Keyword-like runnable config (langchain-ai#26295)

libs/core/langchain_core/runnables/base.py

@@ -25,6 +25,7 @@
     List,
     Mapping,
     Optional,
+    Protocol,
     Sequence,
     Set,
     Tuple,
@@ -5519,12 +5520,36 @@ def wrapper(*args: Any, **kwargs: Any) -> Any:
         return attr
 
 
+class _RunnableCallableSync(Protocol[Input, Output]):
+    def __call__(self, __in: Input, *, config: RunnableConfig) -> Output: ...
+
+
+class _RunnableCallableAsync(Protocol[Input, Output]):
+    def __call__(self, __in: Input, *, config: RunnableConfig) -> Awaitable[Output]: ...
+
+
+class _RunnableCallableIterator(Protocol[Input, Output]):
+    def __call__(
+        self, __in: Iterator[Input], *, config: RunnableConfig
+    ) -> Iterator[Output]: ...
+
+
+class _RunnableCallableAsyncIterator(Protocol[Input, Output]):
+    def __call__(
+        self, __in: AsyncIterator[Input], *, config: RunnableConfig
+    ) -> AsyncIterator[Output]: ...
+
+
 RunnableLike = Union[
     Runnable[Input, Output],
     Callable[[Input], Output],
     Callable[[Input], Awaitable[Output]],
     Callable[[Iterator[Input]], Iterator[Output]],
     Callable[[AsyncIterator[Input]], AsyncIterator[Output]],
+    _RunnableCallableSync[Input, Output],
+    _RunnableCallableAsync[Input, Output],
+    _RunnableCallableIterator[Input, Output],
+    _RunnableCallableAsyncIterator[Input, Output],
     Mapping[str, Any],
 ]