feat(anchor): project settled final answer through anchor

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

@@ -21,9 +21,12 @@ streaming or rendering yet.
   anchor seed excludes renderer presentation state, terminal states are exposed
   as constants with alias normalization, and replay + settlement ordering is
   pinned by tests before visible wiring begins.
-- The next independently reviewable boundary is Phase 3 settlement through the
+- Slice 4 starts RFC Phase 3 by routing settled assistant final prose through the
-  anchor owner. `S.messages`, `INFLIGHT`, stream-local state, and DOM nodes remain
+  anchor owner before `renderMessages()` renders the final assistant body.
-  projection/cache layers until that wiring lands.
+- The next independently reviewable boundary is activity/render-scene projection
+  for reasoning, tool rows, and transparent-stream/worklog metadata. `S.messages`,
+  `INFLIGHT`, stream-local state, and DOM nodes remain projection/cache layers
+  outside the settled final-prose path.
 
 ## State Layers
 
@@ -114,6 +117,25 @@ event identity, lifecycle, final answer reference, and activity events.
 until the matching field is explicitly moved. The fallback order is journal
 replay first, settled transcript second, `INFLIGHT` only for gaps.
 
+## Slice 4 Settled Final Projection
+
+`HermesAssistantTurnAnchors.projectAssistantTurnAnchorSettledMessageFinalAnswer()`
+projects one settled assistant transcript message through a local anchor
+registry. The settled transcript message reference remains the semantic
+authority (`content.final_message_ref`); `content.final_answer` is a derived
+render snapshot for the existing markdown pipeline.
+
+`renderMessages()` uses that projection only for settled assistant messages
+(`!isUser && !m._live`) and only after preserving the current content-array
+flattening behavior. It then continues through the existing inline-thinking and
+markdown rendering pipeline. If the anchor helper is unavailable or cannot
+produce a final answer, `renderMessages()` falls back to the existing message
+content path.
+
+This is intentionally narrower than render-scene ownership: live stream tokens,
+replay hydration, worklog rows, transparent-stream rows, tool cards, `INFLIGHT`,
+and DOM continuity are still not consumed by the anchor registry in this slice.
+
 ## Source Event Classification
 
 Phase 0 classifies current sources before changing render behavior:

static/assistant_turn_anchors.js

@@ -1,9 +1,9 @@
 // Stable Assistant Turn Anchors scaffold (#3926).
 //
-// This file is intentionally inert: it defines the current ownership inventory,
+// This file defines the current ownership inventory, event classifications, and
-// event classifications, and small owner helpers, but it does not register
+// small owner helpers. It does not register anchors globally. The only renderer
-// anchors globally or change any renderer. Later phases can wire these helpers into
+// wiring in this slice is settled assistant final-answer projection; live
-// send(), attachLiveStream(), replay hydration, and renderMessages().
+// streaming, replay hydration, tools, and DOM ownership remain unwired.
 (function(){
   const ROOT=(typeof window!=='undefined')?window:globalThis;
 
