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AzureOpenAI (Legacy LLM)

Reference docs

This page contains reference documentation for the legacy AzureOpenAI LLM. See the docs for conceptual guides, tutorials, and examples on using AzureOpenAI.

langchain_openai.llms.AzureOpenAI

Bases: BaseOpenAI

Azure-specific OpenAI large language models.

To use, you should have the openai python package installed, and the environment variable OPENAI_API_KEY set with your API key.

Any parameters that are valid to be passed to the openai.create call can be passed in, even if not explicitly saved on this class.

Example
from langchain_openai import AzureOpenAI

openai = AzureOpenAI(model_name="gpt-3.5-turbo-instruct")
METHOD DESCRIPTION
get_name

Get the name of the Runnable.

get_input_schema

Get a Pydantic model that can be used to validate input to the Runnable.

get_input_jsonschema

Get a JSON schema that represents the input to the Runnable.

get_output_schema

Get a Pydantic model that can be used to validate output to the Runnable.

get_output_jsonschema

Get a JSON schema that represents the output of the Runnable.

config_schema

The type of config this Runnable accepts specified as a Pydantic model.

get_config_jsonschema

Get a JSON schema that represents the config of the Runnable.

get_graph

Return a graph representation of this Runnable.

get_prompts

Return a list of prompts used by this Runnable.

__or__

Runnable "or" operator.

__ror__

Runnable "reverse-or" operator.

pipe

Pipe Runnable objects.

pick

Pick keys from the output dict of this Runnable.

assign

Assigns new fields to the dict output of this Runnable.

invoke

Transform a single input into an output.

ainvoke

Transform a single input into an output.

batch

Default implementation runs invoke in parallel using a thread pool executor.

batch_as_completed

Run invoke in parallel on a list of inputs.

abatch

Default implementation runs ainvoke in parallel using asyncio.gather.

abatch_as_completed

Run ainvoke in parallel on a list of inputs.

stream

Default implementation of stream, which calls invoke.

astream

Default implementation of astream, which calls ainvoke.

astream_log

Stream all output from a Runnable, as reported to the callback system.

astream_events

Generate a stream of events.

transform

Transform inputs to outputs.

atransform

Transform inputs to outputs.

bind

Bind arguments to a Runnable, returning a new Runnable.

with_config

Bind config to a Runnable, returning a new Runnable.

with_listeners

Bind lifecycle listeners to a Runnable, returning a new Runnable.

with_alisteners

Bind async lifecycle listeners to a Runnable.

with_types

Bind input and output types to a Runnable, returning a new Runnable.

with_retry

Create a new Runnable that retries the original Runnable on exceptions.

map

Return a new Runnable that maps a list of inputs to a list of outputs.

with_fallbacks

Add fallbacks to a Runnable, returning a new Runnable.

as_tool

Create a BaseTool from a Runnable.

__init__
lc_id

Return a unique identifier for this class for serialization purposes.

to_json

Serialize the Runnable to JSON.

to_json_not_implemented

Serialize a "not implemented" object.

configurable_fields

Configure particular Runnable fields at runtime.

configurable_alternatives

Configure alternatives for Runnable objects that can be set at runtime.

set_verbose

If verbose is None, set it.

generate_prompt

Pass a sequence of prompts to the model and return model generations.

agenerate_prompt

Asynchronously pass a sequence of prompts and return model generations.

with_structured_output

Not implemented on this class.

get_token_ids

Get the token IDs using the tiktoken package.

get_num_tokens

Get the number of tokens present in the text.

get_num_tokens_from_messages

Get the number of tokens in the messages.

generate

Pass a sequence of prompts to a model and return generations.

agenerate

Asynchronously pass a sequence of prompts to a model and return generations.

__str__

Return a string representation of the object for printing.

dict

Return a dictionary of the LLM.

save

Save the LLM.

build_extra

Build extra kwargs from additional params that were passed in.

get_sub_prompts

Get the sub prompts for llm call.

create_llm_result

Create the LLMResult from the choices and prompts.

modelname_to_contextsize

Calculate the maximum number of tokens possible to generate for a model.

max_tokens_for_prompt

Calculate the maximum number of tokens possible to generate for a prompt.

get_lc_namespace

Get the namespace of the LangChain object.

is_lc_serializable

Return whether this model can be serialized by LangChain.

validate_environment

Validate that api key and python package exists in environment.

name class-attribute instance-attribute

name: str | None = None

The name of the Runnable. Used for debugging and tracing.

InputType property

InputType: TypeAlias

Get the input type for this Runnable.

OutputType property

OutputType: type[str]

Get the input type for this Runnable.

input_schema property

input_schema: type[BaseModel]

The type of input this Runnable accepts specified as a Pydantic model.

output_schema property

output_schema: type[BaseModel]

Output schema.

The type of output this Runnable produces specified as a Pydantic model.

config_specs property

config_specs: list[ConfigurableFieldSpec]

List configurable fields for this Runnable.

cache class-attribute instance-attribute

cache: BaseCache | bool | None = Field(default=None, exclude=True)

Whether to cache the response.

  • If True, will use the global cache.
  • If False, will not use a cache
  • If None, will use the global cache if it's set, otherwise no cache.
  • If instance of BaseCache, will use the provided cache.

Caching is not currently supported for streaming methods of models.

verbose class-attribute instance-attribute

verbose: bool = Field(default_factory=_get_verbosity, exclude=True, repr=False)

Whether to print out response text.

callbacks class-attribute instance-attribute

callbacks: Callbacks = Field(default=None, exclude=True)

Callbacks to add to the run trace.

tags class-attribute instance-attribute

tags: list[str] | None = Field(default=None, exclude=True)

Tags to add to the run trace.

metadata class-attribute instance-attribute

metadata: dict[str, Any] | None = Field(default=None, exclude=True)

Metadata to add to the run trace.

custom_get_token_ids class-attribute instance-attribute

custom_get_token_ids: Callable[[str], list[int]] | None = Field(
    default=None, exclude=True
)

Optional encoder to use for counting tokens.

model_name class-attribute instance-attribute

model_name: str = Field(default='gpt-3.5-turbo-instruct', alias='model')

Model name to use.

temperature class-attribute instance-attribute

temperature: float = 0.7

What sampling temperature to use.

max_tokens class-attribute instance-attribute

max_tokens: int = 256

The maximum number of tokens to generate in the completion. -1 returns as many tokens as possible given the prompt and the models maximal context size.

top_p class-attribute instance-attribute

top_p: float = 1

Total probability mass of tokens to consider at each step.

frequency_penalty class-attribute instance-attribute

frequency_penalty: float = 0

Penalizes repeated tokens according to frequency.

presence_penalty class-attribute instance-attribute

presence_penalty: float = 0

Penalizes repeated tokens.

n class-attribute instance-attribute

n: int = 1

How many completions to generate for each prompt.

best_of class-attribute instance-attribute

best_of: int = 1

Generates best_of completions server-side and returns the "best".

model_kwargs class-attribute instance-attribute

model_kwargs: dict[str, Any] = Field(default_factory=dict)

Holds any model parameters valid for create call not explicitly specified.

openai_api_base class-attribute instance-attribute

openai_api_base: str | None = Field(
    alias="base_url", default_factory=from_env("OPENAI_API_BASE", default=None)
)

Base URL path for API requests, leave blank if not using a proxy or service emulator.

openai_organization class-attribute instance-attribute

openai_organization: str | None = Field(
    alias="organization",
    default_factory=from_env(["OPENAI_ORG_ID", "OPENAI_ORGANIZATION"], default=None),
)

Automatically inferred from env var OPENAI_ORG_ID if not provided.

batch_size class-attribute instance-attribute

batch_size: int = 20

Batch size to use when passing multiple documents to generate.

request_timeout class-attribute instance-attribute

request_timeout: float | tuple[float, float] | Any | None = Field(
    default=None, alias="timeout"
)

Timeout for requests to OpenAI completion API. Can be float, httpx.Timeout or None.

logit_bias class-attribute instance-attribute

logit_bias: dict[str, float] | None = None

Adjust the probability of specific tokens being generated.

max_retries class-attribute instance-attribute

max_retries: int = 2

Maximum number of retries to make when generating.

