diff --git a/lib/sentry.dart b/lib/sentry.dart
index aa46678652..7b0cbd7c81 100644
--- a/lib/sentry.dart
+++ b/lib/sentry.dart
@@ -306,6 +306,7 @@ class Event {
     this.release,
     this.environment,
     this.message,
+    this.transaction,
     this.exception,
     this.stackTrace,
     this.level,
@@ -314,6 +315,7 @@ class Event {
     this.extra,
     this.fingerprint,
     this.userContext,
+    this.breadcrumbs,
   });
 
   /// The logger that logged the event.
@@ -344,6 +346,10 @@ class Event {
   /// Can be `null`, a [String], or a [StackTrace].
   final dynamic stackTrace;
 
+  /// The name of the transaction which generated this event,
+  /// for example, the route name: `"/users/<username>/"`.
+  final String transaction;
+
   /// How important this event is.
   final SeverityLevel level;
 
@@ -359,6 +365,12 @@ class Event {
   /// they must be JSON-serializable.
   final Map<String, dynamic> extra;
 
+  /// List of breadcrumbs for this event.
+  ///
+  /// See also:
+  /// * https://docs.sentry.io/enriching-error-data/breadcrumbs/?platform=javascript
+  final List<Breadcrumb> breadcrumbs;
+
   /// Information about the current user.
   ///
   /// The value in this field overrides the user context
@@ -401,6 +413,8 @@ class Event {
 
     if (message != null) json['message'] = message;
 
+    if (transaction != null) json['transaction'] = transaction;
+
     if (exception != null) {
       json['exception'] = [
         <String, dynamic>{
@@ -433,6 +447,12 @@ class Event {
     if (fingerprint != null && fingerprint.isNotEmpty)
       json['fingerprint'] = fingerprint;
 
+    if (breadcrumbs != null && breadcrumbs.isNotEmpty) {
+      json['breadcrumbs'] = <String, List<Map<String, dynamic>>>{
+        'values': breadcrumbs.map((b) => b.toJson()).toList(growable: false)
+      };
+    }
+
     return json;
   }
 }
@@ -494,3 +514,64 @@ class User {
     };
   }
 }
+
+/// Structed data to describe more information pior to the event [captured][SentryClient.capture].
+///
+/// The outgoing JSON representation is:
+///
+/// ```
+/// {
+///   "timestamp": 1000
+///   "message": "message",
+///   "category": "category",
+///   "data": {"key": "value"},
+///   "level": "info",
+///   "type": "default"
+/// }
+/// ```
+/// See also:
+/// * https://docs.sentry.io/development/sdk-dev/event-payloads/breadcrumbs/
+class Breadcrumb {
+  final String message;
+  final String category;
+  final Map<String, String> data;
+  final SeverityLevel level;
+
+  /// Describes what type of breadcrumb this is.
+  ///
+  /// Possible values: "default", "http", "navigation".
+  ///
+  /// See also:
+  ///
+  /// * https://docs.sentry.io/development/sdk-dev/event-payloads/breadcrumbs/#breadcrumb-types
+  final String type;
+
+  /// The time the breadcrumb was recorded.
+  ///
+  /// The value is submitted to Sentry with second precision.
+  final DateTime timestamp;
+  const Breadcrumb(this.message, this.timestamp,
+      {this.category, this.data, this.level = SeverityLevel.info, this.type});
+
+  Map<String, dynamic> toJson() {
+    var json = <String, dynamic>{
+      'timestamp': formatDateAsIso8601WithSecondPrecision(timestamp),
+    };
+    if (message != null) {
+      json['message'] = message;
+    }
+    if (category != null) {
+      json['category'] = category;
+    }
+    if (data != null && data.isNotEmpty) {
+      json['data'] = Map.of(data);
+    }
+    if (level != null) {
+      json['level'] = level.name;
+    }
+    if (type != null) {
+      json['type'] = type;
+    }
+    return json;
+  }
+}
diff --git a/test/sentry_test.dart b/test/sentry_test.dart
index 6dc563d1ad..330acf0f99 100644
--- a/test/sentry_test.dart
+++ b/test/sentry_test.dart
@@ -308,6 +308,22 @@ void main() {
   });
 
   group('$Event', () {
+    test('$Breadcrumb serializes', () {
+      expect(
+        Breadcrumb(
+          "example log",
+          DateTime.utc(2019),
+          level: SeverityLevel.debug,
+          category: "test",
+        ).toJson(),
+        <String, dynamic>{
+          'timestamp': '2019-01-01T00:00:00',
+          'message': 'example log',
+          'category': 'test',
+          'level': 'debug',
+        },
+      );
+    });
     test('serializes to JSON', () {
       final user = new User(
           id: "user_id",
@@ -315,9 +331,16 @@ void main() {
           email: "email@email.com",
           ipAddress: "127.0.0.1",
           extras: {"foo": "bar"});
+
+      final breadcrumbs = [
+        Breadcrumb("test log", DateTime.utc(2019),
+            level: SeverityLevel.debug, category: "test"),
+      ];
+
       expect(
         new Event(
           message: 'test-message',
+          transaction: '/test/1',
           exception: new StateError('test-error'),
           level: SeverityLevel.debug,
           culprit: 'Professor Moriarty',
@@ -331,11 +354,13 @@ void main() {
           },
           fingerprint: <String>[Event.defaultFingerprint, 'foo'],
           userContext: user,
+          breadcrumbs: breadcrumbs,
         ).toJson(),
         <String, dynamic>{
           'platform': 'dart',
           'sdk': {'version': sdkVersion, 'name': 'dart'},
           'message': 'test-message',
+          'transaction': '/test/1',
           'exception': [
             {'type': 'StateError', 'value': 'Bad state: test-error'}
           ],
@@ -351,6 +376,16 @@ void main() {
             'ip_address': '127.0.0.1',
             'extras': {'foo': 'bar'}
           },
+          'breadcrumbs': {
+            'values': [
+              {
+                'timestamp': '2019-01-01T00:00:00',
+                'message': 'test log',
+                'category': 'test',
+                'level': 'debug',
+              },
+            ]
+          },
         },
       );
     });