Merge pull request #4115 from nesquena/stage-4108

Release MZ (v0.51.387): Stable Assistant Turn Anchors live shadow feed (inert) (#4108)

CHANGELOG.md

@@ -3,6 +3,12 @@
 
 ## [Unreleased]
 
+## [v0.51.387] — 2026-06-13 — Release MZ (Stable Assistant Turn Anchors live shadow feed, inert, #3926)
+
+### Added
+
+- **Stable Assistant Turn Anchors live shadow feed (#3926).** `attachLiveStream()` now creates a per-stream anchor registry and shadow-feeds non-token live activity boundaries into the existing `HermesAssistantTurnAnchors` owner, including aggregate reasoning, tools, control events, compression lifecycle, app errors, cancel, and a slim `done` payload. The feed is still renderer-neutral: Compact Worklog, Transparent Stream, `renderMessages()`, `S.messages`, `INFLIGHT`, and DOM continuity do not consume the live registry yet; token events and EventSource network `error` remain outside the shadow feed. Settled active assistant messages are stamped with `_anchor_stream_id` for the next reconciliation slice, and that ephemeral stamp is carried forward across session refreshes. Every feed call is wrapped in a guarded helper (`_applyToAnchor`) that no-ops if the anchor API is unavailable and swallows any error (warn-once), so a shadow-feed fault can never break the live stream. (#3926)
+
 ## [v0.51.386] — 2026-06-13 — Release MY (voice mode survives a dropped speechSynthesis onend, #3983)
 
 ### Fixed

docs/architecture/stable-assistant-turn-anchor-phase0.md

@@ -26,10 +26,14 @@ streaming or rendering yet.
 - Slice 5 starts RFC Phase 5 by projecting anchor-owned activity events into a
   renderer-neutral activity scene that Compact Worklog and Transparent Stream
   can later consume from the same ordered rows.
-- The next independently reviewable boundary is wiring one current renderer to
-  the activity scene. `S.messages`, `INFLIGHT`, stream-local state, and DOM nodes
-  remain projection/cache layers outside the settled final-prose path and the
-  inert activity-scene projection.
+- Slice 6 starts the live shadow-feed boundary: `attachLiveStream()` now creates
+  a per-stream anchor registry and feeds non-token live activity events into it
+  without changing either current renderer.
+- The next independently reviewable boundary is a dual-run reconciler that
+  compares current Compact Worklog / Transparent Stream output with the
+  anchor-owned activity scene before visible renderer replacement. `S.messages`,
+  `INFLIGHT`, stream-local state, and DOM nodes remain projection/cache layers
+  outside the settled final-prose path and the live shadow registry.
 
 ## State Layers
 
@@ -153,7 +157,44 @@ IDs, and sanitized payloads with a chronological display hint. This pins the
 shared input shape before either renderer is rewired.
 
 This slice is still inert. No current UI module consumes the activity scene.
-`renderMessages()` and the live streaming hot path are unchanged by this slice.
+`renderMessages()` and the live streaming hot path were unchanged by Slice 5.
+
+## Slice 6 Live Shadow Feed
+
+`attachLiveStream()` now creates or reuses a per-stream local registry in
+`window._liveAnchorRegistries` and feeds current live activity events through
+`HermesAssistantTurnAnchors.applyAssistantTurnAnchorSourceEvent()`. This is a
+shadow feed only: Compact Worklog, Transparent Stream, `renderMessages()`,
+`S.messages`, `INFLIGHT`, and DOM continuity do not read from the registry yet.
+
+The feed intentionally skips `token` events. Token events can arrive at high
+frequency and would turn the anchor into a per-token append log before the
+renderer reconciliation slice has proven the row model. Reasoning deltas are
+also not fed one-by-one; Slice 6 flushes one aggregate reasoning event before a
+terminal or settled-restore path. The feed captures the non-token activity
+boundaries that define the future scene: interim assistant segments, tool
+start/complete, approval, clarify, goal continuation, pending steer leftovers,
+compression lifecycle, app errors, cancel, and done.
+
+The SSE `Last-Event-ID` value is copied into the source event before applying it
+to the registry, with current event-id fallbacks preserved. Existing registries
+are reused by `stream_id` so a reconnect continues the same dedupe ring instead
+of starting a parallel owner. Completed, errored, or cancelled streams schedule
+registry cleanup after a retention window. Permanently failed network-error
+paths schedule a shorter cleanup window after recovery/restore options are
+exhausted.
+
+The `done` feed is deliberately slim: status, usage, and creation timestamp are
+copied, but the full settled session payload is not duplicated into the live
+registry. When the active settled assistant message is available, it is stamped
+with `_anchor_stream_id` so later reconciliation can associate the settled
+message with the live shadow registry. That field is treated as client-side
+ephemeral turn metadata and is carried forward across session refreshes.
+
+EventSource network `error` remains a transport/recovery signal and is not fed
+as an anchor terminal event in this slice. Runtime app errors continue through
+the existing `apperror` event path and are fed as terminal activity only when
+they match the current session.
 