seed class-attribute instance-attribute

seed: int | None = None

Seed for generation

logprobs class-attribute instance-attribute

logprobs: int | None = None

Include the log probabilities on the logprobs most likely output tokens, as well the chosen tokens.

streaming class-attribute instance-attribute

streaming: bool = False

Whether to stream the results or not.

allowed_special class-attribute instance-attribute

allowed_special: Literal['all'] | set[str] = set()

Set of special tokens that are allowed。

disallowed_special class-attribute instance-attribute

disallowed_special: Literal['all'] | Collection[str] = 'all'

Set of special tokens that are not allowed。

tiktoken_model_name class-attribute instance-attribute

tiktoken_model_name: str | None = None

The model name to pass to tiktoken when using this class. Tiktoken is used to count the number of tokens in documents to constrain them to be under a certain limit. By default, when set to None, this will be the same as the embedding model name. However, there are some cases where you may want to use this Embedding class with a model name not supported by tiktoken. This can include when using Azure embeddings or when using one of the many model providers that expose an OpenAI-like API but with different models. In those cases, in order to avoid erroring when tiktoken is called, you can specify a model name to use here.

http_client class-attribute instance-attribute

http_client: Any | None = None

Optional httpx.Client. Only used for sync invocations. Must specify http_async_client as well if you'd like a custom client for async invocations.

http_async_client class-attribute instance-attribute

http_async_client: Any | None = None

Optional httpx.AsyncClient. Only used for async invocations. Must specify http_client as well if you'd like a custom client for sync invocations.

extra_body class-attribute instance-attribute

extra_body: Mapping[str, Any] | None = None

Optional additional JSON properties to include in the request parameters when making requests to OpenAI compatible APIs, such as vLLM.

max_context_size property

max_context_size: int

Get max context size for this model.

azure_endpoint class-attribute instance-attribute

azure_endpoint: str | None = Field(
    default_factory=from_env("AZURE_OPENAI_ENDPOINT", default=None)
)

Your Azure endpoint, including the resource.

Automatically inferred from env var AZURE_OPENAI_ENDPOINT if not provided.

Example: 'https://example-resource.azure.openai.com/'

deployment_name class-attribute instance-attribute

deployment_name: str | None = Field(default=None, alias='azure_deployment')

A model deployment.

If given sets the base client URL to include /deployments/{azure_deployment}.

Note

This means you won't be able to use non-deployment endpoints.

openai_api_version class-attribute instance-attribute

openai_api_version: str | None = Field(
    alias="api_version", default_factory=from_env("OPENAI_API_VERSION", default=None)
)

Automatically inferred from env var OPENAI_API_VERSION if not provided.

openai_api_key class-attribute instance-attribute

openai_api_key: SecretStr | None = Field(
    alias="api_key",
    default_factory=secret_from_env(
        ["AZURE_OPENAI_API_KEY", "OPENAI_API_KEY"], default=None
    ),
)

Automatically inferred from env var OPENAI_API_KEY if not provided.

azure_ad_token class-attribute instance-attribute

azure_ad_token: SecretStr | None = Field(
    default_factory=secret_from_env("AZURE_OPENAI_AD_TOKEN", default=None)
)

Your Azure Active Directory token.

Automatically inferred from env var AZURE_OPENAI_AD_TOKEN if not provided.

For more, see this page <https://www.microsoft.com/en-us/security/business/identity-access/microsoft-entra-id>.__

azure_ad_token_provider class-attribute instance-attribute

azure_ad_token_provider: Callable[[], str] | None = None

A function that returns an Azure Active Directory token.

Will be invoked on every sync request. For async requests, will be invoked if azure_ad_async_token_provider is not provided.

azure_ad_async_token_provider class-attribute instance-attribute

azure_ad_async_token_provider: Callable[[], Awaitable[str]] | None = None

A function that returns an Azure Active Directory token.

Will be invoked on every async request.

openai_api_type class-attribute instance-attribute

openai_api_type: str | None = Field(
    default_factory=from_env("OPENAI_API_TYPE", default="azure")
)

Legacy, for openai<1.0.0 support.

validate_base_url class-attribute instance-attribute

validate_base_url: bool = True

For backwards compatibility. If legacy val openai_api_base is passed in, try to infer if it is a base_url or azure_endpoint and update accordingly.

lc_secrets property

lc_secrets: dict[str, str]

Mapping of secret keys to environment variables.

lc_attributes property

lc_attributes: dict[str, Any]

Attributes relevant to tracing.

get_name

get_name(suffix: str | None = None, *, name: str | None = None) -> str

Get the name of the Runnable.

PARAMETER DESCRIPTION
suffix

An optional suffix to append to the name.

TYPE: str | None DEFAULT: None

name

An optional name to use instead of the Runnable's name.

TYPE: str | None DEFAULT: None

RETURNS DESCRIPTION
str

The name of the Runnable.

get_input_schema

get_input_schema(config: RunnableConfig | None = None) -> type[BaseModel]

Get a Pydantic model that can be used to validate input to the Runnable.

Runnable objects that leverage the configurable_fields and configurable_alternatives methods will have a dynamic input schema that depends on which configuration the Runnable is invoked with.

This method allows to get an input schema for a specific configuration.

PARAMETER DESCRIPTION
config

A config to use when generating the schema.

TYPE: RunnableConfig | None DEFAULT: None

RETURNS DESCRIPTION
type[BaseModel]

A Pydantic model that can be used to validate input.

get_input_jsonschema

get_input_jsonschema(config: RunnableConfig | None = None) -> dict[str, Any]

Get a JSON schema that represents the input to the Runnable.

PARAMETER DESCRIPTION
config

A config to use when generating the schema.

TYPE: RunnableConfig | None DEFAULT: None

RETURNS DESCRIPTION
dict[str, Any]

A JSON schema that represents the input to the Runnable.

Example
from langchain_core.runnables import RunnableLambda


def add_one(x: int) -> int:
    return x + 1


runnable = RunnableLambda(add_one)

print(runnable.get_input_jsonschema())

Added in version 0.3.0

get_output_schema

get_output_schema(config: RunnableConfig | None = None) -> type[BaseModel]

Get a Pydantic model that can be used to validate output to the Runnable.

Runnable objects that leverage the configurable_fields and configurable_alternatives methods will have a dynamic output schema that depends on which configuration the Runnable is invoked with.

This method allows to get an output schema for a specific configuration.

PARAMETER DESCRIPTION
config

A config to use when generating the schema.

TYPE: RunnableConfig | None DEFAULT: None

RETURNS DESCRIPTION
type[BaseModel]

A Pydantic model that can be used to validate output.

get_output_jsonschema

get_output_jsonschema(config: RunnableConfig | None = None) -> dict[str, Any]

Get a JSON schema that represents the output of the Runnable.

PARAMETER DESCRIPTION
config

A config to use when generating the schema.

TYPE: RunnableConfig | None DEFAULT: None

RETURNS DESCRIPTION
dict[str, Any]

A JSON schema that represents the output of the Runnable.

Example
from langchain_core.runnables import RunnableLambda


def add_one(x: int) -> int:
    return x + 1


runnable = RunnableLambda(add_one)

print(runnable.get_output_jsonschema())

Added in version 0.3.0

config_schema

config_schema(*, include: Sequence[str] | None = None) -> type[BaseModel]

The type of config this Runnable accepts specified as a Pydantic model.

To mark a field as configurable, see the configurable_fields and configurable_alternatives methods.

PARAMETER DESCRIPTION
include

A list of fields to include in the config schema.

TYPE: Sequence[str] | None DEFAULT: None

RETURNS DESCRIPTION
type[BaseModel]

A Pydantic model that can be used to validate config.

get_config_jsonschema

get_config_jsonschema(*, include: Sequence[str] | None = None) -> dict[str, Any]

Get a JSON schema that represents the config of the Runnable.

PARAMETER DESCRIPTION
include

A list of fields to include in the config schema.

TYPE: Sequence[str] | None DEFAULT: None

RETURNS DESCRIPTION
dict[str, Any]

A JSON schema that represents the config of the Runnable.

Added in version 0.3.0

get_graph

get_graph(config: RunnableConfig | None = None) -> Graph

Return a graph representation of this Runnable.

get_prompts

get_prompts(config: RunnableConfig | None = None) -> list[BasePromptTemplate]

Return a list of prompts used by this Runnable.