@@ -696,6 +696,96 @@
     });
   }
 
+  function _contextValue(context, keys){
+    return _firstOwn(context&&typeof context==='object'?context:{},keys);
+  }
+
+  function _messageValue(message, keys){
+    return _firstOwn(message&&typeof message==='object'?message:{},keys);
+  }
+
+  function _rawIndexMessageRef(context){
+    const rawIdx=_contextValue(context,['raw_idx','rawIdx']);
+    if(rawIdx===undefined||rawIdx===null||rawIdx==='') return '';
+    return 'raw_idx:'+String(rawIdx);
+  }
+
+  function projectAssistantTurnAnchorSettledMessageFinalAnswer(input, context){
+    const message=(input&&typeof input==='object')?input:{};
+    const ctx=(context&&typeof context==='object')?context:{};
+    const sessionId=_cleanString(_contextValue(ctx,['session_id','sessionId']))
+      ||_cleanString(_messageValue(message,['session_id','sessionId']));
+    if(!sessionId){
+      return Object.freeze({applied:false,reason:'missing_session',final_answer:'',final_message_ref:null,registry:null});
+    }
+    const role=_cleanString(_messageValue(message,['role']))||'assistant';
+    if(role&&role!=='assistant'){
+      return Object.freeze({applied:false,reason:'non_assistant',final_answer:'',final_message_ref:null,registry:null});
+    }
+    const runId=_cleanString(_contextValue(ctx,['run_id','runId']))
+      ||_cleanString(_messageValue(message,['run_id','runId','_run_id','runtime_run_id']));
+    const streamId=_cleanString(_contextValue(ctx,['stream_id','streamId']))
+      ||_cleanString(_messageValue(message,['stream_id','streamId','_stream_id']));
+    const messageRef=_firstTextValue(
+      _messageValue(message,['message_id','id','local_id']),
+      _contextValue(ctx,['message_id','messageId','local_id','localId'])
+    )||_rawIndexMessageRef(ctx);
+    const turnId=_cleanString(_contextValue(ctx,['turn_id','turnId']))
+      ||_cleanString(_messageValue(message,['turn_id','turnId']))
+      ||[
+        'settled',
+        sessionId,
+        runId||streamId||messageRef||'assistant',
+      ].join(':');
+    const registry=createAssistantTurnAnchorRegistry({
+      session_id:sessionId,
+      turn_id:turnId,
+      run_id:runId||null,
+      stream_id:streamId||null,
+      local_id:messageRef||null,
+      source_message_refs:messageRef?[messageRef]:[],
+    });
+    const payload={
+      role:'assistant',
+      id:messageRef||null,
+      content:_hasOwn(ctx,'content')?_own(ctx,'content'):_own(message,'content'),
+    };
+    const usage=_own(message,'usage');
+    const turnUsage=_own(message,'_turnUsage');
+    if(usage&&typeof usage==='object') payload.usage=usage;
+    if(turnUsage&&typeof turnUsage==='object') payload._turnUsage=turnUsage;
+    const result=applyAssistantTurnAnchorSourceEvent(registry,{
+      source_type:'settled_message',
+      payload,
+      local_id:messageRef||null,
+    },{
+      session_id:sessionId,
+      turn_id:turnId,
+      run_id:runId||null,
+      stream_id:streamId||null,
+    });
+    if(!result.applied){
+      return Object.freeze({
+        applied:false,
+        reason:result.reason||null,
+        final_answer:'',
+        final_message_ref:null,
+        registry,
+      });
+    }
+    const rawFinalAnswer=registry.anchor&&registry.anchor.content&&registry.anchor.content.final_answer;
+    const rawFinalMessageRef=registry.anchor&&registry.anchor.content&&registry.anchor.content.final_message_ref;
+    const finalAnswer=typeof rawFinalAnswer==='string'?rawFinalAnswer:'';
+    const finalMessageRef=typeof rawFinalMessageRef==='string'?rawFinalMessageRef:null;
+    return Object.freeze({
+      applied:!!result.applied,
+      reason:result.reason||null,
+      final_answer:finalAnswer,
+      final_message_ref:finalMessageRef,
+      registry,
+    });
+  }
+
   function createAssistantTurnAnchorSeed(input){
     const opts=(input&&typeof input==='object')?input:{};
     const sessionId=_cleanString(opts.session_id);
@@ -755,7 +845,7 @@
   }
 
   ROOT.HermesAssistantTurnAnchors=Object.freeze({
-    version:'slice3-registry-shadow',
+    version:'slice4-final-projection',
     activityEventKinds:ACTIVITY_EVENT_KINDS,
     stateLayers:STATE_LAYERS,
     sourceEventClassification:SOURCE_EVENT_CLASSIFICATION,
@@ -772,6 +862,7 @@
     applyAssistantTurnAnchorSourceEvent,
     applyAssistantTurnAnchorSourceEvents,
     createAssistantTurnAnchorShadowSnapshot,
+    projectAssistantTurnAnchorSettledMessageFinalAnswer,
     isAssistantTurnAnchorActivityKind,
   });
 })();

static/ui.js

@@ -8747,6 +8747,26 @@ function _renderMessagesWithScrollSnapshot(options){
   renderMessages({...(options||{}),preserveScroll:true});
   _restoreMessageScrollSnapshotSameFrame(scrollSnapshot);
 }
+let _assistantTurnAnchorSettledFinalAnswerWarned=false;
+function _assistantTurnAnchorSettledFinalAnswer(message, content, context){
+  try{
+    const api=(typeof window!=='undefined')?window.HermesAssistantTurnAnchors:null;
+    if(!api||typeof api.projectAssistantTurnAnchorSettledMessageFinalAnswer!=='function') return null;
+    const result=api.projectAssistantTurnAnchorSettledMessageFinalAnswer(message,{
+      session_id:context&&context.session_id,
+      raw_idx:context&&context.raw_idx,
+      content,
+    });
+    const finalAnswer=result&&typeof result.final_answer==='string'?result.final_answer:'';
+    return finalAnswer?finalAnswer:null;
+  }catch(err){
+    if(!_assistantTurnAnchorSettledFinalAnswerWarned&&typeof console!=='undefined'&&console.warn){
+      _assistantTurnAnchorSettledFinalAnswerWarned=true;
+      console.warn('assistant turn anchor settled-final projection failed',err);
+    }
+    return null;
+  }
+}
 function _scrollAfterMessageRender(preserveScroll, scrollSnapshot){
   // Terminal stream renders can happen after S.activeStreamId is cleared.
   // In that case, preserveScroll asks the normal pin-state helper to decide:
@@ -9077,6 +9097,13 @@ function renderMessages(options){
     if(Array.isArray(content)){
       content=content.filter(p=>p&&p.type==='text').map(p=>p.text||p.content||'').join('\n');
     }
+    if(m.role==='assistant'&&!m._live&&typeof content==='string'){
+      const anchorFinal=_assistantTurnAnchorSettledFinalAnswer(m, content, {
+        session_id:sid,
+        raw_idx:rawIdx,
+      });
+      if(anchorFinal!==null) content=anchorFinal;
+    }
     if(typeof content==='string'){
       if(typeof window!=='undefined'&&typeof window._extractInlineThinkingFromContentForRender==='function'){
         const split=window._extractInlineThinkingFromContentForRender(content, thinkingText);