 ## Source Event Classification
 

static/messages.js

@@ -1488,6 +1488,10 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
   }
   function _bailOutOfTerminalEventsFromStaleStream(source){
     if(_ownsActiveStreamOrBackground()) return false;
+    // This stale stream no longer owns the session — schedule cleanup of ITS own
+    // anchor registry (identity-guarded, so it can't clobber the newer stream's
+    // registry for the same session) before closing. (Codex leak catch.)
+    _scheduleAnchorRegistryCleanup(120000);
     _closeSource(source);
     return true;
   }
@@ -1638,6 +1642,8 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
     _smdEndParser();
     if(typeof finalizeThinkingCard==='function') finalizeThinkingCard();
     _clearOwnerInflightState();
+    _flushReasoningToAnchor();
+    _scheduleAnchorRegistryCleanup();
     _clearApprovalForOwner();
     _clearClarifyForOwner('terminal');
     if(_isActiveSession()){
@@ -1844,6 +1850,8 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       }
       if(await _restoreSettledSession(source)) return;
       if(_deferStreamErrorIfOffline()||_pageHiddenForStreamError()) return;
+      _flushReasoningToAnchor();
+      _scheduleAnchorRegistryCleanup(120000);
       _handleStreamError(source);
     })();
   }
@@ -1903,6 +1911,69 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
   const _STREAM_FADE_STAGGER_MS=16;
   const _STREAM_FADE_DONE_MAX_MS=320;
   const _STREAM_FADE_DONE_DRAIN_MAX_MS=900;
+  const _anchorApi=(typeof window!=='undefined'&&window.HermesAssistantTurnAnchors)
+    ? window.HermesAssistantTurnAnchors
+    : null;
+  const _anchorRegistryMap=(typeof window!=='undefined')
+    ? (window._liveAnchorRegistries=window._liveAnchorRegistries||new Map())
+    : null;
+  const _existingAnchorRegistry=_anchorRegistryMap?_anchorRegistryMap.get(streamId):null;
+  const _anchorRegistry=_existingAnchorRegistry||(_anchorApi&&typeof _anchorApi.createAssistantTurnAnchorRegistry==='function'
+    ? _anchorApi.createAssistantTurnAnchorRegistry({
+      session_id:activeSid,
+      stream_id:streamId,
+      run_id:null,
+    })
+    : null);
+  let _anchorShadowWarned=false;
+  let _anchorReasoningFlushed=false;
+  if(_anchorRegistryMap&&_anchorRegistry) _anchorRegistryMap.set(streamId,_anchorRegistry);
+  function _scheduleAnchorRegistryCleanup(delayMs=600000){
+    if(!_anchorRegistryMap||!_anchorRegistry) return;
+    setTimeout(()=>{
+      if(_anchorRegistryMap.get(streamId)===_anchorRegistry) _anchorRegistryMap.delete(streamId);
+    },delayMs);
+  }
+  // Backstop: schedule an identity-guarded cleanup at creation so this shadow
+  // registry self-expires no matter which teardown path the stream takes
+  // (incl. external ones like sidebar cancelSessionStream() that bypass the
+  // in-closure SSE handlers). Explicit terminal-path calls above just expire it
+  // sooner; this guarantees window._liveAnchorRegistries can't grow unbounded.
+  _scheduleAnchorRegistryCleanup(600000);
+  function _applyToAnchor(sourceEventType, rawEventData, sseEvent){
+    if(!_anchorRegistry||!_anchorApi||typeof _anchorApi.applyAssistantTurnAnchorSourceEvent!=='function') return null;
+    const raw=(rawEventData&&typeof rawEventData==='object')?rawEventData:{};
+    const eventId=(sseEvent&&sseEvent.lastEventId)||raw.event_id||raw.lastEventId||raw.last_event_id||'';
+    const sourceEvent={
+      ...raw,
+      source_event_type:sourceEventType,
+      activitySegmentSeq:_assistantSegmentSeq,
+      activityBurstId:_currentActivityBurstId,
+    };
+    if(eventId) sourceEvent.event_id=eventId;
+    try{
+      return _anchorApi.applyAssistantTurnAnchorSourceEvent(
+        _anchorRegistry,
+        sourceEvent,
+        {session_id:activeSid,stream_id:streamId}
+      );
+    }catch(err){
+      if(!_anchorShadowWarned&&typeof console!=='undefined'&&console.warn){
+        _anchorShadowWarned=true;
+        console.warn('assistant turn anchor live shadow feed failed',err);
+      }
+      return null;
+    }
+  }
+  function _flushReasoningToAnchor(){
+    if(_anchorReasoningFlushed||!reasoningText) return;
+    _anchorReasoningFlushed=true;
+    _applyToAnchor('reasoning',{
+      text:reasoningText,
+      local_id:'live-reasoning',
+      seq:_runJournalReplayAfterSeq(),
+    },null);
+  }
 
