community[patch]: Make cohere_api_key a SecretStr (langchain-ai#12188)

This PR makes `cohere_api_key` in `llms/cohere` a SecretStr, so that the
API Key is not leaked when `Cohere.cohere_api_key` is represented as a
string.

---------

Signed-off-by: Arun <arun@arun.blog>
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>

libs/community/langchain_community/llms/cohere.py

@@ -9,8 +9,8 @@
 )
 from langchain_core.language_models.llms import LLM
 from langchain_core.load.serializable import Serializable
-from langchain_core.pydantic_v1 import Extra, Field, root_validator
-from langchain_core.utils import get_from_dict_or_env
+from langchain_core.pydantic_v1 import Extra, Field, SecretStr, root_validator
+from langchain_core.utils import convert_to_secret_str, get_from_dict_or_env
 from tenacity import (
     before_sleep_log,
     retry,
@@ -73,7 +73,8 @@ class BaseCohere(Serializable):
     temperature: float = 0.75
     """A non-negative float that tunes the degree of randomness in generation."""
 
-    cohere_api_key: Optional[str] = None
+    cohere_api_key: Optional[SecretStr] = None
+    """Cohere API key. If not provided, will be read from the environment variable."""
 
     stop: Optional[List[str]] = None
 
@@ -94,13 +95,17 @@ def validate_environment(cls, values: Dict) -> Dict:
                 "Please install it with `pip install cohere`."
             )
         else:
-            cohere_api_key = get_from_dict_or_env(
-                values, "cohere_api_key", "COHERE_API_KEY"
+            values["cohere_api_key"] = convert_to_secret_str(
+                get_from_dict_or_env(values, "cohere_api_key", "COHERE_API_KEY")
             )
             client_name = values["user_agent"]
-            values["client"] = cohere.Client(cohere_api_key, client_name=client_name)
+            values["client"] = cohere.Client(
+                api_key=values["cohere_api_key"].get_secret_value(),
+                client_name=client_name,
+            )
             values["async_client"] = cohere.AsyncClient(
-                cohere_api_key, client_name=client_name
+                api_key=values["cohere_api_key"].get_secret_value(),
+                client_name=client_name,
             )
         return values
 

libs/community/tests/integration_tests/llms/test_cohere.py

@@ -2,6 +2,9 @@
 
 from pathlib import Path
 
+from langchain_core.pydantic_v1 import SecretStr
+from pytest import MonkeyPatch
+
 from langchain_community.llms.cohere import Cohere
 from langchain_community.llms.loading import load_llm
 from tests.integration_tests.llms.utils import assert_llm_equality
@@ -14,6 +17,16 @@ def test_cohere_call() -> None:
     assert isinstance(output, str)
 
 
+def test_cohere_api_key(monkeypatch: MonkeyPatch) -> None:
+    """Test that cohere api key is a secret key."""
+    # test initialization from init
+    assert isinstance(Cohere(cohere_api_key="1").cohere_api_key, SecretStr)
+
+    # test initialization from env variable
+    monkeypatch.setenv("COHERE_API_KEY", "secret-api-key")
+    assert isinstance(Cohere().cohere_api_key, SecretStr)
+
+
 def test_saving_loading_llm(tmp_path: Path) -> None:
     """Test saving/loading an Cohere LLM."""
     llm = Cohere(max_tokens=10)