Align tag contracts and index health behavior

reme/components/tag_index/local_tag_index.py

@@ -12,7 +12,13 @@ from ...schema import FileFrontMatter, FileNode
 class LocalTagIndex(BaseTagIndex):
     """Maintain bidirectional path/tag relationships without separate source I/O."""
 
-    reserved_tag_keys = frozenset(FileFrontMatter.model_fields)
+    reserved_tag_keys = frozenset(FileFrontMatter.model_fields) | {
+        "kind",
+        "session_id",
+        "source_conversation",
+        "source_resource",
+        "status",
+    }
 
     def __init__(
         self,
@@ -47,7 +53,7 @@ class LocalTagIndex(BaseTagIndex):
         for item in value:
             if isinstance(item, bool) or not isinstance(item, (str, int)):
                 continue
-            raw = " ".join(str(item).split())
+            raw = "_".join(str(item).split())
             if not raw or len(raw) > self.max_tag_length:
                 continue
             if not any(char.isalnum() for char in raw):
@@ -183,9 +189,9 @@ class LocalTagIndex(BaseTagIndex):
             raise ValueError("order must be one of ['asc', 'desc']")
 
         async with self._maintenance_lock:
-            items: list[TagListItem] = (
-                [(tag, len(paths)) for tag, paths in self.tag_to_paths.items()] if self.is_healthy else []
-            )
+            if not self.is_healthy:
+                raise RuntimeError("tag index is unavailable")
+            items: list[TagListItem] = [(tag, len(paths)) for tag, paths in self.tag_to_paths.items()]
 
         if order_by == "tag":
             items.sort(key=lambda item: item[0], reverse=order == "desc")

reme/config/default.yaml

@@ -207,6 +207,8 @@ jobs:
         - session_id
     steps:
       - backend: auto_memory_cc_step
+      - backend: auto_tag_step
+        max_tags_per_file: 3
 
   auto_resource:
     backend: base

reme/steps/evolve/auto_tag.py

@@ -47,7 +47,7 @@ def normalize_memory_tags(
     for item in value:
         if not isinstance(item, str):
             continue
-        tag = " ".join(item.split())
+        tag = "_".join(item.split())
         if not tag or len(tag) > max_tag_length or not any(char.isalnum() for char in tag):
             continue
         canonical = tag.casefold()
@@ -181,6 +181,11 @@ class AutoTagStep(BaseStep):
             return self.context.response
 
         tag_index = self.file_store.require_tag_index() if targets else None
+        if tag_index is not None and not tag_index.is_healthy:
+            self.context.response.success = False
+            if initial_success:
+                self.context.response.answer = "Error: tag index unavailable"
+            return self.context.response
         max_tag_length = self._index_limit(tag_index, "max_tag_length", _DEFAULT_MAX_MEMORY_TAG_LENGTH)
         index_max_tags = self._index_limit(tag_index, "max_tags_per_file", None)
         if index_max_tags is not None and self.max_tags_per_file > index_max_tags:

tests/unit/test_auto_tag.py

@@ -91,6 +91,16 @@ async def test_auto_tag_handles_noop_and_rejects_invalid_preconditions(tmp_path,
     assert not wrapper.calls
     assert note.read_bytes() == before
 
+    indexed_store.tag_index = LocalTagIndex()
+    indexed_store.tag_index.set_healthy(False)
+    response = await AutoTagStep(file_store=indexed_store, agent_wrapper=wrapper)(
+        RuntimeContext(changes=[{"change": "added", "path": "daily/2026-09-09/note.md"}]),
+    )
+    assert response.success is False
+    assert response.answer == "Error: tag index unavailable"
+    assert not wrapper.calls
+    assert note.read_bytes() == before
+
 
