Add `sentry.replay_id` to flutter logs #3257

denrase · 2025-09-17T13:18:36Z

📜 Description

Add sentry.replay_id to structured logs
Add sentry._internal.replay_is_buffering to structured logs
Fixes a bug in test expectations
Updates native integrations to get scope and non-scope replay id
- On iOS we only get scope replay id, so right now we cannot determine buffer mode.

💡 Motivation and Context

Closes #3245

💚 How did you test it?

Unit tests

📝 Checklist

I reviewed submitted code
I added tests to verify changes
No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
I updated the docs if needed
All tests passing
No breaking changes

Note

Add ReplayLogIntegration to enrich Flutter structured logs with replay metadata and include it only on replay-supported platforms, with tests and changelog updates.

Flutter SDK:
- Replay log metadata: Introduce ReplayLogIntegration to add sentry.replay_id and sentry._internal.replay_is_buffering to SentryLog via OnBeforeCaptureLog.
- Default integrations: Add ReplayLogIntegration only when native.supportsReplay is true.
- Tests:
  - New replay_log_integration_test.dart covering replay id and buffering flag behavior, registration, and cleanup.
  - Update platform integration tests to expect ReplayLogIntegration only on replay-supported platforms.
  - Adjust test/sentry_flutter_util.dart assertion to check by runtimeType for absent integrations.
- Changelog: Document enhancement under Unreleased.

^{Written by Cursor Bugbot for commit 02f86c3. This will update automatically on new commits. Configure here.}

Relates to #3245

codecov · 2025-09-17T13:19:26Z

Codecov Report

❌ Patch coverage is 93.75000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.74%. Comparing base (40c8f93) to head (744d429).

Files with missing lines	Patch %	Lines
...ckages/flutter/lib/src/native/c/sentry_native.dart	0.00%	1 Missing ⚠️
.../flutter/lib/src/native/sentry_native_channel.dart	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3257      +/-   ##
==========================================
+ Coverage   87.84%   89.74%   +1.90%     
==========================================
  Files         290       96     -194     
  Lines       10003     3424    -6579     
==========================================
- Hits         8787     3073    -5714     
+ Misses       1216      351     -865

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

github-actions · 2025-09-17T13:31:42Z

Android Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	452.46 ms	460.69 ms	8.23 ms
Size	13.93 MiB	15.00 MiB	1.06 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`6b69699`	456.06 ms	557.44 ms	101.38 ms
`192b44c`	472.26 ms	477.34 ms	5.08 ms
`1f639ee`	429.98 ms	476.60 ms	46.62 ms
`6f47800`	451.04 ms	509.64 ms	58.60 ms
`7cfee3b`	498.78 ms	516.98 ms	18.20 ms
`7cfbbd6`	499.69 ms	592.24 ms	92.55 ms
`73dca78`	476.53 ms	522.21 ms	45.68 ms
`32914d8`	461.96 ms	495.47 ms	33.51 ms
`2cf9161`	454.12 ms	512.67 ms	58.55 ms
`6bcdc99`	440.23 ms	435.77 ms	-4.46 ms

App size

Revision	Plain	With Sentry	Diff
`6b69699`	6.54 MiB	7.70 MiB	1.17 MiB
`192b44c`	13.93 MiB	14.93 MiB	1.00 MiB
`1f639ee`	13.93 MiB	15.00 MiB	1.06 MiB
`6f47800`	6.54 MiB	7.69 MiB	1.15 MiB
`7cfee3b`	6.54 MiB	7.70 MiB	1.17 MiB
`7cfbbd6`	6.54 MiB	7.70 MiB	1.17 MiB
`73dca78`	6.54 MiB	7.69 MiB	1.15 MiB
`32914d8`	6.54 MiB	7.70 MiB	1.16 MiB
`2cf9161`	6.54 MiB	7.70 MiB	1.16 MiB
`6bcdc99`	13.93 MiB	15.00 MiB	1.06 MiB

Previous results on branch: enha/logs-replay-id

Startup times

Revision	Plain	With Sentry	Diff
`9e888b6`	460.09 ms	462.35 ms	2.26 ms
`f98c32f`	479.02 ms	466.78 ms	-12.25 ms
`234bb86`	453.89 ms	457.28 ms	3.39 ms
`1e63021`	430.72 ms	453.78 ms	23.06 ms
`02f86c3`	453.09 ms	454.63 ms	1.55 ms
`91562e2`	464.50 ms	455.70 ms	-8.80 ms

