feat(flutter): Add experimental Session Replay for Flutter Web by lucas-zimerman · Pull Request #4059 · getsentry/sentry-dart

lucas-zimerman · 2026-10-01T23:53:44Z

📜 Description

Adds experimental Session Replay for Flutter Web, with the same widget-level masking as mobile. It's opt-in through options.replay.enableWebReplay (@experimental, off by default):

options.replay.enableWebReplay = true;
options.replay.sessionSampleRate = 1.0; // and/or onErrorSampleRate

The JS SDK's canvas recording can't mask anything: it screenshots the whole <canvas>, and blocking is all-or-nothing per element. So instead:

Flutter's ScreenshotRecorder captures a masked frame (same masking pipeline as mobile).
SentryWebReplayRecorder draws it onto a hidden "shadow" canvas (#sentry-flutter-replay-canvas) placed behind the Flutter view.
The JS SDK's replayCanvasIntegration runs with enableManualSnapshot: true and snapshots only that shadow canvas, when Dart says a frame is ready.
Flutter's real canvas is blocked via block: ['canvas:not(#sentry-flutter-replay-canvas)']. It has to be a selector because the canvas lives in flt-glass-pane's shadow DOM, where tagging elements doesn't work.

Other changes:

ReplayIntegration is registered on web and drives the recorder through setReplayConfig. On web, its send-time hook leaves error events to the JS SDK, which sends buffered error replays itself. For feedback, captureReplay() flushes the active JS replay, as the JS SDK's own feedback integration does, because the JS SDK only sends a buffered replay for errors and transactions.
WebReplayEventProcessor adds the JS replay's ID to Dart events (replayId tag and trace context). Dart events reach the JS SDK as raw envelopes, which skip the JS event processors that would add it.
The recorder skips captures while the JS replay isn't recording (an unsampled session, or one the JS SDK stopped itself on session expiry or max duration), so those users don't pay for capture and masking.
Scope sync on web: NativeScopeObserver is now registered on web, so the Dart user, tags, extras, contexts and breadcrumbs are mirrored into the JS SDK. JS-captured errors now carry the Dart scope too. The JS calls are guarded, so a JS failure can't surface in Sentry.addBreadcrumb or configureScope. The JS SDK also gets httpContextIntegration (URL, user agent and referrer on JS events).
Replay quality maps to a web capture scale (low 0.5x, medium 0.7x, high 1.0x). The shadow canvas's backing buffer is always CSS size × dpr: Sentry's player (canvasReplayerPlugin) draws each recorded canvas into a copy made on its first draw and shows that copy's backing buffer as an image, so the buffer size is what viewers see.
ScreenshotRecorder.yieldToEventLoop() is a new hook that is a no-op everywhere except web. There it yields between capture phases so a capture doesn't block the browser's main thread.
SentryFlutter.replay controls work on web: start, startBuffering, stop and flush drive the JS SDK's replay and the Flutter recorder together. A stopped replay stays stopped across config changes such as a resize. pause/resume are no-ops on web, because the JS SDK can't pause a replay.
Resize and rotation:
- Config changes no longer restart the capture scheduler on web, so the shadow canvas is resized at the capture rate, not on every frame of a window drag.
- Once the shadow canvas has been recorded, a size change replaces the element instead of resizing it. The player's copy of a canvas never picks up later size changes, which showed up as content squished to one side and leftover duplicated widgets. A new element gets a fresh copy at the new size.
Error-only replays (onErrorSampleRate) work for Dart errors. Dart events reach the JS SDK through client.sendEnvelope(), which skips the afterSendEvent hook that Replay uses to turn a buffering replay into a session, so only JS errors used to trigger it. The binding now emits afterSendEvent for the events in each envelope once it's sent.
The JS SDK's body > flutter-view click breadcrumbs are dropped from replays. They can't say what was tapped; the Dart flutter.ui.click breadcrumb does.

Builds on @buenaflor's web canvas replay work (first two commits).

