Add configurable fields with options (#11601)

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libs/langchain/langchain/schema/runnable/__init__.py

@@ -30,10 +30,16 @@ from langchain.schema.runnable.config import RunnableConfig, patch_config
 from langchain.schema.runnable.fallbacks import RunnableWithFallbacks
 from langchain.schema.runnable.passthrough import RunnablePassthrough
 from langchain.schema.runnable.router import RouterInput, RouterRunnable
-from langchain.schema.runnable.utils import ConfigurableField
+from langchain.schema.runnable.utils import (
+    ConfigurableField,
+    ConfigurableFieldMultiOption,
+    ConfigurableFieldSingleOption,
+)
 
 __all__ = [
     "ConfigurableField",
+    "ConfigurableFieldSingleOption",
+    "ConfigurableFieldMultiOption",
     "GetLocalVar",
     "patch_config",
     "PutLocalVar",

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

@@ -58,6 +58,7 @@ from langchain.schema.runnable.config import (
 )
 from langchain.schema.runnable.utils import (
     AddableDict,
+    AnyConfigurableField,
     ConfigurableField,
     ConfigurableFieldSpec,
     Input,
@@ -975,7 +976,7 @@ class Runnable(Generic[Input, Output], ABC):
 
 class RunnableSerializable(Serializable, Runnable[Input, Output]):
     def configurable_fields(
-        self, **kwargs: ConfigurableField
+        self, **kwargs: AnyConfigurableField
     ) -> RunnableSerializable[Input, Output]:
         from langchain.schema.runnable.configurable import RunnableConfigurableFields
 

libs/langchain/langchain/schema/runnable/configurable.py

@@ -23,7 +23,10 @@ from langchain.schema.runnable.config import (
     get_executor_for_config,
 )
 from langchain.schema.runnable.utils import (
+    AnyConfigurableField,
     ConfigurableField,
+    ConfigurableFieldMultiOption,
+    ConfigurableFieldSingleOption,
     ConfigurableFieldSpec,
     Input,
     Output,
@@ -193,7 +196,7 @@ class DynamicRunnable(RunnableSerializable[Input, Output]):
 
 
 class RunnableConfigurableFields(DynamicRunnable[Input, Output]):
-    fields: Dict[str, ConfigurableField]
+    fields: Dict[str, AnyConfigurableField]
 
     @property
     def config_specs(self) -> Sequence[ConfigurableFieldSpec]:
@@ -207,11 +210,15 @@ class RunnableConfigurableFields(DynamicRunnable[Input, Output]):
                 or self.default.__fields__[field_name].annotation,
                 default=getattr(self.default, field_name),
             )
+            if isinstance(spec, ConfigurableField)
+            else make_options_spec(
+                spec, self.default.__fields__[field_name].field_info.description
+            )
             for field_name, spec in self.fields.items()
         ]
 
     def configurable_fields(
-        self, **kwargs: ConfigurableField
+        self, **kwargs: AnyConfigurableField
     ) -> RunnableSerializable[Input, Output]:
         return self.default.configurable_fields(**{**self.fields, **kwargs})
 
@@ -220,10 +227,28 @@ class RunnableConfigurableFields(DynamicRunnable[Input, Output]):
     ) -> Runnable[Input, Output]:
         config = config or {}
         specs_by_id = {spec.id: (key, spec) for key, spec in self.fields.items()}
-        configurable = {
+        configurable_fields = {
             specs_by_id[k][0]: v
             for k, v in config.get("configurable", {}).items()
-            if k in specs_by_id
+            if k in specs_by_id and isinstance(specs_by_id[k][1], ConfigurableField)
+        }
+        configurable_single_options = {
+            k: v.options[(config.get("configurable", {}).get(v.id) or v.default)]
+            for k, v in self.fields.items()
+            if isinstance(v, ConfigurableFieldSingleOption)
+        }
+        configurable_multi_options = {
+            k: [
+                v.options[o]
+                for o in config.get("configurable", {}).get(v.id, v.default)
+            ]
+            for k, v in self.fields.items()
+            if isinstance(v, ConfigurableFieldMultiOption)
+        }
+        configurable = {
+            **configurable_fields,
+            **configurable_single_options,
+            **configurable_multi_options,
         }
 
         if configurable:
@@ -262,7 +287,7 @@ class RunnableConfigurableAlternatives(DynamicRunnable[Input, Output]):
         ] + [s for alt in self.alternatives.values() for s in alt.config_specs]
 
     def configurable_fields(
-        self, **kwargs: ConfigurableField
+        self, **kwargs: AnyConfigurableField
     ) -> RunnableSerializable[Input, Output]:
         return self.__class__(
             which=self.which,
@@ -281,3 +306,29 @@ class RunnableConfigurableAlternatives(DynamicRunnable[Input, Output]):
             return self.alternatives[which]
         else:
             raise ValueError(f"Unknown alternative: {which}")
+
+
+def make_options_spec(
+    spec: Union[ConfigurableFieldSingleOption, ConfigurableFieldMultiOption],
+    description: Optional[str],
+) -> ConfigurableFieldSpec:
+    enum = StrEnum(  # type: ignore[call-overload]
+        spec.name or spec.id,
+        ((v, v) for v in list(spec.options.keys())),
+    )
+    if isinstance(spec, ConfigurableFieldSingleOption):
+        return ConfigurableFieldSpec(
+            id=spec.id,
+            name=spec.name,
+            description=spec.description or description,
+            annotation=enum,
+            default=spec.default,
+        )
+    else:
+        return ConfigurableFieldSpec(
+            id=spec.id,
+            name=spec.name,
+            description=spec.description or description,
+            annotation=Sequence[enum],  # type: ignore[valid-type]
+            default=spec.default,
+        )

