ChatWatsonx¶
Reference docs
This page contains reference documentation for ChatWatsonx. See the docs for conceptual guides, tutorials, and examples on using ChatWatsonx.
langchain_ibm.chat_models.ChatWatsonx
¶
Bases: BaseChatModel
IBM watsonx.ai chat models integration.
Setup
To use, you should have langchain_ibm python package installed,
and the environment variable WATSONX_API_KEY set with your API key, or pass
it as a named parameter api_key to the constructor.
Deprecated
apikey and WATSONX_APIKEY are deprecated and will be removed in
version 2.0.0. Use api_key and WATSONX_API_KEY instead.
Instantiate
Create a model instance with desired params. For example:
from langchain_ibm import ChatWatsonx
from ibm_watsonx_ai.foundation_models.schema import TextChatParameters
parameters = TextChatParameters(
top_p=1, temperature=0.5, max_completion_tokens=None
)
model = ChatWatsonx(
model_id="meta-llama/llama-3-3-70b-instruct",
url="https://us-south.ml.cloud.ibm.com",
project_id="*****",
params=parameters,
# api_key="*****"
)
Invoke
Generate a response from the model:
messages = [
(
"system",
"You are a helpful translator. Translate the user sentence to French.",
),
("human", "I love programming."),
]
model.invoke(messages)
Results in an AIMessage response:
AIMessage(
content="J'adore programmer.",
additional_kwargs={},
response_metadata={
"token_usage": {
"completion_tokens": 7,
"prompt_tokens": 30,
"total_tokens": 37,
},
"model_name": "ibm/granite-3-3-8b-instruct",
"system_fingerprint": "",
"finish_reason": "stop",
},
id="chatcmpl-529352c4-93ba-4801-8f1d-a3b4e3935194---daed91fb74d0405f200db1e63da9a48a---7a3ef799-4413-47e4-b24c-85d267e37fa2",
usage_metadata={"input_tokens": 30, "output_tokens": 7, "total_tokens": 37},
)
Stream
Stream a response from the model:
Results in a sequence of AIMessageChunk objects with partial content:
AIMessageChunk(content="", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775")
AIMessageChunk(content="J", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775")
AIMessageChunk(content="'", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775")
AIMessageChunk(content="ad", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775")
AIMessageChunk(content="or", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775")
AIMessageChunk(
content=" programmer", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775"
)
AIMessageChunk(content=".", id="run--e48a38d3-1500-4b5e-870c-6313e8cff775")
AIMessageChunk(
content="",
response_metadata={
"finish_reason": "stop",
"model_name": "ibm/granite-3-3-8b-instruct",
},
id="run--e48a38d3-1500-4b5e-870c-6313e8cff775",
)
AIMessageChunk(
content="",
id="run--e48a38d3-1500-4b5e-870c-6313e8cff775",
usage_metadata={"input_tokens": 30, "output_tokens": 7, "total_tokens": 37},
)
To collect the full message, you can concatenate the chunks:
AIMessageChunk(
content="J'adore programmer.",
response_metadata={
"finish_reason": "stop",
"model_name": "ibm/granite-3-3-8b-instruct",
},
id="chatcmpl-88a48b71-c149-4a0c-9c02-d6b97ca5dc6c---b7ba15879a8c5283b1e8a3b8db0229f0---0037ca4f-8a74-4f84-a46c-ab3fd1294f24",
usage_metadata={"input_tokens": 30, "output_tokens": 7, "total_tokens": 37},
)
Async
Asynchronous equivalents of invoke, stream, and batch are also available:
# Invoke
await model.ainvoke(messages)
# Stream
async for chunk in model.astream(messages):
print(chunk.text)
# Batch
await model.abatch([messages])
Results in an AIMessage response:
AIMessage(
content="J'adore programmer.",
additional_kwargs={},
response_metadata={
"token_usage": {
"completion_tokens": 7,
"prompt_tokens": 30,
"total_tokens": 37,
},
"model_name": "ibm/granite-3-3-8b-instruct",
"system_fingerprint": "",
"finish_reason": "stop",
},
id="chatcmpl-5bef2d81-ef56-463b-a8fa-c2bcc2a3c348---821e7750d18925f2b36226db66667e26---6396c786-9da9-4468-883e-11ed90a05937",
usage_metadata={"input_tokens": 30, "output_tokens": 7, "total_tokens": 37},
)
For batched calls, results in a list[AIMessage].
