From 2025e607c5c8851474af40d069b92b2744565e04 Mon Sep 17 00:00:00 2001
From: Alexander Pantiukhov <alex@apantiukhov.com>
Date: Tue, 27 Jan 2026 15:45:03 +0100
Subject: [PATCH 1/2] SDK Handling HTTP 413

---
 CHANGELOG.md                                  |  3 +
 .../io/sentry/react/RNSentryModuleImpl.java   | 11 +++-
 packages/core/ios/RNSentry.mm                 |  4 +-
 packages/core/src/js/NativeRNSentry.ts        |  2 +-
 packages/core/src/js/wrapper.ts               | 21 ++++++-
 packages/core/test/wrapper.test.ts            | 55 +++++++++++++++++++
 6 files changed, 90 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dbfb633f8d..4c315dc57b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@
 
 ### Features
 
+- Add handling for HTTP 413 (Content Too Large) responses from Relay ([#5566](https://github.com/getsentry/sentry-react-native/issues/5566))
+  - SDK now logs actionable error messages when envelopes are rejected due to size limits
+  - Prepared infrastructure to capture HTTP status codes from native transport layer for future enhancements
 - Add experimental `sentry-span-attributes` prop to attach custom attributes to user interaction spans ([#5569](https://github.com/getsentry/sentry-react-native/pull/5569))
   ```tsx
   <Pressable
diff --git a/packages/core/android/src/main/java/io/sentry/react/RNSentryModuleImpl.java b/packages/core/android/src/main/java/io/sentry/react/RNSentryModuleImpl.java
index 5a24e7d54c..23750666dc 100644
--- a/packages/core/android/src/main/java/io/sentry/react/RNSentryModuleImpl.java
+++ b/packages/core/android/src/main/java/io/sentry/react/RNSentryModuleImpl.java
@@ -694,11 +694,16 @@ public void captureEnvelope(String rawBytes, ReadableMap options, Promise promis
     try {
       InternalSentrySdk.captureEnvelope(
           bytes, !options.hasKey("hardCrashed") || !options.getBoolean("hardCrashed"));
+
+      // TODO(alwx): Capture transport response from sentry-android when available
+      WritableMap response = new WritableNativeMap();
+      promise.resolve(response);
     } catch (Throwable e) { // NOPMD - We don't want to crash in any case
-      logger.log(SentryLevel.ERROR, "Error while capturing envelope");
-      promise.resolve(false);
+      logger.log(SentryLevel.ERROR, "Error while capturing envelope", e);
+      WritableMap errorResponse = new WritableNativeMap();
+      errorResponse.putString("message", "Error while capturing envelope: " + e.getMessage());
+      promise.resolve(errorResponse);
     }
-    promise.resolve(true);
   }
 
   public void captureScreenshot(Promise promise) {
diff --git a/packages/core/ios/RNSentry.mm b/packages/core/ios/RNSentry.mm
index f5fefc0cd6..27fb9a76de 100644
--- a/packages/core/ios/RNSentry.mm
+++ b/packages/core/ios/RNSentry.mm
@@ -555,7 +555,9 @@ - (void)stopObserving
         [PrivateSentrySDKOnly captureEnvelope:envelope];
     }
 #endif
-    resolve(@YES);
+
+    // TODO(alwx): Capture transport response from sentry-cocoa when available
+    resolve(@{});
 }
 
 RCT_EXPORT_METHOD(
diff --git a/packages/core/src/js/NativeRNSentry.ts b/packages/core/src/js/NativeRNSentry.ts
index 3e75967c27..eece3c4643 100644
--- a/packages/core/src/js/NativeRNSentry.ts
+++ b/packages/core/src/js/NativeRNSentry.ts
@@ -15,7 +15,7 @@ export interface Spec extends TurboModule {
     options: {
       hardCrashed: boolean;
     },
-  ): Promise<boolean>;
+  ): Promise<{ status?: string; message?: string }>;
   captureScreenshot(): Promise<NativeScreenshot[] | undefined | null>;
   clearBreadcrumbs(): void;
   crash(): void;
diff --git a/packages/core/src/js/wrapper.ts b/packages/core/src/js/wrapper.ts
index 4089bc5c75..df7d7e77e2 100644
--- a/packages/core/src/js/wrapper.ts
+++ b/packages/core/src/js/wrapper.ts
@@ -218,7 +218,26 @@ export const NATIVE: SentryNativeWrapper = {
