diff --git a/dart/lib/src/sentry_client.dart b/dart/lib/src/sentry_client.dart
index b250badf7e..a10c52079e 100644
--- a/dart/lib/src/sentry_client.dart
+++ b/dart/lib/src/sentry_client.dart
@@ -133,6 +133,7 @@ class SentryClient {
     final envelope = SentryEnvelope.fromEvent(
       preparedEvent,
       _options.sdk,
+      dsn: _options.dsn,
       traceContext: scope?.span?.traceContext(),
       attachments: scope?.attachments,
     );
diff --git a/dart/lib/src/sentry_envelope.dart b/dart/lib/src/sentry_envelope.dart
index f090e26ea3..450a3bb8d3 100644
--- a/dart/lib/src/sentry_envelope.dart
+++ b/dart/lib/src/sentry_envelope.dart
@@ -24,6 +24,7 @@ class SentryEnvelope {
   factory SentryEnvelope.fromEvent(
     SentryEvent event,
     SdkVersion sdkVersion, {
+    String? dsn,
     SentryTraceContextHeader? traceContext,
     List<SentryAttachment>? attachments,
   }) {
@@ -31,6 +32,7 @@ class SentryEnvelope {
       SentryEnvelopeHeader(
         event.eventId,
         sdkVersion,
+        dsn: dsn,
         traceContext: traceContext,
       ),
       [
@@ -56,6 +58,7 @@ class SentryEnvelope {
   factory SentryEnvelope.fromTransaction(
     SentryTransaction transaction,
     SdkVersion sdkVersion, {
+    String? dsn,
     SentryTraceContextHeader? traceContext,
     List<SentryAttachment>? attachments,
   }) {
@@ -63,6 +66,7 @@ class SentryEnvelope {
       SentryEnvelopeHeader(
         transaction.eventId,
         sdkVersion,
+        dsn: dsn,
         traceContext: traceContext,
       ),
       [
diff --git a/dart/lib/src/sentry_envelope_header.dart b/dart/lib/src/sentry_envelope_header.dart
index 5fe941ab04..c6b2bb9ead 100644
--- a/dart/lib/src/sentry_envelope_header.dart
+++ b/dart/lib/src/sentry_envelope_header.dart
@@ -7,11 +7,13 @@ class SentryEnvelopeHeader {
   SentryEnvelopeHeader(
     this.eventId,
     this.sdkVersion, {
+    this.dsn,
     this.traceContext,
   });
   SentryEnvelopeHeader.newEventId()
       : eventId = SentryId.newId(),
         sdkVersion = null,
+        dsn = null,
         traceContext = null;
 
   /// The identifier of encoded `SentryEvent`.
@@ -22,6 +24,9 @@ class SentryEnvelopeHeader {
 
   final SentryTraceContextHeader? traceContext;
 
+  /// The `DSN` of the Sentry project.
+  final String? dsn;
+
   /// Header encoded as JSON
   Map<String, dynamic> toJson() {
     final json = <String, dynamic>{};
@@ -41,6 +46,9 @@ class SentryEnvelopeHeader {
       json['trace'] = tempTraceContext.toJson();
     }
 
+    if (dsn != null) {
+      json['dsn'] = dsn;
+    }
     return json;
   }
 }
diff --git a/dart/test/mocks.dart b/dart/test/mocks.dart
index cb36172d06..836dccc762 100644
--- a/dart/test/mocks.dart
+++ b/dart/test/mocks.dart
@@ -129,7 +129,10 @@ typedef EventProcessorFunction = FutureOr<SentryEvent?>
     Function(SentryEvent event, {dynamic hint});
 
 var fakeEnvelope = SentryEnvelope.fromEvent(
-    fakeEvent, SdkVersion(name: 'sdk1', version: '1.0.0'));
+  fakeEvent,
+  SdkVersion(name: 'sdk1', version: '1.0.0'),
+  dsn: fakeDsn,
+);
 
 class MockRateLimiter implements RateLimiter {
   bool filterReturnsNull = false;
diff --git a/dart/test/sentry_envelope_test.dart b/dart/test/sentry_envelope_test.dart
index c7c683995a..d5b24a9d92 100644
--- a/dart/test/sentry_envelope_test.dart
+++ b/dart/test/sentry_envelope_test.dart
@@ -64,9 +64,11 @@ void main() {
         'trace_id': '${SentryId.newId()}',
         'public_key': '123',
       });
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
       final sut = SentryEnvelope.fromEvent(
         sentryEvent,
         sdkVersion,
+        dsn: fakeDsn,
         traceContext: context,
       );
 
