wip

libs/langchain/langchain/schema/runnable/base.py

@@ -253,7 +253,7 @@ class Runnable(Generic[Input, Output], ABC):
     ) -> Output:
         """Helper method to transform an Input value to an Output value,
         with callbacks. Use this method to implement invoke() in subclasses."""
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_callback_manager(config)
         run_manager = callback_manager.on_chain_start(
             dumpd(self),
@@ -283,7 +283,7 @@ class Runnable(Generic[Input, Output], ABC):
     ) -> Output:
         """Helper method to transform an Input value to an Output value,
         with callbacks. Use this method to implement ainvoke() in subclasses."""
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_async_callback_manager(config)
         run_manager = await callback_manager.on_chain_start(
             dumpd(self),
@@ -322,7 +322,7 @@ class Runnable(Generic[Input, Output], ABC):
         final_output: Optional[Output] = None
         final_output_supported = True
 
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_callback_manager(config)
         run_manager = callback_manager.on_chain_start(
             dumpd(self),
@@ -387,7 +387,7 @@ class Runnable(Generic[Input, Output], ABC):
         final_output: Optional[Output] = None
         final_output_supported = True
 
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_async_callback_manager(config)
         run_manager = await callback_manager.on_chain_start(
             dumpd(self),
@@ -462,7 +462,7 @@ class RunnableWithFallbacks(Serializable, Runnable[Input, Output]):
 
     def invoke(self, input: Input, config: Optional[RunnableConfig] = None) -> Output:
         # setup callbacks
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_callback_manager(config)
         # start the root run
         run_manager = callback_manager.on_chain_start(
@@ -495,7 +495,7 @@ class RunnableWithFallbacks(Serializable, Runnable[Input, Output]):
         self, input: Input, config: Optional[RunnableConfig] = None
     ) -> Output:
         # setup callbacks
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_async_callback_manager(config)
         # start the root run
         run_manager = await callback_manager.on_chain_start(
@@ -1068,7 +1068,7 @@ class RunnableMap(Serializable, Runnable[Input, Dict[str, Any]]):
         from langchain.callbacks.manager import CallbackManager
 
         # setup callbacks
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = CallbackManager.configure(
             inheritable_callbacks=config.get("callbacks"),
             local_callbacks=None,
@@ -1091,7 +1091,7 @@ class RunnableMap(Serializable, Runnable[Input, Dict[str, Any]]):
                         step.invoke,
                         input,
                         # mark each step as a child run
-                        patch_config(config, run_manager.get_child()),
+                        patch_config(deepcopy(config), run_manager.get_child()),
                     )
                     for step in steps.values()
                 ]
@@ -1108,7 +1108,7 @@ class RunnableMap(Serializable, Runnable[Input, Dict[str, Any]]):
         self, input: Input, config: Optional[RunnableConfig] = None
     ) -> Dict[str, Any]:
         # setup callbacks
-        config = config or {}
+        config = config or _empty_config()
         callback_manager = _get_async_callback_manager(config)
         # start the root run
         run_manager = await callback_manager.on_chain_start(

libs/langchain/tests/unit_tests/schema/runnable/test_locals.py

@@ -1,6 +1,13 @@
 import pytest
 
-from langchain.schema.runnable import GetLocalVar, PutLocalVar
+from langchain import PromptTemplate
+from langchain.llms import FakeListLLM
+from langchain.schema.runnable import (
+    GetLocalVar,
+    PutLocalVar,
+    RunnablePassthrough,
+    RunnableSequence,
+)
 
 
 @pytest.mark.asyncio
@@ -29,3 +36,30 @@ def test_get_missing_var_invoke() -> None:
     with pytest.raises(KeyError):
         runnable.invoke("foo")
 
+
+def test_get_in_map() -> None:
+    runnable: RunnableSequence = PutLocalVar("input") | {"bar": GetLocalVar("input")}
+    assert runnable.invoke("foo") == {"bar": "foo"}
+
+
+def test_cant_put_in_map() -> None:
+    runnable: RunnableSequence = {"bar": PutLocalVar("input")} | GetLocalVar("input")
+    with pytest.raises(KeyError):
+        runnable.invoke("foo")
+
+
+def test_get_passthrough_key() -> None:
+    runnable = PutLocalVar("input") | GetLocalVar("input", passthrough_key="output")
+    assert runnable.invoke("foo") == {"input": "foo", "output": "foo"}
+
+
+def test_multi_step_sequence() -> None:
+    prompt = PromptTemplate.from_template("say {foo}")
+    runnable = (
+        PutLocalVar("foo")
+        | {"foo": RunnablePassthrough()}
+        | prompt
+        | FakeListLLM(responses=["bar"])
+        | GetLocalVar("foo", passthrough_key="output")
+    )
+    assert runnable.invoke("hello") == {"foo": "hello", "output": "bar"}