/client.dart
@@ -1,15 +1,15 @@
 class Client {
-  String locale;
+  String? locale;
 
-  String hostname;
+  String? hostname;
 
-  String os;
+  String? os;
 
-  String osVersion;
+  String? osVersion;
 
-  String rootPackage;
+  String? rootPackage;
 
-  Map<String, String> dart;
+  Map<String, String>? dart;
 
   /// Converts the object into a Json encodable map.
   ///
diff --git a/rollbar_dart/lib/src/api/payload/data.dart b/rollbar_dart/lib/src/api/payload/data.dart
index 7232495..557a019 100644
--- a/rollbar_dart/lib/src/api/payload/data.dart
+++ b/rollbar_dart/lib/src/api/payload/data.dart
@@ -4,19 +4,19 @@ import 'level.dart';
 
 /// Contains the data for the occurrence to be sent to Rollbar.
 class Data {
-  Map<String, String> notifier;
-  String environment;
-  Client client;
-  String platform;
-  String language;
-  String framework;
-  String codeVersion;
-  Level level;
-  int timestamp;
-  Body body;
-  Map<String, Object> custom;
-  Map platformPayload;
-  Map server;
+  late Map<String, String> notifier;
+  String? environment;
+  late Client client;
+  String? platform;
+  late String language;
+  String? framework;
+  String? codeVersion;
+  Level? level;
+  int? timestamp;
+  late Body body;
+  Map<String, Object>? custom;
+  Map? platformPayload;
+  Map? server;
 
   Map<String, dynamic> toJson() {
     var result = {
diff --git a/rollbar_dart/lib/src/api/payload/exception_info.dart b/rollbar_dart/lib/src/api/payload/exception_info.dart
index 24be2f2..10f20c8 100644
--- a/rollbar_dart/lib/src/api/payload/exception_info.dart
+++ b/rollbar_dart/lib/src/api/payload/exception_info.dart
@@ -1,8 +1,8 @@
 /// Contains all the error details except the stack trace.
 class ExceptionInfo {
-  String clazz;
-  String message;
-  String description;
+  String? clazz;
+  String? message;
+  String? description;
 
   Map<String, dynamic> toJson() {
     var result = {'class': clazz, 'message': message};
diff --git a/rollbar_dart/lib/src/api/payload/frame.dart b/rollbar_dart/lib/src/api/payload/frame.dart
index a11a0d4..90f5cc8 100644
--- a/rollbar_dart/lib/src/api/payload/frame.dart
+++ b/rollbar_dart/lib/src/api/payload/frame.dart
@@ -1,10 +1,10 @@
 /// Contains the information of a single frame in a stack trace.
 class Frame {
-  int colno;
-  int lineno;
-  String method;
-  String filename;
-  String className;
+  int? colno;
+  int? lineno;
+  String? method;
+  String? filename;
+  String? className;
 
   Map<String, dynamic> toJson() {
     var result = <String, dynamic>{};
@@ -29,10 +29,10 @@ class Frame {
   static Frame fromMap(Map attributes) {
     var result = Frame();
     if (attributes.containsKey('colno')) {
-      result.colno = attributes['colno'] as int;
+      result.colno = attributes['colno'] as int?;
     }
     if (attributes.containsKey('lineno')) {
-      result.lineno = attributes['lineno'] as int;
+      result.lineno = attributes['lineno'] as int?;
     }
     if (attributes.containsKey('method')) {
       result.method = attributes['method'];
diff --git a/rollbar_dart/lib/src/api/payload/level.dart b/rollbar_dart/lib/src/api/payload/level.dart
index 1d0db2d..c4b9b5f 100644
--- a/rollbar_dart/lib/src/api/payload/level.dart
+++ b/rollbar_dart/lib/src/api/payload/level.dart
@@ -1,10 +1,10 @@
 /// The level of an occurrence.
 enum Level { debug, info, warning, error, critical }
 
-extension LevelExtension on Level {
+extension LevelExtension on Level? {
   // The 'foundation' library, which contains `describeEnum`, is part of flutter,
   // so we don't want to add it as a dependency in rollbar-dart.
-  String get name {
+  String? get name {
     switch (this) {
       case Level.debug:
         return 'debug';
@@ -16,7 +16,8 @@ extension LevelExtension on Level {
         return 'error';
       case Level.critical:
         return 'critical';
+      default:
+        return null;
     }
-    return null;
   }
 }
diff --git a/rollbar_dart/lib/src/api/payload/payload.dart b/rollbar_dart/lib/src/api/payload/payload.dart
index 773bb2d..7cbf048 100644
--- a/rollbar_dart/lib/src/api/payload/payload.dart
+++ b/rollbar_dart/lib/src/api/payload/payload.dart
@@ -3,8 +3,8 @@ import 'data.dart';
 /// Represents the payload to be sent to Rollbar. A successfully constructed Payload matches Rollbar's
 /// spec, and can be POSTed to the correct endpoint when serialized as JSON.
 class Payload {
-  String accessToken;
-  Data data;
+  String? accessToken;
+  late Data data;
 
   Map<String, dynamic> toJson() {
     return {'access_token': accessToken, 'data': data.toJson()};
diff --git a/rollbar_dart/lib/src/api/response.dart b/rollbar_dart/lib/src/api/response.dart
index fb0ea8f..a32e814 100644
--- a/rollbar_dart/lib/src/api/response.dart
+++ b/rollbar_dart/lib/src/api/response.dart
@@ -1,8 +1,8 @@
 /// Represents the response from the Rollbar API.
 class Response {
-  int err;
-  String message;
-  Result result;
+  int? err;
+  String? message;
+  Result? result;
 
   bool isError() {
     return err != null && err != 0;
@@ -10,5 +10,5 @@ class Response {
 }
 
 class Result {
-  String uuid;
+  String? uuid;
 }
diff --git a/rollbar_dart/lib/src/config.dart b/rollbar_dart/lib/src/config.dart
index e53a7b5..0531ede 100644
--- a/rollbar_dart/lib/src/config.dart
+++ b/rollbar_dart/lib/src/config.dart
@@ -1,4 +1,4 @@
-import 'package:rollbar_dart/src/http_sender.dart';
+import 'http_sender.dart';
 
 import 'transformer.dart';
 import 'sender.dart';
@@ -7,13 +7,13 @@ import 'sender.dart';
 class Config {
   final String accessToken;
   final String endpoint;
-  final String environment;
-  final String framework;
-  final String codeVersion;
-  final String package;
-  final bool handleUncaughtErrors;
-  final bool includePlatformLogs;
-  final Transformer Function(Config) transformer;
+  final String? environment;
+  final String? framework;
+  final String? codeVersion;
+  final String? package;
+  final bool? handleUncaughtErrors;
+  final bool? includePlatformLogs;
+  final Transformer Function(Config)? transformer;
   final Sender Function(Config) sender;
 
   Config._(
@@ -66,23 +66,23 @@ class Config {
 class ConfigBuilder {
   final String accessToken;
   String endpoint = 'https://api.rollbar.com/api/1/item/';
-  String environment;
-  String framework;
-  String codeVersion;
-  String package;
+  String? environment;
+  String? framework;
+  String? codeVersion;
+  String? package;
 
-  bool handleUncaughtErrors = false;
-  bool includePlatformLogs = false;
+  bool? handleUncaughtErrors = false;
+  bool? includePlatformLogs = false;
 
   /// If [handleUncaughtErrors] is enabled, the transformer function *must* be a static
   /// or free function, and cannot be a closure or instance function, since it will need
   /// to be passed to an error handler isolate as a message.
-  Transformer Function(Config) transformer;
+  Transformer Function(Config)? transformer;
 