tests/test_stable_assistant_turn_anchor_normalizer.py

@@ -182,7 +182,7 @@ def test_normalizer_maps_live_and_replay_to_same_anchor_event_identity():
     live = data["liveToken"]
     replay = data["replayToken"]
 
-    assert data["version"] == "slice3-registry-shadow"
+    assert data["version"] == "slice4-final-projection"
     assert live["classification"] == "activity"
     assert live["dedupe_key"] == 'event_id:"run-1:7"'
     assert replay["dedupe_key"] == live["dedupe_key"]

tests/test_stable_assistant_turn_anchor_phase0.py

@@ -88,8 +88,11 @@ def test_phase0_scaffold_is_loaded_before_current_rendering_modules():
     messages_pos = html.index('static/messages.js?v=__WEBUI_VERSION__')
 
     assert anchor_pos < ui_pos < sessions_pos < messages_pos
+    ui_src = _read(UI_JS)
     assert "'./static/assistant_turn_anchors.js' + VQ" in _read(SW_JS)
-    assert "HermesAssistantTurnAnchors" not in _read(UI_JS)
+    assert "projectAssistantTurnAnchorSettledMessageFinalAnswer" in ui_src
+    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)
 

tests/test_stable_assistant_turn_anchor_registry.py

@@ -112,6 +112,59 @@ console.log(JSON.stringify({{
     return json.loads(result.stdout)
 
 
+def _final_projection_snapshot() -> dict:
+    assert NODE, "node is required for assistant_turn_anchors.js registry tests"
+    script = f"""
+const fs = require('fs');
+const vm = require('vm');
+const src = fs.readFileSync({json.dumps(str(ANCHORS_JS))}, 'utf8');
+const sandbox = {{window:{{}}}};
+vm.createContext(sandbox);
+vm.runInContext(src, sandbox, {{filename:'assistant_turn_anchors.js'}});
+const api = sandbox.window.HermesAssistantTurnAnchors;
+const projected = api.projectAssistantTurnAnchorSettledMessageFinalAnswer({{
+  role:'assistant',
+  id:'message-final',
+  content:'raw content should be replaced by render-preserved content',
+  _turnUsage:{{input_tokens:8, output_tokens:13}},
+}}, {{
+  session_id:'sid-project',
+  raw_idx:7,
+  content:'line one\\nline two',
+}});
+const projectedByRawIdx = api.projectAssistantTurnAnchorSettledMessageFinalAnswer({{
+  role:'assistant',
+  content:'message without id',
+}}, {{
+  session_id:'sid-project',
+  raw_idx:11,
+  content:'raw index final',
+}});
+const missingSession = api.projectAssistantTurnAnchorSettledMessageFinalAnswer({{
+  role:'assistant',
+  id:'message-missing-session',
+  content:'final',
+}}, {{}});
+const nonAssistant = api.projectAssistantTurnAnchorSettledMessageFinalAnswer({{
+  role:'user',
+  id:'message-user',
+  content:'user text',
+}}, {{
+  session_id:'sid-project',
+}});
+console.log(JSON.stringify({{
+  version:api.version,
+  projected,
+  projectedByRawIdx,
+  missingSession,
+  nonAssistant,
+}}));
+"""
+    result = subprocess.run([NODE, "-e", script], text=True, capture_output=True, check=False)
+    assert result.returncode == 0, result.stderr
+    return json.loads(result.stdout)
+
+
 def _hardening_snapshot() -> dict:
     assert NODE, "node is required for assistant_turn_anchors.js registry tests"
     script = f"""
@@ -289,7 +342,7 @@ def test_registry_owns_one_anchor_and_dedupes_live_plus_replay_events():
     registry = data["registry"]
     anchor = registry["anchor"]
 
