Fix nested hint transcript retry stability

reme/steps/evolve/auto_memory.py

@@ -153,26 +153,38 @@ def _canonical_message_json(msg: Msg) -> str:
     return json.dumps(persisted, ensure_ascii=False, sort_keys=True, separators=(",", ":"))
 
 
+def _stabilize_content_block(raw_block: dict, path: tuple[int, ...], message_timestamp: str | None) -> dict:
+    """Stabilize defaults generated while parsing a raw content block."""
+    block = dict(raw_block)
+    if isinstance(block.get("hint"), list):
+        block["hint"] = [
+            _stabilize_content_block(child, (*path, index), message_timestamp) if isinstance(child, dict) else child
+            for index, child in enumerate(block["hint"])
+        ]
+
+    if "id" not in block:
+        canonical = json.dumps(raw_block, ensure_ascii=False, sort_keys=True, separators=(",", ":"), default=str)
+        position = str(path[0]) if len(path) == 1 else ".".join(map(str, path))
+        block["id"] = hashlib.sha256(f"{position}:{canonical}".encode("utf-8")).hexdigest()
+    if "created_at" not in block and message_timestamp:
+        block["created_at"] = message_timestamp
+    if block.get("type") == "hint" and "finished_at" not in block and message_timestamp:
+        block["finished_at"] = message_timestamp
+    return block
+
+
 def _stabilize_raw_content_ids(item: dict) -> dict:
-    """Give raw content blocks stable IDs when the caller did not supply one."""
+    """Stabilize generated IDs and timestamps in raw (including nested hint) blocks."""
     content = item.get("content")
     if not isinstance(content, list):
         return item
 
-    stable_content = []
-    changed = False
-    for index, raw_block in enumerate(content):
-        if not isinstance(raw_block, dict):
-            stable_content.append(raw_block)
-            continue
-        block = dict(raw_block)
-        if "id" not in block:
-            canonical = json.dumps(block, ensure_ascii=False, sort_keys=True, separators=(",", ":"), default=str)
-            block["id"] = hashlib.sha256(f"{index}:{canonical}".encode("utf-8")).hexdigest()
-        if "created_at" not in block and item.get("created_at"):
-            block["created_at"] = item["created_at"]
-        stable_content.append(block)
-        changed = changed or block != raw_block
+    timestamp = item.get("created_at")
+    stable_content = [
+        _stabilize_content_block(block, (index,), timestamp) if isinstance(block, dict) else block
+        for index, block in enumerate(content)
+    ]
+    changed = stable_content != content
     return {**item, "content": stable_content} if changed else item
 
 

tests/unit/test_auto_memory_session_messages.py

@@ -264,14 +264,29 @@ async def test_metadata_bool_to_int_correction_is_persisted(step, append_new):
 
 
 @pytest.mark.asyncio
-async def test_identical_raw_retry_with_generated_content_ids_does_not_rewrite(step, monkeypatch):
-    """Parsing the same raw messages twice should not create false block-ID changes."""
+@pytest.mark.parametrize(
+    "content",
+    [
+        [{"type": "text", "text": "same raw payload"}],
+        [{"type": "hint", "hint": "notification"}],
+        [
+            {
+                "type": "hint",
+                "hint": [{"type": "text", "text": "notification"}],
+                "finished_at": "2026-10-01T10:00:00",
+            },
+        ],
+    ],
+    ids=["text", "hint", "nested hint"],
+)
+async def test_identical_raw_retry_with_generated_content_defaults_does_not_rewrite(step, monkeypatch, content):
+    """Parsing identical raw messages twice should not churn generated block defaults."""
     raw = {
         "id": "m0",
-        "name": "Alice",
-        "role": "user",
+        "name": "Assistant",
+        "role": "assistant",
         "created_at": "2026-10-01T10:00:00",
-        "content": [{"type": "text", "text": "same raw payload"}],
+        "content": content,
     }
     first = step._build_messages([raw])
     await step._save_session_messages(_SESSION, first)
@@ -292,6 +307,43 @@ async def test_identical_raw_retry_with_generated_content_ids_does_not_rewrite(s
     assert step._session_path(_SESSION).read_bytes() == original
 
 
+def test_raw_hint_conversion_preserves_explicit_nested_ids_and_timestamps(step):
+    """Caller-provided IDs and timestamps remain authoritative at every hint depth."""
+    message = step._to_msg(
+        {
+            "id": "m0",
+            "name": "Alice",
+            "role": "assistant",
+            "created_at": "2026-10-01T10:00:00",
+            "content": [
+                {
+                    "type": "hint",
+                    "id": "outer-id",
+                    "created_at": "2026-10-01T10:00:01",
+                    "finished_at": "2026-10-01T10:00:02",
+                    "hint": [
+                        {
+                            "type": "text",
+                            "text": "notification",
+                            "id": "nested-id",
+                            "created_at": "2026-10-01T10:00:03",
+                        },
+                    ],
+                },
+            ],
+        },
+    )
+
+    outer = message.content[0]
+    nested = outer.hint[0]
+    assert (outer.id, outer.created_at, outer.finished_at) == (
+        "outer-id",
+        "2026-10-01T10:00:01",
+        "2026-10-01T10:00:02",
+    )
+    assert (nested.id, nested.created_at) == ("nested-id", "2026-10-01T10:00:03")
+
+
 def test_raw_message_conversion_preserves_explicit_content_block_ids(step):
     """Caller-provided block IDs remain authoritative during normalization."""
     message = step._to_msg(