   /// If [handleUncaughtErrors] is enabled, the sender factory *must* be a static
   /// or free function, and cannot be a closure or instance function, since it will need
   /// to be passed to an error handler isolate as a message.
-  Sender Function(Config) sender;
+  Sender Function(Config)? sender;
 
   ConfigBuilder(this.accessToken);
 
diff --git a/rollbar_dart/lib/src/core_notifier.dart b/rollbar_dart/lib/src/core_notifier.dart
index f8a30b9..a28e201 100644
--- a/rollbar_dart/lib/src/core_notifier.dart
+++ b/rollbar_dart/lib/src/core_notifier.dart
@@ -20,18 +20,20 @@ import 'sender.dart';
 /// - Send the occurrence payload to Rollbar via a [Sender].
 class CoreNotifier {
   final Config _config;
-  final Sender _sender;
-  final Transformer _transformer;
+  final Sender? _sender;
+  final Transformer? _transformer;
 
-  static const NOTIFIER_VERSION = '0.1.0-beta';
-  static const NOTIFIER_NAME = 'rollbar-dart';
+  // notifierVersion to be updated with each new release:
+  static const notifierVersion = '0.2.0-beta';
+
+  static const notifierName = 'rollbar-dart';
 
   CoreNotifier(this._config)
       : _sender = _make(_config, _config.sender),
         _transformer = _make(_config, _config.transformer);
 
-  Future<Response> log(
-      Level level, dynamic error, StackTrace stackTrace, String message) async {
+  Future<Response?> log(Level level, dynamic error, StackTrace? stackTrace,
+      String? message) async {
     var body = await _prepareBody(message, error, stackTrace);
 
     var client = Client()
@@ -54,7 +56,7 @@ class CoreNotifier {
       ..codeVersion = _config.codeVersion
       ..client = client
       ..environment = _config.environment
-      ..notifier = {'version': NOTIFIER_VERSION, 'name': NOTIFIER_NAME};
+      ..notifier = {'version': notifierVersion, 'name': notifierName};
 
     if (client.rootPackage != null) {
       // Root detection compatibility, currently checked under the server element
@@ -64,18 +66,18 @@ class CoreNotifier {
     }
 
     if (_transformer != null) {
-      data = await _transformer.transform(error, stackTrace, data);
+      data = await _transformer!.transform(error, stackTrace, data);
     }
 
     var payload = Payload()
       ..accessToken = _config.accessToken
       ..data = data;
 
-    return await _sender.send(payload.toJson());
+    return await _sender!.send(payload.toJson());
   }
 
   Future<Body> _prepareBody(
-      String message, dynamic error, StackTrace stackTrace) async {
+      String? message, dynamic error, StackTrace? stackTrace) async {
     if (error != null) {
       return await _prepareTracePayload(error, stackTrace, message);
     } else {
@@ -84,7 +86,7 @@ class CoreNotifier {
   }
 
   Future<TraceInfo> _prepareTracePayload(
-      dynamic error, StackTrace trace, String description) async {
+      dynamic error, StackTrace? trace, String? description) async {
     var traceInfo = TraceInfo()
       ..exception = _getExceptionInfo(error, description);
 
@@ -106,7 +108,7 @@ class CoreNotifier {
     return traceInfo;
   }
 
-  static ExceptionInfo _getExceptionInfo(dynamic error, String description) {
+  static ExceptionInfo _getExceptionInfo(dynamic error, String? description) {
     ExceptionInfo result;
     if (error is ExceptionInfo) {
       result = error;
@@ -121,7 +123,7 @@ class CoreNotifier {
     return result;
   }
 
-  static T _make<T>(Config config, T Function(Config) factoryFunction) {
+  static T? _make<T>(Config config, T Function(Config)? factoryFunction) {
     if (factoryFunction == null) {
       return null;
     } else {
diff --git a/rollbar_dart/lib/src/http_sender.dart b/rollbar_dart/lib/src/http_sender.dart
index 25e61da..8ec9d42 100644
--- a/rollbar_dart/lib/src/http_sender.dart
+++ b/rollbar_dart/lib/src/http_sender.dart
@@ -1,7 +1,7 @@
 import 'package:http/http.dart' as http;
 import 'dart:convert';
-import 'sender.dart';
 import 'api/response.dart';
+import 'sender.dart';
 
 /// Default HTTP [Sender] implementation.
 class HttpSender implements Sender {
@@ -12,7 +12,11 @@ class HttpSender implements Sender {
 
   /// Sends the provided payload as the body of POST request to the configured endpoint.
   @override
-  Future<Response> send(Map<String, dynamic> payload) async {
+  Future<Response?> send(Map<String, dynamic>? payload) async {
+    if (payload == null) {
+      return null;
+    }
+
     final headers = <String, String>{
       'User-Agent': 'rollbar-dart',
       'Content-Type': 'application/json',
@@ -30,6 +34,7 @@ class HttpSender implements Sender {
 
 Future<Response> toRollbarResponse(Future<http.Response> response) async {
   Map data = json.decode((await response).body);
+
   var result = Response();
   if (data.containsKey('err')) {
     result.err = data['err'].toInt();
diff --git a/rollbar_dart/lib/src/logging.dart b/rollbar_dart/lib/src/logging.dart
index 5335744..208f0a3 100644
--- a/rollbar_dart/lib/src/logging.dart
+++ b/rollbar_dart/lib/src/logging.dart
@@ -1,23 +1,26 @@
 import 'dart:developer' as developer;
 
-void info(String message, dynamic error) {
-  _log(800, message, error);
-}
+/// Internal SDK logging (for the SDK use only!!!):
+class Logging {
+  static void info(String message, dynamic error) {
+    _log(800, message, error);
+  }
 
-void warning(String message, dynamic error) {
-  _log(900, message, error);
-}
+  static void warning(String message, dynamic error) {
+    _log(900, message, error);
+  }
 
-void error(String message, dynamic error) {
-  _log(1000, message, error);
-}
+  static void error(String message, dynamic error) {
+    _log(1000, message, error);
+  }
 
-void _log(int level, String message, dynamic error) {
-  var logName = 'com.rollbar.rollbar-dart';
-  if (error != null) {
-    developer.log(message,
-        level: level, name: logName, error: error.toString());
-  } else {
-    developer.log(message, level: level, name: logName);
+  static void _log(int level, String message, dynamic error) {
+    var logName = 'com.rollbar.rollbar-dart';
+    if (error != null) {
+      developer.log(message,
+          level: level, name: logName, error: error.toString());
+    } else {
+      developer.log(message, level: level, name: logName);
+    }
   }
 }
diff --git a/rollbar_dart/lib/src/rollbar.dart b/rollbar_dart/lib/src/rollbar.dart
index f79b00f..8c31e5a 100644
--- a/rollbar_dart/lib/src/rollbar.dart
+++ b/rollbar_dart/lib/src/rollbar.dart
@@ -4,7 +4,7 @@ import 'dart:isolate';
 import 'config.dart';
 import 'core_notifier.dart';
 import 'uncaught_error.dart';
-import 'logging.dart' as logging;
+import 'logging.dart';
 import 'api/response.dart';
 import 'api/payload/level.dart';
 
@@ -22,7 +22,7 @@ class Rollbar {
   /// Some initialization operations are asynchronous, such as initializing
   /// the [Isolate] that handles uncaught errors. This future can be awaited
   /// to ensure all async initialization operations are complete.
-  Future<void> ensureInitialized() async {
+  Future<UncaughtErrorHandler> ensureInitialized() async {
     return _errorHandler;
   }
 