-    assert data["version"] == "slice3-registry-shadow"
+    assert data["version"] == "slice4-final-projection"
     assert [item["reason"] for item in data["results"][:2]] == [None, "duplicate"]
     assert registry["event_index"]["dedupe_keys"][:2] == [
         'event_id:"run-1:1"',
@@ -389,7 +442,7 @@ def test_registry_does_not_destructively_dedupe_seqless_local_tool_lifecycle():
     registry = data["toolRegistry"]
     anchor = registry["anchor"]
 
-    assert data["version"] == "slice3-registry-shadow"
+    assert data["version"] == "slice4-final-projection"
     assert data["toolResults"] == [
         {"applied": True, "reason": None},
         {"applied": True, "reason": None},
@@ -439,7 +492,7 @@ def test_shadow_snapshot_feeds_current_source_families_into_one_registry_owner()
     registry = data["registry"]
     anchor = registry["anchor"]
 
-    assert data["version"] == "slice3-registry-shadow"
+    assert data["version"] == "slice4-final-projection"
     assert data["results"]["live"] == [{"applied": True, "reason": None}]
     assert data["results"]["replay"] == [
         {"applied": False, "reason": "duplicate"},
@@ -463,6 +516,70 @@ def test_shadow_snapshot_feeds_current_source_families_into_one_registry_owner()
     assert anchor["content"]["final_answer"] == "shadow final"
 
 
+def test_final_projection_routes_settled_assistant_message_through_anchor_owner():
+    data = _final_projection_snapshot()
+    projected = data["projected"]
+    registry = projected["registry"]
+    anchor = registry["anchor"]
+
+    assert data["version"] == "slice4-final-projection"
+    assert projected["applied"] is True
+    assert projected["reason"] is None
+    assert projected["final_message_ref"] == "message-final"
+    assert projected["final_answer"] == "line one\nline two"
+    assert registry["stats"]["applied"] == 1
+    assert anchor["identity"]["session_id"] == "sid-project"
+    assert anchor["content"]["final_answer"] == "line one\nline two"
+    assert anchor["content"]["final_message_ref"] == "message-final"
+    assert anchor["usage"] == {"input_tokens": 8, "output_tokens": 13}
+    assert [event["source_event_type"] for event in anchor["metadata_events"]] == [
+        "settled_message",
+    ]
+    assert data["projectedByRawIdx"]["final_message_ref"] == "raw_idx:11"
+    assert data["projectedByRawIdx"]["registry"]["anchor"]["identity"][
+        "source_message_refs"
+    ] == ["raw_idx:11"]
+    anchor_src = _read(ANCHORS_JS)
+    assert "if(!result.applied)" in anchor_src
+
+
+def test_final_projection_is_scoped_to_settled_assistant_messages():
+    data = _final_projection_snapshot()
+
+    assert data["missingSession"] == {
+        "applied": False,
+        "reason": "missing_session",
+        "final_answer": "",
+        "final_message_ref": None,
+        "registry": None,
+    }
+    assert data["nonAssistant"] == {
+        "applied": False,
+        "reason": "non_assistant",
+        "final_answer": "",
+        "final_message_ref": None,
+        "registry": None,
+    }
+
+
+def test_render_messages_uses_anchor_projection_only_for_settled_final_prose():
+    src = _read(UI_JS)
+    start = src.index("function renderMessages")
+    end = src.index("function _toolDisplayName", start)
+    render_body = src[start:end]
+
+    flatten_idx = render_body.index("content=content.filter(p=>p&&p.type==='text')")
+    projection_idx = render_body.index("_assistantTurnAnchorSettledFinalAnswer(m, content")
+    thinking_idx = render_body.index("_extractInlineThinkingFromContentForRender(content")
+
+    assert flatten_idx < projection_idx < thinking_idx
+    assert "if(m.role==='assistant'&&!m._live&&typeof content==='string'){" in render_body
+    assert "createAssistantTurnAnchorRegistry" not in render_body
+    assert "applyAssistantTurnAnchorSourceEvent" not in render_body
+    assert "_assistantTurnAnchorSettledFinalAnswerWarned" in src
+    assert "console.warn('assistant turn anchor settled-final projection failed',err)" in src
+
+
 def test_registry_instances_do_not_share_owner_state():
     data = _registry_snapshot()
     isolated = data["isolated"]
@@ -473,7 +590,7 @@ def test_registry_instances_do_not_share_owner_state():
     assert isolated["anchor"]["activity_events"] == []
 
 
-def test_slice3_registry_is_still_unwired_from_rendering_hot_paths():
+def test_slice4_projection_does_not_wire_registry_into_rendering_hot_paths():
     helper_names = [
         "createAssistantTurnAnchorRegistry",
         "applyAssistantTurnAnchorNormalizedEvent",
@@ -485,3 +602,4 @@ def test_slice3_registry_is_still_unwired_from_rendering_hot_paths():
         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)