chore: Better error messages (#6681)

libs/sdk-py/langgraph_sdk/__init__.py

@@ -3,6 +3,6 @@ from langgraph_sdk.client import get_client, get_sync_client
 from langgraph_sdk.encryption import Encryption
 from langgraph_sdk.encryption.types import EncryptionContext
 
-__version__ = "0.3.2"
+__version__ = "0.3.3"
 
 __all__ = ["Auth", "Encryption", "EncryptionContext", "get_client", "get_sync_client"]

libs/sdk-py/langgraph_sdk/errors.py

@@ -38,7 +38,7 @@ class APIError(httpx.HTTPStatusError, LangGraphError):
             response = None
 
         httpx.HTTPStatusError.__init__(self, message, request=req, response=response)  # type: ignore[arg-type]
-        LangGraphError.__init__(self)
+        LangGraphError.__init__(self, message)
 
         self.request = req
         self.message = message

libs/sdk-py/tests/test_errors.py

@@ -106,3 +106,39 @@ def test_field_extraction_from_json_body() -> None:
     assert err.code == "invalid_param"
     assert err.param == "limit"
     assert err.type == "invalid_request_error"
+
+
+def test_error_message_in_str_and_args() -> None:
+    """Test that error message is accessible via str() and args."""
+    r = make_response(422, json_body={"message": "Validation failed"})
+    with pytest.raises(UnprocessableEntityError) as ei:
+        _raise_for_status_typed(r)
+    err = cast("UnprocessableEntityError", ei.value)
+    assert str(err) == "Validation failed"
+    assert err.args == ("Validation failed",)
+    assert err.message == "Validation failed"
+
+
+@pytest.mark.parametrize(
+    "status,exc_type",
+    [
+        (400, BadRequestError),
+        (401, AuthenticationError),
+        (403, PermissionDeniedError),
+        (404, NotFoundError),
+        (409, ConflictError),
+        (422, UnprocessableEntityError),
+        (429, RateLimitError),
+        (500, InternalServerError),
+    ],
+)
+def test_all_error_types_display_message(
+    status: int, exc_type: type[APIStatusError]
+) -> None:
+    """Test that all error subclasses properly display their message."""
+    r = make_response(status, json_body={"message": "test error message"})
+    with pytest.raises(exc_type) as ei:
+        _raise_for_status_typed(r)
+    err = ei.value
+    assert str(err) == "test error message"
+    assert "test error message" in err.args