@@ -32,7 +32,7 @@ class Rollbar {
   /// ```dart
   /// Isolate.current.addErrorListener(await rollbar.errorHandler);
   /// ```
-  Future<SendPort> get errorHandler async {
+  Future<SendPort?>? get errorHandler async {
     return (await _errorHandler).errorHandlerPort;
   }
 
@@ -111,19 +111,21 @@ class Rollbar {
     try {
       return await action;
     } on Exception catch (e) {
-      logging.error('Internal error encountered while initializing Rollbar', e);
+      Logging.error('Internal error encountered while initializing Rollbar', e);
       rethrow;
     }
   }
 
-  static Future<void> _processResponse(Future<Response> rollbarAction) async {
+  static Future<void> _processResponse(Future<Response?> rollbarAction) async {
     try {
       var response = await rollbarAction;
-      if (response.isError()) {
-        logging.error('Error while sending data to Rollbar', response.message);
+      if (response == null) {
+        Logging.error('No response while sending data to Rollbar', null);
+      } else if (response.isError()) {
+        Logging.error('Error while sending data to Rollbar', response.message);
       }
     } on Exception catch (e) {
-      logging.error(
+      Logging.error(
           'Internal error encountered while sending data to Rollbar', e);
       rethrow;
     }
diff --git a/rollbar_dart/lib/src/sender.dart b/rollbar_dart/lib/src/sender.dart
index fa0cdfb..06dd447 100644
--- a/rollbar_dart/lib/src/sender.dart
+++ b/rollbar_dart/lib/src/sender.dart
@@ -2,5 +2,5 @@ import 'api/response.dart';
 
 /// Sender interface to send payload data to Rollbar.
 abstract class Sender {
-  Future<Response> send(Map<String, dynamic> payload);
+  Future<Response?> send(Map<String, dynamic>? payload);
 }
diff --git a/rollbar_dart/lib/src/trace.dart b/rollbar_dart/lib/src/trace.dart
index c569d21..6614381 100644
--- a/rollbar_dart/lib/src/trace.dart
+++ b/rollbar_dart/lib/src/trace.dart
@@ -35,10 +35,10 @@ ParseTraceResult _parseNativeTrace(String traceString) {
 }
 
 class ParseTraceResult {
-  Trace trace;
+  late Trace trace;
 
   /// The original, unparsed trace. It will only be present when the original trace
   /// might require further backend processing, eg. symbolication. Otherwise this
   /// value will be null.
-  String rawTrace;
+  String? rawTrace;
 }
diff --git a/rollbar_dart/lib/src/transformer.dart b/rollbar_dart/lib/src/transformer.dart
index 3f86606..6d16a35 100644
--- a/rollbar_dart/lib/src/transformer.dart
+++ b/rollbar_dart/lib/src/transformer.dart
@@ -7,5 +7,5 @@ abstract class Transformer {
   /// Implementations are free to mutate the [Data] object they receive,
   /// reuse some of its parts, or create an entirely new object, but a
   // `Data` instance *must* be returned in all cases.
-  Future<Data> transform(dynamic error, StackTrace trace, Data data);
+  Future<Data> transform(dynamic error, StackTrace? trace, Data data);
 }
diff --git a/rollbar_dart/lib/src/uncaught_error.dart b/rollbar_dart/lib/src/uncaught_error.dart
index e7ffa2b..2c1e3be 100644
--- a/rollbar_dart/lib/src/uncaught_error.dart
+++ b/rollbar_dart/lib/src/uncaught_error.dart
@@ -3,7 +3,7 @@ import 'dart:async';
 
 import 'config.dart';
 import 'core_notifier.dart';
-import 'logging.dart' as logging;
+import 'logging.dart';
 import 'api/payload/exception_info.dart';
 import 'api/payload/level.dart';
 
@@ -13,7 +13,7 @@ import 'api/payload/level.dart';
 class UncaughtErrorHandler {
   Config _config;
 
-  Future<SendPort> _errorPort;
+  late Future<SendPort?> _errorPort;
 
   UncaughtErrorHandler._(this._config) {
     _errorPort = _getErrorMessageHandler(_config);
@@ -22,15 +22,17 @@ class UncaughtErrorHandler {
   static Future<UncaughtErrorHandler> build(Config config) async {
     var handler = UncaughtErrorHandler._(config);
 
-    if (config.handleUncaughtErrors) {
+    if (config.handleUncaughtErrors!) {
       var errorPort = await handler._errorPort;
-      Isolate.current.addErrorListener(errorPort);
+      if (errorPort != null) {
+        Isolate.current.addErrorListener(errorPort);
+      }
     }
 
     return handler;
   }
 
-  Future<SendPort> get errorHandlerPort {
+  Future<SendPort?> get errorHandlerPort {
     return _errorPort;
   }
 
@@ -44,8 +46,8 @@ class UncaughtErrorHandler {
     }
   }
 
-  Future<SendPort> _getErrorMessageHandler(Config config) async {
-    if (config.handleUncaughtErrors) {
+  Future<SendPort?> _getErrorMessageHandler(Config config) async {
+    if (config.handleUncaughtErrors!) {
       var receivePort = ReceivePort();
       await Isolate.spawn(_handleError, receivePort.sendPort);
       var errorPort = await receivePort.first;
@@ -64,7 +66,7 @@ class UncaughtErrorHandler {
 
       sendPort.send(port.sendPort);
 
-      CoreNotifier rollbarCore;
+      CoreNotifier? rollbarCore;
 
       await for (var msg in port) {
         try {
@@ -76,21 +78,21 @@ class UncaughtErrorHandler {
               var trace = _getTrace(msg[1]);
               await rollbarCore.log(Level.error, error, trace, null);
             } else {
-              logging.warning(
+              Logging.warning(
                   'An error has been reported to the uncaught error handler before the Rollbar instance was configured',
                   error);
             }
           }
         } on Exception catch (e) {
-          logging.error('Failed to process rollbar error message', e);
+          Logging.error('Failed to process rollbar error message', e);
         }
       }
     } on Exception catch (e) {
-      logging.error('The rollbar uncaught error handler has crashed', e);
+      Logging.error('The rollbar uncaught error handler has crashed', e);
     }
   }
 
-  static StackTrace _getTrace(dynamic trace) {
+  static StackTrace? _getTrace(dynamic trace) {
     if (trace is StackTrace) {
       return trace;
     } else if (trace is String) {
@@ -115,7 +117,7 @@ class UncaughtErrorHandler {
   static dynamic _tryParseError(String error) {
     var match = _exceptionClassPattern.firstMatch(error);
     if (match != null) {
-      var exceptionPart = match.group(0);
+      var exceptionPart = match.group(0)!;
 