Tool calling
from pydantic import BaseModel, Field
class GetWeather(BaseModel):
'''Get the current weather in a given location'''
location: str = Field(
..., description="The city and state, e.g. San Francisco, CA"
)
class GetPopulation(BaseModel):
'''Get the current population in a given location'''
location: str = Field(
..., description="The city and state, e.g. San Francisco, CA"
)
model_with_tools = model.bind_tools(
[GetWeather, GetPopulation]
# strict = True # Enforce tool args schema is respected
)
ai_msg = model_with_tools.invoke(
"Which city is hotter today and which is bigger: LA or NY?"
)
ai_msg.tool_calls
[
{
"name": "GetWeather",
"args": {"location": "Los Angeles, CA"},
"id": "chatcmpl-tool-59632abcee8f48a18a5f3a81422b917b",
"type": "tool_call",
},
{
"name": "GetWeather",
"args": {"location": "New York, NY"},
"id": "chatcmpl-tool-c6f3b033b4594918bb53f656525b0979",
"type": "tool_call",
},
{
"name": "GetPopulation",
"args": {"location": "Los Angeles, CA"},
"id": "chatcmpl-tool-175a23281e4747ea81cbe472b8e47012",
"type": "tool_call",
},
{
"name": "GetPopulation",
"args": {"location": "New York, NY"},
"id": "chatcmpl-tool-e1ccc534835945aebab708eb5e685bf7",
"type": "tool_call",
},
]
Reasoning output
from langchain_ibm import ChatWatsonx
from ibm_watsonx_ai.foundation_models.schema import TextChatParameters
parameters = TextChatParameters(
include_reasoning=True, reasoning_effort="medium"
)
model = ChatWatsonx(
model_id="openai/gpt-oss-120b",
url="https://us-south.ml.cloud.ibm.com",
project_id="*****",
params=parameters,
# api_key="*****"
)
response = model.invoke("What is 3^3?")
# Response text
print(f"Output: {response.content}")
# Reasoning summaries
print(f"Reasoning: {response.additional_kwargs['reasoning_content']}")
Added in version 0.3.19: Updated AIMessage format
langchain-ibm >= 0.3.19
allows users to set Reasoning output parameters and will format output from
reasoning summaries into additional_kwargs field.
Structured output
from pydantic import BaseModel, Field
class Joke(BaseModel):
'''Joke to tell user.'''
setup: str = Field(description="The setup of the joke")
punchline: str = Field(description="The punchline to the joke")
rating: int | None = Field(description="How funny the joke is, 1 to 10")
structured_model = model.with_structured_output(Joke)
structured_model.invoke("Tell me a joke about cats")
Joke(
setup="Why was the cat sitting on the computer?",
punchline="To keep an eye on the mouse!",
rating=None,
)
See with_structured_output for more info.