__or__

__or__(
    other: Runnable[Any, Other]
    | Callable[[Iterator[Any]], Iterator[Other]]
    | Callable[[AsyncIterator[Any]], AsyncIterator[Other]]
    | Callable[[Any], Other]
    | Mapping[str, Runnable[Any, Other] | Callable[[Any], Other] | Any],
) -> RunnableSerializable[Input, Other]

Runnable "or" operator.

Compose this Runnable with another object to create a RunnableSequence.

PARAMETER DESCRIPTION
other

Another Runnable or a Runnable-like object.

TYPE: Runnable[Any, Other] | Callable[[Iterator[Any]], Iterator[Other]] | Callable[[AsyncIterator[Any]], AsyncIterator[Other]] | Callable[[Any], Other] | Mapping[str, Runnable[Any, Other] | Callable[[Any], Other] | Any]

RETURNS DESCRIPTION
RunnableSerializable[Input, Other]

A new Runnable.

__ror__

__ror__(
    other: Runnable[Other, Any]
    | Callable[[Iterator[Other]], Iterator[Any]]
    | Callable[[AsyncIterator[Other]], AsyncIterator[Any]]
    | Callable[[Other], Any]
    | Mapping[str, Runnable[Other, Any] | Callable[[Other], Any] | Any],
) -> RunnableSerializable[Other, Output]

Runnable "reverse-or" operator.

Compose this Runnable with another object to create a RunnableSequence.

PARAMETER DESCRIPTION
other

Another Runnable or a Runnable-like object.

TYPE: Runnable[Other, Any] | Callable[[Iterator[Other]], Iterator[Any]] | Callable[[AsyncIterator[Other]], AsyncIterator[Any]] | Callable[[Other], Any] | Mapping[str, Runnable[Other, Any] | Callable[[Other], Any] | Any]

RETURNS DESCRIPTION
RunnableSerializable[Other, Output]

A new Runnable.

pipe

pipe(
    *others: Runnable[Any, Other] | Callable[[Any], Other], name: str | None = None
) -> RunnableSerializable[Input, Other]

Pipe Runnable objects.

Compose this Runnable with Runnable-like objects to make a RunnableSequence.

Equivalent to RunnableSequence(self, *others) or self | others[0] | ...

Example
from langchain_core.runnables import RunnableLambda


def add_one(x: int) -> int:
    return x + 1


def mul_two(x: int) -> int:
    return x * 2


runnable_1 = RunnableLambda(add_one)
runnable_2 = RunnableLambda(mul_two)
sequence = runnable_1.pipe(runnable_2)
# Or equivalently:
# sequence = runnable_1 | runnable_2
# sequence = RunnableSequence(first=runnable_1, last=runnable_2)
sequence.invoke(1)
await sequence.ainvoke(1)
# -> 4

sequence.batch([1, 2, 3])
await sequence.abatch([1, 2, 3])
# -> [4, 6, 8]
PARAMETER DESCRIPTION
*others

Other Runnable or Runnable-like objects to compose

TYPE: Runnable[Any, Other] | Callable[[Any], Other] DEFAULT: ()

name

An optional name for the resulting RunnableSequence.

TYPE: str | None DEFAULT: None

RETURNS DESCRIPTION
RunnableSerializable[Input, Other]

A new Runnable.

pick

pick(keys: str | list[str]) -> RunnableSerializable[Any, Any]

Pick keys from the output dict of this Runnable.

Pick a single key:

import json

from langchain_core.runnables import RunnableLambda, RunnableMap

as_str = RunnableLambda(str)
as_json = RunnableLambda(json.loads)
chain = RunnableMap(str=as_str, json=as_json)

chain.invoke("[1, 2, 3]")
# -> {"str": "[1, 2, 3]", "json": [1, 2, 3]}

json_only_chain = chain.pick("json")
json_only_chain.invoke("[1, 2, 3]")
# -> [1, 2, 3]

Pick a list of keys:

from typing import Any

import json

from langchain_core.runnables import RunnableLambda, RunnableMap

as_str = RunnableLambda(str)
as_json = RunnableLambda(json.loads)


def as_bytes(x: Any) -> bytes:
    return bytes(x, "utf-8")


chain = RunnableMap(str=as_str, json=as_json, bytes=RunnableLambda(as_bytes))

chain.invoke("[1, 2, 3]")
# -> {"str": "[1, 2, 3]", "json": [1, 2, 3], "bytes": b"[1, 2, 3]"}

json_and_bytes_chain = chain.pick(["json", "bytes"])
json_and_bytes_chain.invoke("[1, 2, 3]")
# -> {"json": [1, 2, 3], "bytes": b"[1, 2, 3]"}
PARAMETER DESCRIPTION
keys

A key or list of keys to pick from the output dict.

TYPE: str | list[str]

RETURNS DESCRIPTION
RunnableSerializable[Any, Any]

a new Runnable.

assign

Assigns new fields to the dict output of this Runnable.

from langchain_community.llms.fake import FakeStreamingListLLM
from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import SystemMessagePromptTemplate
from langchain_core.runnables import Runnable
from operator import itemgetter

prompt = (
    SystemMessagePromptTemplate.from_template("You are a nice assistant.")
    + "{question}"
)
model = FakeStreamingListLLM(responses=["foo-lish"])

chain: Runnable = prompt | model | {"str": StrOutputParser()}

chain_with_assign = chain.assign(hello=itemgetter("str") | model)

print(chain_with_assign.input_schema.model_json_schema())
# {'title': 'PromptInput', 'type': 'object', 'properties':
{'question': {'title': 'Question', 'type': 'string'}}}
print(chain_with_assign.output_schema.model_json_schema())
# {'title': 'RunnableSequenceOutput', 'type': 'object', 'properties':
{'str': {'title': 'Str',
'type': 'string'}, 'hello': {'title': 'Hello', 'type': 'string'}}}
PARAMETER DESCRIPTION
**kwargs

A mapping of keys to Runnable or Runnable-like objects that will be invoked with the entire output dict of this Runnable.

TYPE: Runnable[dict[str, Any], Any] | Callable[[dict[str, Any]], Any] | Mapping[str, Runnable[dict[str, Any], Any] | Callable[[dict[str, Any]], Any]] DEFAULT: {}

RETURNS DESCRIPTION
RunnableSerializable[Any, Any]

A new Runnable.

invoke

invoke(
    input: LanguageModelInput,
    config: RunnableConfig | None = None,
    *,
    stop: list[str] | None = None,
    **kwargs: Any,
) -> str

Transform a single input into an output.

PARAMETER DESCRIPTION
input

The input to the Runnable.

TYPE: Input

config

A config to use when invoking the Runnable. The config supports standard keys like 'tags', 'metadata' for tracing purposes, 'max_concurrency' for controlling how much work to do in parallel, and other keys. Please refer to the RunnableConfig for more details.

TYPE: RunnableConfig | None DEFAULT: None

RETURNS DESCRIPTION
Output

The output of the Runnable.

ainvoke async

ainvoke(
    input: LanguageModelInput,
    config: RunnableConfig | None = None,
    *,
    stop: list[str] | None = None,
    **kwargs: Any,
) -> str

Transform a single input into an output.

PARAMETER DESCRIPTION
input

The input to the Runnable.

TYPE: Input

config

A config to use when invoking the Runnable. The config supports standard keys like 'tags', 'metadata' for tracing purposes, 'max_concurrency' for controlling how much work to do in parallel, and other keys. Please refer to the RunnableConfig for more details.

TYPE: RunnableConfig | None DEFAULT: None

RETURNS DESCRIPTION
Output

The output of the Runnable.

batch

batch(
    inputs: list[LanguageModelInput],
    config: RunnableConfig | list[RunnableConfig] | None = None,
    *,
    return_exceptions: bool = False,
    **kwargs: Any,
) -> list[str]

Default implementation runs invoke in parallel using a thread pool executor.

The default implementation of batch works well for IO bound runnables.

Subclasses must override this method if they can batch more efficiently; e.g., if the underlying Runnable uses an API which supports a batch mode.

PARAMETER DESCRIPTION
inputs

A list of inputs to the Runnable.

TYPE: list[Input]

config

A config to use when invoking the Runnable. The config supports standard keys like 'tags', 'metadata' for tracing purposes, 'max_concurrency' for controlling how much work to do in parallel, and other keys. Please refer to the RunnableConfig for more details.