       // `length - 1` to remove colon
       var clazz = exceptionPart.substring(0, exceptionPart.length - 1).trim();
diff --git a/rollbar_dart/pubspec.yaml b/rollbar_dart/pubspec.yaml
index e6e6d20..bff54f0 100644
--- a/rollbar_dart/pubspec.yaml
+++ b/rollbar_dart/pubspec.yaml
@@ -1,19 +1,20 @@
 name: rollbar_dart
 description: Connect your Dart applications to Rollbar for error reporting
-version: 0.1.0-beta
+version: 0.2.0-beta
 homepage: https://www.rollbar.com
 documentation: https://docs.rollbar.com/docs/flutter#dart
 repository: https://github.com/rollbar/rollbar-flutter
 
 environment:
-  sdk: '>=2.8.1 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies: 
   http: '>=0.12.2 <0.14.0'
   stack_trace: '>=1.9.5 <1.11.0'
 
 dev_dependencies:
-  pedantic: '>=1.9.2 <1.12.0'
+  lints: ^1.0.1
   test: ^1.14.4
-  mockito: '>=4.1.0 <=5.0.7'
+  build_runner: ^1.11.0
+  mockito: '>=5.0.0 <6.0.0'
   pubspec_parse: '>=0.1.8 <=1.0.0'
diff --git a/rollbar_dart/test/ReadMe.md b/rollbar_dart/test/ReadMe.md
new file mode 100644
index 0000000..6964dac
--- /dev/null
+++ b/rollbar_dart/test/ReadMe.md
@@ -0,0 +1,23 @@
+# References
+https://pub.dev/documentation/mockito/latest/
+
+# Notes
+
+## Useful Imports
+import 'package:mockito/mockito.dart';
+import 'package:mockito/annotations.dart';
+
+
+## Generating Mocks
+
+    // Annotation which generates the cat.mocks.dart library and the MockCat class.
+    @GenerateMocks([Cat])
+    void main() {
+        // Create mock object.
+        var cat = MockCat();
+    }
+
+To force the mock code generation run:
+
+    dart run build_runner build
+
diff --git a/rollbar_dart/test/body_test.dart b/rollbar_dart/test/body_test.dart
index 6c3ff82..cf69ef6 100644
--- a/rollbar_dart/test/body_test.dart
+++ b/rollbar_dart/test/body_test.dart
@@ -30,15 +30,18 @@ void main() {
 
       var asJson = jsonEncode(traceInfo.toJson());
 
-      [(v) => TraceInfo.fromMap(v), (v) => Body.fromMap(v)].forEach((builder) {
+      for (var builder in [
+        (v) => TraceInfo.fromMap(v),
+        (v) => Body.fromMap(v)
+      ]) {
         var recovered = builder(jsonDecode(asJson)) as TraceInfo;
 
-        expect(recovered.exception.clazz, equals('TestException'));
-        expect(
-            recovered.exception.message, equals('Attempted to test some code'));
+        expect(recovered.exception!.clazz, equals('TestException'));
+        expect(recovered.exception!.message,
+            equals('Attempted to test some code'));
         expect(recovered.frames.length, equals(2));
         expect(recovered.rawTrace, equals('stack frame 1 2 3'));
-      });
+      }
     });
 
     test('TraceChain json roundtrip serialization test', () {
@@ -70,16 +73,20 @@ void main() {
       var chain = TraceChain()..traces = [traceInfo1, traceInfo2];
       var asJson = jsonEncode(chain.toJson());
 
-      [(v) => TraceChain.fromMap(v), (v) => Body.fromMap(v)].forEach((builder) {
+      for (var builder in [
+        (v) => TraceChain.fromMap(v),
+        (v) => Body.fromMap(v)
+      ]) {
         var recovered = builder(jsonDecode(asJson)) as TraceChain;
 
-        expect(recovered.traces.length, equals(2));
-        expect(recovered.traces[0].frames.length, equals(2));
-        expect(recovered.traces[0].frames[0].method, equals('inAChain'));
+        expect(recovered.traces!.length, equals(2));
+        expect(recovered.traces![0]!.frames.length, equals(2));
+        expect(recovered.traces![0]!.frames[0].method, equals('inAChain'));
 
-        expect(recovered.traces[1].frames.length, equals(1));
-        expect(recovered.traces[1].frames[0].method, equals('_AnotherMethod'));
-      });
+        expect(recovered.traces![1]!.frames.length, equals(1));
+        expect(
+            recovered.traces![1]!.frames[0].method, equals('_AnotherMethod'));
+      }
     });
 
     test('Message json roundtrip serialization test', () {
@@ -87,11 +94,11 @@ void main() {
 
       var asJson = jsonEncode(message.toJson());
 
-      [(v) => Message.fromMap(v), (v) => Body.fromMap(v)].forEach((builder) {
+      for (var builder in [(v) => Message.fromMap(v), (v) => Body.fromMap(v)]) {
         var recovered = builder(jsonDecode(asJson)) as Message;
 
         expect(recovered.body, equals('This is a test body'));
-      });
+      }
     });
   });
 }
diff --git a/rollbar_dart/test/client_server_utils.dart b/rollbar_dart/test/client_server_utils.dart
index dba0339..1739b2b 100644
--- a/rollbar_dart/test/client_server_utils.dart
+++ b/rollbar_dart/test/client_server_utils.dart
@@ -6,11 +6,11 @@ import 'dart:isolate';
 import 'package:rollbar_dart/rollbar.dart';
 import 'package:rollbar_dart/src/api/response.dart';
 
-const PREFIX = 'http://raw:';
+const endpointPrefix = 'http://raw:';
 
 Sender createTextSender(Config c) {
-  if (c.endpoint.startsWith(PREFIX)) {
-    var port = int.parse(c.endpoint.substring(PREFIX.length));
+  if (c.endpoint.startsWith(endpointPrefix)) {
+    var port = int.parse(c.endpoint.substring(endpointPrefix.length));
     return RawTextSender(port);
   } else {
     throw Exception('Invalid endpoint ${c.endpoint}');
@@ -20,15 +20,15 @@ Sender createTextSender(Config c) {
 /// Useful class to do some basic tests across isolates, without setting up a full blown
 /// HTTP server. It accepts and collects raw text over a TCP socket, 1 message per line.
 class RawTextSocket {
-  Isolate _isolate;
-  int _port;
-  ReceivePort _receivePort;
+  late Isolate _isolate;
+  int? _port;
+  late ReceivePort _receivePort;
 
   RawTextSocket._();
 
-  String get endpoint => '$PREFIX$port';
+  String get endpoint => '$endpointPrefix$port';
 
-  Future<int> _start() async {
+  Future<int?> _start() async {
     _receivePort = ReceivePort();
 
     var tcpInfoPort = ReceivePort();
@@ -36,13 +36,13 @@ class RawTextSocket {
     _isolate = await Isolate.spawn(
         _server, [tcpInfoPort.sendPort, _receivePort.sendPort]);
 
-    int port = await tcpInfoPort.first;
+    var port = await tcpInfoPort.first;
     tcpInfoPort.close();
 
     return port;
   }
 
-  int get port {
+  int? get port {
     return _port;
   }
 
@@ -50,12 +50,12 @@ class RawTextSocket {
   /// do something like
   /// `var message = await server.messages.first.timeout(Duration(milliseconds: 500));`
   /// ...with an appropriate timeout for the scenario being tested.
-  Stream<String> get messages {
-    return _receivePort.map((v) => v as String);
+  Stream<String?> get messages {
+    return _receivePort.map((v) => v as String?);
   }
 
   Future<void> close() async {
-    final socket = await Socket.connect('localhost', port);
+    final socket = await Socket.connect('localhost', port!);
     try {
       socket.add('close\n'.codeUnits);
     } finally {
@@ -113,7 +113,11 @@ class RawTextSender implements Sender {
   RawTextSender(this.port);
 