 @pytest.mark.asyncio
 async def test_auto_tag_filters_paths_and_continues_after_one_file_fails(tmp_path, monkeypatch):

tests/unit/test_evolve_utils.py

@@ -88,7 +88,7 @@ def test_auto_tag_normalizes_frontmatter_tags():
             "宁德时代",
             "黄金",
         ],
-    ) == ["OpenAI", "Sam Altman", "宁德时代"]
+    ) == ["OpenAI", "Sam_Altman", "宁德时代"]
     # pylint: disable=use-implicit-booleaness-not-comparison
     assert normalize_memory_tags(None) == []
     assert normalize_memory_tags("OpenAI") == []

tests/unit/test_injected_job_kwargs.py

@@ -263,6 +263,10 @@ def test_configs_define_original_jobs_without_daily_variants():
         {"backend": "auto_memory_step"},
         {"backend": "auto_tag_step", "max_tags_per_file": 3},
     ]
+    assert default["jobs"]["auto_memory_cc"]["steps"] == [
+        {"backend": "auto_memory_cc_step"},
+        {"backend": "auto_tag_step", "max_tags_per_file": 3},
+    ]
 
 
 if __name__ == "__main__":

tests/unit/test_tag_index.py

@@ -30,12 +30,12 @@ def test_tag_normalization_and_bidirectional_mutations() -> None:
     async def run() -> None:
         index = LocalTagIndex(max_tags_per_file=3)
         await index.start()
-        await index.upsert_nodes([_node("daily/a.md", ["Python", "PYTHON", "C++", ".NET", "ignored"])])
+        await index.upsert_nodes([_node("daily/a.md", ["Python Tag", "PYTHON TAG", "C++", ".NET", "ignored"])])
 
-        assert await index.tags_for_path("daily/a.md") == ["python", "c++", ".net"]
-        assert await index.paths_for_tags(["PYTHON"]) == ["daily/a.md"]
+        assert await index.tags_for_path("daily/a.md") == ["python_tag", "c++", ".net"]
+        assert await index.paths_for_tags(["PYTHON TAG"]) == ["daily/a.md"]
         assert index.tag_to_paths == {
-            "python": {"daily/a.md"},
+            "python_tag": {"daily/a.md"},
             "c++": {"daily/a.md"},
             ".net": {"daily/a.md"},
         }
@@ -99,7 +99,7 @@ def test_queries_are_not_truncated_by_per_file_tag_limit() -> None:
             "daily/a.md",
             "daily/c.md",
         ]
-        assert index.normalize_query_tags([" A ", "B", "c", "a", "too-long-tag", " "]) == ["a", "b", "c"]
+        assert index.normalize_query_tags([" A ", "B", "c c", "a", "too-long-tag", " "]) == ["a", "b", "c_c"]
 
     asyncio.run(run())
 
@@ -180,6 +180,10 @@ def test_list_tags_paginates_and_applies_default_sort_orders() -> None:
             with pytest.raises(ValueError, match=message):
                 await index.list_tags(**kwargs)
 
+        index.set_healthy(False)
+        with pytest.raises(RuntimeError, match="tag index is unavailable"):
+            await index.list_tags()
+
         store = LocalFileStore(name="test", embedding_store="", tag_index="")
         store.tag_index = LocalTagIndex()
         await store.tag_index.rebuild([_node("daily/a.md", ["ReMe"])])
@@ -229,6 +233,11 @@ def test_configured_frontmatter_key_contract() -> None:
         (123, "tag_key must be a non-empty string", False),
         ("name", "tag_key must not be a reserved frontmatter key", False),
         ("description", "tag_key must not be a reserved frontmatter key", False),
+        ("kind", "tag_key must not be a reserved frontmatter key", False),
+        ("session_id", "tag_key must not be a reserved frontmatter key", False),
+        ("source_conversation", "tag_key must not be a reserved frontmatter key", False),
+        ("source_resource", "tag_key must not be a reserved frontmatter key", False),
+        ("status", "tag_key must not be a reserved frontmatter key", False),
         ("", "tag_key must be a non-empty string", True),
         ("name", "tag_key must not be a reserved frontmatter key", True),
         ("description", "tag_key must not be a reserved frontmatter key", True),
@@ -508,3 +517,7 @@ def test_default_config_enables_tag_index_with_explicit_key() -> None:
         {"backend": "auto_memory_step"},
         {"backend": "auto_tag_step", "max_tags_per_file": 3},
     ]
+    assert config["jobs"]["auto_memory_cc"]["steps"] == [
+        {"backend": "auto_memory_cc_step"},
+        {"backend": "auto_tag_step", "max_tags_per_file": 3},
+    ]