Opt-in: `enableWebReplay`

Web replay only starts when options.replay.enableWebReplay is true and replay.sessionSampleRate or replay.onErrorSampleRate is above 0. The flag is marked @experimental: its API and behavior may change in a minor release. Recording also needs the CanvasKit or Skwasm renderer; with any other renderer the replay bundle isn't loaded and nothing records.

Apps that already set a replay sample rate for mobile are unaffected on web until they set the flag: no replay JS bundle is loaded and nothing records. In that case init logs a debug message saying how to enable it. Native builds are unaffected: all web replay code sits behind dart.library.js_interop conditional exports.

💡 Motivation and Context

Closes #2897

💚 How did you test it?

Sample Replay: https://sentry-sdks.sentry.io/explore/replays/0596cac52a994bdcae6eb2f2d6be33f8/?playlistEnd=2026-10-20T22%3A15%3A00&playlistStart=2026-10-13T22%3A15%3A00&project=5428562&query=&referrer=replayList

Unit tests for the recorder, the JS-free bridge interface, the click filter, capture scale, SentryWeb and WebSdkIntegration.
Browser tests against the real DOM bridge: flutter test --platform chrome test/web/ (148 passing). Full VM suite passing.
enableWebReplay on and off against the built example app in headless Chromium: with the flag on, the replay records in session mode and uploads replay_event/replay_recording; with it off (same sample rates), there's no replay ID, no shadow canvas and no replay envelopes.
End to end against the built example app (flutter build web), by intercepting the replay envelopes with Playwright and decoding them:
- Flutter's real canvas is serialized as a blocked placeholder (rr_width/rr_height, no rr_dataURL).
- The shadow canvas is recorded via canvas mutations, and decoded frames show the masked app.
- Resize and dpr=2 keep the backing buffer at CSS × dpr.
Resize and rotation against real Firefox replays (fetched through the Sentry API) and a local harness that drags the window in headless Edge and checks the recorded events: after the fixes, no canvas changes size after its first draw.
stop/start/flush against the real JS SDK in Chrome.
Error-only replays end to end: an example build with only onErrorSampleRate set and a Dart error, with Sentry requests answered locally. Before the fix the replay stayed in buffer with no upload; after it, it switches to session and uploads replay_event/replay_recording (3/3 runs).
Manual playback checked in the Sentry dashboard during development.

📝 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
Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec
No breaking changes

🔮 Next steps

Semantics DOM: flt-semantics-host / flt-text-editing-host show up in the recording. They rely only on the JS SDK's default text/input masking and aren't explicitly blocked; this needs a decision.
Frame rate: web is limited by the JS SDK's quality presets for sampling.canvas (1/2/4 fps), even for manual snapshots. It needs a deliberate setting.
Known limitation, resizing: while the window is being resized, the canvas can lag the viewport by up to the capture interval (about 1s), leaving parts of the page empty until the next capture.
Edge cases: multiple Flutter views and platform views (HtmlElementView). Cross-origin iframes can't be captured at all; that's a browser limit.
Network tab: Dart HTTP requests show up as timeline breadcrumbs but not in the replay's Network tab. That will be done in a follow-up PR.
Shadow canvas visibility: the shadow canvas sits behind the Flutter view (z-index: -1). An app with a transparent background or a custom host element could show it. Hiding it needs a browser check that rrweb still records it.
Docs.

Changelog Entry

Add experimental Session Replay support for Flutter Web with widget masking. Opt in with options.replay.enableWebReplay = true along with replay.sessionSampleRate or replay.onErrorSampleRate. Requires the CanvasKit or Skwasm renderer. SentryFlutter.replay start/stop/flush also work on web, and the Dart scope (user, tags, extras, contexts, breadcrumbs) now syncs to the JS SDK on web (#2897)

Enable an internal Flutter Web option for JS Replay canvas recording and attach the active replay ID to Dart events sent through the web transport. Co-Authored-By: GPT-5.5 <noreply@openai.com> Co-authored-by: Cursor <cursoragent@cursor.com>