   @override
-  Future<Response> send(Map<String, dynamic> payload) async {
+  Future<Response?> send(Map<String, dynamic>? payload) async {
+    if (payload == null) {
+      return null;
+    }
+
     final socket = await Socket.connect('localhost', port);
     log('Client connected with port ${socket.port}');
     try {
diff --git a/rollbar_dart/test/core_notifier_test.dart b/rollbar_dart/test/core_notifier_test.dart
index b284c8a..614164f 100644
--- a/rollbar_dart/test/core_notifier_test.dart
+++ b/rollbar_dart/test/core_notifier_test.dart
@@ -10,7 +10,7 @@ void main() {
       // Dart tests run from the current package directory, so we can just read pubspec.yaml
       var pubspecYaml = await File('pubspec.yaml').readAsString();
       var pubspec = Pubspec.parse(pubspecYaml);
-      expect(CoreNotifier.NOTIFIER_VERSION, equals(pubspec.version.toString()));
+      expect(CoreNotifier.notifierVersion, equals(pubspec.version.toString()));
     });
   });
 }
diff --git a/rollbar_dart/test/http_sender_test.dart b/rollbar_dart/test/http_sender_test.dart
index a3f7bf7..37be5d3 100644
--- a/rollbar_dart/test/http_sender_test.dart
+++ b/rollbar_dart/test/http_sender_test.dart
@@ -2,11 +2,15 @@ import 'package:http/http.dart' as http;
 import 'package:rollbar_dart/src/http_sender.dart';
 import 'package:test/test.dart';
 import 'package:mockito/mockito.dart';
+import 'package:mockito/annotations.dart';
 
+import 'http_sender_test.mocks.dart';
+
+@GenerateMocks([http.Response])
 void main() {
   group('Response conversion', () {
     test('Can convert successful API response', () async {
-      var response = MockHttpResponse();
+      var response = MockResponse();
       when(response.body).thenReturn('''{
     "err": 0,
     "result": {
@@ -18,12 +22,12 @@ void main() {
 
       expect(rollbarResponse.err, equals(0));
       expect(rollbarResponse.result, isNotNull);
-      expect(rollbarResponse.result.uuid,
+      expect(rollbarResponse.result!.uuid,
           equals('67ce3d7bfab14fd99218ae5c985071e7'));
     });
 
     test('Can convert error API response', () async {
-      var response = MockHttpResponse();
+      var response = MockResponse();
       when(response.body).thenReturn('''{
     "err": 1,
     "message": "invalid token"
@@ -36,5 +40,3 @@ void main() {
     });
   });
 }
-
-class MockHttpResponse extends Mock implements http.Response {}
diff --git a/rollbar_dart/test/http_sender_test.mocks.dart b/rollbar_dart/test/http_sender_test.mocks.dart
new file mode 100644
index 0000000..c547932
--- /dev/null
+++ b/rollbar_dart/test/http_sender_test.mocks.dart
@@ -0,0 +1,50 @@
+// Mocks generated by Mockito 5.0.7 from annotations
+// in rollbar_dart/test/http_sender_test.dart.
+// Do not manually edit this file.
+
+import 'dart:typed_data' as _i2;
+
+import 'package:http/src/response.dart' as _i3;
+import 'package:mockito/mockito.dart' as _i1;
+
+// ignore_for_file: comment_references
+// ignore_for_file: unnecessary_parenthesis
+
+// ignore_for_file: prefer_const_constructors
+
+// ignore_for_file: avoid_redundant_argument_values
+
+class _FakeUint8List extends _i1.Fake {}
+
+/// A class which mocks [Response].
+///
+/// See the documentation for Mockito's code generation for more information.
+class MockResponse extends _i1.Mock implements _i3.Response {
+  MockResponse() {
+    _i1.throwOnMissingStub(this);
+  }
+
+  @override
+  _i2.Uint8List get bodyBytes =>
+      (super.noSuchMethod(Invocation.getter(#bodyBytes),
+          returnValue: _FakeUint8List()) as _i2.Uint8List);
+  @override
+  String get body =>
+      (super.noSuchMethod(Invocation.getter(#body), returnValue: '') as String);
+  @override
+  int get statusCode =>
+      (super.noSuchMethod(Invocation.getter(#statusCode), returnValue: 0)
+          as int);
+  @override
+  Map<String, String> get headers =>
+      (super.noSuchMethod(Invocation.getter(#headers),
+          returnValue: <String, String>{}) as Map<String, String>);
+  @override
+  bool get isRedirect =>
+      (super.noSuchMethod(Invocation.getter(#isRedirect), returnValue: false)
+          as bool);
+  @override
+  bool get persistentConnection =>
+      (super.noSuchMethod(Invocation.getter(#persistentConnection),
+          returnValue: false) as bool);
+}
diff --git a/rollbar_dart/test/rollbar_test.dart b/rollbar_dart/test/rollbar_test.dart
index 56b1903..50e01dd 100644
--- a/rollbar_dart/test/rollbar_test.dart
+++ b/rollbar_dart/test/rollbar_test.dart
@@ -1,21 +1,16 @@
+import 'package:test/test.dart';
 import 'package:mockito/mockito.dart';
+
 import 'package:rollbar_dart/rollbar.dart';
-import 'package:rollbar_dart/src/api/payload/body.dart';
-import 'package:rollbar_dart/src/api/payload/data.dart';
-import 'package:rollbar_dart/src/api/payload/exception_info.dart';
-import 'package:rollbar_dart/src/api/response.dart';
-import 'package:rollbar_dart/src/transformer.dart';
-import 'package:test/test.dart';
 
 void main() {
   group('Rollbar notifier tests', () {
-    Rollbar rollbar;
-    Sender sender;
+    late Rollbar rollbar;
+    late Sender sender;
 
     setUp(() async {
       sender = MockSender();
-      when(sender.send(any))
-          .thenAnswer((_invocation) => Future.value(Response()));
+      when(sender.send(any)).thenAnswer((_) async => Response());
       // handleUncaughtErrors must be set to false otherwise we can't use a closure with a
       // mock as the sender factory.
       var config = (ConfigBuilder('BlaBlaAccessToken')
@@ -71,7 +66,7 @@ void main() {
         await rollbar.error(error, stackTrace);
         var payload = verify(await sender.send(captureAny)).captured.single;
 
-        Map data = payload['data'];
+        Map? data = payload['data'];
         expect(data, isNot(contains('code_version')));
         expect(data, isNot(contains('framework')));
         expect(data, isNot(contains('custom')));
@@ -111,10 +106,10 @@ void failingFunction() {
 
 class ExpandableTransformer implements Transformer {
   @override
-  Future<Data> transform(dynamic error, StackTrace trace, Data data) async {
+  Future<Data> transform(dynamic error, StackTrace? trace, Data data) async {
     // Simulates for example what we'd do with a PlatformException in Flutter
     if (error is ExpandableException) {
-      var traceChain = error.messages.map((message) {
+      List<TraceInfo?> traceChain = error.messages.map((message) {
         return TraceInfo()
           ..frames = []
           ..exception = (ExceptionInfo()
@@ -122,7 +117,7 @@ class ExpandableTransformer implements Transformer {
             ..message = message);
       }).toList();
 
-      traceChain.addAll(data.body.getTraces());
+      traceChain.addAll(data.body.getTraces()!);
       data.body = TraceChain()..traces = traceChain;
     }
     return data;
@@ -139,20 +134,26 @@ class ExpandableException implements Exception {
   }
 }
 
-class MockSender extends Mock implements Sender {}
+class MockSender extends Mock implements Sender {
+  @override
+  Future<Response?> send(Map<String, dynamic>? payload) {
+    return super.noSuchMethod(Invocation.method(#send, [payload]),
+        returnValue: Future<Response?>.value(Response()));
+  }
+}
 