@@ -136,16 +138,19 @@ void main() {
       final sentryEvent = SentryEvent(eventId: eventId);
       final sdkVersion =
           SdkVersion(name: 'fixture-name', version: 'fixture-version');
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
 
       final sut = SentryEnvelope.fromEvent(
         sentryEvent,
         sdkVersion,
+        dsn: fakeDsn,
         attachments: [attachment],
       );
 
       final expectedEnvelopeItem = SentryEnvelope.fromEvent(
         sentryEvent,
         sdkVersion,
+        dsn: fakeDsn,
       );
 
       final sutEnvelopeData = <int>[];
@@ -165,12 +170,14 @@ void main() {
     // This is a test for https://github.com/getsentry/sentry-dart/issues/523
     test('serialize with non-serializable class', () async {
       final event = SentryEvent(extra: {'non-ecodable': NonEncodable()});
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
       final sut = SentryEnvelope.fromEvent(
         event,
         SdkVersion(
           name: 'test',
           version: '1',
         ),
+        dsn: fakeDsn,
       );
 
       final _ = sut.envelopeStream(SentryOptions()).map((e) => e);
diff --git a/dart/test/sentry_envelope_vm_test.dart b/dart/test/sentry_envelope_vm_test.dart
index 33dce0515d..fdb136d9d6 100644
--- a/dart/test/sentry_envelope_vm_test.dart
+++ b/dart/test/sentry_envelope_vm_test.dart
@@ -50,7 +50,6 @@ void main() {
       final sdkVersion = SdkVersion(name: '', version: '');
       final attachment =
           IoSentryAttachment.fromPath('this_path_does_not_exist.txt');
-
       final envelope = SentryEnvelope.fromEvent(
         event,
         sdkVersion,
diff --git a/dart/test/transport/http_transport_test.dart b/dart/test/transport/http_transport_test.dart
index d6394c9c3f..e8df1cf372 100644
--- a/dart/test/transport/http_transport_test.dart
+++ b/dart/test/transport/http_transport_test.dart
@@ -2,17 +2,16 @@ import 'dart:convert';
 
 import 'package:http/http.dart' as http;
 import 'package:http/testing.dart';
+import 'package:sentry/sentry.dart';
 import 'package:sentry/src/client_reports/discard_reason.dart';
 import 'package:sentry/src/sentry_envelope_header.dart';
 import 'package:sentry/src/sentry_envelope_item_header.dart';
 import 'package:sentry/src/sentry_item_type.dart';
+import 'package:sentry/src/sentry_tracer.dart';
 import 'package:sentry/src/transport/data_category.dart';
+import 'package:sentry/src/transport/http_transport.dart';
 import 'package:sentry/src/transport/rate_limiter.dart';
 import 'package:test/test.dart';
-import 'package:sentry/src/sentry_tracer.dart';
-
-import 'package:sentry/sentry.dart';
-import 'package:sentry/src/transport/http_transport.dart';
 
 import '../mocks.dart';
 import '../mocks/mock_client_report_recorder.dart';
@@ -70,8 +69,10 @@ void main() {
       final sut = fixture.getSut(httpMock, mockRateLimiter);
 
       final sentryEvent = SentryEvent();
-      final envelope =
-          SentryEnvelope.fromEvent(sentryEvent, fixture.options.sdk);
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
+      final envelope = SentryEnvelope.fromEvent(
+          sentryEvent, fixture.options.sdk,
+          dsn: fakeDsn);
       await sut.send(envelope);
 