Mirror Dart scope mutations into the browser JS SDK on web so native JavaScript events receive Flutter scope data. Emit replay-compatible breadcrumbs for Flutter cases that the JS replay bundle filters from its generic breadcrumb handler. Co-Authored-By: GPT-5.5 <noreply@openai.com> Co-authored-by: Cursor <cursoragent@cursor.com>

Capture masked frames with the Flutter screenshot recorder and draw them onto a shadow canvas that the JS SDK's replay canvas integration snapshots manually. Flutter's own canvas is blocked by selector, since it lives in flt-glass-pane's shadow DOM. - Register ReplayIntegration on web; the JS SDK handles error mode - Map replay quality to a web capture scale (0.5x/0.7x/1.0x) - Drop the JS SDK's flutter-view click breadcrumbs in replays - Enable web replay from the replay sample rates instead of the internal enableWebCanvasRecording flag - Add a replay playground screen to the example app Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

github-actions · 2026-10-01T23:54:00Z

Semver Impact of This PR

🟡 Minor (new features)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

Features

Add experimental Session Replay support for Flutter Web with widget masking. Opt in with options.replay.enableWebReplay = true along with replay.sessionSampleRate or replay.onErrorSampleRate. Requires the CanvasKit or Skwasm renderer. SentryFlutter.replay start/stop/flush also work on web, and the Dart scope (user, tags, extras, contexts, breadcrumbs) now syncs to the JS SDK on web (#2897) by lucas-zimerman, buenaflor and 3 others with sentry-junior in #4059

Fixes

(flutter) Use static SwiftPM binaries by philprime and lucas-zimerman in #4118

Dependencies

Deps

chore(deps): update Cocoa SDK to v9.32.0 by github-actions in #4128
chore(deps): update Native SDK to v0.17.5 by github-actions in #4127
chore(deps): update Android SDK to v8.62.0 by github-actions in #4124

Internal Changes

(flutter) Use Cocoa internal serializer by philprime, buenaflor and christophaigner in #4100
Use dark-mode-aware Sentry logo in READMEs by szokeasaurusrex with sentry-junior in #4123

_{🤖 This preview updates automatically when you update the PR.}

github-actions · 2026-10-01T23:54:01Z

🚨 Detected changes in high risk code 🚨

High-risk code has higher potential to break the SDK and may be hard to test. To prevent severe bugs, apply the rollout process for releasing such changes and be extra careful when changing and reviewing these files:

packages/flutter/lib/src/screenshot/recorder.dart

codecov · 2026-10-02T00:00:06Z

Codecov Report

❌ Patch coverage is 95.29412% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.08%. Comparing base (f8991b2) to head (13bfebd).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...lib/src/web/replay/sentry_web_replay_recorder.dart	92.68%	3 Missing ⚠️
...ckages/flutter/lib/src/native/c/sentry_native.dart	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4059      +/-   ##
==========================================
+ Coverage   88.81%   93.08%   +4.26%     
==========================================
  Files         348      118     -230     
  Lines       12631     4713    -7918     
==========================================
- Hits        11218     4387    -6831     
+ Misses       1413      326    -1087

Flag	Coverage Δ
sentry	`?`
sentry_dio	`?`
sentry_drift	`?`
sentry_file	`?`
sentry_firebase_remote_config	`100.00% <ø> (ø)`
sentry_flutter	`92.81% <95.29%> (+0.12%)`	⬆️
sentry_grpc	`?`
sentry_hive	`?`
sentry_isar	`?`
sentry_link	`?`
sentry_logging	`?`
sentry_sqflite	`?`
sentry_supabase	`97.48% <ø> (ø)`

Flags with carried forward coverage won't be shown. Click here to find out more.