App size

Revision	Plain	With Sentry	Diff
`9e888b6`	13.93 MiB	15.00 MiB	1.06 MiB
`f98c32f`	13.93 MiB	15.00 MiB	1.06 MiB
`234bb86`	13.93 MiB	15.00 MiB	1.06 MiB
`1e63021`	13.93 MiB	15.00 MiB	1.06 MiB
`02f86c3`	13.93 MiB	15.00 MiB	1.06 MiB
`91562e2`	13.93 MiB	15.00 MiB	1.06 MiB

github-actions · 2025-09-17T13:32:51Z

iOS Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1254.51 ms	1254.19 ms	-0.32 ms
Size	5.53 MiB	6.00 MiB	483.36 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`aeb02f2`	1244.29 ms	1256.55 ms	12.26 ms
`54acf91`	1257.65 ms	1277.96 ms	20.31 ms
`73a3c38`	1263.37 ms	1277.90 ms	14.53 ms
`944b773`	1252.82 ms	1254.08 ms	1.27 ms
`827bf09`	1261.86 ms	1276.41 ms	14.55 ms
`192b44c`	1269.08 ms	1275.52 ms	6.44 ms
`c1e775e`	1263.08 ms	1275.32 ms	12.24 ms
`cf443d2`	1255.79 ms	1248.38 ms	-7.40 ms
`81f83eb`	1259.53 ms	1273.39 ms	13.86 ms
`0fb3800`	1256.60 ms	1266.28 ms	9.68 ms

App size

Revision	Plain	With Sentry	Diff
`aeb02f2`	7.86 MiB	9.44 MiB	1.58 MiB
`54acf91`	20.70 MiB	22.46 MiB	1.75 MiB
`73a3c38`	7.86 MiB	9.44 MiB	1.58 MiB
`944b773`	5.53 MiB	6.00 MiB	479.98 KiB
`827bf09`	7.86 MiB	9.44 MiB	1.58 MiB
`192b44c`	5.53 MiB	5.96 MiB	444.33 KiB
`c1e775e`	20.70 MiB	22.46 MiB	1.75 MiB
`cf443d2`	5.53 MiB	6.00 MiB	479.99 KiB
`81f83eb`	7.86 MiB	9.44 MiB	1.58 MiB
`0fb3800`	7.86 MiB	9.44 MiB	1.58 MiB

Previous results on branch: enha/logs-replay-id

Startup times

Revision	Plain	With Sentry	Diff
`91562e2`	1242.54 ms	1254.08 ms	11.54 ms
`f98c32f`	1256.22 ms	1265.67 ms	9.44 ms
`1e63021`	1244.62 ms	1246.37 ms	1.76 ms
`9e888b6`	1247.65 ms	1245.32 ms	-2.33 ms
`234bb86`	1241.00 ms	1250.87 ms	9.88 ms
`02f86c3`	1262.54 ms	1263.67 ms	1.13 ms

App size

Revision	Plain	With Sentry	Diff
`91562e2`	5.53 MiB	6.00 MiB	480.92 KiB
`f98c32f`	5.53 MiB	6.00 MiB	483.36 KiB
`1e63021`	5.53 MiB	6.00 MiB	483.21 KiB
`9e888b6`	5.53 MiB	6.00 MiB	483.21 KiB
`234bb86`	5.53 MiB	6.00 MiB	479.96 KiB
`02f86c3`	5.53 MiB	6.00 MiB	480.79 KiB

denrase · 2025-09-22T12:44:24Z

@stefanosiano Same here, review pls :)

stefanosiano · 2025-09-22T12:57:52Z

looks good, but i'll put it on hold, until the last point has been decided on: https://www.notion.so/sentry/Logs-Replays-Notes-2738b10e4b5d8035b027c6cb0fc57174
TLDR: when replay is in buffering mode, we'd send a replay id even if the replay is not sent. There is a discussion on what to do

stefanosiano · 2025-09-25T09:48:10Z

@denrase decision was made
We are going to add a sentry._internal.replay_is_buffering if replay is in buffer mode, and we don't send it if replay is not sampled or in session mode.