   function _mergeSettledToolCallsWithLiveMetadata(rawCalls){
     const liveCalls=Array.isArray(S.toolCalls)?S.toolCalls:[];
@@ -2802,6 +2873,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       if(!visible){
         return;
       }
+      _applyToAnchor('interim_assistant',d,e);
       liveReasoningText='';
       if(alreadyStreamed){
         if(!S.session||S.session.session_id!==activeSid){
@@ -2890,6 +2962,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       _completeAutomaticCompressionOnLiveProgress(activeSid);
       const tc=upsertLiveToolCall(d,'start');
       if(!tc) return;
+      _applyToAnchor('tool',{...d,...tc},e);
 
       if(S.session&&S.session.session_id===activeSid&&typeof scheduleRenderSessionArtifacts==='function') scheduleRenderSessionArtifacts();
       if(!S.session||S.session.session_id!==activeSid) return;
@@ -2922,6 +2995,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       const tc=upsertLiveToolCall(d,'complete');
       if(!tc) return;
       tc.is_error=!!d.is_error;
+      _applyToAnchor('tool_complete',{...d,...tc,is_error:!!d.is_error},e);
       if(typeof noteWorkspaceMutationsFromToolCall==='function') noteWorkspaceMutationsFromToolCall(tc);
       if(S.session&&S.session.session_id===activeSid&&typeof scheduleRenderSessionArtifacts==='function') scheduleRenderSessionArtifacts();
       if(!S.session||S.session.session_id!==activeSid) return;
@@ -2989,6 +3063,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
 
     source.addEventListener('approval',e=>{
       const d=JSON.parse(e.data);
+      _applyToAnchor('approval',d,e);
       showApprovalForSession(activeSid, d, 1);
       playAttentionSound(_attentionSoundKey(activeSid,'approval',1));
       sendBrowserNotification('Approval required',d.description||'Tool approval needed',{sid:activeSid});
@@ -2996,6 +3071,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
 
