diff --git a/tests/test_hooks_cli.py b/tests/test_hooks_cli.py
index 8eeffed..d6951e2 100644
--- a/tests/test_hooks_cli.py
+++ b/tests/test_hooks_cli.py
@@ -42,29 +42,43 @@ def _write_transcript(path: Path, entries: list[dict]):
 
 def test_count_human_messages_basic(tmp_path):
     transcript = tmp_path / "t.jsonl"
-    _write_transcript(transcript, [
-        {"message": {"role": "user", "content": "hello"}},
-        {"message": {"role": "assistant", "content": "hi"}},
-        {"message": {"role": "user", "content": "bye"}},
-    ])
+    _write_transcript(
+        transcript,
+        [
+            {"message": {"role": "user", "content": "hello"}},
+            {"message": {"role": "assistant", "content": "hi"}},
+            {"message": {"role": "user", "content": "bye"}},
+        ],
+    )
     assert _count_human_messages(str(transcript)) == 2
 
 
 def test_count_skips_command_messages(tmp_path):
     transcript = tmp_path / "t.jsonl"
-    _write_transcript(transcript, [
-        {"message": {"role": "user", "content": "<command-message>status</command-message>"}},
-        {"message": {"role": "user", "content": "real question"}},
-    ])
+    _write_transcript(
+        transcript,
+        [
+            {"message": {"role": "user", "content": "<command-message>status</command-message>"}},
+            {"message": {"role": "user", "content": "real question"}},
+        ],
+    )
     assert _count_human_messages(str(transcript)) == 1
 
 
 def test_count_handles_list_content(tmp_path):
     transcript = tmp_path / "t.jsonl"
-    _write_transcript(transcript, [
-        {"message": {"role": "user", "content": [{"type": "text", "text": "hello"}]}},
-        {"message": {"role": "user", "content": [{"type": "text", "text": "<command-message>x</command-message>"}]}},
-    ])
+    _write_transcript(
+        transcript,
+        [
+            {"message": {"role": "user", "content": [{"type": "text", "text": "hello"}]}},
+            {
+                "message": {
+                    "role": "user",
+                    "content": [{"type": "text", "text": "<command-message>x</command-message>"}],
+                }
+            },
+        ],
+    )
     assert _count_human_messages(str(transcript)) == 1
 
 
@@ -90,6 +104,7 @@ def test_count_malformed_json_lines(tmp_path):
 def _capture_hook_output(hook_fn, data, harness="claude-code", state_dir=None):
     """Run a hook and capture its JSON stdout output."""
     import io
+
     buf = io.StringIO()
     patches = [patch("mempalace.hooks_cli._output", side_effect=lambda d: buf.write(json.dumps(d)))]
     if state_dir:
@@ -123,10 +138,10 @@ def test_stop_hook_passthrough_when_active_string(tmp_path):
 
 def test_stop_hook_passthrough_below_interval(tmp_path):
     transcript = tmp_path / "t.jsonl"
-    _write_transcript(transcript, [
-        {"message": {"role": "user", "content": f"msg {i}"}}
-        for i in range(SAVE_INTERVAL - 1)
-    ])
+    _write_transcript(
+        transcript,
+        [{"message": {"role": "user", "content": f"msg {i}"}} for i in range(SAVE_INTERVAL - 1)],
+    )
     result = _capture_hook_output(
         hook_stop,
         {"session_id": "test", "stop_hook_active": False, "transcript_path": str(transcript)},
@@ -137,10 +152,10 @@ def test_stop_hook_passthrough_below_interval(tmp_path):
 
 def test_stop_hook_blocks_at_interval(tmp_path):
     transcript = tmp_path / "t.jsonl"
-    _write_transcript(transcript, [
-        {"message": {"role": "user", "content": f"msg {i}"}}
-        for i in range(SAVE_INTERVAL)
-    ])
+    _write_transcript(
+        transcript,
+        [{"message": {"role": "user", "content": f"msg {i}"}} for i in range(SAVE_INTERVAL)],
+    )
     result = _capture_hook_output(
         hook_stop,
         {"session_id": "test", "stop_hook_active": False, "transcript_path": str(transcript)},
@@ -152,10 +167,10 @@ def test_stop_hook_blocks_at_interval(tmp_path):
 
 def test_stop_hook_tracks_save_point(tmp_path):
     transcript = tmp_path / "t.jsonl"
-    _write_transcript(transcript, [
-        {"message": {"role": "user", "content": f"msg {i}"}}
-        for i in range(SAVE_INTERVAL)
-    ])
+    _write_transcript(
+        transcript,
+        [{"message": {"role": "user", "content": f"msg {i}"}} for i in range(SAVE_INTERVAL)],
+    )
     data = {"session_id": "test", "stop_hook_active": False, "transcript_path": str(transcript)}
 
     # First call blocks
diff --git a/tests/test_knowledge_graph.py b/tests/test_knowledge_graph.py
index 535eace..d7d9838 100644
--- a/tests/test_knowledge_graph.py
+++ b/tests/test_knowledge_graph.py
@@ -6,7 +6,6 @@ timeline, stats, and edge cases (duplicate triples, ID collisions).
 """
 
 
-
 class TestEntityOperations:
     def test_add_entity(self, kg):
         eid = kg.add_entity("Alice", entity_type="person")
@@ -125,6 +124,7 @@ class TestWALMode:
         conn.close()
         assert mode == "wal"
 
+
 class TestStats:
     def test_stats_empty(self, kg):
         stats = kg.stats()