Then we keep the sentry.replay_id flag as you already did in this PR 👍

denrase · 2025-09-29T14:41:00Z

@stefanosiano Pls take a look if i interpreted the flag correctly.

stefanosiano · 2025-09-30T13:48:44Z

@denrase
The logic should be this:

Session replay is running -> set sentry.replay_id
Buffer replay is running -> set sentry.replay_id and sentry._internal.replay_is_buffering
No replay is running -> don't set anything

In Android we have this distinction because the replay id is set in the scope when the replay is captured (and it's in session mode), and is only available in the replay integration (and not in the scope) when it's running in buffer mode.
Can we do something similar here?
Also, why are you creating a new integration if you can check it directly in the client in captureLog()?

denrase · 2025-10-01T09:35:15Z

@stefanosiano Thank you, didn't have access to SentryFlutterOptions in captureLog

stefanosiano · 2025-10-01T09:40:00Z

Thank you, didn't have access to SentryFlutterOptions in captureLog

i guess it's fine if you try to cast the options of the scope to SentryFlutterOptions.
At least the logic of enhancing the logs is not scattered in different classes, imho

denrase · 2025-10-01T12:28:50Z

@stefanosiano AFAIK this only works in the Flutter repo, as the Dart repo does not know about the SentryFlutterOptions class at all.

stefanosiano · 2025-10-01T12:38:14Z

@stefanosiano AFAIK this only works in the Flutter repo, as the Dart repo does not know about the SentryFlutterOptions class at all.

yeah right

packages/flutter/lib/src/integrations/replay_log_integration.dart

CHANGELOG.md

denrase · 2025-10-06T14:52:27Z

@stefanosiano Took me a while to debug this and figure out how everything fits together. We have the following issues:

On iOS we read the replay ID from the Scope, but do not have access to an internal/integration ID, so we cannot reliably tell if we are in buffer mode. This is called continuously for every screenshot.
On Android we get the replay ID from the integration, which we set to the scope, so it's immediately set, even when in buffer mode. This is called once when the recorder is starting.

So the latter is currently incorrect I think. Need to think about how we wan't to tackle this.

\cc @buenaflor

buenaflor · 2025-10-07T09:57:45Z

@denrase sounds like we need some internal hybrids SDK api from cocoa for this

buenaflor · 2025-10-07T09:58:04Z

I think it might be good to align with RN here

denrase · 2025-10-08T08:09:01Z

@buenaflor Checked RN. Right now they are only setting the replay_id without buffering info.

https://github.com/getsentry/sentry-react-native/blob/0b647531c13884b6be72c6f652482d79c6d2d96f/packages/core/src/js/integrations/logEnricherIntegration.ts#L91

…t into enha/logs-replay-id

cursor

Bug: Replay ID Persistence Causes Log Association Errors

When the replay recorder stops, the _replayId field isn't cleared, even though the scope's replayId is. This inconsistency means the native binding's replayId getter returns a stale ID, which could cause the ReplayLogIntegration to incorrectly associate logs with a stopped replay.

packages/flutter/lib/src/native/java/sentry_native_java.dart#L58-L68

sentry-dart/packages/flutter/lib/src/native/java/sentry_native_java.dart

Lines 58 to 68 in 744d429

    
             break; 
        
           case 'ReplayRecorder.stop': 
        
             hub.configureScope((s) { 
        
               // ignore: invalid_use_of_internal_member 
        
               s.replayId = null; 
        
             }); 
        
             final future = _replayRecorder?.stop(); 
        
             _replayRecorder = null; 
        
             await future;

buenaflor · 2025-10-08T10:41:01Z

@buenaflor Checked RN. Right now they are only setting the replay_id without buffering info.

is sentry._internal.replay_is_buffering a strict requirement right now? or should we move forward without it and handle this in another PR?

denrase · 2025-10-08T12:05:55Z

@buenaflor On Android this works as expected AFAIK, on iOS we can only detect full sessions or onError sessions as soon as they are set to the scope. @stefanosiano Do you know if this would be ok as a step between? RN also only sets replay_id without buffering info, though i did not check if this is already released.

buenaflor · 2025-10-09T09:50:46Z

packages/flutter/android/src/main/kotlin/io/sentry/flutter/SentryFlutterReplayRecorder.kt

+        var scopeReplayId: String? = null
+        Sentry.configureScope { scope ->
+          scopeReplayId = scope.replayId?.toString()
+        }
        channel.invokeMethod(
          "ReplayRecorder.start",
          mapOf(
+            "scope.replayId" to scopeReplayId,
            "replayId" to integration.getReplayId().toString(),


what's the difference between the two? (replay id from scope vs replay id from integration), seems a bit confusing to me if you don't know the context around this

Add sentry.replay_id to flutter logs

234bb86

Relates to #3245

add cl entry

c365316

denrase marked this pull request as ready for review September 18, 2025 08:12

denrase requested review from buenaflor and stefanosiano as code owners September 18, 2025 08:12

denrase added 4 commits September 29, 2025 15:16

Merge branch 'main' into enha/logs-replay-id

006a60d

Add sentry._internal.replay_is_buffering attribute

f0030f0

remove in client

91562e2

remove old test

1fafd0c