from __future__ import annotations
import enum
import threading
from abc import abstractmethod
from collections.abc import AsyncIterator, Iterator, Sequence
from collections.abc import Mapping as Mapping
from functools import wraps
from typing import (
Any,
Callable,
Optional,
Union,
cast,
)
from weakref import WeakValueDictionary
from pydantic import BaseModel, ConfigDict
from typing_extensions import override
from langchain_core.runnables.base import Runnable, RunnableSerializable
from langchain_core.runnables.config import (
RunnableConfig,
ensure_config,
get_config_list,
get_executor_for_config,
merge_configs,
)
from langchain_core.runnables.graph import Graph
from langchain_core.runnables.utils import (
AnyConfigurableField,
ConfigurableField,
ConfigurableFieldMultiOption,
ConfigurableFieldSingleOption,
ConfigurableFieldSpec,
Input,
Output,
gather_with_concurrency,
get_unique_config_specs,
)
[docs]
class DynamicRunnable(RunnableSerializable[Input, Output]):
"""Serializable Runnable that can be dynamically configured.
A DynamicRunnable should be initiated using the `configurable_fields` or
`configurable_alternatives` method of a Runnable.
Parameters:
default: The default Runnable to use.
config: The configuration to use.
"""
default: RunnableSerializable[Input, Output]
config: Optional[RunnableConfig] = None
model_config = ConfigDict(
arbitrary_types_allowed=True,
)
@classmethod
def is_lc_serializable(cls) -> bool:
return True
@classmethod
def get_lc_namespace(cls) -> list[str]:
"""Get the namespace of the langchain object."""
return ["langchain", "schema", "runnable"]
@property
@override
def InputType(self) -> type[Input]:
return self.default.InputType
@property
@override
def OutputType(self) -> type[Output]:
return self.default.OutputType
def get_input_schema(
self, config: Optional[RunnableConfig] = None
) -> type[BaseModel]:
runnable, config = self.prepare(config)
return runnable.get_input_schema(config)
def get_output_schema(
self, config: Optional[RunnableConfig] = None
) -> type[BaseModel]:
runnable, config = self.prepare(config)
return runnable.get_output_schema(config)
def get_graph(self, config: Optional[RunnableConfig] = None) -> Graph:
runnable, config = self.prepare(config)
return runnable.get_graph(config)
[docs]
def with_config(
self,
config: Optional[RunnableConfig] = None,
# Sadly Unpack is not well supported by mypy so this will have to be untyped
**kwargs: Any,
) -> Runnable[Input, Output]:
return self.__class__(
**{**self.__dict__, "config": ensure_config(merge_configs(config, kwargs))} # type: ignore[arg-type]
)
[docs]
def prepare(
self, config: Optional[RunnableConfig] = None
) -> tuple[Runnable[Input, Output], RunnableConfig]:
"""Prepare the Runnable for invocation.
Args:
config: The configuration to use. Defaults to None.
Returns:
Tuple[Runnable[Input, Output], RunnableConfig]: The prepared Runnable and
configuration.
"""
runnable: Runnable[Input, Output] = self
while isinstance(runnable, DynamicRunnable):
runnable, config = runnable._prepare(merge_configs(runnable.config, config))
return runnable, cast(RunnableConfig, config)
@abstractmethod
def _prepare(
self, config: Optional[RunnableConfig] = None
) -> tuple[Runnable[Input, Output], RunnableConfig]: ...