JSON mode
Image input
import base64
import httpx
from langchain.messages import HumanMessage
image_url = "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg"
image_data = base64.b64encode(httpx.get(image_url).content).decode("utf-8")
message = HumanMessage(
content=[
{"type": "text", "text": "describe the weather in this image"},
{
"type": "image_url",
"image_url": {"url": f"data:image/jpeg;base64,{image_data}"},
},
]
)
ai_msg = model.invoke([message])
ai_msg.content
Token usage
Logprobs
logprobs_model = model.bind(logprobs=True)
ai_msg = logprobs_model.invoke(messages)
ai_msg.response_metadata["logprobs"]
{
'content': [
{
'token': 'J',
'logprob': -0.0017940393
},
{
'token': "'",
'logprob': -1.7523613e-05
},
{
'token': 'ad',
'logprob': -0.16112353
},
{
'token': 'ore',
'logprob': -0.0003091811
},
{
'token': ' programmer',
'logprob': -0.24849245
},
{
'token': '.',
'logprob': -2.5033638e-05
},
{
'token': '<|end_of_text|>',
'logprob': -7.080781e-05
}
]
}
Response metadata
| METHOD | DESCRIPTION |
|---|---|
is_lc_serializable |
Is lc serializable. |
validate_environment |
Validate that credentials and python package exists in environment. |
bind_tools |
Bind tool-like objects to this chat model. |
with_structured_output |
Model wrapper that returns outputs formatted to match the given schema. |
get_name |
Get the name of the |
get_input_schema |
Get a Pydantic model that can be used to validate input to the |
get_input_jsonschema |
Get a JSON schema that represents the input to the |
get_output_schema |
Get a Pydantic model that can be used to validate output to the |
get_output_jsonschema |
Get a JSON schema that represents the output of the |
config_schema |
The type of config this |
get_config_jsonschema |
Get a JSON schema that represents the config of the |
get_graph |
Return a graph representation of this |
get_prompts |
Return a list of prompts used by this |
__or__ |
Runnable "or" operator. |
__ror__ |
Runnable "reverse-or" operator. |
pipe |
Pipe |
pick |
Pick keys from the output |
assign |
Assigns new fields to the |
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 |
abatch |
Default implementation runs |
abatch_as_completed |
Run |
stream |
Default implementation of |
astream |
Default implementation of |
astream_log |
Stream all output from a |
astream_events |
Generate a stream of events. |
transform |
Transform inputs to outputs. |
atransform |
Transform inputs to outputs. |
bind |
Bind arguments to a |
with_config |
Bind config to a |
with_listeners |
Bind lifecycle listeners to a |
with_alisteners |
Bind async lifecycle listeners to a |
with_types |
Bind input and output types to a |
with_retry |
Create a new |
map |
Return a new |
with_fallbacks |
Add fallbacks to a |
as_tool |
Create a |
__init__ |
|
get_lc_namespace |
Get the namespace of the LangChain object. |
lc_id |
Return a unique identifier for this class for serialization purposes. |
to_json |
Serialize the |
to_json_not_implemented |
Serialize a "not implemented" object. |
configurable_fields |
Configure particular |
configurable_alternatives |
Configure alternatives for |
set_verbose |
If verbose is |
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. |
get_token_ids |
Return the ordered IDs of the tokens in a text. |
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 the model and return model generations. |
agenerate |
Asynchronously pass a sequence of prompts to a model and return generations. |
dict |
Return a dictionary of the LLM. |
model
class-attribute
instance-attribute
¶
model: str | None = None
Name or alias of the foundation model to use. When using IBM's watsonx.ai Model Gateway (public preview), you can specify any supported third-party model—OpenAI, Anthropic, NVIDIA, Cerebras, or IBM's own Granite series—via a single, OpenAI-compatible interface. Models must be explicitly provisioned (opt-in) through the Gateway to ensure secure, vendor-agnostic access and easy switch-over without reconfiguration.
For more details on configuration and usage, see IBM watsonx Model Gateway docs
deployment_id
class-attribute
instance-attribute
¶
deployment_id: str | None = None
Type of deployed model to use.
project_id
class-attribute
instance-attribute
¶
project_id: str | None = None
ID of the Watson Studio project.
space_id
class-attribute
instance-attribute
¶
space_id: str | None = None
ID of the Watson Studio space.
url
class-attribute
instance-attribute
¶
URL to the Watson Machine Learning or CPD instance.
api_key
class-attribute
instance-attribute
¶
api_key: SecretStr | None = Field(
default_factory=secret_from_env_multi(
names_priority=["WATSONX_API_KEY", "WATSONX_APIKEY"],
deprecated={"WATSONX_APIKEY"},
),
serialization_alias="api_key",
validation_alias=AliasChoices("api_key", "apikey"),
description="API key to the Watson Machine Learning or CPD instance.",
)
API key to the Watson Machine Learning or CPD instance.
token
class-attribute
instance-attribute
¶
token: SecretStr | None = Field(
alias="token", default_factory=secret_from_env("WATSONX_TOKEN", default=None)
)
Token to the CPD instance.
password
class-attribute
instance-attribute
¶
password: SecretStr | None = Field(
alias="password", default_factory=secret_from_env("WATSONX_PASSWORD", default=None)
)
Password to the CPD instance.