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

github-actions · 2026-10-02T00:05:50Z

iOS Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1249.41 ms	1250.46 ms	1.04 ms
Size	5.91 MiB	6.35 MiB	450.72 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`5367726`	1211.00 ms	1216.73 ms	5.73 ms
`c492ba7`	1248.33 ms	1258.42 ms	10.09 ms
`7b21e8b`	1256.79 ms	1267.12 ms	10.33 ms
`827bf09`	1261.86 ms	1276.41 ms	14.55 ms
`0bea8d9`	1234.39 ms	1239.59 ms	5.20 ms
`819c1e7`	1250.59 ms	1249.08 ms	-1.51 ms
`e04b24b`	1230.22 ms	1233.90 ms	3.67 ms
`3801d52`	1267.76 ms	1266.10 ms	-1.65 ms
`af26bcd`	1243.98 ms	1243.49 ms	-0.49 ms
`98188da`	1252.31 ms	1251.41 ms	-0.90 ms

App size

Revision	Plain	With Sentry	Diff
`5367726`	5.73 MiB	6.17 MiB	455.87 KiB
`c492ba7`	5.91 MiB	6.35 MiB	449.92 KiB
`7b21e8b`	5.53 MiB	6.00 MiB	479.96 KiB
`827bf09`	7.86 MiB	9.44 MiB	1.58 MiB
`0bea8d9`	5.73 MiB	6.18 MiB	463.52 KiB
`819c1e7`	5.53 MiB	6.00 MiB	479.96 KiB
`e04b24b`	5.53 MiB	6.00 MiB	480.00 KiB
`3801d52`	5.73 MiB	6.17 MiB	455.54 KiB
`af26bcd`	5.83 MiB	6.28 MiB	460.44 KiB
`98188da`	5.83 MiB	6.28 MiB	459.62 KiB

Previous results on branch: lz/replay/web-mask

Startup times

Revision	Plain	With Sentry	Diff
`e749de6`	1253.47 ms	1263.08 ms	9.61 ms
`c5b01dc`	1247.21 ms	1251.60 ms	4.40 ms
`fd971e7`	1255.60 ms	1261.22 ms	5.62 ms
`f85c15f`	1254.51 ms	1248.76 ms	-5.76 ms
`1dd802b`	1256.45 ms	1266.90 ms	10.45 ms
`c26554e`	1241.11 ms	1250.79 ms	9.68 ms

App size

Revision	Plain	With Sentry	Diff
`e749de6`	5.91 MiB	6.35 MiB	450.57 KiB
`c5b01dc`	5.91 MiB	6.35 MiB	450.66 KiB
`fd971e7`	5.91 MiB	6.35 MiB	450.71 KiB
`f85c15f`	5.91 MiB	6.35 MiB	450.71 KiB
`1dd802b`	5.91 MiB	6.35 MiB	450.72 KiB
`c26554e`	5.91 MiB	6.35 MiB	450.57 KiB

lucas-zimerman · 2026-10-02T00:10:02Z

Will target main once #4056 is merged.
PR doesn't depend on it, but it's a nice to have change for testing.

The replay playground has its own PR (#4056). This PR now targets that branch, so the example still has the playground for testing without duplicating it here. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- Script loader: track scripts as they load and remove them if a later one fails, so close() cleans up and a retry doesn't inject duplicates - SentryWeb.close(): await the replay recorder's stop before closing the JS SDK, so an in-flight capture can't snapshot into it - setReplayConfig: mark the recorder started only after start() succeeds, so a failed start is retried on the next config Adds a createReplayCanvasBridge seam to SentryWeb for testing. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

# Conflicts: # packages/flutter/lib/src/replay/integration.dart # packages/flutter/lib/src/screen_capture/recorder.dart # packages/flutter/lib/src/sentry_flutter.dart # packages/flutter/lib/src/web/script_loader/sentry_script_loader.dart # packages/flutter/lib/src/web/sentry_js_sdk_version.dart # packages/flutter/lib/src/web/sentry_web.dart # packages/flutter/lib/src/web/web_sentry_js_binding.dart # packages/flutter/test/sentry_flutter_test.dart # packages/flutter/test/web/sentry_web_test.dart # packages/flutter/test/web/web_sentry_js_binding_test.dart