TYPE: RunnableConfig | list[RunnableConfig] | None DEFAULT: None

return_exceptions

Whether to return exceptions instead of raising them.

TYPE: bool DEFAULT: False

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

RETURNS DESCRIPTION
list[Output]

A list of outputs from the Runnable.

batch_as_completed

batch_as_completed(
    inputs: Sequence[Input],
    config: RunnableConfig | Sequence[RunnableConfig] | None = None,
    *,
    return_exceptions: bool = False,
    **kwargs: Any | None,
) -> Iterator[tuple[int, Output | Exception]]

Run invoke in parallel on a list of inputs.

Yields results as they complete.

PARAMETER DESCRIPTION
inputs

A list of inputs to the Runnable.

TYPE: Sequence[Input]

config

A config to use when invoking the Runnable. The config supports standard keys like 'tags', 'metadata' for tracing purposes, 'max_concurrency' for controlling how much work to do in parallel, and other keys. Please refer to the RunnableConfig for more details.

TYPE: RunnableConfig | Sequence[RunnableConfig] | None DEFAULT: None

return_exceptions

Whether to return exceptions instead of raising them.

TYPE: bool DEFAULT: False

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

YIELDS DESCRIPTION
tuple[int, Output | Exception]

Tuples of the index of the input and the output from the Runnable.

abatch async

abatch(
    inputs: list[LanguageModelInput],
    config: RunnableConfig | list[RunnableConfig] | None = None,
    *,
    return_exceptions: bool = False,
    **kwargs: Any,
) -> list[str]

Default implementation runs ainvoke in parallel using asyncio.gather.

The default implementation of batch works well for IO bound runnables.

Subclasses must override this method if they can batch more efficiently; e.g., if the underlying Runnable uses an API which supports a batch mode.

PARAMETER DESCRIPTION
inputs

A list of inputs to the Runnable.

TYPE: list[Input]

config

A config to use when invoking the Runnable. The config supports standard keys like 'tags', 'metadata' for tracing purposes, 'max_concurrency' for controlling how much work to do in parallel, and other keys. Please refer to the RunnableConfig for more details.

TYPE: RunnableConfig | list[RunnableConfig] | None DEFAULT: None

return_exceptions

Whether to return exceptions instead of raising them.

TYPE: bool DEFAULT: False

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

RETURNS DESCRIPTION
list[Output]

A list of outputs from the Runnable.

abatch_as_completed async

abatch_as_completed(
    inputs: Sequence[Input],
    config: RunnableConfig | Sequence[RunnableConfig] | None = None,
    *,
    return_exceptions: bool = False,
    **kwargs: Any | None,
) -> AsyncIterator[tuple[int, Output | Exception]]

Run ainvoke in parallel on a list of inputs.

Yields results as they complete.

PARAMETER DESCRIPTION
inputs

A list of inputs to the Runnable.

TYPE: Sequence[Input]

config

A config to use when invoking the Runnable. The config supports standard keys like 'tags', 'metadata' for tracing purposes, 'max_concurrency' for controlling how much work to do in parallel, and other keys. Please refer to the RunnableConfig for more details.

TYPE: RunnableConfig | Sequence[RunnableConfig] | None DEFAULT: None

return_exceptions

Whether to return exceptions instead of raising them.

TYPE: bool DEFAULT: False

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

YIELDS DESCRIPTION
AsyncIterator[tuple[int, Output | Exception]]

A tuple of the index of the input and the output from the Runnable.

stream

stream(
    input: LanguageModelInput,
    config: RunnableConfig | None = None,
    *,
    stop: list[str] | None = None,
    **kwargs: Any,
) -> Iterator[str]

Default implementation of stream, which calls invoke.

Subclasses must override this method if they support streaming output.

PARAMETER DESCRIPTION
input

The input to the Runnable.

TYPE: Input

config

The config to use for the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

YIELDS DESCRIPTION
Output

The output of the Runnable.

astream async

astream(
    input: LanguageModelInput,
    config: RunnableConfig | None = None,
    *,
    stop: list[str] | None = None,
    **kwargs: Any,
) -> AsyncIterator[str]

Default implementation of astream, which calls ainvoke.

Subclasses must override this method if they support streaming output.

PARAMETER DESCRIPTION
input

The input to the Runnable.

TYPE: Input

config

The config to use for the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

YIELDS DESCRIPTION
AsyncIterator[Output]

The output of the Runnable.

astream_log async

astream_log(
    input: Any,
    config: RunnableConfig | None = None,
    *,
    diff: bool = True,
    with_streamed_output_list: bool = True,
    include_names: Sequence[str] | None = None,
    include_types: Sequence[str] | None = None,
    include_tags: Sequence[str] | None = None,
    exclude_names: Sequence[str] | None = None,
    exclude_types: Sequence[str] | None = None,
    exclude_tags: Sequence[str] | None = None,
    **kwargs: Any,
) -> AsyncIterator[RunLogPatch] | AsyncIterator[RunLog]

Stream all output from a Runnable, as reported to the callback system.

This includes all inner runs of LLMs, Retrievers, Tools, etc.

Output is streamed as Log objects, which include a list of Jsonpatch ops that describe how the state of the run has changed in each step, and the final state of the run.

The Jsonpatch ops can be applied in order to construct state.

PARAMETER DESCRIPTION
input

The input to the Runnable.

TYPE: Any

config

The config to use for the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

diff

Whether to yield diffs between each step or the current state.

TYPE: bool DEFAULT: True

with_streamed_output_list

Whether to yield the streamed_output list.

TYPE: bool DEFAULT: True

include_names

Only include logs with these names.

TYPE: Sequence[str] | None DEFAULT: None

include_types

Only include logs with these types.

TYPE: Sequence[str] | None DEFAULT: None

include_tags

Only include logs with these tags.

TYPE: Sequence[str] | None DEFAULT: None

exclude_names

Exclude logs with these names.

TYPE: Sequence[str] | None DEFAULT: None

exclude_types

Exclude logs with these types.

TYPE: Sequence[str] | None DEFAULT: None

exclude_tags

Exclude logs with these tags.

TYPE: Sequence[str] | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any DEFAULT: {}

YIELDS DESCRIPTION
AsyncIterator[RunLogPatch] | AsyncIterator[RunLog]

A RunLogPatch or RunLog object.

astream_events async

astream_events(
    input: Any,
    config: RunnableConfig | None = None,
    *,
    version: Literal["v1", "v2"] = "v2",
    include_names: Sequence[str] | None = None,
    include_types: Sequence[str] | None = None,
    include_tags: Sequence[str] | None = None,
    exclude_names: Sequence[str] | None = None,
    exclude_types: Sequence[str] | None = None,
    exclude_tags: Sequence[str] | None = None,
    **kwargs: Any,
) -> AsyncIterator[StreamEvent]

Generate a stream of events.

Use to create an iterator over StreamEvent that provide real-time information about the progress of the Runnable, including StreamEvent from intermediate results.

A StreamEvent is a dictionary with the following schema:

  • event: Event names are of the format: on_[runnable_type]_(start|stream|end).
  • name: The name of the Runnable that generated the event.
  • run_id: Randomly generated ID associated with the given execution of the Runnable that emitted the event. A child Runnable that gets invoked as part of the execution of a parent Runnable is assigned its own unique ID.
  • parent_ids: The IDs of the parent runnables that generated the event. The root Runnable will have an empty list. The order of the parent IDs is from the root to the immediate parent. Only available for v2 version of the API. The v1 version of the API will return an empty list.
  • tags: The tags of the Runnable that generated the event.
  • metadata: The metadata of the Runnable that generated the event.
  • data: The data associated with the event. The contents of this field depend on the type of event. See the table below for more details.

Below is a table that illustrates some events that might be emitted by various chains. Metadata fields have been omitted from the table for brevity. Chain definitions have been included after the table.

