The open creator report ('I still cannot post a chat message in the TEST tab',
feedback 'Chat polling couldn't start — Mock Chat Input is disabled') was a single
cause: the liveChatId never resolved. Two YouTube API facts:
1. The id lives in snippet.liveChatId — contentDetails has no such property
(TASK 44 read part=contentDetails: could never resolve).
https://developers.google.com/youtube/v3/live/docs/liveBroadcasts
2. It only exists once the broadcast is LIVE — the official sample lists
broadcastStatus=active, and our fetch ran before the frame pump pushed RTMP
(enableAutoStart flips ready→live). A ready-state list legitimately returns
no id.
https://github.com/youtube/api-samples/blob/master/java/src/main/java/com/google/api/services/samples/youtube/cmdline/live/GetLiveChatId.java
Fix: GetBroadcastLiveChatIdAsync reads part=snippet and polls with a bounded
retry (10x/2s); PrepareAndStartLiveAsync starts the frame pump FIRST, then
resolves the id. Chat stays non-fatal. Docs ai.md/TASKS.md/HANDOFF.md +
MyMistakes recipe updated same commit. TASK 44.
Good Dog: ONE integration test (GetBroadcastLiveChatIdAsync_Polls_Snippet_...
) drives a broadcast that gains its id mid-retry and asserts every request used
part=snippet. Gate: clean build 0 warnings, vstest 318/318.
startup.log 2026-09-22 (user runs of the new build): ALL THREE session stops
logged 'Broadcast transition(complete) failed (403) invalidTransition → End
close-out: enableAutoStop will finish'. The old ai.md assumption ('invalidTransition
when autoStop already fired') was wrong — the blind complete POST races
YouTube/autoStop marking the broadcast complete (enableAutoStop=true is always
set, tests included), so a blind POST earned only the 403 + log noise. Per the
transition errors table, invalidTransition is a current-status problem and
complete is not gated on streamStatus (only testing/live are):
https://developers.google.com/youtube/v3/live/docs/liveBroadcasts/transition
Fix: EndBroadcastAsync pre-flights liveBroadcasts.list -> status.lifeCycleStatus
and skips the POST when the broadcast is already complete/revoked; an inconclusive
pre-check still posts (old behavior) rather than silently stranding a live
broadcast; still never throws (enableAutoStop finishes every skip).
Good Dog: EndBroadcast test rewritten to the one contract — live -> GET pre-check
+ POST transition (URL shape asserted); already complete -> zero transition POSTs;
inconclusive pre-check + 403 POST -> error string, never a throw. Full suite
315/315 (one-run audio/mouse timing flakes cleared), build 0 warnings.
Recipe recorded in MyMistakes.md; ai.md / Services index / TASK-9 note corrected.
startup.log 2026-09-22 (via the user's run of the new build): every session
start logged 'Stream health poll failed: The requested operation requires an
element of type String, but the target element has type Object'.
Root cause: GetStreamHealthAsync did status.healthStatus.GetString(), but the
real API nests it as status.healthStatus = {status, lastUpdateTimeSeconds,
configurationIssues[]} — an OBJECT, per the liveStreams reference
https://developers.google.com/youtube/v3/live/docs/liveStreams (checked the
docs before fixing, per derivative-work rule). Our flat-string fixture was the
wrong assumption since TASK 9; the report-by-exception health banner had been
silently dead.
Fix: read the nested healthStatus.status + nested configurationIssues[], tolerating
the legacy flat-string shape so nothing else breaks. Tests flipped to the real
object shape (the Good Dog for this change). Full suite 315/315, build 0 warnings.
Also recorded in MyMistakes.md (API-shape recipe) and ai.md/Services index. End-of-session
transition(complete) 403 invalidTransition (enableAutoStop fallback) observed on all three
2026-09-22 stops — separate racy-design issue, carried, not in this change.
Test button next to Start runs the real private-only go-live pipeline as a
session variant (IsTestStream): BeginTestStream -> extracted
StartStreamingSession(alsoRecord:false) shared with the dialog path — no Go
Live dialog, no 'last live' stamp, no recording. Gold top bar + TEST badge +
'End Test' button face; TEST drawer (third right-rail pull-out, three-way
exclusivity) auto-opens once the liveChatId resolves.
Chat tooling: Mock Chat Input sends a REAL liveChat/messages.insert
(YouTubeStreamService.InsertChatMessageAsync) that round-trips the real ~2s
poll and renders through the live overlay; simulated Subscriber/New
Member/Super Chat events inject through the poller's MessageReceived seam
(YouTubeChatService.InjectSimulatedMessage, ChatMessage.IsSimulated) — the
insert API only creates textMessageEvent, so non-text events are local-only
by design (ref: developers.google.com/youtube/v3/live/docs/liveChatMessages/insert).
Scopes youtube + youtube.force-ssl already cover insert; no re-consent.
Good Dog: ytLive.Tests/TestStreamTests.cs — coordinator protocol with fake
HTTP + real-window drawer exclusivity/gate. 0 warnings; 314/314 pass (clean
run; intermittent host abort is the pre-existing WinRT-webcam flake).
Docs ride in the same change: TASKS.md row 41, TASKS/task-41-test-stream-mode.md,
ai.md (YouTube Live API constraints), HANDOFF rewrite.
The specced 'End stream -> transition(complete)' call never existed: stopping relied
entirely on enableAutoStop (viewers sat on a frozen stream-offline for ~a minute, VOD
finalized late). Found during the 2026-09-01 recording-verification pass while the
creator asked 'if there's proper close-out info yt needs, we'll provide it?'
EndBroadcastAsync POSTs liveBroadcasts/transition?broadcastStatus=complete&id=..&part=status,
called after the pump stops (RTMP EOF first) and only when a live session had a broadcast —
record-only stops stay offline. invalidTransition/410 (autoStop already ended it) is logged
and returned as an error string, never thrown: a stop must never fail over close-out.
ONE integration test (URL shape + never-throws on 403). ai.md/TASKS.md design lines marked
SHIPPED with the map-lie note.
Ref: https://developers.google.com/youtube/v3/live/docs/liveBroadcasts/transition
- YouTubeStreamService: added GetBroadcastLiveChatIdAsync to fetch liveChatId from broadcast contentDetails
- YouTubeChatService.Poll(): parse snippet.type to handle textMessageEvent, superChatEvent, newSponsorEvent
- MainViewModel: wire _youtubeChat.Start(liveChatId) in PrepareAndStartLiveAsync after broadcast creation
- MainViewModel: wire _youtubeChat.Stop() in StopStream before encoder stop
- MainViewModel: wire _youtubeChat.Dispose() in Shutdown
- MainWindow.xaml: updated chat DataTemplate with member badge (⭐), Super Chat highlight (💰 + gold border), timestamps (HH:mm)
- MainWindow.xaml.cs: auto-scroll ChatListBox on new messages via CollectionChanged
- Chat lifecycle is non-fatal: failures log and the stream continues without on-panel chat
gramps