fix(anchor): harden normalizer payload shaping

static/assistant_turn_anchors.js

@@ -143,6 +143,8 @@
     if(Array.isArray(value)){
       return value.map((item)=>_sanitizePayload(item,depth+1)).filter((item)=>item!==undefined);
     }
+    const proto=Object.getPrototypeOf(value);
+    if(proto!==null&&Object.prototype.toString.call(value)!=='[object Object]') return '[Object]';
     const out={};
     Object.keys(value).sort().forEach((key)=>{
       const safe=_sanitizePayload(value[key],depth+1);
@@ -190,6 +192,7 @@
       'source_event_type',
       'sourceType',
       'source_type',
+      'event_type',
       'type',
       'event',
       'event_id',
@@ -266,7 +269,17 @@
   function normalizeAssistantTurnAnchorSourceEvent(input, context){
     const event=(input&&typeof input==='object')?input:{};
     const ctx=(context&&typeof context==='object')?context:{};
-    const payload=_sanitizePayload(_sourceEventPayload(event))||{};
+    const sanitizedPayload=_sanitizePayload(_sourceEventPayload(event));
+    const rawPayload=(sanitizedPayload&&typeof sanitizedPayload==='object'&&!Array.isArray(sanitizedPayload))?sanitizedPayload:{};
+    const {
+      session_id:_payloadSessionId,
+      turn_id:_payloadTurnId,
+      run_id:_payloadRunId,
+      stream_id:_payloadStreamId,
+      event_id:_payloadEventId,
+      seq:_payloadSeq,
+      ...payload
+    }=rawPayload;
     const sourceType=_sourceEventType(event,payload);
     const meta=classifyAssistantTurnAnchorSourceEvent(sourceType);
     const classification=meta.classification;
@@ -278,17 +291,17 @@
         dedupe_key:'',
       });
     }
-    const eventId=_cleanString(event.event_id||event.lastEventId||event.last_event_id||payload.event_id);
+    const eventId=_cleanString(event.event_id||event.lastEventId||event.last_event_id||rawPayload.event_id);
     const seq=_coerceSeq(
       event.seq!==undefined?event.seq:
-        payload.seq!==undefined?payload.seq:
+        rawPayload.seq!==undefined?rawPayload.seq:
           ctx.seq!==undefined?ctx.seq:
             _eventIdSeq(eventId)
     );
-    const runId=_cleanString(event.run_id||payload.run_id||ctx.run_id)||_eventIdRunId(eventId)||null;
-    const sessionId=_cleanString(event.session_id||payload.session_id||ctx.session_id);
-    const turnId=_cleanString(event.turn_id||payload.turn_id||ctx.turn_id);
-    const streamId=_cleanString(event.stream_id||payload.stream_id||ctx.stream_id)||null;
+    const runId=_cleanString(event.run_id||rawPayload.run_id||ctx.run_id)||_eventIdRunId(eventId)||null;
+    const sessionId=_cleanString(event.session_id||rawPayload.session_id||ctx.session_id);
+    const turnId=_cleanString(event.turn_id||rawPayload.turn_id||ctx.turn_id);
+    const streamId=_cleanString(event.stream_id||rawPayload.stream_id||ctx.stream_id)||null;
     const localId=_localIdForSourceEvent(sourceType, {...ctx,seq}, payload);
     const anchorEvent={
       event_id:eventId||null,

tests/test_stable_assistant_turn_anchor_normalizer.py

@@ -89,6 +89,30 @@ const directParsedPayload = api.normalizeAssistantTurnAnchorSourceEvent({{
   event_id:'run-1:14',
   seq:14,
 }}, context);
+const eventTypePayload = api.normalizeAssistantTurnAnchorSourceEvent({{
+  event_type:'tool',
+  event_id:'run-1:15',
+  tool_call_id:'tool-1',
+  someField:'x',
+}}, context);
+const nonPlainPayload = api.normalizeAssistantTurnAnchorSourceEvent({{
+  type:'token',
+  payload:{{text:'date payload', meta:new Date('2026-06-11T00:00:00Z')}},
+  event_id:'run-1:16',
+}}, context);
+const promotedIdentityPayload = api.normalizeAssistantTurnAnchorSourceEvent({{
+  type:'token',
+  payload:{{
+    text:'identity fields should be promoted only',
+    session_id:'payload-session',
+    turn_id:'payload-turn',
+    run_id:'payload-run',
+    stream_id:'payload-stream',
+    event_id:'payload-event',
+    seq:99,
+  }},
+  event_id:'run-1:17',
+}}, context);
 console.log(JSON.stringify({{
   version: api.version,
   liveToken,
@@ -101,6 +125,9 @@ console.log(JSON.stringify({{
   deduped,
   invalidPayload,
   directParsedPayload,
+  eventTypePayload,
+  nonPlainPayload,
+  promotedIdentityPayload,
 }}));
 """
     result = subprocess.run([NODE, "-e", script], text=True, capture_output=True, check=False)
@@ -124,7 +151,7 @@ def test_normalizer_maps_live_and_replay_to_same_anchor_event_identity():
     assert live["anchor_event"]["run_id"] == "run-1"
     assert live["anchor_event"]["stream_id"] == "stream-1"
     assert live["anchor_event"]["seq"] == 7
-    assert live["anchor_event"]["payload"] == {"session_id": "sid-1", "text": "hello"}
+    assert live["anchor_event"]["payload"] == {"text": "hello"}
 
 
 def test_normalizer_keeps_artifact_side_effect_metadata_and_transport_distinct():
@@ -168,6 +195,37 @@ def test_normalizer_excludes_unknown_sources_and_sanitizes_non_json_data():
     assert data["directParsedPayload"]["anchor_event"]["seq"] == 14
 
 
+def test_normalizer_strips_discriminators_and_promoted_identity_fields_from_payload():
+    data = _normalizer_snapshot()
+
+    event_type_payload = data["eventTypePayload"]
+    assert event_type_payload["anchor_event"]["source_event_type"] == "tool"
+    assert event_type_payload["anchor_event"]["payload"] == {
+        "someField": "x",
+        "tool_call_id": "tool-1",
+    }
+
+    promoted = data["promotedIdentityPayload"]
+    assert promoted["anchor_event"]["event_id"] == "run-1:17"
+    assert promoted["anchor_event"]["session_id"] == "payload-session"
+    assert promoted["anchor_event"]["turn_id"] == "payload-turn"
+    assert promoted["anchor_event"]["run_id"] == "payload-run"
+    assert promoted["anchor_event"]["stream_id"] == "payload-stream"
+    assert promoted["anchor_event"]["seq"] == 99
+    assert promoted["anchor_event"]["payload"] == {
+        "text": "identity fields should be promoted only"
+    }
+
+
+def test_normalizer_marks_non_plain_payload_objects_explicitly():
+    data = _normalizer_snapshot()
+
+    assert data["nonPlainPayload"]["anchor_event"]["payload"] == {
+        "meta": "[Object]",
+        "text": "date payload",
+    }
+
+
 def test_batch_normalizer_dedupes_live_plus_replay_by_event_envelope():
     data = _normalizer_snapshot()
     deduped = data["deduped"]