username
class-attribute
instance-attribute
¶
username: SecretStr | None = Field(
alias="username", default_factory=secret_from_env("WATSONX_USERNAME", default=None)
)
Username to the CPD instance.
instance_id
class-attribute
instance-attribute
¶
instance_id: SecretStr | None = Field(
alias="instance_id",
default_factory=secret_from_env("WATSONX_INSTANCE_ID", default=None),
)
Instance_id of the CPD instance.
version
class-attribute
instance-attribute
¶
version: SecretStr | None = None
Version of the CPD instance.
params
class-attribute
instance-attribute
¶
params: dict | TextChatParameters | None = None
Model parameters to use during request generation.
Note
ValueError is raised if the same Chat generation parameter is provided
within the params attribute and as keyword argument.
frequency_penalty
class-attribute
instance-attribute
¶
frequency_penalty: float | None = None
Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model's likelihood to repeat the same line verbatim.
logprobs
class-attribute
instance-attribute
¶
logprobs: bool | None = None
Whether to return log probabilities of the output tokens or not. If true, returns the log probabilities of each output token returned in the content of message.
top_logprobs
class-attribute
instance-attribute
¶
top_logprobs: int | None = None
An integer specifying the number of most likely tokens to return at each token position, each with an associated log probability. The option logprobs must be set to true if this parameter is used.
max_tokens
class-attribute
instance-attribute
¶
max_tokens: int | None = None
The maximum number of tokens that can be generated in the chat completion. The total length of input tokens and generated tokens is limited by the model's context length. This value is now deprecated in favor of 'max_completion_tokens' parameter.
max_completion_tokens
class-attribute
instance-attribute
¶
max_completion_tokens: int | None = None
The maximum number of tokens that can be generated in the chat completion. The total length of input tokens and generated tokens is limited by the model's context length.
n
class-attribute
instance-attribute
¶
n: int | None = None
How many chat completion choices to generate for each input message. Note that you will be charged based on the number of generated tokens across all of the choices. Keep n as 1 to minimize costs.
presence_penalty
class-attribute
instance-attribute
¶
presence_penalty: float | None = None
Positive values penalize new tokens based on whether they appear in the text so far, increasing the model's likelihood to talk about new topics.
temperature
class-attribute
instance-attribute
¶
temperature: float | None = None
What sampling temperature to use. Higher values like 0.8 will make the output more random, while lower values like 0.2 will make it more focused and deterministic.
We generally recommend altering this or top_p but not both.
response_format
class-attribute
instance-attribute
¶
response_format: dict | None = None
The chat response format parameters.
top_p
class-attribute
instance-attribute
¶
top_p: float | None = None
An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10% probability mass are considered.
We generally recommend altering this or temperature but not both.
time_limit
class-attribute
instance-attribute
¶
time_limit: int | None = None
Time limit in milliseconds - if not completed within this time, generation will stop.
logit_bias
class-attribute
instance-attribute
¶
logit_bias: dict | None = None
Increasing or decreasing probability of tokens being selected during generation.
seed
class-attribute
instance-attribute
¶
seed: int | None = None
Random number generator seed to use in sampling mode for experimental repeatability.
stop
class-attribute
instance-attribute
¶
Stop sequences are one or more strings which will cause the text generation to stop if/when they are produced as part of the output.
chat_template_kwargs
class-attribute
instance-attribute
¶
chat_template_kwargs: dict | None = None
Additional chat template parameters.
verify
class-attribute
instance-attribute
¶
You can pass one of following as verify: * the path to a CA_BUNDLE file * the path of directory with certificates of trusted CAs * True - default path to truststore will be taken * False - no verification will be made
validate_model
class-attribute
instance-attribute
¶
validate_model: bool = True
Model ID validation.
streaming
class-attribute
instance-attribute
¶
streaming: bool = False
Whether to stream the results or not.
name
class-attribute
instance-attribute
¶
name: str | None = None
The name of the Runnable. Used for debugging and tracing.
input_schema
property
¶
The type of input this Runnable accepts specified as a Pydantic model.
output_schema
property
¶
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.
lc_attributes
property
¶
lc_attributes: dict
List of attribute names that should be included in the serialized kwargs.