[docs]
def invoke(
self, input: Input, config: Optional[RunnableConfig] = None, **kwargs: Any
) -> Output:
runnable, config = self.prepare(config)
return runnable.invoke(input, config, **kwargs)
[docs]
async def ainvoke(
self, input: Input, config: Optional[RunnableConfig] = None, **kwargs: Any
) -> Output:
runnable, config = self.prepare(config)
return await runnable.ainvoke(input, config, **kwargs)
[docs]
def batch(
self,
inputs: list[Input],
config: Optional[Union[RunnableConfig, list[RunnableConfig]]] = None,
*,
return_exceptions: bool = False,
**kwargs: Optional[Any],
) -> list[Output]:
configs = get_config_list(config, len(inputs))
prepared = [self.prepare(c) for c in configs]
if all(p is self.default for p, _ in prepared):
return self.default.batch(
inputs,
[c for _, c in prepared],
return_exceptions=return_exceptions,
**kwargs,
)
if not inputs:
return []
def invoke(
prepared: tuple[Runnable[Input, Output], RunnableConfig],
input: Input,
) -> Union[Output, Exception]:
bound, config = prepared
if return_exceptions:
try:
return bound.invoke(input, config, **kwargs)
except Exception as e:
return e
else:
return bound.invoke(input, config, **kwargs)
# If there's only one input, don't bother with the executor
if len(inputs) == 1:
return cast(list[Output], [invoke(prepared[0], inputs[0])])
with get_executor_for_config(configs[0]) as executor:
return cast(list[Output], list(executor.map(invoke, prepared, inputs)))
[docs]
async def abatch(
self,
inputs: list[Input],
config: Optional[Union[RunnableConfig, list[RunnableConfig]]] = None,
*,
return_exceptions: bool = False,
**kwargs: Optional[Any],
) -> list[Output]:
configs = get_config_list(config, len(inputs))
prepared = [self.prepare(c) for c in configs]
if all(p is self.default for p, _ in prepared):
return await self.default.abatch(
inputs,
[c for _, c in prepared],
return_exceptions=return_exceptions,
**kwargs,
)
if not inputs:
return []
async def ainvoke(
prepared: tuple[Runnable[Input, Output], RunnableConfig],
input: Input,
) -> Union[Output, Exception]:
bound, config = prepared
if return_exceptions:
try:
return await bound.ainvoke(input, config, **kwargs)
except Exception as e:
return e
else:
return await bound.ainvoke(input, config, **kwargs)
coros = map(ainvoke, prepared, inputs)
return await gather_with_concurrency(configs[0].get("max_concurrency"), *coros)
[docs]
def stream(
self,
input: Input,
config: Optional[RunnableConfig] = None,
**kwargs: Optional[Any],
) -> Iterator[Output]:
runnable, config = self.prepare(config)
return runnable.stream(input, config, **kwargs)
[docs]
async def astream(
self,
input: Input,
config: Optional[RunnableConfig] = None,
**kwargs: Optional[Any],
) -> AsyncIterator[Output]:
runnable, config = self.prepare(config)
async for chunk in runnable.astream(input, config, **kwargs):
yield chunk
def transform(
self,
input: Iterator[Input],
config: Optional[RunnableConfig] = None,
**kwargs: Optional[Any],
) -> Iterator[Output]:
runnable, config = self.prepare(config)
return runnable.transform(input, config, **kwargs)
async def atransform(
self,
input: AsyncIterator[Input],
config: Optional[RunnableConfig] = None,
**kwargs: Optional[Any],
) -> AsyncIterator[Output]:
runnable, config = self.prepare(config)
async for chunk in runnable.atransform(input, config, **kwargs):
yield chunk
def __getattr__(self, name: str) -> Any:
attr = getattr(self.default, name)
if callable(attr):
@wraps(attr)
def wrapper(*args: Any, **kwargs: Any) -> Any:
for key, arg in kwargs.items():
if key == "config" and (
isinstance(arg, dict)
and "configurable" in arg
and isinstance(arg["configurable"], dict)
):
runnable, config = self.prepare(cast(RunnableConfig, arg))
kwargs = {**kwargs, "config": config}
return getattr(runnable, name)(*args, **kwargs)
for idx, arg in enumerate(args):
if (
isinstance(arg, dict)
and "configurable" in arg
and isinstance(arg["configurable"], dict)
):
runnable, config = self.prepare(cast(RunnableConfig, arg))
argsl = list(args)
argsl[idx] = config
return getattr(runnable, name)(*argsl, **kwargs)
if self.config:
runnable, config = self.prepare()
return getattr(runnable, name)(*args, **kwargs)
return attr(*args, **kwargs)
return wrapper
else:
return attr
[docs]
class RunnableConfigurableFields(DynamicRunnable[Input, Output]):
"""Runnable that can be dynamically configured.