Note

This reference table is for the v2 version of the schema.

event name chunk input output
on_chat_model_start '[model name]' {"messages": [[SystemMessage, HumanMessage]]}
on_chat_model_stream '[model name]' AIMessageChunk(content="hello")
on_chat_model_end '[model name]' {"messages": [[SystemMessage, HumanMessage]]} AIMessageChunk(content="hello world")
on_llm_start '[model name]' {'input': 'hello'}
on_llm_stream '[model name]' 'Hello'
on_llm_end '[model name]' 'Hello human!'
on_chain_start 'format_docs'
on_chain_stream 'format_docs' 'hello world!, goodbye world!'
on_chain_end 'format_docs' [Document(...)] 'hello world!, goodbye world!'
on_tool_start 'some_tool' {"x": 1, "y": "2"}
on_tool_end 'some_tool' {"x": 1, "y": "2"}
on_retriever_start '[retriever name]' {"query": "hello"}
on_retriever_end '[retriever name]' {"query": "hello"} [Document(...), ..]
on_prompt_start '[template_name]' {"question": "hello"}
on_prompt_end '[template_name]' {"question": "hello"} ChatPromptValue(messages: [SystemMessage, ...])

In addition to the standard events, users can also dispatch custom events (see example below).

Custom events will be only be surfaced with in the v2 version of the API!

A custom event has following format:

Attribute Type Description
name str A user defined name for the event.
data Any The data associated with the event. This can be anything, though we suggest making it JSON serializable.

Here are declarations associated with the standard events shown above:

format_docs:

def format_docs(docs: list[Document]) -> str:
    '''Format the docs.'''
    return ", ".join([doc.page_content for doc in docs])


format_docs = RunnableLambda(format_docs)

some_tool:

@tool
def some_tool(x: int, y: str) -> dict:
    '''Some_tool.'''
    return {"x": x, "y": y}

prompt:

template = ChatPromptTemplate.from_messages(
    [
        ("system", "You are Cat Agent 007"),
        ("human", "{question}"),
    ]
).with_config({"run_name": "my_template", "tags": ["my_template"]})

For instance:

from langchain_core.runnables import RunnableLambda


async def reverse(s: str) -> str:
    return s[::-1]


chain = RunnableLambda(func=reverse)

events = [event async for event in chain.astream_events("hello", version="v2")]

# Will produce the following events
# (run_id, and parent_ids has been omitted for brevity):
[
    {
        "data": {"input": "hello"},
        "event": "on_chain_start",
        "metadata": {},
        "name": "reverse",
        "tags": [],
    },
    {
        "data": {"chunk": "olleh"},
        "event": "on_chain_stream",
        "metadata": {},
        "name": "reverse",
        "tags": [],
    },
    {
        "data": {"output": "olleh"},
        "event": "on_chain_end",
        "metadata": {},
        "name": "reverse",
        "tags": [],
    },
]
Example: Dispatch Custom Event
from langchain_core.callbacks.manager import (
    adispatch_custom_event,
)
from langchain_core.runnables import RunnableLambda, RunnableConfig
import asyncio


async def slow_thing(some_input: str, config: RunnableConfig) -> str:
    """Do something that takes a long time."""
    await asyncio.sleep(1) # Placeholder for some slow operation
    await adispatch_custom_event(
        "progress_event",
        {"message": "Finished step 1 of 3"},
        config=config # Must be included for python < 3.10
    )
    await asyncio.sleep(1) # Placeholder for some slow operation
    await adispatch_custom_event(
        "progress_event",
        {"message": "Finished step 2 of 3"},
        config=config # Must be included for python < 3.10
    )
    await asyncio.sleep(1) # Placeholder for some slow operation
    return "Done"

slow_thing = RunnableLambda(slow_thing)

async for event in slow_thing.astream_events("some_input", version="v2"):
    print(event)
PARAMETER DESCRIPTION
input

The input to the Runnable.

TYPE: Any

config

The config to use for the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

version

The version of the schema to use either 'v2' or 'v1'. Users should use 'v2'. 'v1' is for backwards compatibility and will be deprecated in 0.4.0. No default will be assigned until the API is stabilized. custom events will only be surfaced in 'v2'.

TYPE: Literal['v1', 'v2'] DEFAULT: 'v2'

include_names

Only include events from Runnable objects with matching names.

TYPE: Sequence[str] | None DEFAULT: None

include_types

Only include events from Runnable objects with matching types.

TYPE: Sequence[str] | None DEFAULT: None

include_tags

Only include events from Runnable objects with matching tags.

TYPE: Sequence[str] | None DEFAULT: None

exclude_names

Exclude events from Runnable objects with matching names.

TYPE: Sequence[str] | None DEFAULT: None

exclude_types

Exclude events from Runnable objects with matching types.

TYPE: Sequence[str] | None DEFAULT: None

exclude_tags

Exclude events from Runnable objects with matching tags.

TYPE: Sequence[str] | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable. These will be passed to astream_log as this implementation of astream_events is built on top of astream_log.

TYPE: Any DEFAULT: {}

YIELDS DESCRIPTION
AsyncIterator[StreamEvent]

An async stream of StreamEvent.

RAISES DESCRIPTION
NotImplementedError

If the version is not 'v1' or 'v2'.

transform

transform(
    input: Iterator[Input], config: RunnableConfig | None = None, **kwargs: Any | None
) -> Iterator[Output]

Transform inputs to outputs.

Default implementation of transform, which buffers input and calls astream.

Subclasses must override this method if they can start producing output while input is still being generated.

PARAMETER DESCRIPTION
input

An iterator of inputs to the Runnable.

TYPE: Iterator[Input]

config

The config to use for the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

YIELDS DESCRIPTION
Output

The output of the Runnable.

atransform async

atransform(
    input: AsyncIterator[Input],
    config: RunnableConfig | None = None,
    **kwargs: Any | None,
) -> AsyncIterator[Output]

Transform inputs to outputs.

Default implementation of atransform, which buffers input and calls astream.

Subclasses must override this method if they can start producing output while input is still being generated.

PARAMETER DESCRIPTION
input

An async iterator of inputs to the Runnable.

TYPE: AsyncIterator[Input]

config

The config to use for the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any | None DEFAULT: {}

YIELDS DESCRIPTION
AsyncIterator[Output]

The output of the Runnable.

bind

bind(**kwargs: Any) -> Runnable[Input, Output]

Bind arguments to a Runnable, returning a new Runnable.

Useful when a Runnable in a chain requires an argument that is not in the output of the previous Runnable or included in the user input.

PARAMETER DESCRIPTION
**kwargs

The arguments to bind to the Runnable.

TYPE: Any DEFAULT: {}

RETURNS DESCRIPTION
Runnable[Input, Output]

A new Runnable with the arguments bound.

Example
from langchain_ollama import ChatOllama
from langchain_core.output_parsers import StrOutputParser

model = ChatOllama(model="llama3.1")

# Without bind
chain = model | StrOutputParser()

chain.invoke("Repeat quoted words exactly: 'One two three four five.'")
# Output is 'One two three four five.'

# With bind
chain = model.bind(stop=["three"]) | StrOutputParser()

chain.invoke("Repeat quoted words exactly: 'One two three four five.'")
# Output is 'One two'

with_config

with_config(
    config: RunnableConfig | None = None, **kwargs: Any
) -> Runnable[Input, Output]

Bind config to a Runnable, returning a new Runnable.

PARAMETER DESCRIPTION
config

The config to bind to the Runnable.

TYPE: RunnableConfig | None DEFAULT: None

**kwargs

Additional keyword arguments to pass to the Runnable.

TYPE: Any DEFAULT: {}

RETURNS DESCRIPTION
Runnable[Input, Output]

A new Runnable with the config bound.

with_listeners

with_listeners(
    *,
    on_start: Callable[[Run], None]
    | Callable[[Run, RunnableConfig], None]
    | None = None,
    on_end: Callable[[Run], None] | Callable[[Run, RunnableConfig], None] | None = None,
    on_error: Callable[[Run], None]
    | Callable[[Run, RunnableConfig], None]
    | None = None,
) -> Runnable[Input, Output]

Bind lifecycle listeners to a Runnable, returning a new Runnable.

The Run object contains information about the run, including its id, type, input, output, error, start_time, end_time, and any tags or metadata added to the run.

PARAMETER DESCRIPTION
on_start

Called before the Runnable starts running, with the Run object.

TYPE: Callable[[Run], None] | Callable[[Run, RunnableConfig], None] | None DEFAULT: None

on_end

Called after the Runnable finishes running, with the Run object.