…lz/replay/web-mask

A window drag or rotation changes the replay config every frame, and each change restarted the capture scheduler, which captures on the next frame. The shadow canvas was resized at frame rate while rrweb throttled the matching snapshots, so recordings got canvas sizes out of sync with their content. While running with an unchanged frame rate, store the new config without restarting: capture() reads it on every run, so the next scheduled capture already uses the new size. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Sentry's replay player clones a canvas on its first recorded draw and keeps drawing into that clone, so later width/height changes never reach it. After a resize, smaller frames only covered the clone's top-left corner, leaving the previous frame around them (duplicated widgets) and squishing content to one side. Once the shadow canvas has been snapshotted, a size change now swaps in a new element, which the player clones fresh at the new size. Its first snapshot waits a task, until rrweb has registered the node. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

github-actions · 2026-10-14T21:36:40Z

Android Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	416.91 ms	462.62 ms	45.71 ms
Size	14.77 MiB	16.08 MiB	1.31 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`c58ce03`	469.42 ms	472.40 ms	2.98 ms
`9c9cb8e`	360.30 ms	373.57 ms	13.27 ms
`e3f3ea1`	420.16 ms	436.54 ms	16.39 ms
`e200a70`	433.06 ms	437.00 ms	3.94 ms
`d8f332d`	365.31 ms	349.98 ms	-15.33 ms
`9993fa9`	389.44 ms	390.85 ms	1.41 ms
`5fc86f6`	347.73 ms	334.13 ms	-13.59 ms
`25ed82c`	363.31 ms	352.83 ms	-10.48 ms
`6b69699`	456.06 ms	557.44 ms	101.38 ms
`5a95d04`	378.92 ms	364.33 ms	-14.59 ms

App size

Revision	Plain	With Sentry	Diff
`c58ce03`	14.31 MiB	15.49 MiB	1.19 MiB
`9c9cb8e`	14.55 MiB	15.87 MiB	1.31 MiB
`e3f3ea1`	13.93 MiB	15.18 MiB	1.25 MiB
`e200a70`	13.93 MiB	15.18 MiB	1.25 MiB
`d8f332d`	14.55 MiB	15.87 MiB	1.31 MiB
`9993fa9`	14.55 MiB	15.87 MiB	1.31 MiB
`5fc86f6`	14.55 MiB	15.87 MiB	1.31 MiB
`25ed82c`	14.55 MiB	15.87 MiB	1.31 MiB
`6b69699`	6.54 MiB	7.70 MiB	1.17 MiB
`5a95d04`	13.93 MiB	15.06 MiB	1.13 MiB

Previous results on branch: lz/replay/web-mask

Startup times

Revision	Plain	With Sentry	Diff
`f85c15f`	373.65 ms	392.72 ms	19.07 ms
`c26554e`	374.06 ms	376.54 ms	2.48 ms
`1dd802b`	378.25 ms	376.87 ms	-1.38 ms
`fd971e7`	378.36 ms	391.00 ms	12.64 ms
`e749de6`	370.47 ms	369.67 ms	-0.80 ms
`c5b01dc`	388.46 ms	424.62 ms	36.16 ms

App size

Revision	Plain	With Sentry	Diff
`f85c15f`	14.77 MiB	16.08 MiB	1.31 MiB
`c26554e`	14.77 MiB	16.08 MiB	1.31 MiB
`1dd802b`	14.77 MiB	16.08 MiB	1.31 MiB
`fd971e7`	14.77 MiB	16.08 MiB	1.31 MiB
`e749de6`	14.77 MiB	16.08 MiB	1.31 MiB
`c5b01dc`	14.77 MiB	16.02 MiB	1.25 MiB