A RunnableConfigurableFields should be initiated using the
`configurable_fields` method of a Runnable.
Parameters:
fields: The configurable fields to use.
Here is an example of using a RunnableConfigurableFields with LLMs:
.. code-block:: python
from langchain_core.prompts import PromptTemplate
from langchain_core.runnables import ConfigurableField
from langchain_openai import ChatOpenAI
model = ChatOpenAI(temperature=0).configurable_fields(
temperature=ConfigurableField(
id="temperature",
name="LLM Temperature",
description="The temperature of the LLM",
)
)
# This creates a RunnableConfigurableFields for a chat model.
# When invoking the created RunnableSequence, you can pass in the
# value for your ConfigurableField's id which in this case
# will be change in temperature
prompt = PromptTemplate.from_template("Pick a random number above {x}")
chain = prompt | model
chain.invoke({"x": 0})
chain.invoke({"x": 0}, config={"configurable": {"temperature": 0.9}})
Here is an example of using a RunnableConfigurableFields with HubRunnables:
.. code-block:: python
from langchain_core.prompts import PromptTemplate
from langchain_core.runnables import ConfigurableField
from langchain_openai import ChatOpenAI
from langchain.runnables.hub import HubRunnable
prompt = HubRunnable("rlm/rag-prompt").configurable_fields(
owner_repo_commit=ConfigurableField(
id="hub_commit",
name="Hub Commit",
description="The Hub commit to pull from",
)
)
prompt.invoke({"question": "foo", "context": "bar"})
# Invoking prompt with `with_config` method
prompt.invoke(
{"question": "foo", "context": "bar"},
config={"configurable": {"hub_commit": "rlm/rag-prompt-llama"}},
)
"""
fields: dict[str, AnyConfigurableField]
@classmethod
def get_lc_namespace(cls) -> list[str]:
"""Get the namespace of the langchain object."""
return ["langchain", "schema", "runnable"]
@property
def config_specs(self) -> list[ConfigurableFieldSpec]:
"""Get the configuration specs for the RunnableConfigurableFields.
Returns:
List[ConfigurableFieldSpec]: The configuration specs.
"""
config_specs = []
for field_name, spec in self.fields.items():
if isinstance(spec, ConfigurableField):
config_specs.append(
ConfigurableFieldSpec(
id=spec.id,
name=spec.name,
description=spec.description
or self.default.model_fields[field_name].description,
annotation=spec.annotation
or self.default.model_fields[field_name].annotation,
default=getattr(self.default, field_name),
is_shared=spec.is_shared,
)
)
else:
config_specs.append(
make_options_spec(
spec, self.default.model_fields[field_name].description
)
)
config_specs.extend(self.default.config_specs)
return get_unique_config_specs(config_specs)
[docs]
def configurable_fields(
self, **kwargs: AnyConfigurableField
) -> RunnableSerializable[Input, Output]:
"""Get a new RunnableConfigurableFields with the specified
configurable fields."""
return self.default.configurable_fields(**{**self.fields, **kwargs})
def _prepare(
self, config: Optional[RunnableConfig] = None
) -> tuple[Runnable[Input, Output], RunnableConfig]:
config = ensure_config(config)
specs_by_id = {spec.id: (key, spec) for key, spec in self.fields.items()}
configurable_fields = {
specs_by_id[k][0]: v
for k, v in config.get("configurable", {}).items()
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:
init_params = {
k: v
for k, v in self.default.__dict__.items()
if k in self.default.model_fields
}
return (
self.default.__class__(**{**init_params, **configurable}),
config,
)
else:
return (self.default, config)
RunnableConfigurableFields.model_rebuild()
# Before Python 3.11 native StrEnum is not available
[docs]
class StrEnum(str, enum.Enum):
"""String enum."""