TYPE: Callable[[Run], None] | Callable[[Run, RunnableConfig], None] | None DEFAULT: None

on_error

Called if the Runnable throws an error, with the Run object.

TYPE: Callable[[Run], None] | Callable[[Run, RunnableConfig], None] | None DEFAULT: None

RETURNS DESCRIPTION
Runnable[Input, Output]

A new Runnable with the listeners bound.

Example
from langchain_core.runnables import RunnableLambda
from langchain_core.tracers.schemas import Run

import time


def test_runnable(time_to_sleep: int):
    time.sleep(time_to_sleep)


def fn_start(run_obj: Run):
    print("start_time:", run_obj.start_time)


def fn_end(run_obj: Run):
    print("end_time:", run_obj.end_time)


chain = RunnableLambda(test_runnable).with_listeners(
    on_start=fn_start, on_end=fn_end
)
chain.invoke(2)

with_alisteners

with_alisteners(
    *,
    on_start: AsyncListener | None = None,
    on_end: AsyncListener | None = None,
    on_error: AsyncListener | None = None,
) -> Runnable[Input, Output]

Bind async lifecycle listeners to a Runnable.

Returns a new Runnable.

The Run object contains information about the run, including its id, type, input, output, error, start_time, end_time, and any tags or metadata added to the run.

PARAMETER DESCRIPTION
on_start

Called asynchronously before the Runnable starts running, with the Run object.

TYPE: AsyncListener | None DEFAULT: None

on_end

Called asynchronously after the Runnable finishes running, with the Run object.

TYPE: AsyncListener | None DEFAULT: None

on_error

Called asynchronously if the Runnable throws an error, with the Run object.

TYPE: AsyncListener | None DEFAULT: None

RETURNS DESCRIPTION
Runnable[Input, Output]

A new Runnable with the listeners bound.

Example
from langchain_core.runnables import RunnableLambda, Runnable
from datetime import datetime, timezone
import time
import asyncio

def format_t(timestamp: float) -> str:
    return datetime.fromtimestamp(timestamp, tz=timezone.utc).isoformat()

async def test_runnable(time_to_sleep: int):
    print(f"Runnable[{time_to_sleep}s]: starts at {format_t(time.time())}")
    await asyncio.sleep(time_to_sleep)
    print(f"Runnable[{time_to_sleep}s]: ends at {format_t(time.time())}")

async def fn_start(run_obj: Runnable):
    print(f"on start callback starts at {format_t(time.time())}")
    await asyncio.sleep(3)
    print(f"on start callback ends at {format_t(time.time())}")

async def fn_end(run_obj: Runnable):
    print(f"on end callback starts at {format_t(time.time())}")
    await asyncio.sleep(2)
    print(f"on end callback ends at {format_t(time.time())}")

runnable = RunnableLambda(test_runnable).with_alisteners(
    on_start=fn_start,
    on_end=fn_end
)
async def concurrent_runs():
    await asyncio.gather(runnable.ainvoke(2), runnable.ainvoke(3))

asyncio.run(concurrent_runs())
Result:
on start callback starts at 2025-03-01T07:05:22.875378+00:00
on start callback starts at 2025-03-01T07:05:22.875495+00:00
on start callback ends at 2025-03-01T07:05:25.878862+00:00
on start callback ends at 2025-03-01T07:05:25.878947+00:00
Runnable[2s]: starts at 2025-03-01T07:05:25.879392+00:00
Runnable[3s]: starts at 2025-03-01T07:05:25.879804+00:00
Runnable[2s]: ends at 2025-03-01T07:05:27.881998+00:00
on end callback starts at 2025-03-01T07:05:27.882360+00:00
Runnable[3s]: ends at 2025-03-01T07:05:28.881737+00:00
on end callback starts at 2025-03-01T07:05:28.882428+00:00
on end callback ends at 2025-03-01T07:05:29.883893+00:00
on end callback ends at 2025-03-01T07:05:30.884831+00:00

with_types

with_types(
    *, input_type: type[Input] | None = None, output_type: type[Output] | None = None
) -> Runnable[Input, Output]

Bind input and output types to a Runnable, returning a new Runnable.

PARAMETER DESCRIPTION
input_type

The input type to bind to the Runnable.

TYPE: type[Input] | None DEFAULT: None

output_type

The output type to bind to the Runnable.

TYPE: type[Output] | None DEFAULT: None

RETURNS DESCRIPTION
Runnable[Input, Output]

A new Runnable with the types bound.

with_retry

with_retry(
    *,
    retry_if_exception_type: tuple[type[BaseException], ...] = (Exception,),
    wait_exponential_jitter: bool = True,
    exponential_jitter_params: ExponentialJitterParams | None = None,
    stop_after_attempt: int = 3,
) -> Runnable[Input, Output]

Create a new Runnable that retries the original Runnable on exceptions.

PARAMETER DESCRIPTION
retry_if_exception_type

A tuple of exception types to retry on.

TYPE: tuple[type[BaseException], ...] DEFAULT: (Exception,)

wait_exponential_jitter

Whether to add jitter to the wait time between retries.

TYPE: bool DEFAULT: True

stop_after_attempt

The maximum number of attempts to make before giving up.

TYPE: int DEFAULT: 3

exponential_jitter_params

Parameters for tenacity.wait_exponential_jitter. Namely: initial, max, exp_base, and jitter (all float values).

TYPE: ExponentialJitterParams | None DEFAULT: None

RETURNS DESCRIPTION
Runnable[Input, Output]

A new Runnable that retries the original Runnable on exceptions.

Example
from langchain_core.runnables import RunnableLambda

count = 0


def _lambda(x: int) -> None:
    global count
    count = count + 1
    if x == 1:
        raise ValueError("x is 1")
    else:
        pass


runnable = RunnableLambda(_lambda)
try:
    runnable.with_retry(
        stop_after_attempt=2,
        retry_if_exception_type=(ValueError,),
    ).invoke(1)
except ValueError:
    pass

assert count == 2

map

map() -> Runnable[list[Input], list[Output]]

Return a new Runnable that maps a list of inputs to a list of outputs.

Calls invoke with each input.

RETURNS DESCRIPTION
Runnable[list[Input], list[Output]]

A new Runnable that maps a list of inputs to a list of outputs.

Example
from langchain_core.runnables import RunnableLambda


def _lambda(x: int) -> int:
    return x + 1


runnable = RunnableLambda(_lambda)
print(runnable.map().invoke([1, 2, 3]))  # [2, 3, 4]

with_fallbacks

with_fallbacks(
    fallbacks: Sequence[Runnable[Input, Output]],
    *,
    exceptions_to_handle: tuple[type[BaseException], ...] = (Exception,),
    exception_key: str | None = None,
) -> RunnableWithFallbacks[Input, Output]

Add fallbacks to a Runnable, returning a new Runnable.

The new Runnable will try the original Runnable, and then each fallback in order, upon failures.

PARAMETER DESCRIPTION
fallbacks

A sequence of runnables to try if the original Runnable fails.

TYPE: Sequence[Runnable[Input, Output]]

exceptions_to_handle

A tuple of exception types to handle.

TYPE: tuple[type[BaseException], ...] DEFAULT: (Exception,)

exception_key

If string is specified then handled exceptions will be passed to fallbacks as part of the input under the specified key. If None, exceptions will not be passed to fallbacks. If used, the base Runnable and its fallbacks must accept a dictionary as input.

TYPE: str | None DEFAULT: None

RETURNS DESCRIPTION
RunnableWithFallbacks[Input, Output]

A new Runnable that will try the original Runnable, and then each Fallback in order, upon failures.

Example
from typing import Iterator

from langchain_core.runnables import RunnableGenerator


def _generate_immediate_error(input: Iterator) -> Iterator[str]:
    raise ValueError()
    yield ""


def _generate(input: Iterator) -> Iterator[str]:
    yield from "foo bar"


runnable = RunnableGenerator(_generate_immediate_error).with_fallbacks(
    [RunnableGenerator(_generate)]
)
print("".join(runnable.stream({})))  # foo bar
PARAMETER DESCRIPTION
fallbacks

A sequence of runnables to try if the original Runnable fails.

TYPE: Sequence[Runnable[Input, Output]]

exceptions_to_handle

A tuple of exception types to handle.