-dynamic getPath(Map<String, dynamic> source, List<String> path) {
+dynamic getPath(Map<String, dynamic>? source, List<String> path) {
   // We're in a test, let the bounds checker handle the edge case of an empty path
   for (var i = 0;; ++i) {
     var key = path[i];
 
     expect(source, contains(key));
-    var value = source[key];
+    var value = source![key];
 
     if (i == path.length - 1) {
       return value;
     } else {
-      source = value as Map<String, dynamic>;
+      source = value as Map<String, dynamic>?;
     }
   }
 }
diff --git a/rollbar_dart/test/uncaught_error_handler_test.dart b/rollbar_dart/test/uncaught_error_handler_test.dart
index 6d12f41..60983bd 100644
--- a/rollbar_dart/test/uncaught_error_handler_test.dart
+++ b/rollbar_dart/test/uncaught_error_handler_test.dart
@@ -10,8 +10,8 @@ import 'client_server_utils.dart';
 
 void main() {
   group('UncaughtErrorHandler tests', () {
-    RawTextSocket _server;
-    UncaughtErrorHandler _handler;
+    late RawTextSocket _server;
+    late UncaughtErrorHandler _handler;
 
     setUp(() async {
       _server = await RawTextSocket.build();
@@ -29,12 +29,13 @@ void main() {
       try {
         await throwyMethodA();
       } catch (error, trace) {
-        errorPort.send([error.toString(), trace.toString()]);
+        errorPort!.send([error.toString(), trace.toString()]);
       }
 
       var payloadJson =
           await _server.messages.first.timeout(Duration(milliseconds: 500));
-      var payload = json.decode(payloadJson);
+      expect(payloadJson != null, equals(true));
+      var payload = json.decode(payloadJson!);
 
       var data = payload['data'];
       expect(data['language'], equals('dart'));
@@ -54,7 +55,8 @@ void main() {
       try {
         var payloadJson =
             await _server.messages.first.timeout(Duration(milliseconds: 500));
-        var payload = json.decode(payloadJson);
+        expect(payloadJson != null, equals(true));
+        var payload = json.decode(payloadJson!);
 
         var data = payload['data'];
         expect(data['language'], equals('dart'));
@@ -97,8 +99,8 @@ Future<UncaughtErrorHandler> _createErrorHandler(String endpoint) async {
   return await UncaughtErrorHandler.build(config);
 }
 
-Future<void> secondIsolateMethod(SendPort errorPort) async {
-  Isolate.current.addErrorListener(errorPort);
+Future<void> secondIsolateMethod(SendPort? errorPort) async {
+  Isolate.current.addErrorListener(errorPort!);
   // No try catch here, our handler should take care of it
   await inDifferentIsolate();
 }
diff --git a/rollbar_flutter/.gitignore b/rollbar_flutter/.gitignore
index 68d8939..a20168a 100644
--- a/rollbar_flutter/.gitignore
+++ b/rollbar_flutter/.gitignore
@@ -1,5 +1,3 @@
-.DS_Store
-
 # Files and directories created by pub
 .dart_tool/
 .packages
diff --git a/rollbar_flutter/CHANGELOG.md b/rollbar_flutter/CHANGELOG.md
index 46e9d36..61ee1cb 100644
--- a/rollbar_flutter/CHANGELOG.md
+++ b/rollbar_flutter/CHANGELOG.md
@@ -1,3 +1,5 @@
-## 0.1.0-beta
+## 0.2.0-beta
+- Added null-safety.
 
+## 0.1.0-beta
 - Initial version of rollbar-flutter.
diff --git a/rollbar_flutter/analysis_options.yaml b/rollbar_flutter/analysis_options.yaml
deleted file mode 120000
index c9e0d9f..0000000
--- a/rollbar_flutter/analysis_options.yaml
+++ /dev/null
@@ -1 +0,0 @@
-../analysis_options.yaml
\ No newline at end of file
diff --git a/rollbar_flutter/analysis_options.yaml b/rollbar_flutter/analysis_options.yaml
new file mode 100644
index 0000000..0d22695
--- /dev/null
+++ b/rollbar_flutter/analysis_options.yaml
@@ -0,0 +1,31 @@
+# Defines a default set of lint rules enforced for
+# projects at Google. For details and rationale,
+# see https://github.com/dart-lang/pedantic#enabled-lints.
+
+include: package:flutter_lints/flutter.yaml
+
+# For lint rules and documentation, see http://dart-lang.github.io/linter/lints.
+# Uncomment to specify additional rules.
+# linter:
+#   rules:
+#     - camel_case_types
+
+linter:
+  rules:
+    - always_declare_return_types
+    - prefer_single_quotes
+    - sort_child_properties_last
+    - unawaited_futures
+    - unsafe_html
+    - use_full_hex_values_for_flutter_colors
+    # - cancel_subscriptions
+    # - close_sinks
+    # - comment_references
+    # - one_member_abstracts
+    # - only_throw_errors
+    # - package_api_docs
+    # - prefer_final_in_for_each
+
+analyzer:
+  exclude:
+    - 'example/**'
diff --git a/rollbar_flutter/example/lib/main.dart b/rollbar_flutter/example/lib/main.dart
index 48b25ea..e0c087a 100644
--- a/rollbar_flutter/example/lib/main.dart
+++ b/rollbar_flutter/example/lib/main.dart
@@ -2,13 +2,15 @@ import 'dart:io' show Platform;
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+
+import 'package:rollbar_dart/rollbar.dart';
 import 'package:rollbar_flutter/rollbar.dart';
 
 /// Example Flutter application using rollbar-flutter.
 Future<void> main() async {
   var config = (ConfigBuilder('<YOUR ROLLBAR TOKEN HERE>')
         ..environment = 'development'
-        ..codeVersion = '0.1.0'
+        ..codeVersion = '0.2.0'
         ..package = 'rollbar_flutter_example'
         ..handleUncaughtErrors = true
         ..includePlatformLogs = false)
@@ -34,7 +36,7 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
+  MyHomePage({Key? key = null, required this.title}) : super(key: key);
 
   final String title;
 
diff --git a/rollbar_flutter/example/pubspec.yaml b/rollbar_flutter/example/pubspec.yaml
index f6fa7a9..209d1de 100644
--- a/rollbar_flutter/example/pubspec.yaml
+++ b/rollbar_flutter/example/pubspec.yaml
@@ -5,7 +5,7 @@ version: 0.1.0+1
 publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
   flutter:
diff --git a/rollbar_flutter/lib/src/platform_transformer.dart b/rollbar_flutter/lib/src/platform_transformer.dart
index 740e514..21aff94 100644
--- a/rollbar_flutter/lib/src/platform_transformer.dart
+++ b/rollbar_flutter/lib/src/platform_transformer.dart
@@ -2,21 +2,20 @@ import 'dart:convert';
 
 import 'package:flutter/services.dart' show PlatformException;
 import 'package:rollbar_dart/rollbar.dart'
-    show Body, Data, RollbarPlatformInfo, TraceChain, Transformer;
-import 'package:rollbar_dart/src/api/payload/body.dart';
+    show Body, Data, RollbarPlatformInfo, TraceChain, TraceInfo, Transformer;
 
 /// This trasformer inspects some platform specific exception types, which
 /// carry additional occurrence details in their exception messages.
 /// This allows the Rollbar Dart notifier to report a complete trace including
 /// both platform specific and Dart frames.
 class PlatformTransformer implements Transformer {
-  final Transformer wrapped;
+  final Transformer? wrapped;
   final bool appendToChain;
 
   PlatformTransformer({this.wrapped, this.appendToChain = false});
 