pass
_enums_for_spec: WeakValueDictionary[
Union[
ConfigurableFieldSingleOption, ConfigurableFieldMultiOption, ConfigurableField
],
type[StrEnum],
] = WeakValueDictionary()
_enums_for_spec_lock = threading.Lock()
[docs]
class RunnableConfigurableAlternatives(DynamicRunnable[Input, Output]):
"""Runnable that can be dynamically configured.
A RunnableConfigurableAlternatives should be initiated using the
`configurable_alternatives` method of a Runnable or can be
initiated directly as well.
Here is an example of using a RunnableConfigurableAlternatives that uses
alternative prompts to illustrate its functionality:
.. code-block:: python
from langchain_core.runnables import ConfigurableField
from langchain_openai import ChatOpenAI
# This creates a RunnableConfigurableAlternatives for Prompt Runnable
# with two alternatives.
prompt = PromptTemplate.from_template(
"Tell me a joke about {topic}"
).configurable_alternatives(
ConfigurableField(id="prompt"),
default_key="joke",
poem=PromptTemplate.from_template("Write a short poem about {topic}")
)
# When invoking the created RunnableSequence, you can pass in the
# value for your ConfigurableField's id which in this case will either be
# `joke` or `poem`.
chain = prompt | ChatOpenAI(model="gpt-3.5-turbo-0125", temperature=0)
# The `with_config` method brings in the desired Prompt Runnable in your
# Runnable Sequence.
chain.with_config(configurable={"prompt": "poem"}).invoke({"topic": "bears"})
Equivalently, you can initialize RunnableConfigurableAlternatives directly
and use in LCEL in the same way:
.. code-block:: python
from langchain_core.runnables import ConfigurableField
from langchain_core.runnables.configurable import RunnableConfigurableAlternatives
from langchain_openai import ChatOpenAI
prompt = RunnableConfigurableAlternatives(
which=ConfigurableField(id='prompt'),
default=PromptTemplate.from_template("Tell me a joke about {topic}"),
default_key='joke',
prefix_keys=False,
alternatives={"poem":PromptTemplate.from_template("Write a short poem about {topic}")}
)
chain = prompt | ChatOpenAI(model="gpt-3.5-turbo-0125", temperature=0)
chain.with_config(configurable={"prompt": "poem"}).invoke({"topic": "bears"})
""" # noqa: E501
which: ConfigurableField
"""The ConfigurableField to use to choose between alternatives."""
alternatives: dict[
str,
Union[Runnable[Input, Output], Callable[[], Runnable[Input, Output]]],
]
"""The alternatives to choose from."""
default_key: str = "default"
"""The enum value to use for the default option. Defaults to "default"."""
prefix_keys: bool
"""Whether to prefix configurable fields of each alternative with a namespace
of the form <which.id>==<alternative_key>, eg. a key named "temperature" used by
the alternative named "gpt3" becomes "model==gpt3/temperature"."""
@classmethod
def get_lc_namespace(cls) -> list[str]:
"""Get the namespace of the langchain object."""