     source.addEventListener('clarify',e=>{
       const d=JSON.parse(e.data);
+      _applyToAnchor('clarify',d,e);
       showClarifyForSession(activeSid, d);
       playAttentionSound(_attentionSoundKey(activeSid,'clarify',1));
       sendBrowserNotification('Clarification needed',d.question||'Tool clarification needed',{sid:activeSid});
@@ -3083,6 +3159,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
         const sid=d.session_id||activeSid;
         const continuation_prompt=String(d.continuation_prompt||d.text||'').trim();
         if(!continuation_prompt||sid!==activeSid)return;
+        _applyToAnchor('goal_continue',d,e);
         const _modelState=_chatPayloadModelState();
         _pendingGoalContinuation={
           sid,
@@ -3132,6 +3209,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       _terminalStateReached=true;
       if(_persistTimer){clearTimeout(_persistTimer);_persistTimer=null;}
       const _doneData=JSON.parse(e.data);
+      const _doneEvent=e;
       const _finishDone=()=>{
         // Bug A fix: cancel any pending rAF and mark stream finalized before
         // the DOM is settled by renderMessages, so no trailing token/reasoning rAF
@@ -3154,6 +3232,13 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
           _smdEndParser();
         }
         const d=_doneData;
+        _flushReasoningToAnchor();
+        _applyToAnchor('done',{
+          status:d.status||'completed',
+          usage:d.usage||null,
+          created_at:d.created_at||null,
+        },_doneEvent);
+        _scheduleAnchorRegistryCleanup();
         const isActiveSession=_isSessionCurrentPane(activeSid);
         const isSessionViewed=_isSessionActivelyViewed(activeSid);
         const completedSession=d.session||{session_id:activeSid};
@@ -3201,6 +3286,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
           }
           // Find the last assistant message once for both reasoning persistence and timestamp
           const lastAsst=[...S.messages].reverse().find(m=>m.role==='assistant');
+          if(_anchorRegistry&&lastAsst) lastAsst._anchor_stream_id=streamId;
           // Persist reasoning trace for Worklog Thinking Cards; normal transcript
           // rendering keeps provider reasoning out of the final answer.
           if(reasoningText&&lastAsst&&!lastAsst.reasoning) lastAsst.reasoning=reasoningText;
@@ -3383,6 +3469,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
         const sid=d.session_id||activeSid;
         const txt=String(d.text||'').trim();
         if(!txt||sid!==activeSid) return;
+        _applyToAnchor('pending_steer_leftover',d,e);
         if(typeof queueSessionMessage==='function'){
           const _modelState=_chatPayloadModelState();
           queueSessionMessage(sid,{
@@ -3404,6 +3491,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       let d={};
       try{ d=JSON.parse(e.data||'{}')||{}; }catch(_){ d={}; }
       if(d.session_id&&d.session_id!==activeSid) return;
+      _applyToAnchor('compressing',d,e);
       const state={
         sessionId:activeSid,
         phase:'running',
@@ -3438,6 +3526,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       const continuationSid=d.new_session_id||d.continuation_session_id||'';
       const eventMatchesCurrent=!!(currentSid&&(eventSid===currentSid||d.new_session_id===currentSid||d.continuation_session_id===currentSid));
       if(!eventMatchesCurrent) return;
+      _applyToAnchor('compressed',d,e);
       const displaySid=currentSid;
       if(d.usage&&typeof _syncCtxIndicator==='function'){
         S.lastUsage=typeof _mergeUsageForCtxIndicator==='function'
@@ -3502,8 +3591,22 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       const eventSid=d.old_session_id||d.session_id||'';
       const continuationSid=(d.session&&d.session.session_id)||d.new_session_id||d.continuation_session_id||'';
       const eventMatchesCurrent=!!(currentSid&&(eventSid===currentSid||continuationSid===currentSid));
+      if(eventMatchesCurrent){
+        _flushReasoningToAnchor();
+        _applyToAnchor('apperror',{
+          type:d.type||'error',
+          status:d.status||d.type||'error',
+          message:d.message||'',
+          hint:d.hint||'',
+          details:d.details||'',
+          session_id:d.session_id||eventSid||activeSid,
+          old_session_id:d.old_session_id||null,
+          new_session_id:d.new_session_id||d.continuation_session_id||null,
+        },e);
+      }
       if(S.session&&eventMatchesCurrent){
         S.activeStreamId=null;
+        _scheduleAnchorRegistryCleanup();
         clearLiveToolCards();if(!assistantText)removeThinking();
         let isRecoveryControlMessage=false;
         try{
@@ -3622,6 +3725,8 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
           if(await _restoreSettledSession(source)) return;
           if(_deferStreamErrorIfOffline()) return;
           if(_deferStreamErrorIfPageHidden(source)) return;
+          _flushReasoningToAnchor();
+          _scheduleAnchorRegistryCleanup(120000);
           _handleStreamError(source);
         },1500);
         return;
@@ -3629,6 +3734,8 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       if(await _restoreSettledSession(source)) return;
       if(_deferStreamErrorIfOffline()) return;
       if(_deferStreamErrorIfPageHidden(source)) return;
+      _flushReasoningToAnchor();
+      _scheduleAnchorRegistryCleanup(120000);
       _handleStreamError(source);
     });
 
