[Android] snapshot returns 1 node on Telegram while stock uiautomator dump sees the full tree (descent stops at depth 4)

[TheVilfer]

Summary

On Telegram for Android (stock APK from telegram.org), agent-device snapshot returns a single node and the "sparse accessibility snapshot" hint, on every screen I could reach. Plain adb shell uiautomator dump captures the full view tree on the exact same screen, including TextViews with their texts and EditTexts — so the hierarchy is there and is reachable through UiAutomation; the snapshot helper just stops descending.

snapshot --raw shows the Telegram window is found, but the walk ends at a full-screen android.view.View at depth 4 with no children, while com.android.systemui in the same capture is walked down to depth 11.

This looks related to #850 (Fabric: only system window returned), but the app here is not React Native — it is Telegram's own native custom-view UI.

Environment

• agent-device: 0.20.7
• Host: macOS 26.5.2, Apple M4 Pro, Node v24.18.0
• adb: 1.0.41 (platform-tools 37.0.1), emulator 37.1.11
• Device: AVD pixel_7, system-images;android-35;google_apis;arm64-v8a, SDK 35, abi arm64-v8a, headless (-no-window), 6 GB RAM
• App: Telegram org.telegram.messenger.web, versionName 12.9.2, versionCode 69919, targetSdk 35 (universal APK from https://telegram.org/dl/android/apk)

Repro

adb install -r telegram.apk
agent-device open org.telegram.messenger.web --platform android --device <avd> --foreground

Actual — agent-device

$ agent-device snapshot -i --platform android --device agentfarm-a35
Page: org.telegram.messenger.web
App: org.telegram.messenger.web
Snapshot: 1 nodes
Hint: sparse accessibility snapshot returned 1 node; snapshot state is invalid or unavailable for this screen.

snapshot --raw — all six Telegram nodes, descent stops at depth 4:

{"index":27,"type":"android.widget.FrameLayout","bundleId":"org.telegram.messenger.web","rect":{"x":0,"y":0,"width":1080,"height":2400},"depth":0,"ref":"e28"}
{"index":28,"type":"android.widget.FrameLayout","bundleId":"org.telegram.messenger.web","depth":1,"parentIndex":27,"ref":"e29"}
{"index":29,"type":"android.widget.LinearLayout","bundleId":"org.telegram.messenger.web","depth":1,"parentIndex":27,"ref":"e30"}
{"index":30,"type":"android.widget.FrameLayout","identifier":"android:id/content","bundleId":"org.telegram.messenger.web","depth":2,"parentIndex":29,"ref":"e31"}
{"index":31,"type":"android.widget.FrameLayout","bundleId":"org.telegram.messenger.web","depth":3,"parentIndex":30,"ref":"e32"}
{"index":32,"type":"android.view.View","bundleId":"org.telegram.messenger.web","rect":{"x":0,"y":0,"width":1080,"height":2400},"hittable":true,"depth":4,"parentIndex":31,"ref":"e33"}

Expected — stock UiAutomator on the same screen

$ pkill -f agent-device            # see "Diagnostic trap" below
$ adb shell uiautomator dump /sdcard/tg.xml
$ adb shell cat /sdcard/tg.xml
... class="android.widget.ScrollView"
... class="android.widget.TextView" text="Telegram"
... class="android.widget.TextView" text="The world's fastest messaging app.
It is free and secure."
... class="android.widget.TextView" text="Start Messaging"

On the phone-number screen further in, the same dump additionally shows android.widget.EditText nodes and the "Your phone number" / "Please confirm your country code…" texts. uiautomator dump --compressed returns an equally rich tree, so this is not an important-for-accessibility filtering effect.

Ruled out

• Not app-wide / not the backend in general — stock Settings (com.android.settings) returns 13 interactive / 28 nodes, and third-party sideloaded F-Droid (org.fdroid.fdroid) returns 14 / 18 on the same AVD in the same session. Telegram is the outlier.
• Not memory — reproduced with 2 GB and 6 GB AVD RAM; MemAvailable ~4.3 GB at capture time.
• Not the renderer — reproduced with both -gpu swiftshader_indirect and -gpu host.
• Not the persistent helper session — AGENT_DEVICE_ANDROID_SNAPSHOT_HELPER_SESSION=0 with a fresh daemon gives the identical 1-node result.
• Not a settle/timing race — repeated snapshots after several seconds, and after press … --settle, are identical.
• Not compressed-hierarchy filtering — both uiautomator dump and uiautomator dump --compressed return the full tree.
• Not window scoping — --raw proves the Telegram window is captured; only the descent is truncated.

Diagnostic trap worth documenting

While a agent-device daemon is alive, adb shell uiautomator dump fails with rc=137 / Killed, and logcat shows:

E AndroidRuntime: FATAL EXCEPTION: main
E AndroidRuntime: java.lang.IllegalStateException: UiAutomationService android.accessibilityservice.IAccessibilityServiceClient$Stub$Proxy@… already registered!
	at android.app.UiAutomationConnection.registerUiTestAutomationServiceLocked(UiAutomationConnection.java:651)
	at com.android.commands.uiautomator.DumpCommand.run(DumpCommand.java:78)

Anyone cross-checking a sparse snapshot against stock UiAutomator must pkill -f agent-device first, otherwise the control experiment silently fails and looks like a device/app problem. This tripped me up for several iterations and may be worth a line in help debugging.