TYPE: tuple[type[BaseException], ...] DEFAULT: (Exception,)

exception_key

If string is specified then handled exceptions will be passed to fallbacks as part of the input under the specified key. If None, exceptions will not be passed to fallbacks. If used, the base Runnable and its fallbacks must accept a dictionary as input.

TYPE: str | None DEFAULT: None

RETURNS DESCRIPTION
RunnableWithFallbacks[Input, Output]

A new Runnable that will try the original Runnable, and then each Fallback in order, upon failures.

as_tool

as_tool(
    args_schema: type[BaseModel] | None = None,
    *,
    name: str | None = None,
    description: str | None = None,
    arg_types: dict[str, type] | None = None,
) -> BaseTool

Create a BaseTool from a Runnable.

as_tool will instantiate a BaseTool with a name, description, and args_schema from a Runnable. Where possible, schemas are inferred from runnable.get_input_schema. Alternatively (e.g., if the Runnable takes a dict as input and the specific dict keys are not typed), the schema can be specified directly with args_schema. You can also pass arg_types to just specify the required arguments and their types.

PARAMETER DESCRIPTION
args_schema

The schema for the tool.

TYPE: type[BaseModel] | None DEFAULT: None

name

The name of the tool.

TYPE: str | None DEFAULT: None

description

The description of the tool.

TYPE: str | None DEFAULT: None

arg_types

A dictionary of argument names to types.

TYPE: dict[str, type] | None DEFAULT: None

RETURNS DESCRIPTION
BaseTool

A BaseTool instance.

Typed dict input:

from typing_extensions import TypedDict
from langchain_core.runnables import RunnableLambda


class Args(TypedDict):
    a: int
    b: list[int]


def f(x: Args) -> str:
    return str(x["a"] * max(x["b"]))


runnable = RunnableLambda(f)
as_tool = runnable.as_tool()
as_tool.invoke({"a": 3, "b": [1, 2]})

dict input, specifying schema via args_schema:

from typing import Any
from pydantic import BaseModel, Field
from langchain_core.runnables import RunnableLambda

def f(x: dict[str, Any]) -> str:
    return str(x["a"] * max(x["b"]))

class FSchema(BaseModel):
    """Apply a function to an integer and list of integers."""

    a: int = Field(..., description="Integer")
    b: list[int] = Field(..., description="List of ints")

runnable = RunnableLambda(f)
as_tool = runnable.as_tool(FSchema)
as_tool.invoke({"a": 3, "b": [1, 2]})

dict input, specifying schema via arg_types:

from typing import Any
from langchain_core.runnables import RunnableLambda


def f(x: dict[str, Any]) -> str:
    return str(x["a"] * max(x["b"]))


runnable = RunnableLambda(f)
as_tool = runnable.as_tool(arg_types={"a": int, "b": list[int]})
as_tool.invoke({"a": 3, "b": [1, 2]})

String input:

from langchain_core.runnables import RunnableLambda


def f(x: str) -> str:
    return x + "a"


def g(x: str) -> str:
    return x + "z"


runnable = RunnableLambda(f) | g
as_tool = runnable.as_tool()
as_tool.invoke("b")

Added in version 0.2.14

__init__

__init__(*args: Any, **kwargs: Any) -> None

lc_id classmethod

lc_id() -> list[str]

Return a unique identifier for this class for serialization purposes.

The unique identifier is a list of strings that describes the path to the object.

For example, for the class langchain.llms.openai.OpenAI, the id is ["langchain", "llms", "openai", "OpenAI"].

to_json

to_json() -> SerializedConstructor | SerializedNotImplemented

Serialize the Runnable to JSON.

RETURNS DESCRIPTION
SerializedConstructor | SerializedNotImplemented

A JSON-serializable representation of the Runnable.

to_json_not_implemented

to_json_not_implemented() -> SerializedNotImplemented

Serialize a "not implemented" object.

RETURNS DESCRIPTION
SerializedNotImplemented

SerializedNotImplemented.

configurable_fields

configurable_fields(
    **kwargs: AnyConfigurableField,
) -> RunnableSerializable[Input, Output]

Configure particular Runnable fields at runtime.

PARAMETER DESCRIPTION
**kwargs

A dictionary of ConfigurableField instances to configure.

TYPE: AnyConfigurableField DEFAULT: {}

RAISES DESCRIPTION
ValueError

If a configuration key is not found in the Runnable.

RETURNS DESCRIPTION
RunnableSerializable[Input, Output]

A new Runnable with the fields configured.

from langchain_core.runnables import ConfigurableField
from langchain_openai import ChatOpenAI

model = ChatOpenAI(max_tokens=20).configurable_fields(
    max_tokens=ConfigurableField(
        id="output_token_number",
        name="Max tokens in the output",
        description="The maximum number of tokens in the output",
    )
)

# max_tokens = 20
print("max_tokens_20: ", model.invoke("tell me something about chess").content)

# max_tokens = 200
print(
    "max_tokens_200: ",
    model.with_config(configurable={"output_token_number": 200})
    .invoke("tell me something about chess")
    .content,
)

configurable_alternatives

configurable_alternatives(
    which: ConfigurableField,
    *,
    default_key: str = "default",
    prefix_keys: bool = False,
    **kwargs: Runnable[Input, Output] | Callable[[], Runnable[Input, Output]],
) -> RunnableSerializable[Input, Output]

Configure alternatives for Runnable objects that can be set at runtime.

PARAMETER DESCRIPTION
which

The ConfigurableField instance that will be used to select the alternative.

TYPE: ConfigurableField

default_key

The default key to use if no alternative is selected.

TYPE: str DEFAULT: 'default'

prefix_keys

Whether to prefix the keys with the ConfigurableField id.

TYPE: bool DEFAULT: False

**kwargs

A dictionary of keys to Runnable instances or callables that return Runnable instances.

TYPE: Runnable[Input, Output] | Callable[[], Runnable[Input, Output]] DEFAULT: {}

RETURNS DESCRIPTION
RunnableSerializable[Input, Output]

A new Runnable with the alternatives configured.

from langchain_anthropic import ChatAnthropic
from langchain_core.runnables.utils import ConfigurableField
from langchain_openai import ChatOpenAI

model = ChatAnthropic(
    model_name="claude-3-7-sonnet-20250219"
).configurable_alternatives(
    ConfigurableField(id="llm"),
    default_key="anthropic",
    openai=ChatOpenAI(),
)

# uses the default model ChatAnthropic
print(model.invoke("which organization created you?").content)

# uses ChatOpenAI
print(
    model.with_config(configurable={"llm": "openai"})
    .invoke("which organization created you?")
    .content
)

set_verbose

set_verbose(verbose: bool | None) -> bool

If verbose is None, set it.

This allows users to pass in None as verbose to access the global setting.

PARAMETER DESCRIPTION
verbose

The verbosity setting to use.

TYPE: bool | None

RETURNS DESCRIPTION
bool

The verbosity setting to use.

generate_prompt

generate_prompt(
    prompts: list[PromptValue],
    stop: list[str] | None = None,
    callbacks: Callbacks | list[Callbacks] | None = None,
    **kwargs: Any,
) -> LLMResult

Pass a sequence of prompts to the model and return model generations.

This method should make use of batched calls for models that expose a batched API.

Use this method when you want to:

  1. Take advantage of batched calls,
  2. Need more output from the model than just the top generated value,
  3. Are building chains that are agnostic to the underlying language model type (e.g., pure text completion models vs chat models).
PARAMETER DESCRIPTION
prompts

List of PromptValue objects. A PromptValue is an object that can be converted to match the format of any language model (string for pure text generation models and BaseMessage objects for chat models).

TYPE: list[PromptValue]

stop

Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings.

TYPE: list[str] | None DEFAULT: None

callbacks

Callbacks to pass through. Used for executing additional functionality, such as logging or streaming, throughout generation.

TYPE: Callbacks DEFAULT: None

**kwargs

Arbitrary additional keyword arguments. These are usually passed to the model provider API call.

TYPE: Any DEFAULT: {}

RETURNS DESCRIPTION
LLMResult

An LLMResult, which contains a list of candidate Generation objects for each input prompt and additional model provider-specific output.

agenerate_prompt async

agenerate_prompt(
    prompts: list[PromptValue],
    stop: list[str] | None = None,
    callbacks: Callbacks | list[Callbacks] | None = None,
    **kwargs: Any,
) -> LLMResult

Asynchronously pass a sequence of prompts and return model generations.