@@ -3646,6 +3753,15 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       _clearOwnerInflightState();
       _clearApprovalForOwner();
       _clearClarifyForOwner('cancelled');
+      let _cancelData={};
+      try{ _cancelData=JSON.parse(e.data||'{}')||{}; }catch(_){ _cancelData={}; }
+      _flushReasoningToAnchor();
+      _applyToAnchor('cancel',{
+        status:_cancelData.status||_cancelData.type||'cancelled',
+        message:_cancelData.message||'',
+        session_id:_cancelData.session_id||activeSid,
+      },e);
+      _scheduleAnchorRegistryCleanup();
       if(S.session&&S.session.session_id===activeSid){
         S.activeStreamId=null;
       }
@@ -3701,7 +3817,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
     }
     return `${m.role}|${ts}|${body.slice(0,160)}`;
   }
-  const _EPHEMERAL_TURN_FIELDS=['_turnUsage','_turnDuration','_turnTps','_gatewayRouting','_statusCard'];
+  const _EPHEMERAL_TURN_FIELDS=['_turnUsage','_turnDuration','_turnTps','_gatewayRouting','_statusCard','_anchor_stream_id'];
   function _carryForwardEphemeralTurnFields(prevMessages, nextMessages){
     if(!Array.isArray(prevMessages)||!Array.isArray(nextMessages)) return nextMessages;
     if(!prevMessages.length||!nextMessages.length) return nextMessages;
@@ -3746,6 +3862,8 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       _smdEndParser();
       if(typeof finalizeThinkingCard==='function') finalizeThinkingCard();
       _clearOwnerInflightState();
+      _flushReasoningToAnchor();
+      _scheduleAnchorRegistryCleanup();
       _closeSource(source);
       _clearApprovalForOwner();
       _clearClarifyForOwner('terminal');
@@ -3855,6 +3973,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
             renderMessages({preserveScroll:true});
             renderSessionList();
           }
+          _scheduleAnchorRegistryCleanup(120000);
           return;
         }
       }catch(_){}

static/sessions.js

@@ -22,7 +22,7 @@ let _loadingSessionId = null;
 // clears them on a force-reload of the active session. Consumed by
 // _ensureMessagesLoaded() when calling _carryForwardEphemeralTurnFields so
 // ephemeral fields (_turnUsage, _turnDuration, _turnTps, _gatewayRouting,
-// _statusCard) survive the wholesale replace. null when there is nothing
+// _statusCard, _anchor_stream_id) survive the wholesale replace. null when there is nothing
 // to carry forward (initial load, switch-to-different-session, etc.).
 let _pendingCarryForwardSnapshot = null;
 
@@ -900,7 +900,7 @@ async function loadSession(sid){
     // poll triggering a refresh), snapshot the existing messages BEFORE we
     // clear them. _ensureMessagesLoaded() runs the ephemeral-field
     // carry-forward (_turnUsage, _turnDuration, _turnTps, _gatewayRouting,
-    // _statusCard) against S.messages, but by the time the API fetch returns
+    // _statusCard, _anchor_stream_id) against S.messages, but by the time the API fetch returns
     // S.messages has already been reset to [] here and the carry-forward is a
     // no-op. The visible symptom is the token-usage badge vanishing ~10s
     // after each assistant turn completes. Stash the snapshot so the
@@ -1914,7 +1914,7 @@ async function _ensureMessagesLoaded(sid) {
   }
   clearLiveToolCards();
   // #3018: preserve client-side ephemeral turn fields (_turnUsage, _turnDuration,
-  // _turnTps, _gatewayRouting, _statusCard) across the loadSession replace.
+  // _turnTps, _gatewayRouting, _statusCard, _anchor_stream_id) across the loadSession replace.
   if(typeof window._carryForwardEphemeralTurnFields==='function'){
     // #3306: Prefer the pre-clear snapshot stashed by loadSession() on a
     // force-reload of the active session; S.messages was reset to [] there
@@ -2391,7 +2391,7 @@ async function _loadOlderMessages() {
     const container = $('messages');
     const prevScrollH = container ? container.scrollHeight : 0;
     // Carry forward ephemeral turn fields (_turnUsage/_turnDuration/_turnTps/
-    // _gatewayRouting/_statusCard) before the wholesale replace so the badge
+    // _gatewayRouting/_statusCard/_anchor_stream_id) before the wholesale replace so the badge
     // does not briefly appear and disappear during older-message expansion.
     if (typeof window._carryForwardEphemeralTurnFields === 'function') {
       nextMessages = window._carryForwardEphemeralTurnFields(S.messages || [], nextMessages);
@@ -2482,7 +2482,7 @@ async function _ensureAllMessagesLoaded() {
     // #3306: Same ephemeral-field carry-forward as _ensureMessagesLoaded.
     // Loading older messages also does a wholesale replace of S.messages
     // and would otherwise drop _turnUsage/_turnDuration/_turnTps/
-    // _gatewayRouting/_statusCard on the existing turns.
+    // _gatewayRouting/_statusCard/_anchor_stream_id on the existing turns.
     let _msgsToAssign = msgs;
     if (typeof window._carryForwardEphemeralTurnFields === 'function') {
       _msgsToAssign = window._carryForwardEphemeralTurnFields(S.messages || [], msgs);
@@ -3823,7 +3823,8 @@ function startGatewaySSE(){
                     if (next.length < prev) return;
                     if (prev > 0 && !_isCliImportRefreshPrefixMatch(S.messages, next)) return;
                     // Carry forward ephemeral turn fields (_turnUsage/
-                    // _turnDuration/_turnTps/_gatewayRouting/_statusCard) so
+                    // _turnDuration/_turnTps/_gatewayRouting/_statusCard/
+                    // _anchor_stream_id) so
                     // gateway-driven CLI refreshes do not drop the badge.
                     let _nextToAssign = next;
                     if (typeof window._carryForwardEphemeralTurnFields === 'function') {