SentryFlutter.replay's start, startBuffering, stop and flush now drive the JS SDK's replay on web instead of logging "not supported", and start or stop the Flutter recorder with it. A stopped replay stays stopped across config changes (e.g. a window resize) until started again. pause/resume remain no-ops: the JS SDK can't pause a replay. The real-binding tests clear the JS SDK's stored replay session first; a session left by another test on the same origin resumed in `session` mode, so stop() hung uploading to the fake DSN. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Tap breadcrumbs carry the widget's label and the labels in its touch path when sendDefaultPii is on. The replay copy kept them, so text the replay video masks showed up in the replay timeline. Strip them from the replay breadcrumb only; the event breadcrumb is unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assert the production script lists in release mode, with and without replay; always picking the debug lists used to pass. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Dart events reach the JS SDK through client.sendEnvelope(), which skips the afterSendEvent hook that client.sendEvent() runs. Replay switches a buffering replay to a session from that hook, so with onErrorSampleRate a Dart error never uploaded the buffered replay; only JS errors did. Pass the events and transactions in each envelope to the binding, which emits afterSendEvent for them once the envelope is sent. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- Catch errors from the deferred snapshot of a replaced replay canvas; it runs outside the recorder's error handling. - close() closes the JS SDK even if stopping the recorder fails. - stopReplay() during an in-flight recorder start now stops the recorder once the start completes, instead of leaving it capturing. Tests: wrap the canvas bridge tests in one subject group, match JS integration names exactly, and close the SDK after replay-enabled mock tests so their schedulers stop. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- The cadence test measures from a rendered frame to the next capture instead of waiting a fixed 50ms, so a slow capture can't hide a scheduler restart. - Pin the replay block selector as a literal, not the production constant. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

If stopping the replay recorder threw, stopReplay() skipped stopping the JS replay and left the recorder marked as started, so a later startReplay() never restarted it. Always stop the JS replay, and mark the recorder stopped before stopping it. Also folds the replay controls test group into its parent to keep test nesting within three levels. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lucas-zimerman · 2026-10-15T22:37:46Z

Will link to captured replays tomorrow.

cursor

Stale Bugbot comment from a previous run.

Replay start, stop, flush, config changes and close now run one at a time in call order, replacing the flags that tracked their interleavings. Document the JS SDK behavior the web replay relies on, and model buffer mode in the event processor test fake. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

cursor

Stale Bugbot comment from a previous run.

buenaflor

Pls check and resolve the AI reviews first

- Always stop the web replay recorder on close, so a failed start doesn't leave the shadow canvas in the DOM. - Add ReplayTelemetryIntegration on web and check replay support when it runs: the replay sample rates are set after the default integrations are created. - Read back the captured image before yielding to the event loop. - Pin a supported renderer in the replay script loading tests. Co-Authored-By: Lucas Zimerman Fraulob <lzfstudio+sentry@hotmail.com>

cursor

Stale Bugbot comment from a previous run.

Nothing puts the JS replay's ID on the Dart scope, so ReplayTelemetryIntegration marked every web replay as buffering. Bindings can now report whether the replay is buffering; web asks the JS Replay for its recording mode, as the JS SDK does for sentry._internal.replay_is_buffering. Native bindings return null and keep inferring it from the scope.

Replace the microtask spin loops waiting for bridgeStart with a Completer on the fake bridge, bounded by a timeout, so a start that never runs fails the test instead of hanging it.

A rejected client.sendEnvelope() drops the envelope, so log it at error level with its stack trace instead of debug. Also tighten the web replay tests: pin the shadow canvas id as a literal and check that the block selector spares it while matching other canvases, and keep the real-binding replay tests in buffer mode so they never upload to the test DSN.

Enable replay in the attachment-only envelope test, so event collection is on and the empty-events check means something. Assert that the manual canvas integration has enableManualSnapshot set.

cursor

Stale Bugbot comment from a previous run.

Flutter Web reports inactive when a visible page loses focus. The resumed-only capture guard, meant for native GPU surface teardown, froze the replay canvas then. Let the web recorder also capture while inactive.