       envelopeBytes = newBytes;
     }
 
-    await RNSentry.captureEnvelope(base64StringFromByteArray(envelopeBytes), { hardCrashed });
+    const response = await RNSentry.captureEnvelope(base64StringFromByteArray(envelopeBytes), { hardCrashed });
+
+    if (response?.status) {
+      const statusCode = parseInt(response.status, 10);
+
+      // Handle HTTP 413 - Content Too Large
+      if (statusCode === 413) {
+        debug.error(
+          'Failed to send event to Sentry: HTTP 413 - Envelope exceeds size limit.\n' +
+            'The event was rejected because the envelope size exceeds the maximum allowed size.\n' +
+            'Consider reducing the size of breadcrumbs, context data, or attachments.',
+        );
+      }
+      // Log other error status codes
+      else if (statusCode >= 400) {
+        debug.error(
+          `Failed to send event to Sentry: HTTP ${statusCode}${response.message ? ` - ${response.message}` : ''}`,
+        );
+      }
+    }
   },
 
   /**
diff --git a/packages/core/test/wrapper.test.ts b/packages/core/test/wrapper.test.ts
index cc7b79c0d9..012b64a11d 100644
--- a/packages/core/test/wrapper.test.ts
+++ b/packages/core/test/wrapper.test.ts
@@ -696,6 +696,61 @@ describe('Tests Native Wrapper', () => {
         { hardCrashed: false },
       );
     });
+
+    test('handles HTTP 413 response from native', async () => {
+      const errorSpy = jest.spyOn(debug, 'error');
+
+      // Mock native module to return HTTP 413
+      (RNSentry.captureEnvelope as jest.Mock).mockResolvedValueOnce({
+        status: '413',
+        message: 'Payload Too Large',
+      });
+
+      const event = {
+        event_id: 'event0',
+        message: 'test',
+      };
+
+      const env = createEnvelope<EventEnvelope>({ event_id: event.event_id, sent_at: '123' }, [
+        [{ type: 'event' }, event] as EventItem,
+      ]);
+
+      await NATIVE.sendEnvelope(env);
+
+      expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining('HTTP 413 - Envelope exceeds size limit'));
+      expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining('Consider reducing the size of breadcrumbs'));
+
+      errorSpy.mockRestore();
+      // Reset mock to default behavior
+      (RNSentry.captureEnvelope as jest.Mock).mockResolvedValue({});
+    });
+
+    test('handles other HTTP error responses from native', async () => {
+      const errorSpy = jest.spyOn(debug, 'error');
+
+      // Mock native module to return HTTP 400
+      (RNSentry.captureEnvelope as jest.Mock).mockResolvedValueOnce({
+        status: '400',
+        message: 'Bad Request',
+      });
+
+      const event = {
+        event_id: 'event0',
+        message: 'test',
+      };
+
+      const env = createEnvelope<EventEnvelope>({ event_id: event.event_id, sent_at: '123' }, [
+        [{ type: 'event' }, event] as EventItem,
+      ]);
+
+      await NATIVE.sendEnvelope(env);
+
+      expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining('HTTP 400 - Bad Request'));
+
+      errorSpy.mockRestore();
+      // Reset mock to default behavior
+      (RNSentry.captureEnvelope as jest.Mock).mockResolvedValue({});
+    });
   });
 
   describe('fetchRelease', () => {

From 8cacfd3a433b8108bb2d5815ca8901ca491d5188 Mon Sep 17 00:00:00 2001
From: Alexander Pantiukhov <alex@apantiukhov.com>
Date: Tue, 27 Jan 2026 15:45:17 +0100
Subject: [PATCH 2/2] Code fix

---
 packages/core/ios/RNSentry.mm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/core/ios/RNSentry.mm b/packages/core/ios/RNSentry.mm
index 27fb9a76de..b2b596c315 100644
--- a/packages/core/ios/RNSentry.mm
+++ b/packages/core/ios/RNSentry.mm
@@ -557,7 +557,7 @@ - (void)stopObserving
 #endif
 
     // TODO(alwx): Capture transport response from sentry-cocoa when available
-    resolve(@{});
+    resolve(@ {});
 }
 
 RCT_EXPORT_METHOD(