   @override
-  Future<Data> transform(dynamic error, StackTrace trace, Data data) async {
+  Future<Data> transform(dynamic error, StackTrace? trace, Data data) async {
     if (error is PlatformException) {
       if (RollbarPlatformInfo.isAndroid) {
         _enrichAndroidTrace(error, data);
@@ -24,42 +23,41 @@ class PlatformTransformer implements Transformer {
     }
 
     if (wrapped != null) {
-      return await wrapped.transform(error, trace, data);
+      return await wrapped!.transform(error, trace, data);
     }
 
     return data;
   }
 
-  static const String ANDROID_TRACE_PAYLOAD_PREFIX =
+  static const String androidTracePayloadPrefix =
       'com.rollbar.flutter.RollbarTracePayload:';
 
   void _enrichAndroidTrace(PlatformException error, Data data) {
     // We cannot use error.stackTrace here, it will contain 'com.rollbar.flutter.RollbarTracePayload:'
     // only in debug mode, but not in release
-    if (error.message.startsWith(ANDROID_TRACE_PAYLOAD_PREFIX)) {
-      var message =
-          error.message.substring(ANDROID_TRACE_PAYLOAD_PREFIX.length);
+    if (error.message!.startsWith(androidTracePayloadPrefix)) {
+      var message = error.message!.substring(androidTracePayloadPrefix.length);
       _attachPlatformPayload(message, data);
     }
   }
 
   void _attachPlatformPayload(String message, Data data) {
     var embeddedPayload = jsonDecode(message);
-    var embeddedBody = embeddedPayload['data']['body'] as Map;
+    var embeddedBody = embeddedPayload['data']['body'] as Map?;
 
     if (appendToChain) {
-      data.body = _prependPlatformTraceToChain(data.body, embeddedBody);
+      data.body = _prependPlatformTraceToChain(data.body, embeddedBody!);
     } else {
       data.platformPayload = embeddedPayload;
       _restoreDartChainMessage(
-          data.body.getTraces(), Body.fromMap(embeddedBody).getTraces());
+          data.body.getTraces(), Body.fromMap(embeddedBody!)!.getTraces()!);
     }
   }
 
   Body _prependPlatformTraceToChain(Body dartBody, Map embeddedBody) {
-    var embeddedChain = Body.fromMap(embeddedBody).getTraces();
+    var embeddedChain = Body.fromMap(embeddedBody)!.getTraces()!;
 
-    var dartChain = dartBody.getTraces();
+    var dartChain = dartBody.getTraces()!;
 
     _restoreDartChainMessage(dartChain, embeddedChain);
 
@@ -69,16 +67,16 @@ class PlatformTransformer implements Transformer {
 
   // Fix message, we hijacked it on the platform side to carry the payload
   void _restoreDartChainMessage(
-      List<TraceInfo> dartChain, List<TraceInfo> embeddedChain) {
+      List<TraceInfo?>? dartChain, List<TraceInfo?> embeddedChain) {
     if (embeddedChain.isNotEmpty) {
-      dartChain.forEach((element) {
-        if (element.exception != null &&
-            element.exception.message.startsWith('PlatformException') &&
-            element.exception.message.contains(ANDROID_TRACE_PAYLOAD_PREFIX)) {
-          element.exception.message =
-              'PlatformException(error, "${embeddedChain[0].exception.message}")';
+      for (var element in dartChain!) {
+        if (element!.exception != null &&
+            element.exception!.message!.startsWith('PlatformException') &&
+            element.exception!.message!.contains(androidTracePayloadPrefix)) {
+          element.exception!.message =
+              'PlatformException(error, "${embeddedChain[0]!.exception!.message}")';
         }
-      });
+      }
     }
   }
 }
diff --git a/rollbar_flutter/lib/src/rollbar.dart b/rollbar_flutter/lib/src/rollbar.dart
index 61d2dd5..486b425 100644
--- a/rollbar_flutter/lib/src/rollbar.dart
+++ b/rollbar_flutter/lib/src/rollbar.dart
@@ -4,9 +4,6 @@ import 'dart:isolate';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:rollbar_dart/rollbar.dart';
-import 'package:rollbar_dart/src/logging.dart' as logging;
-
-export 'package:rollbar_dart/rollbar.dart' show Config, ConfigBuilder;
 
 import 'platform_transformer.dart';
 
@@ -21,7 +18,7 @@ class RollbarFlutter extends Rollbar {
 
   static Future<void> run(
       Config config, FutureOr<void> Function(RollbarFlutter) action) async {
-    if (config.handleUncaughtErrors) {
+    if (config.handleUncaughtErrors!) {
       var rollbar = RollbarFlutter._(config);
 
       await runZonedGuarded(() async {
@@ -29,13 +26,16 @@ class RollbarFlutter extends Rollbar {
 
         var previousOnError = FlutterError.onError;
         FlutterError.onError = (FlutterErrorDetails details) async {
-          await rollbar._unhandledError(details.exception, details.stack);
+          await rollbar._unhandledError(details.exception, details.stack!);
           if (previousOnError != null) {
             previousOnError.call(details);
           }
         };
 
-        var errorHandler = await rollbar.errorHandler;
+        var errorHandler = await (rollbar.errorHandler as Future<SendPort?>);
+        if (errorHandler == null) {
+          return;
+        }
         Isolate.current.addErrorListener(errorHandler);
 
         await rollbar._initializePlatformInstance();
@@ -67,9 +67,9 @@ class RollbarFlutter extends Rollbar {
 
   Future<void> _unhandledError(dynamic exception, StackTrace trace) async {
     try {
-      await error(exception, trace);
+      await super.error(exception, trace);
     } on Exception catch (e) {
-      logging.error(
+      Logging.error(
           'Internal error encountered while sending data to Rollbar', e);
     }
   }
diff --git a/rollbar_flutter/pubspec.yaml b/rollbar_flutter/pubspec.yaml
index 9a7a35e..ada1039 100644
--- a/rollbar_flutter/pubspec.yaml
+++ b/rollbar_flutter/pubspec.yaml
@@ -1,25 +1,32 @@
 name: rollbar_flutter
 description: Connect your Flutter applications to Rollbar for error reporting.
-version: 0.1.0-beta
+version: 0.2.0-beta
 homepage: https://www.rollbar.com
 documentation: https://docs.rollbar.com/docs/flutter#flutter
 repository: https://github.com/rollbar/rollbar-flutter
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
-  flutter: ">=1.20.0"
+  sdk: '>=2.12.0 <3.0.0'
+  flutter: '>=1.20.0'
 
 dependencies:
   flutter:
     sdk: flutter
-  rollbar_dart: ">=0.1.0-beta <0.2.0"
-  logging: '>=0.11.4 <1.1.0'
+  logging: ^1.0.2
+  rollbar_dart: '>=0.2.0-beta <0.2.0'
 
+dependency_overrides:
+  rollbar_dart:
+    path: ../rollbar_dart
+ 
 dev_dependencies:
+  lints: ^1.0.1
+  flutter_lints: ^1.0.4
   flutter_test:
     sdk: flutter
-  pedantic: '>=1.9.0 <=1.11.0'
-  mockito: '>=4.1.0 <=5.0.7'
+  pedantic: ^1.11.1
+  build_runner: ^1.11.0
+  mockito: '>=5.0.0 <6.0.0'
 
 flutter:
   plugin:
diff --git a/rollbar_flutter/test/platform_exception_utils.dart b/rollbar_flutter/test/platform_exception_utils.dart
index 3b30220..ab47198 100644
--- a/rollbar_flutter/test/platform_exception_utils.dart
+++ b/rollbar_flutter/test/platform_exception_utils.dart
@@ -2,7 +2,7 @@ import 'dart:convert';
 import 'package:flutter/services.dart';
 