tests/test_stable_assistant_turn_anchor_normalizer.py

@@ -324,15 +324,17 @@ def test_structured_fallback_dedupe_keys_do_not_collide_on_delimiters():
     assert data["localNoSeqKey"] == ""
 
 
-def test_normalizer_and_registry_helpers_are_still_unwired_from_rendering_hot_paths():
+def test_normalizer_helpers_remain_unwired_from_rendering_and_live_hot_paths():
     helper_names = [
         "normalizeAssistantTurnAnchorSourceEvent",
         "normalizeAssistantTurnAnchorSourceEvents",
-        "createAssistantTurnAnchorRegistry",
-        "applyAssistantTurnAnchorSourceEvent",
         "applyAssistantTurnAnchorSourceEvents",
     ]
     for helper in helper_names:
         assert helper not in _read(UI_JS)
         assert helper not in _read(SESSIONS_JS)
         assert helper not in _read(MESSAGES_JS)
+
+    messages_src = _read(MESSAGES_JS)
+    assert "createAssistantTurnAnchorRegistry" in messages_src
+    assert "applyAssistantTurnAnchorSourceEvent" in messages_src

tests/test_stable_assistant_turn_anchor_phase0.py

@@ -1,8 +1,7 @@
 """Phase 0 contract tests for Stable Assistant Turn Anchors (#3926).
 
-The first implementation slice is intentionally non-visual. It adds the
-inventory and pure helper surface that later phases can wire into send(),
-attachLiveStream(), replay hydration, and renderMessages().
+The first implementation slice was intentionally non-visual. Later slices keep
+the same inventory contract while adding narrow, tested wiring points.
 """
 from __future__ import annotations
 
@@ -94,7 +93,11 @@ def test_phase0_scaffold_is_loaded_before_current_rendering_modules():
     assert "createAssistantTurnAnchorRegistry" not in ui_src
     assert "applyAssistantTurnAnchorSourceEvent" not in ui_src
     assert "HermesAssistantTurnAnchors" not in _read(SESSIONS_JS)
-    assert "HermesAssistantTurnAnchors" not in _read(MESSAGES_JS)
+    messages_src = _read(MESSAGES_JS)
+    assert "window._liveAnchorRegistries" in messages_src
+    assert "createAssistantTurnAnchorRegistry" in messages_src
+    assert "applyAssistantTurnAnchorSourceEvent" in messages_src
+    assert "projectAssistantTurnAnchorActivityScene" not in messages_src
 
 
 def test_phase0_inventory_names_current_state_layers_in_authority_order():

tests/test_stable_assistant_turn_anchor_registry.py

@@ -18,6 +18,19 @@ def _read(path: Path) -> str:
     return path.read_text(encoding="utf-8")
 