These attributes must be accepted by the constructor.
Default is an empty dictionary.
cache
class-attribute
instance-attribute
¶
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
¶
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 to add to the run trace.
metadata
class-attribute
instance-attribute
¶
Metadata to add to the run trace.
custom_get_token_ids
class-attribute
instance-attribute
¶
Optional encoder to use for counting tokens.
rate_limiter
class-attribute
instance-attribute
¶
rate_limiter: BaseRateLimiter | None = Field(default=None, exclude=True)
An optional rate limiter to use for limiting the number of requests.
disable_streaming
class-attribute
instance-attribute
¶
Whether to disable streaming for this model.
If streaming is bypassed, then stream/astream/astream_events will
defer to invoke/ainvoke.
- If
True, will always bypass streaming case. - If
'tool_calling', will bypass streaming case only when the model is called with atoolskeyword argument. In other words, LangChain will automatically switch to non-streaming behavior (invoke) only when the tools argument is provided. This offers the best of both worlds. - If
False(Default), will always use streaming case if available.
The main reason for this flag is that code might be written using stream and
a user may want to swap out a given model for another model whose the implementation
does not properly support streaming.
output_version
class-attribute
instance-attribute
¶
Version of AIMessage output format to store in message content.
AIMessage.content_blocks will lazily parse the contents of content into a
standard format. This flag can be used to additionally store the standard format
in message content, e.g., for serialization purposes.
Supported values:
'v0': provider-specific format in content (can lazily-parse withcontent_blocks)'v1': standardized format in content (consistent withcontent_blocks)
Partner packages (e.g.,
langchain-openai) can also use this
field to roll out new content formats in a backward-compatible way.
Added in langchain-core 1.0
profile
property
¶
profile: ModelProfile
Return profiling information for the model.
This property relies on the langchain-model-profiles package to retrieve chat
model capabilities, such as context window sizes and supported features.
| RAISES | DESCRIPTION |
|---|---|
ImportError
|
If |
| RETURNS | DESCRIPTION |
|---|---|
ModelProfile
|
A |
validate_environment
¶
validate_environment() -> Self
Validate that credentials and python package exists in environment.
bind_tools
¶
bind_tools(
tools: Sequence[dict[str, Any] | type | Callable | BaseTool],
*,
tool_choice: dict | str | bool | None = None,
strict: bool | None = None,
**kwargs: Any,
) -> Runnable[LanguageModelInput, AIMessage]
Bind tool-like objects to this chat model.
| PARAMETER | DESCRIPTION |
|---|---|
tools
|
A list of tool definitions to bind to this chat model. Can be a dictionary, pydantic model, callable, or BaseTool. Pydantic models, callables, and BaseTools will be automatically converted to their schema dictionary representation. |
tool_choice
|
Which tool to require the model to call. Options are:
|
strict
|
If
TYPE:
|
kwargs
|
Any additional parameters are passed directly to
TYPE:
|
with_structured_output
¶
with_structured_output(
schema: dict | type | None = None,
*,
method: Literal[
"function_calling", "json_mode", "json_schema"
] = "function_calling",
include_raw: bool = False,
strict: bool | None = None,
**kwargs: Any,
) -> Runnable[LanguageModelInput, dict | BaseModel]
Model wrapper that returns outputs formatted to match the given schema.
| PARAMETER | DESCRIPTION |
|---|---|
schema
|
The output schema. Can be passed in as:
If |
method
|
The method for steering model generation, one of:
TYPE:
|
include_raw
|
If False then only the parsed structured output is returned. If
an error occurs during model output parsing it will be raised. If True
then both the raw model response (a BaseMessage) and the parsed model
response will be returned. If an error occurs during output parsing it
will be caught and returned as well. The final output is always a dict
with keys
TYPE:
|
strict
|
TYPE:
|
kwargs
|
Additional keyword args
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[LanguageModelInput, dict | BaseModel]
|
A Runnable that takes same inputs as a |
Runnable[LanguageModelInput, dict | BaseModel]
|
If |
Runnable[LanguageModelInput, dict | BaseModel]
|
|
Runnable[LanguageModelInput, dict | BaseModel]
|
|
Runnable[LanguageModelInput, dict | BaseModel]
|
|
Example: schema=Pydantic class, method='function_calling', include_raw=True
from langchain_ibm import ChatWatsonx
from pydantic import BaseModel
class AnswerWithJustification(BaseModel):
'''An answer to the user question along with justification for the answer.'''
