diff --git a/packages/jupyter-ai/jupyter_ai/config_manager.py b/packages/jupyter-ai/jupyter_ai/config_manager.py
index 608bea77f..71ca3f185 100644
--- a/packages/jupyter-ai/jupyter_ai/config_manager.py
+++ b/packages/jupyter-ai/jupyter_ai/config_manager.py
@@ -3,9 +3,9 @@
 import os
 import shutil
 import time
+from copy import deepcopy
 from typing import List, Optional, Type, Union
 
-from copy import deepcopy
 from deepmerge import always_merger as Merger
 from jsonschema import Draft202012Validator as Validator
 from jupyter_ai.models import DescribeConfigResponse, GlobalConfig, UpdateConfigRequest
diff --git a/packages/jupyter-ai/jupyter_ai/tests/test_config_manager.py b/packages/jupyter-ai/jupyter_ai/tests/test_config_manager.py
index c807cf91b..168c675f7 100644
--- a/packages/jupyter-ai/jupyter_ai/tests/test_config_manager.py
+++ b/packages/jupyter-ai/jupyter_ai/tests/test_config_manager.py
@@ -24,6 +24,7 @@ def config_path(jp_data_dir):
 def schema_path(jp_data_dir):
     return str(jp_data_dir / "config_schema.json")
 
+
 @pytest.fixture
 def config_file_with_model_fields(jp_data_dir):
     """
@@ -33,21 +34,16 @@ def config_file_with_model_fields(jp_data_dir):
     config_data = {
         "model_provider_id:": "openai-chat:gpt-4o",
         "embeddings_provider_id": None,
-        "api_keys": {
-            "openai_api_key": "foobar"
-        },
+        "api_keys": {"openai_api_key": "foobar"},
         "send_with_shift_enter": False,
-        "fields": {
-            "openai-chat:gpt-4o": {
-                "openai_api_base": "https://example.com"
-            }
-        },
+        "fields": {"openai-chat:gpt-4o": {"openai_api_base": "https://example.com"}},
     }
     config_path = jp_data_dir / "config.json"
     with open(config_path, "w") as file:
         json.dump(config_data, file)
     return str(config_path)
 
+
 @pytest.fixture
 def common_cm_kwargs(config_path, schema_path):
     """Kwargs that are commonly used when initializing the CM."""
@@ -197,6 +193,7 @@ def configure_to_openai(cm: ConfigManager):
     cm.update_config(req)
     return LM_GID, EM_GID, LM_LID, EM_LID, API_PARAMS
 
+
 def configure_with_fields(cm: ConfigManager):
     """
     Configures the ConfigManager with fields and API keys.
@@ -204,22 +201,21 @@ def configure_with_fields(cm: ConfigManager):
     """
     req = UpdateConfigRequest(
         model_provider_id="openai-chat:gpt-4o",
-        api_keys={
-            "OPENAI_API_KEY": "foobar"
-        },
+        api_keys={"OPENAI_API_KEY": "foobar"},
         fields={
             "openai-chat:gpt-4o": {
                 "openai_api_base": "https://example.com",
             }
-        }
+        },
     )
     cm.update_config(req)
     return {
         "model_id": "gpt-4o",
         "openai_api_key": "foobar",
-        "openai_api_base": "https://example.com"
+        "openai_api_base": "https://example.com",
     }
 
+
 def test_snapshot_default_config(cm: ConfigManager, snapshot):
     config_from_cm: DescribeConfigResponse = cm.get_config()
     assert config_from_cm == snapshot(exclude=lambda prop, path: prop == "last_read")
@@ -448,6 +444,7 @@ def test_handle_bad_provider_ids(cm_with_bad_provider_ids):
     assert config_desc.model_provider_id is None
     assert config_desc.embeddings_provider_id is None
 
+
 def test_config_manager_returns_fields(cm):
     """
     Asserts that `ConfigManager.lm_provider_params` returns model fields set by
@@ -456,12 +453,16 @@ def test_config_manager_returns_fields(cm):
     expected_model_args = configure_with_fields(cm)
     assert cm.lm_provider_params == expected_model_args
 
-def test_config_manager_does_not_write_to_defaults(config_file_with_model_fields, schema_path):
+
+def test_config_manager_does_not_write_to_defaults(
+    config_file_with_model_fields, schema_path
+):
     """
     Asserts that `ConfigManager` does not write to the `defaults` argument when
     the configured chat model differs from the one specified in `defaults`.
     """
     from copy import deepcopy
+
     config_path = config_file_with_model_fields
     log = logging.getLogger()
     lm_providers = get_lm_providers()
@@ -471,7 +472,7 @@ def test_config_manager_does_not_write_to_defaults(config_file_with_model_fields
         "model_provider_id": None,
         "embeddings_provider_id": None,
         "api_keys": {},
-        "fields": {}
+        "fields": {},
     }
     expected_defaults = deepcopy(defaults)