 
+def _event_listener_body(src: str, event_name: str) -> str:
+    start = src.index(f"source.addEventListener('{event_name}'")
+    end = src.find("\n    source.addEventListener(", start + 1)
+    if end < 0:
+        end = src.find("\n    source.onerror", start + 1)
+    if end < 0:
+        end = src.find("\n  }catch", start + 1)
+    if end < 0:
+        end = len(src)
+    assert end > start
+    return src[start:end]
+
+
 def _registry_snapshot() -> dict:
     assert NODE, "node is required for assistant_turn_anchors.js registry tests"
     script = f"""
@@ -806,18 +819,76 @@ def test_registry_instances_do_not_share_owner_state():
     assert isolated["anchor"]["activity_events"] == []
 
 def test_slice5_scene_projection_does_not_wire_activity_scene_into_rendering_hot_paths():
-    helper_names = [
-        "createAssistantTurnAnchorRegistry",
+    scene_helper = "projectAssistantTurnAnchorActivityScene"
+    for helper in [
         "applyAssistantTurnAnchorNormalizedEvent",
-        "applyAssistantTurnAnchorSourceEvent",
         "applyAssistantTurnAnchorSourceEvents",
         "createAssistantTurnAnchorShadowSnapshot",
-    ]
-    for helper in helper_names:
+        scene_helper,
+    ]:
         assert helper not in _read(UI_JS)
         assert helper not in _read(SESSIONS_JS)
         assert helper not in _read(MESSAGES_JS)
     assert "projectAssistantTurnAnchorSettledMessageFinalAnswer" in _read(UI_JS)
-    assert "projectAssistantTurnAnchorActivityScene" not in _read(UI_JS)
-    assert "projectAssistantTurnAnchorActivityScene" not in _read(SESSIONS_JS)
-    assert "projectAssistantTurnAnchorActivityScene" not in _read(MESSAGES_JS)
+    assert scene_helper not in _read(UI_JS)
+    assert scene_helper not in _read(SESSIONS_JS)
+    assert scene_helper not in _read(MESSAGES_JS)
+
+
+def test_slice6_live_shadow_feed_wires_non_token_events_without_renderer_scene_consumption():
+    src = _read(MESSAGES_JS)
+    helper_body = src.split("function _applyToAnchor", 1)[1].split(
+        "function _mergeSettledToolCallsWithLiveMetadata", 1
+    )[0]
+
+    assert "window._liveAnchorRegistries=window._liveAnchorRegistries||new Map()" in src
+    assert "_anchorRegistryMap.get(streamId)" in src
+    assert "_anchorRegistryMap.set(streamId,_anchorRegistry)" in src
+    assert "createAssistantTurnAnchorRegistry" in src
+    assert "applyAssistantTurnAnchorSourceEvent" in src
+    assert "const eventId=(sseEvent&&sseEvent.lastEventId)||raw.event_id||raw.lastEventId||raw.last_event_id||'';" in helper_body
+    assert helper_body.index("...raw,") < helper_body.index("source_event_type:sourceEventType")
+
+    for event_name in [
+        "interim_assistant",
+        "tool",
+        "tool_complete",
+        "approval",
+        "clarify",
+        "goal_continue",
+        "pending_steer_leftover",
+        "compressing",
+        "compressed",
+        "apperror",
+        "cancel",
+    ]:
+        assert f"_applyToAnchor('{event_name}'" in _event_listener_body(src, event_name)
+
+    token_body = _event_listener_body(src, "token")
+    assert "_applyToAnchor" not in token_body
+    reasoning_body = _event_listener_body(src, "reasoning")
+    assert "_applyToAnchor" not in reasoning_body
+    assert "function _flushReasoningToAnchor()" in src
+    assert "_applyToAnchor('reasoning',{" in src
+    assert "local_id:'live-reasoning'" in src
+    error_body = _event_listener_body(src, "error")
+    assert "_applyToAnchor('error'" not in error_body
+    assert "_flushReasoningToAnchor();" in error_body
+    assert "_scheduleAnchorRegistryCleanup(120000);" in error_body
+    assert "_handleStreamError(source)" in error_body
+    assert "projectAssistantTurnAnchorActivityScene" not in src
+
+    tool_body = _event_listener_body(src, "tool")
+    assert tool_body.index("upsertLiveToolCall(d,'start')") < tool_body.index(
+        "_applyToAnchor('tool'"
+    )
+    done_body = _event_listener_body(src, "done")
+    assert "_applyToAnchor('done',{" in done_body
+    assert "usage:d.usage||null" in done_body
+    assert "created_at:d.created_at||null" in done_body
+    assert "_applyToAnchor('done',{...d" not in done_body
+    assert "_flushReasoningToAnchor();" in done_body
+    assert "_scheduleAnchorRegistryCleanup();" in done_body
+    assert "lastAsst._anchor_stream_id=streamId" in done_body
+    assert "'_anchor_stream_id'" in src
+    assert src.index("'_anchor_stream_id'") < src.index("function _carryForwardEphemeralTurnFields")