From ae56fd020a780bc70f5d4b8582a025903a6db0f5 Mon Sep 17 00:00:00 2001
From: Nuno Campos <nuno@langchain.dev>
Date: Mon, 5 Feb 2024 12:15:11 -0800
Subject: [PATCH] Fix condition on custom root type in runnable history
 (#17017)

<!-- Thank you for contributing to LangChain!

Please title your PR "<package>: <description>", where <package> is
whichever of langchain, community, core, experimental, etc. is being
modified.

Replace this entire comment with:
  - **Description:** a description of the change,
  - **Issue:** the issue # it fixes if applicable,
  - **Dependencies:** any dependencies required for this change,
- **Twitter handle:** we announce bigger features on Twitter. If your PR
gets announced, and you'd like a mention, we'll gladly shout you out!

Please make sure your PR is passing linting and testing before
submitting. Run `make format`, `make lint` and `make test` from the root
of the package you've modified to check this locally.

See contribution guidelines for more information on how to write/run
tests, lint, etc: https://python.langchain.com/docs/contributing/

If you're adding a new integration, please include:
1. a test for the integration, preferably unit tests that do not rely on
network access,
2. an example notebook showing its use. It lives in
`docs/docs/integrations` directory.

If no one reviews your PR within a few days, please @-mention one of
@baskaryan, @eyurtsev, @hwchase17.
 -->
---
 libs/core/langchain_core/runnables/history.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libs/core/langchain_core/runnables/history.py b/libs/core/langchain_core/runnables/history.py
index bd72e40538..f83de39cee 100644
--- a/libs/core/langchain_core/runnables/history.py
+++ b/libs/core/langchain_core/runnables/history.py
@@ -341,7 +341,9 @@ class RunnableWithMessageHistory(RunnableBindingBase):
         self, config: Optional[RunnableConfig] = None
     ) -> Type[BaseModel]:
         super_schema = super().get_input_schema(config)
-        if super_schema.__custom_root_type__ is not None:
+        if super_schema.__custom_root_type__ or not super_schema.schema().get(
+            "properties"
+        ):
             from langchain_core.messages import BaseMessage
 
             fields: Dict = {}