 PlatformException createAndroidPlatformException(
-    {String topFrameMethod,
+    {String? topFrameMethod,
     bool includeLineNumber = true,
     bool createChain = false}) {
   var topTrace = <String, dynamic>{
diff --git a/rollbar_flutter/test/platform_transformer_test.dart b/rollbar_flutter/test/platform_transformer_test.dart
index e0bc313..b790bab 100644
--- a/rollbar_flutter/test/platform_transformer_test.dart
+++ b/rollbar_flutter/test/platform_transformer_test.dart
@@ -1,13 +1,12 @@
 import 'package:flutter_test/flutter_test.dart';
 import 'package:rollbar_dart/rollbar.dart';
-import 'package:rollbar_dart/src/platform.dart';
 import 'package:rollbar_flutter/src/platform_transformer.dart';
 
 import 'platform_exception_utils.dart';
 
 void main() {
   group('PlatformTransformer tests', () {
-    String expectedMessage;
+    String? expectedMessage;
 
     setUp(() {
       RollbarPlatformInfo.isAndroid = true;
@@ -19,7 +18,7 @@ void main() {
     });
 
     group('Platform transformer (appendToChain: true)', () {
-      PlatformTransformer transformer;
+      late PlatformTransformer transformer;
 
       setUp(() {
         transformer = PlatformTransformer(appendToChain: true);
@@ -39,21 +38,21 @@ void main() {
         var updated =
             await transformer.transform(exception, StackTrace.empty, original);
 
-        var traces = updated.body.getTraces();
+        var traces = updated.body.getTraces()!;
         expect(traces, hasLength(2));
 
-        var rootCause = traces[0];
+        var rootCause = traces[0]!;
         expect(rootCause.frames.length, greaterThan(1));
         expect(rootCause.frames[0].method, equals('letsSeeYouParseThis'));
 
-        var dartTrace = traces[1];
+        var dartTrace = traces[1]!;
         expect(dartTrace.frames, hasLength(2));
         expect(dartTrace.frames[0].method, equals('testThis'));
         expect(dartTrace.frames[1].method, equals('what'));
 
         // The message was temporarily hijacked to transfer the platform payload, let's make sure
         // it's been restored
-        expect(dartTrace.exception.message, equals(expectedMessage));
+        expect(dartTrace.exception!.message, equals(expectedMessage));
       });
 
       test(
@@ -76,28 +75,28 @@ void main() {
         var updated =
             await transformer.transform(exception, StackTrace.empty, original);
 
-        var traces = updated.body.getTraces();
+        var traces = updated.body.getTraces()!;
         expect(traces, hasLength(3));
 
-        var rootCause = traces[0];
+        var rootCause = traces[0]!;
         expect(rootCause.frames.length, greaterThan(1));
         expect(rootCause.frames[0].method, equals('thisWillBeRethrown'));
 
-        var rethrownTrace = traces[1];
+        var rethrownTrace = traces[1]!;
         expect(rethrownTrace.frames, hasLength(2));
         expect(rethrownTrace.frames[0].method, equals('processError'));
         expect(rethrownTrace.frames[1].method, equals('catchAndThrow'));
 
-        var dartTrace = traces[2];
+        var dartTrace = traces[2]!;
         expect(dartTrace.frames, hasLength(1));
         expect(dartTrace.frames[0].method, equals('onTheDartSide'));
 
-        expect(dartTrace.exception.message, equals(expectedMessage));
+        expect(dartTrace.exception!.message, equals(expectedMessage));
       });
     });
 
     group('Platform transformer (appendToChain: false)', () {
-      PlatformTransformer transformer;
+      late PlatformTransformer transformer;
 
       setUp(() {
         transformer = PlatformTransformer(appendToChain: false);
@@ -117,19 +116,19 @@ void main() {
         var updated =
             await transformer.transform(exception, StackTrace.empty, original);
 
-        var traces = updated.body.getTraces();
+        var traces = updated.body.getTraces()!;
         expect(traces, hasLength(1));
 
-        var dartTrace = traces[0];
+        var dartTrace = traces[0]!;
         expect(dartTrace.frames, hasLength(1));
         expect(dartTrace.frames[0].method, equals('thisFails'));
 
-        expect(dartTrace.exception.message, equals(expectedMessage));
+        expect(dartTrace.exception!.message, equals(expectedMessage));
 
         expect(updated.platformPayload, isNotNull);
-        expect(updated.platformPayload['data']['notifier']['name'],
+        expect(updated.platformPayload!['data']['notifier']['name'],
             equals('rollbar-java'));
-        var trace = updated.platformPayload['data']['body']['trace'];
+        var trace = updated.platformPayload!['data']['body']['trace'];
         expect(trace['frames'].length, equals(2));
         expect(trace['frames'][0]['method'], equals('toBeAttached'));
       });
@@ -154,20 +153,20 @@ void main() {
         var updated =
             await transformer.transform(exception, StackTrace.empty, original);
 
-        var traces = updated.body.getTraces();
+        var traces = updated.body.getTraces()!;
         expect(traces, hasLength(1));
 
-        var dartTrace = traces[0];
+        var dartTrace = traces[0]!;
         expect(dartTrace.frames, hasLength(1));
         expect(dartTrace.frames[0].method, equals('attachedFailureChain'));
 
-        expect(dartTrace.exception.message, equals(expectedMessage));
+        expect(dartTrace.exception!.message, equals(expectedMessage));
 
         expect(updated.platformPayload, isNotNull);
-        expect(updated.platformPayload['data']['notifier']['name'],
+        expect(updated.platformPayload!['data']['notifier']['name'],
             equals('rollbar-java'));
 
-        var chain = updated.platformPayload['data']['body']['trace_chain'];
+        var chain = updated.platformPayload!['data']['body']['trace_chain'];
         expect(chain.length, equals(2));
 
         var topTrace = chain[0];
diff --git a/rollbar_flutter/test/rollbar_flutter_test.dart b/rollbar_flutter/test/rollbar_flutter_test.dart
index a2c85e7..fc4c0d5 100644
--- a/rollbar_flutter/test/rollbar_flutter_test.dart
+++ b/rollbar_flutter/test/rollbar_flutter_test.dart
@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/mockito.dart';
+import 'package:rollbar_dart/rollbar_dart.dart';
 import 'flutter1_workarounds.dart' as rbdart;
 import 'package:rollbar_flutter/rollbar.dart';
 
@@ -12,14 +13,13 @@ void main() {
   const channel = MethodChannel('rollbar_flutter');
 
   TestWidgetsFlutterBinding.ensureInitialized();
-  List<MethodCall> callsReceived;
-  MockSender sender;
+  late List<MethodCall> callsReceived;
+  late MockSender sender;
 
   setUp(() async {
     rbdart.RollbarPlatformInfo.isAndroid = true;
     sender = MockSender();
-    when(sender.send(any))
-        .thenAnswer((_invocation) => Future.value(rbdart.Response()));
+    when(sender.send(any)).thenAnswer((_) async => Response());
 
     callsReceived = [];
     channel.setMockMethodCallHandler((MethodCall methodCall) async {
@@ -117,7 +117,13 @@ Future<void> _runRollbarFlutter(
   expect(run, equals(true));
 }
 
-class MockSender extends Mock implements rbdart.Sender {}
+class MockSender extends Mock implements rbdart.Sender {
+  @override
+  Future<Response?> send(Map<String, dynamic>? payload) {
+    return super.noSuchMethod(Invocation.method(#send, [payload]),
+        returnValue: Future<Response?>.value(Response()));
+  }
+}
 
 MockSender createMockSender(Config c) {
   return MockSender();