libs/langchain/langchain/schema/runnable/utils.py

@@ -14,6 +14,7 @@ from typing import (
     Dict,
     Iterable,
     List,
+    Mapping,
     NamedTuple,
     Optional,
     Protocol,
@@ -218,11 +219,35 @@ async def aadd(addables: AsyncIterable[Addable]) -> Optional[Addable]:
 
 class ConfigurableField(NamedTuple):
     id: str
+
     name: Optional[str] = None
     description: Optional[str] = None
     annotation: Optional[Any] = None
 
 
+class ConfigurableFieldSingleOption(NamedTuple):
+    id: str
+    options: Mapping[str, Any]
+    default: str
+
+    name: Optional[str] = None
+    description: Optional[str] = None
+
+
+class ConfigurableFieldMultiOption(NamedTuple):
+    id: str
+    options: Mapping[str, Any]
+    default: Sequence[str]
+
+    name: Optional[str] = None
+    description: Optional[str] = None
+
+
+AnyConfigurableField = Union[
+    ConfigurableField, ConfigurableFieldSingleOption, ConfigurableFieldMultiOption
+]
+
+
 class ConfigurableFieldSpec(NamedTuple):
     id: str
     name: Optional[str]

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

@@ -59,7 +59,11 @@ from langchain.schema.runnable import (
     RunnableWithFallbacks,
 )
 from langchain.schema.runnable.base import ConfigurableField, RunnableGenerator
-from langchain.schema.runnable.utils import add
+from langchain.schema.runnable.utils import (
+    ConfigurableFieldMultiOption,
+    ConfigurableFieldSingleOption,
+    add,
+)
 from langchain.tools.base import BaseTool, tool
 from langchain.tools.json.tool import JsonListKeysTool, JsonSpec
 
@@ -903,6 +907,18 @@ def test_configurable_fields() -> None:
 
 
 def test_configurable_fields_example() -> None:
+    fake_chat = FakeListChatModel(responses=["b"]).configurable_fields(
+        responses=ConfigurableFieldMultiOption(
+            id="chat_responses",
+            name="Chat Responses",
+            options={
+                "hello": "A good morning to you!",
+                "bye": "See you later!",
+                "helpful": "How can I help you?",
+            },
+            default=["hello", "bye"],
+        )
+    )
     fake_llm = (
         FakeListLLM(responses=["a"])
         .configurable_fields(
@@ -914,15 +930,20 @@ def test_configurable_fields_example() -> None:
         )
         .configurable_alternatives(
             ConfigurableField(id="llm", name="LLM"),
-            chat=FakeListChatModel(responses=["b"]) | StrOutputParser(),
+            chat=fake_chat | StrOutputParser(),
         )
     )
 
     prompt = PromptTemplate.from_template("Hello, {name}!").configurable_fields(
-        template=ConfigurableField(
+        template=ConfigurableFieldSingleOption(
             id="prompt_template",
             name="Prompt Template",
             description="The prompt template for this chain",
+            options={
+                "hello": "Hello, {name}!",
+                "good_morning": "A very good morning to you, {name}!",
+            },
+            default="hello",
         )
     )
 
@@ -941,10 +962,28 @@ def test_configurable_fields_example() -> None:
                 "enum": ["chat", "default"],
                 "type": "string",
             },
+            "Chat_Responses": {
+                "description": "An enumeration.",
+                "enum": ["hello", "bye", "helpful"],
+                "title": "Chat Responses",
+                "type": "string",
+            },
+            "Prompt_Template": {
+                "description": "An enumeration.",
+                "enum": ["hello", "good_morning"],
+                "title": "Prompt Template",
+                "type": "string",
+            },
             "Configurable": {
                 "title": "Configurable",
                 "type": "object",
                 "properties": {
+                    "chat_responses": {
+                        "default": ["hello", "bye"],
+                        "items": {"$ref": "#/definitions/Chat_Responses"},
+                        "title": "Chat Responses",
+                        "type": "array",
+                    },
                     "llm": {
                         "title": "LLM",
                         "default": "default",
@@ -960,8 +999,8 @@ def test_configurable_fields_example() -> None:
                     "prompt_template": {
                         "title": "Prompt Template",
                         "description": "The prompt template for this chain",
-                        "default": "Hello, {name}!",
+                        "default": "hello",
-                        "type": "string",
+                        "allOf": [{"$ref": "#/definitions/Prompt_Template"}],
                     },
                 },
             },
@@ -972,7 +1011,14 @@ def test_configurable_fields_example() -> None:
         chain_configurable.with_config(configurable={"llm": "chat"}).invoke(
             {"name": "John"}
         )
-        == "b"
+        == "A good morning to you!"
+    )
+
+    assert (
+        chain_configurable.with_config(
+            configurable={"llm": "chat", "chat_responses": ["helpful"]}
+        ).invoke({"name": "John"})
+        == "How can I help you?"
     )