This method should make use of batched calls for models that expose a batched API.

Use this method when you want to:

  1. Take advantage of batched calls,
  2. Need more output from the model than just the top generated value,
  3. Are building chains that are agnostic to the underlying language model type (e.g., pure text completion models vs chat models).
PARAMETER DESCRIPTION
prompts

List of PromptValue objects. A PromptValue is an object that can be converted to match the format of any language model (string for pure text generation models and BaseMessage objects for chat models).

TYPE: list[PromptValue]

stop

Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings.

TYPE: list[str] | None DEFAULT: None

callbacks

Callbacks to pass through. Used for executing additional functionality, such as logging or streaming, throughout generation.

TYPE: Callbacks DEFAULT: None

**kwargs

Arbitrary additional keyword arguments. These are usually passed to the model provider API call.

TYPE: Any DEFAULT: {}

RETURNS DESCRIPTION
LLMResult

An LLMResult, which contains a list of candidate Generation objects for each input prompt and additional model provider-specific output.

with_structured_output

with_structured_output(
    schema: dict | type, **kwargs: Any
) -> Runnable[LanguageModelInput, dict | BaseModel]

Not implemented on this class.

get_token_ids

get_token_ids(text: str) -> list[int]

Get the token IDs using the tiktoken package.

get_num_tokens

get_num_tokens(text: str) -> int

Get the number of tokens present in the text.

Useful for checking if an input fits in a model's context window.

PARAMETER DESCRIPTION
text

The string input to tokenize.

TYPE: str

RETURNS DESCRIPTION
int

The integer number of tokens in the text.

get_num_tokens_from_messages

get_num_tokens_from_messages(
    messages: list[BaseMessage], tools: Sequence | None = None
) -> int

Get the number of tokens in the messages.

Useful for checking if an input fits in a model's context window.

Note

The base implementation of get_num_tokens_from_messages ignores tool schemas.

PARAMETER DESCRIPTION
messages

The message inputs to tokenize.

TYPE: list[BaseMessage]

tools

If provided, sequence of dict, BaseModel, function, or BaseTool objects to be converted to tool schemas.

TYPE: Sequence | None DEFAULT: None

RETURNS DESCRIPTION
int

The sum of the number of tokens across the messages.

generate

generate(
    prompts: list[str],
    stop: list[str] | None = None,
    callbacks: Callbacks | list[Callbacks] | None = None,
    *,
    tags: list[str] | list[list[str]] | None = None,
    metadata: dict[str, Any] | list[dict[str, Any]] | None = None,
    run_name: str | list[str] | None = None,
    run_id: UUID | list[UUID | None] | None = None,
    **kwargs: Any,
) -> LLMResult

Pass a sequence of prompts to a model and return generations.

This method should make use of batched calls for models that expose a batched API.

Use this method when you want to:

  1. Take advantage of batched calls,
  2. Need more output from the model than just the top generated value,
  3. Are building chains that are agnostic to the underlying language model type (e.g., pure text completion models vs chat models).
PARAMETER DESCRIPTION
prompts

List of string prompts.

TYPE: list[str]

stop

Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings.

TYPE: list[str] | None DEFAULT: None

callbacks

Callbacks to pass through. Used for executing additional functionality, such as logging or streaming, throughout generation.

TYPE: Callbacks | list[Callbacks] | None DEFAULT: None

tags

List of tags to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: list[str] | list[list[str]] | None DEFAULT: None

metadata

List of metadata dictionaries to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: dict[str, Any] | list[dict[str, Any]] | None DEFAULT: None

run_name

List of run names to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: str | list[str] | None DEFAULT: None

run_id

List of run IDs to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: UUID | list[UUID | None] | None DEFAULT: None

**kwargs

Arbitrary additional keyword arguments. These are usually passed to the model provider API call.

TYPE: Any DEFAULT: {}

RAISES DESCRIPTION
ValueError

If prompts is not a list.

ValueError

If the length of callbacks, tags, metadata, or run_name (if provided) does not match the length of prompts.

RETURNS DESCRIPTION
LLMResult

An LLMResult, which contains a list of candidate Generations for each input prompt and additional model provider-specific output.

agenerate async

agenerate(
    prompts: list[str],
    stop: list[str] | None = None,
    callbacks: Callbacks | list[Callbacks] | None = None,
    *,
    tags: list[str] | list[list[str]] | None = None,
    metadata: dict[str, Any] | list[dict[str, Any]] | None = None,
    run_name: str | list[str] | None = None,
    run_id: UUID | list[UUID | None] | None = None,
    **kwargs: Any,
) -> LLMResult

Asynchronously pass a sequence of prompts to a model and return generations.

This method should make use of batched calls for models that expose a batched API.

Use this method when you want to:

  1. Take advantage of batched calls,
  2. Need more output from the model than just the top generated value,
  3. Are building chains that are agnostic to the underlying language model type (e.g., pure text completion models vs chat models).
PARAMETER DESCRIPTION
prompts

List of string prompts.

TYPE: list[str]

stop

Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings.

TYPE: list[str] | None DEFAULT: None

callbacks

Callbacks to pass through. Used for executing additional functionality, such as logging or streaming, throughout generation.

TYPE: Callbacks | list[Callbacks] | None DEFAULT: None

tags

List of tags to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: list[str] | list[list[str]] | None DEFAULT: None

metadata

List of metadata dictionaries to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: dict[str, Any] | list[dict[str, Any]] | None DEFAULT: None

run_name

List of run names to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: str | list[str] | None DEFAULT: None

run_id

List of run IDs to associate with each prompt. If provided, the length of the list must match the length of the prompts list.

TYPE: UUID | list[UUID | None] | None DEFAULT: None

**kwargs

Arbitrary additional keyword arguments. These are usually passed to the model provider API call.

TYPE: Any DEFAULT: {}

RAISES DESCRIPTION
ValueError

If the length of callbacks, tags, metadata, or run_name (if provided) does not match the length of prompts.

RETURNS DESCRIPTION
LLMResult

An LLMResult, which contains a list of candidate Generations for each input prompt and additional model provider-specific output.

__str__

__str__() -> str

Return a string representation of the object for printing.

dict

dict(**kwargs: Any) -> dict

Return a dictionary of the LLM.

save

save(file_path: Path | str) -> None

Save the LLM.

PARAMETER DESCRIPTION
file_path

Path to file to save the LLM to.

TYPE: Path | str

RAISES DESCRIPTION
ValueError

If the file path is not a string or Path object.

Example
llm.save(file_path="path/llm.yaml")

build_extra classmethod

build_extra(values: dict[str, Any]) -> Any

Build extra kwargs from additional params that were passed in.

get_sub_prompts

get_sub_prompts(
    params: dict[str, Any], prompts: list[str], stop: list[str] | None = None
) -> list[list[str]]

Get the sub prompts for llm call.

create_llm_result

create_llm_result(
    choices: Any,
    prompts: list[str],
    params: dict[str, Any],
    token_usage: dict[str, int],
    *,
    system_fingerprint: str | None = None,
) -> LLMResult

Create the LLMResult from the choices and prompts.

modelname_to_contextsize staticmethod

modelname_to_contextsize(modelname: str) -> int

Calculate the maximum number of tokens possible to generate for a model.

PARAMETER DESCRIPTION
modelname

The modelname we want to know the context size for.

TYPE: str

RETURNS DESCRIPTION
int

The maximum context size

Example
max_tokens = openai.modelname_to_contextsize("gpt-3.5-turbo-instruct")

max_tokens_for_prompt

max_tokens_for_prompt(prompt: str) -> int

Calculate the maximum number of tokens possible to generate for a prompt.

PARAMETER DESCRIPTION
prompt

The prompt to pass into the model.

TYPE: str

RETURNS DESCRIPTION
int

The maximum number of tokens to generate for a prompt.

Example
max_tokens = openai.max_tokens_for_prompt("Tell me a joke.")

get_lc_namespace classmethod

get_lc_namespace() -> list[str]

Get the namespace of the LangChain object.

is_lc_serializable classmethod

is_lc_serializable() -> bool

Return whether this model can be serialized by LangChain.

validate_environment

validate_environment() -> Self

Validate that api key and python package exists in environment.