Rename web replay tests to plain verb phrases, split the scope payload test per method, pin the JS SDK name and replay-canvas URLs as literals, and clarify the isReplayBuffering null contract. Co-Authored-By: Lucas Zimerman Fraulob <lzfstudio+sentry@hotmail.com>

buenaflor

1st review pass, so far looks good!

- Clear the shadow canvas before drawing each frame so transparent pixels don't keep the previous frame - Pick the replay bundle from the binding's supportsReplay - Drop the unused name-based replayCanvas integration - Add a regression test feeding a real JS SDK flutter-view click through the replay click filter Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- Drop the no-replay script test, already covered by the default supportsReplay stub - Name the click filter tests with verb phrases Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

buenaflor

as discussed let's add an opt-in flag and mark it experimental

feel free to add some ideas on the naming of the flag

maybe smth like "enableWebReplay"?

lucas-zimerman · 2026-10-29T21:24:02Z

enableWebReplay goes straight to the point, can't think of a better name :D

Add the experimental `options.replay.enableWebReplay` flag, off by default. Web Session Replay now only starts when it is set alongside a replay sample rate; otherwise init logs how to enable it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

cursor

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cursor · 2026-10-29T22:12:46Z

+      if (breadcrumb.message != null) 'message': breadcrumb.message,
+      if (breadcrumb.category != null) 'category': breadcrumb.category,
+      if (breadcrumb.data?.isNotEmpty ?? false)
+        'data': normalizeMap(breadcrumb.data),


Replay path labels survive normalization

Medium Severity

normalize stringifies each tap-path node because production _getTouchPath returns List<Map<String, String?>>, and Map is invariant, so those nodes are not Map<String, dynamic>. _withoutLabels then never sees maps and cannot drop label. Replay click breadcrumbs keep widget text that this path was written to exclude.

Additional Locations (1)

packages/flutter/lib/src/web/sentry_web.dart#L608-L621

^{Triggered by project rule: PR Review Guidelines for Cursor Bot (Root)}

^{Reviewed by Cursor Bugbot for commit 13bfebd. Configure here.}

buenaflor and others added 3 commits October 1, 2026 20:40

feat(flutter): Add web canvas replay

b91c9d8

Enable an internal Flutter Web option for JS Replay canvas recording and attach the active replay ID to Dart events sent through the web transport. Co-Authored-By: GPT-5.5 <noreply@openai.com> Co-authored-by: Cursor <cursoragent@cursor.com>

sentry-warden Bot reviewed Oct 2, 2026

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Comment thread packages/flutter/lib/src/web/script_loader/sentry_script_loader.dart Outdated

Comment thread packages/flutter/lib/src/web/sentry_web.dart

Comment thread packages/flutter/lib/src/web/sentry_web.dart Outdated

chore(example): Drop playground, now in #4056

c5b01dc

The replay playground has its own PR (#4056). This PR now targets that branch, so the example still has the playground for testing without duplicating it here. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lucas-zimerman changed the base branch from main to lz/replay-playground October 2, 2026 00:21

sentry-warden Bot reviewed Oct 2, 2026

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Comment thread packages/flutter/lib/src/web/replay/web_replay_event_processor.dart

Comment thread packages/flutter/lib/src/web/sentry_web.dart

Comment thread packages/flutter/test/web/web_sdk_integration_test.dart Outdated

lucas-zimerman and others added 2 commits October 1, 2026 21:58

Base automatically changed from lz/replay-playground to main October 13, 2026 21:05

lucas-zimerman and others added 3 commits October 13, 2026 22:07

Merge branch 'main' of https://github.com/getsentry/sentry-dart into …

84903b2

…lz/replay/web-mask

lucas-zimerman and others added 5 commits October 14, 2026 22:39

Merge branch 'main' into lz/replay/web-mask

f85c15f

test(flutter): Cover release web script selection

fd971e7

Assert the production script lists in release mode, with and without replay; always picking the debug lists used to pass. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

sentry-warden Bot reviewed Oct 14, 2026

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lucas-zimerman and others added 2 commits October 14, 2026 23:39

sentry-warden Bot reviewed Oct 14, 2026

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lucas-zimerman and others added 2 commits October 15, 2026 19:21

