x

langserve/server.py

@@ -114,6 +114,13 @@ def _unpack_request_config(
         else:
             raise TypeError(f"Expected a string, dict or BaseModel got {type(config)}")
     config = merge_configs(*config_dicts)
+    if "configurable" in config and config["configurable"]:
+        if "configurable" not in keys:
+            raise HTTPException(
+                422,
+                "Server code has modified the default accepted config keys to "
+                "not accept `configurable`. ",
+            )
     projected_config = {k: config[k] for k in keys if k in config}
     return (
         per_req_config_modifier(projected_config, request)
@@ -405,7 +412,7 @@ def add_routes(
     path: str = "",
     input_type: Union[Type, Literal["auto"], BaseModel] = "auto",
     output_type: Union[Type, Literal["auto"], BaseModel] = "auto",
-    config_keys: Sequence[str] = (),
+    config_keys: Sequence[str] = ("configurable",),
     include_callback_events: bool = False,
     enable_feedback_endpoint: bool = False,
     per_req_config_modifier: Optional[PerRequestConfigModifier] = None,
@@ -438,7 +445,8 @@ def add_routes(
             Favor using runnable.with_types(input_type=..., output_type=...) instead.
             This parameter may get deprecated!
         config_keys: list of config keys that will be accepted, by default
-                     no config keys are accepted.
+            will accept `configurable` key in the config. Will only be used
+            if the runnable is configurable.
         include_callback_events: Whether to include callback events in the response.
             If true, the client will be able to show trace information
             including events that occurred on the server side.

tests/unit_tests/test_server_client.py

@@ -1084,7 +1084,7 @@ async def test_configurable_runnables(event_loop: AbstractEventLoop) -> None:
     assert chain.invoke({"name": "cat"}) == "say cat"
 
     app = FastAPI()
-    add_routes(app, chain, config_keys=["tags", "configurable"])
+    add_routes(app, chain)
 
     async with get_async_remote_runnable(app) as remote_runnable:
         # Test with hard-coded LLM
@@ -1094,19 +1094,30 @@ async def test_configurable_runnables(event_loop: AbstractEventLoop) -> None:
         assert (
             await remote_runnable.ainvoke(
                 {"name": "foo"},
-                {"configurable": {"template": "hear {name}"}, "tags": ["h"]},
+                {"configurable": {"template": "hear {name}"}},
             )
             == "hear foo"
         )
         # Test with alternative passthrough LLM
         assert (
             await remote_runnable.ainvoke(
                 {"name": "foo"},
-                {"configurable": {"llm": "hardcoded_llm"}, "tags": ["h"]},
+                {"configurable": {"llm": "hardcoded_llm"}},
             )
             == "hello Mr. Kitten!"
         )
 
+    add_routes(app, chain, path="/no_config", config_keys=["tags"])
+
+    async with get_async_remote_runnable(app, path="/no_config") as remote_runnable:
+        with pytest.raises(httpx.HTTPError) as cb:
+            await remote_runnable.ainvoke(
+                {"name": "foo"},
+                {"configurable": {"template": "hear {name}"}},
+            )
+
+        assert cb.value.response.status_code == 422
+
 
 # Test for utilities