       final envelopeData = <int>[];
@@ -94,8 +95,10 @@ void main() {
       final sut = fixture.getSut(httpMock, mockRateLimiter);
 
       final sentryEvent = SentryEvent();
-      final envelope =
-          SentryEnvelope.fromEvent(sentryEvent, fixture.options.sdk);
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
+      final envelope = SentryEnvelope.fromEvent(
+          sentryEvent, fixture.options.sdk,
+          dsn: fakeDsn);
       final eventId = await sut.send(envelope);
 
       expect(eventId, SentryId.empty());
@@ -118,8 +121,10 @@ void main() {
       final sut = fixture.getSut(httpMock, mockRateLimiter);
 
       final sentryEvent = SentryEvent();
-      final envelope =
-          SentryEnvelope.fromEvent(sentryEvent, fixture.options.sdk);
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
+      final envelope = SentryEnvelope.fromEvent(
+          sentryEvent, fixture.options.sdk,
+          dsn: fakeDsn);
       await sut.send(envelope);
 
       expect(mockRateLimiter.envelopeToFilter?.header.eventId,
@@ -139,8 +144,10 @@ void main() {
       final sut = fixture.getSut(httpMock, mockRateLimiter);
 
       final sentryEvent = SentryEvent();
-      final envelope =
-          SentryEnvelope.fromEvent(sentryEvent, fixture.options.sdk);
+      final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
+      final envelope = SentryEnvelope.fromEvent(
+          sentryEvent, fixture.options.sdk,
+          dsn: fakeDsn);
       await sut.send(envelope);
 
       expect(mockRateLimiter.errorCode, 200);
diff --git a/dio/test/mocks.dart b/dio/test/mocks.dart
index b17a27e8b6..f12bc2c4aa 100644
--- a/dio/test/mocks.dart
+++ b/dio/test/mocks.dart
@@ -131,6 +131,7 @@ typedef EventProcessorFunction = FutureOr<SentryEvent?>
 var fakeEnvelope = SentryEnvelope.fromEvent(
   fakeEvent,
   SdkVersion(name: 'sdk1', version: '1.0.0'),
+  dsn: fakeDsn,
 );
 
 class MockRateLimiter implements RateLimiter {
diff --git a/flutter/test/file_system_transport_test.dart b/flutter/test/file_system_transport_test.dart
index 6d066d53c7..fccb953ac8 100644
--- a/flutter/test/file_system_transport_test.dart
+++ b/flutter/test/file_system_transport_test.dart
@@ -32,8 +32,9 @@ void main() {
     final event = SentryEvent();
     final sdkVersion =
         SdkVersion(name: 'fixture-sdkName', version: 'fixture-sdkVersion');
+    final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
 
-    final envelope = SentryEnvelope.fromEvent(event, sdkVersion);
+    final envelope = SentryEnvelope.fromEvent(event, sdkVersion, dsn: fakeDsn);
     final sentryId = await transport.send(envelope);
 
     expect(sentryId, sentryId);
@@ -48,8 +49,9 @@ void main() {
     final event = SentryEvent();
     final sdkVersion =
         SdkVersion(name: 'fixture-sdkName', version: 'fixture-sdkVersion');
+    final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
 
-    final envelope = SentryEnvelope.fromEvent(event, sdkVersion);
+    final envelope = SentryEnvelope.fromEvent(event, sdkVersion, dsn: fakeDsn);
     final sentryId = await transport.send(envelope);
 
     expect(SentryId.empty(), sentryId);
@@ -67,7 +69,8 @@ void main() {
         SentryEvent(message: SentryMessage('hi I am a special char ◤'));
     final sdkVersion =
         SdkVersion(name: 'fixture-sdkName', version: 'fixture-sdkVersion');
-    final envelope = SentryEnvelope.fromEvent(event, sdkVersion);
+    final fakeDsn = 'https://abc@def.ingest.sentry.io/1234567';
+    final envelope = SentryEnvelope.fromEvent(event, sdkVersion, dsn: fakeDsn);
     await transport.send(envelope);
 
     final envelopeList = arguments as List;