From 62b6965d2ac2489b883def790ac4a08ab447a7d0 Mon Sep 17 00:00:00 2001
From: Nuno Campos <nuno@langchain.dev>
Date: Thu, 18 Jul 2024 15:28:52 -0700
Subject: [PATCH] core: In ensure_config don't copy dunder configurable keys to
 metadata (#24420)

---
 libs/core/langchain_core/runnables/config.py          | 6 +++++-
 libs/core/tests/unit_tests/runnables/test_runnable.py | 8 ++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/libs/core/langchain_core/runnables/config.py b/libs/core/langchain_core/runnables/config.py
index a0e03703762..4485237799a 100644
--- a/libs/core/langchain_core/runnables/config.py
+++ b/libs/core/langchain_core/runnables/config.py
@@ -154,7 +154,11 @@ def ensure_config(config: Optional[RunnableConfig] = None) -> RunnableConfig:
             cast(RunnableConfig, {k: v for k, v in config.items() if v is not None})
         )
     for key, value in empty.get("configurable", {}).items():
-        if isinstance(value, (str, int, float, bool)) and key not in empty["metadata"]:
+        if (
+            not key.startswith("__")
+            and isinstance(value, (str, int, float, bool))
+            and key not in empty["metadata"]
+        ):
             empty["metadata"][key] = value
     return empty
 
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable.py b/libs/core/tests/unit_tests/runnables/test_runnable.py
index 969615f9bed..162f67cdad9 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable.py
@@ -1271,7 +1271,11 @@ async def test_with_config_metadata_passthrough(mocker: MockerFixture) -> None:
 
     assert (
         fakew.with_config(tags=["a-tag"]).invoke(
-            "hello", {"configurable": {"hello": "there"}, "metadata": {"bye": "now"}}
+            "hello",
+            {
+                "configurable": {"hello": "there", "__secret_key": "nahnah"},
+                "metadata": {"bye": "now"},
+            },
         )
         == 5
     )
@@ -1281,7 +1285,7 @@ async def test_with_config_metadata_passthrough(mocker: MockerFixture) -> None:
             tags=["a-tag"],
             callbacks=None,
             recursion_limit=25,
-            configurable={"hello": "there"},
+            configurable={"hello": "there", "__secret_key": "nahnah"},
             metadata={"hello": "there", "bye": "now"},
         ),
     )