allow langsmith and langchain env vars (#518)

Co-authored-by: William Fu-Hinthorn <[email protected]>

python/langsmith/client.py

@@ -288,20 +288,19 @@ def _get_tracing_sampling_rate() -> float | None:
 
 
 def _get_api_key(api_key: Optional[str]) -> Optional[str]:
-    api_key = api_key if api_key is not None else os.getenv("LANGCHAIN_API_KEY")
+    api_key = api_key or os.getenv("LANGSMITH_API_KEY", os.getenv("LANGCHAIN_API_KEY"))
     if api_key is None or not api_key.strip():
         return None
     return api_key.strip().strip('"').strip("'")
 
 
-def _get_api_url(api_url: Optional[str], api_key: Optional[str]) -> str:
-    _api_url = (
-        api_url
-        if api_url is not None
-        else os.getenv(
+def _get_api_url(api_url: Optional[str]) -> str:
+    _api_url = api_url or os.getenv(
+        "LANGSMITH_ENDPOINT",
+        os.getenv(
             "LANGCHAIN_ENDPOINT",
             "https://api.smith.langchain.com",
-        )
+        ),
     )
     if not _api_url.strip():
         raise ls_utils.LangSmithUserError("LangSmith API URL cannot be empty")
@@ -413,7 +412,7 @@ def __init__(
         self.tracing_sample_rate = _get_tracing_sampling_rate()
         self._sampled_post_uuids: set[uuid.UUID] = set()
         self.api_key = _get_api_key(api_key)
-        self.api_url = _get_api_url(api_url, self.api_key)
+        self.api_url = _get_api_url(api_url)
         _validate_api_key_if_hosted(self.api_url, self.api_key)
         self.retry_config = retry_config or _default_retry_config()
         self.timeout_ms = timeout_ms or 10000

python/tests/unit_tests/test_client.py

@@ -57,13 +57,78 @@ def test__is_langchain_hosted() -> None:
 
 def test_validate_api_key_if_hosted(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.delenv("LANGCHAIN_API_KEY", raising=False)
+    monkeypatch.delenv("LANGSMITH_API_KEY", raising=False)
     with pytest.raises(ls_utils.LangSmithUserError, match="API key must be provided"):
         Client(api_url="https://api.smith.langchain.com")
     client = Client(api_url="http://localhost:1984")
     assert client.api_url == "http://localhost:1984"
     assert client.api_key is None
 
 
+def test_validate_api_url(monkeypatch: pytest.MonkeyPatch) -> None:
+    # Scenario 1: Both LANGCHAIN_ENDPOINT and LANGSMITH_ENDPOINT
+    # are set, but api_url is not
+    monkeypatch.setenv("LANGCHAIN_ENDPOINT", "https://api.smith.langchain-endpoint.com")
+    monkeypatch.setenv("LANGSMITH_ENDPOINT", "https://api.smith.langsmith-endpoint.com")
+
+    client = Client()
+    assert client.api_url == "https://api.smith.langsmith-endpoint.com"
+
+    # Scenario 2: Both LANGCHAIN_ENDPOINT and LANGSMITH_ENDPOINT
+    #  are set, and api_url is set
+    monkeypatch.setenv("LANGCHAIN_ENDPOINT", "https://api.smith.langchain-endpoint.com")
+    monkeypatch.setenv("LANGSMITH_ENDPOINT", "https://api.smith.langsmith-endpoint.com")
+
+    client = Client(api_url="https://api.smith.langchain.com", api_key="123")
+    assert client.api_url == "https://api.smith.langchain.com"
+
+    # Scenario 3: LANGCHAIN_ENDPOINT is set, but LANGSMITH_ENDPOINT is not
+    monkeypatch.setenv("LANGCHAIN_ENDPOINT", "https://api.smith.langchain-endpoint.com")
+    monkeypatch.delenv("LANGSMITH_ENDPOINT", raising=False)
+
+    client = Client()
+    assert client.api_url == "https://api.smith.langchain-endpoint.com"
+
+    # Scenario 4: LANGCHAIN_ENDPOINT is not set, but LANGSMITH_ENDPOINT is set
+    monkeypatch.delenv("LANGCHAIN_ENDPOINT", raising=False)
+    monkeypatch.setenv("LANGSMITH_ENDPOINT", "https://api.smith.langsmith-endpoint.com")
+
+    client = Client()
+    assert client.api_url == "https://api.smith.langsmith-endpoint.com"
+
+
+def test_validate_api_key(monkeypatch: pytest.MonkeyPatch) -> None:
+    # Scenario 1: Both LANGCHAIN_API_KEY and LANGSMITH_API_KEY are set,
+    #  but api_key is not
+    monkeypatch.setenv("LANGCHAIN_API_KEY", "env_langchain_api_key")
+    monkeypatch.setenv("LANGSMITH_API_KEY", "env_langsmith_api_key")
+
+    client = Client()
+    assert client.api_key == "env_langsmith_api_key"
+
+    # Scenario 2: Both LANGCHAIN_API_KEY and LANGSMITH_API_KEY are set,
+    #  and api_key is set
+    monkeypatch.setenv("LANGCHAIN_API_KEY", "env_langchain_api_key")
+    monkeypatch.setenv("LANGSMITH_API_KEY", "env_langsmith_api_key")
+
+    client = Client(api_url="https://api.smith.langchain.com", api_key="123")
+    assert client.api_key == "123"
+
+    # Scenario 3: LANGCHAIN_API_KEY is set, but LANGSMITH_API_KEY is not
+    monkeypatch.setenv("LANGCHAIN_API_KEY", "env_langchain_api_key")
+    monkeypatch.delenv("LANGSMITH_API_KEY", raising=False)
+
+    client = Client()
+    assert client.api_key == "env_langchain_api_key"
+
+    # Scenario 4: LANGCHAIN_API_KEY is not set, but LANGSMITH_API_KEY is set
+    monkeypatch.delenv("LANGCHAIN_API_KEY", raising=False)
+    monkeypatch.setenv("LANGSMITH_API_KEY", "env_langsmith_api_key")
+
+    client = Client()
+    assert client.api_key == "env_langsmith_api_key"
+
+
 def test_headers(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.delenv("LANGCHAIN_API_KEY", raising=False)
     client = Client(api_url="http://localhost:1984", api_key="123")