Merge remote-tracking branch 'origin/main' into lz/replay/web-mask

62b8a16

cursor Bot reviewed Oct 15, 2026

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Comment thread packages/flutter/lib/src/web/sentry_web.dart

Merge branch 'main' into lz/replay/web-mask

93291ee

sentry-warden Bot reviewed Oct 16, 2026

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Comment thread packages/flutter/lib/src/web/sentry_web.dart Outdated

cursor Bot reviewed Oct 16, 2026

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Comment thread packages/flutter/lib/src/web/sentry_web.dart Outdated

sentry-warden Bot reviewed Oct 16, 2026

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Comment thread packages/flutter/lib/src/screen_capture/recorder.dart Outdated

Comment thread packages/flutter/test/web/web_sdk_integration_test.dart Outdated

buenaflor reviewed Oct 19, 2026

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cursor Bot reviewed Oct 19, 2026

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Comment thread packages/flutter/lib/src/replay/replay_telemetry_integration.dart

sentry-warden Bot reviewed Oct 19, 2026

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Comment thread packages/flutter/test/web/sentry_web_test.dart Outdated

test(flutter): Signal web replay bridge start

512c66d

Replace the microtask spin loops waiting for bridgeStart with a Completer on the fake bridge, bounded by a timeout, so a start that never runs fails the test instead of hanging it.

sentry-warden Bot reviewed Oct 19, 2026

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Comment thread packages/flutter/lib/src/web/web_sentry_js_binding.dart Outdated

Comment thread packages/flutter/test/web/replay/real_web_replay_canvas_bridge_test.dart Outdated

Comment thread packages/flutter/test/web/sentry_web_test.dart Outdated

sentry-warden Bot reviewed Oct 19, 2026

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Comment thread packages/flutter/test/web/sentry_web_test.dart

Comment thread packages/flutter/test/web/web_sentry_js_binding_test.dart

sentry-junior Bot and others added 2 commits October 19, 2026 20:20

test(flutter): Tighten web replay envelope tests

d98e7ee

Enable replay in the attachment-only envelope test, so event collection is on and the empty-events check means something. Assert that the manual canvas integration has enableManualSnapshot set.

Merge branch 'main' into lz/replay/web-mask

21d503c

cursor Bot reviewed Oct 19, 2026

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Comment thread packages/flutter/lib/src/replay/scheduled_recorder.dart

sentry-junior Bot and others added 2 commits October 19, 2026 21:10

fix(flutter): Capture web replay while unfocused

27530fa

Flutter Web reports inactive when a visible page loses focus. The resumed-only capture guard, meant for native GPU surface teardown, froze the replay canvas then. Let the web recorder also capture while inactive.

buenaflor reviewed Oct 23, 2026

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lucas-zimerman and others added 2 commits October 27, 2026 10:18

test(flutter): Address Warden review findings

7011dce

- Drop the no-replay script test, already covered by the default supportsReplay stub - Name the click filter tests with verb phrases Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

buenaflor reviewed Oct 29, 2026

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lucas-zimerman and others added 2 commits October 29, 2026 21:53

Merge remote-tracking branch 'origin/main' into lz/replay/web-mask

73518b5

lucas-zimerman changed the title ~~feat(flutter): Add Session Replay for Flutter Web~~ feat(flutter): Add experimental Session Replay for Flutter Web Oct 29, 2026

cursor Bot reviewed Oct 29, 2026

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📜 Description

Opt-in: enableWebReplay

💡 Motivation and Context

💚 How did you test it?

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🚨 Detected changes in high risk code 🚨

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iOS Performance metrics 🚀

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lucas-zimerman commented Oct 15, 2026

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lucas-zimerman commented Oct 1, 2026 •

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Opt-in: `enableWebReplay`

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