return ["langchain", "schema", "runnable"]
@property
def config_specs(self) -> list[ConfigurableFieldSpec]:
with _enums_for_spec_lock:
if which_enum := _enums_for_spec.get(self.which):
pass
else:
which_enum = StrEnum( # type: ignore[call-overload]
self.which.name or self.which.id,
(
(v, v)
for v in list(self.alternatives.keys()) + [self.default_key]
),
)
_enums_for_spec[self.which] = cast(type[StrEnum], which_enum)
return get_unique_config_specs(
# which alternative
[
ConfigurableFieldSpec(
id=self.which.id,
name=self.which.name,
description=self.which.description,
annotation=which_enum,
default=self.default_key,
is_shared=self.which.is_shared,
),
]
# config specs of the default option
+ (
[
prefix_config_spec(s, f"{self.which.id}=={self.default_key}")
for s in self.default.config_specs
]
if self.prefix_keys
else self.default.config_specs
)
# config specs of the alternatives
+ [
(
prefix_config_spec(s, f"{self.which.id}=={alt_key}")
if self.prefix_keys
else s
)
for alt_key, alt in self.alternatives.items()
if isinstance(alt, RunnableSerializable)
for s in alt.config_specs
]
)
[docs]
def configurable_fields(
self, **kwargs: AnyConfigurableField
) -> RunnableSerializable[Input, Output]:
return self.__class__(
which=self.which,
default=self.default.configurable_fields(**kwargs),
alternatives=self.alternatives,
default_key=self.default_key,
prefix_keys=self.prefix_keys,
)
def _prepare(
self, config: Optional[RunnableConfig] = None
) -> tuple[Runnable[Input, Output], RunnableConfig]:
config = ensure_config(config)
which = config.get("configurable", {}).get(self.which.id, self.default_key)
# remap configurable keys for the chosen alternative
if self.prefix_keys:
config = cast(
RunnableConfig,
{
**config,
"configurable": {
_strremoveprefix(k, f"{self.which.id}=={which}/"): v
for k, v in config.get("configurable", {}).items()
},
},
)
# return the chosen alternative
if which == self.default_key:
return (self.default, config)
elif which in self.alternatives:
alt = self.alternatives[which]
if isinstance(alt, Runnable):
return (alt, config)
else:
return (alt(), config)
else:
raise ValueError(f"Unknown alternative: {which}")
def _strremoveprefix(s: str, prefix: str) -> str:
"""str.removeprefix() is only available in Python 3.9+."""
return s.replace(prefix, "", 1) if s.startswith(prefix) else s
[docs]
def prefix_config_spec(
spec: ConfigurableFieldSpec, prefix: str
) -> ConfigurableFieldSpec:
"""Prefix the id of a ConfigurableFieldSpec.
This is useful when a RunnableConfigurableAlternatives is used as a
ConfigurableField of another RunnableConfigurableAlternatives.
Args:
spec: The ConfigurableFieldSpec to prefix.
prefix: The prefix to add.
Returns:
ConfigurableFieldSpec: The prefixed ConfigurableFieldSpec.
"""
return (
ConfigurableFieldSpec(
id=f"{prefix}/{spec.id}",
name=spec.name,
description=spec.description,
annotation=spec.annotation,
default=spec.default,
is_shared=spec.is_shared,
)
if not spec.is_shared
else spec
)
[docs]
def make_options_spec(
spec: Union[ConfigurableFieldSingleOption, ConfigurableFieldMultiOption],
description: Optional[str],
) -> ConfigurableFieldSpec:
"""Make a ConfigurableFieldSpec for a ConfigurableFieldSingleOption or
ConfigurableFieldMultiOption.
Args:
spec: The ConfigurableFieldSingleOption or ConfigurableFieldMultiOption.
description: The description to use if the spec does not have one.
Returns:
The ConfigurableFieldSpec.
"""
with _enums_for_spec_lock:
if enum := _enums_for_spec.get(spec):
pass
else:
enum = StrEnum( # type: ignore[call-overload]
spec.name or spec.id,
((v, v) for v in list(spec.options.keys())),
)
_enums_for_spec[spec] = cast(type[StrEnum], enum)
if isinstance(spec, ConfigurableFieldSingleOption):
return ConfigurableFieldSpec(
id=spec.id,
name=spec.name,
description=spec.description or description,
annotation=enum,
default=spec.default,
is_shared=spec.is_shared,
)
else:
return ConfigurableFieldSpec(
id=spec.id,
name=spec.name,
description=spec.description or description,
annotation=Sequence[enum], # type: ignore[valid-type]
default=spec.default,
is_shared=spec.is_shared,
)