answer: str
justification: str
model = ChatWatsonx(...)
structured_model = model.with_structured_output(
AnswerWithJustification, include_raw=True
)
structured_model.invoke(
"What weighs more a pound of bricks or a pound of feathers"
)
{
"raw": AIMessage(
content="",
additional_kwargs={
"tool_calls": [
{
"id": "call_Ao02pnFYXD6GN1yzc0uXPsvF",
"function": {
"arguments": '{"answer":"They weigh the same.","justification":"Both a pound of bricks and a pound of feathers weigh one pound. The weight is the same, but the volume or density of the objects may differ."}',
"name": "AnswerWithJustification",
},
"type": "function",
}
]
},
),
"parsed": AnswerWithJustification(
answer="They weigh the same.",
justification="Both a pound of bricks and a pound of feathers weigh one pound. The weight is the same, but the volume or density of the objects may differ.",
),
"parsing_error": None,
}
Example: schema=JSON schema, method='function_calling', include_raw=False
from langchain_ibm import ChatWatsonx
from pydantic import BaseModel
from langchain_core.utils.function_calling import convert_to_openai_tool
class AnswerWithJustification(BaseModel):
'''An answer to the user question along with justification for the answer.'''
answer: str
justification: str
dict_schema = convert_to_openai_tool(AnswerWithJustification)
model = ChatWatsonx(...)
structured_model = model.with_structured_output(dict_schema)
structured_model.invoke(
"What weighs more a pound of bricks or a pound of feathers"
)
Example: schema=Pydantic class, method='json_schema', include_raw=True
from langchain_ibm import ChatWatsonx
from pydantic import BaseModel
class AnswerWithJustification(BaseModel):
'''An answer to the user question along with justification for the answer.'''
answer: str
justification: str
model = ChatWatsonx(...)
structured_model = model.with_structured_output(
AnswerWithJustification, method="json_schema", include_raw=True
)
structured_model.invoke(
"What weighs more a pound of bricks or a pound of feathers"
)
{
"raw": AIMessage(
content="",
additional_kwargs={
"tool_calls": [
{
"id": "chatcmpl-tool-bfbd6f6dd33b438990c5ddf277485971",
"type": "function",
"function": {
"name": "AnswerWithJustification",
"arguments": '{"answer": "They weigh the same", "justification": "A pound is a unit of weight or mass, so both a pound of bricks and a pound of feathers weigh the same amount, one pound."}',
},
}
]
},
response_metadata={
"token_usage": {
"completion_tokens": 45,
"prompt_tokens": 275,
"total_tokens": 320,
},
"model_name": "meta-llama/llama-3-3-70b-instruct",
"system_fingerprint": "",
"finish_reason": "stop",
},
id="chatcmpl-461ca5bd-1982-412c-b886-017c483bf481---8c18b06eead65ae4691364798787bda7---71896588-efa5-439f-a25f-d1abfe289f5a",
tool_calls=[
{
"name": "AnswerWithJustification",
"args": {
"answer": "They weigh the same",
"justification": "A pound is a unit of weight or mass, so both a pound of bricks and a pound of feathers weigh the same amount, one pound.",
},
"id": "chatcmpl-tool-bfbd6f6dd33b438990c5ddf277485971",
"type": "tool_call",
}
],
usage_metadata={
"input_tokens": 275,
"output_tokens": 45,
"total_tokens": 320,
},
),
"parsed": AnswerWithJustification(
answer="They weigh the same",
justification="A pound is a unit of weight or mass, so both a pound of bricks and a pound of feathers weigh the same amount, one pound.",
),
"parsing_error": None,
}
Example: schema=function schema, method='json_schema', include_raw=False
from langchain_ibm import ChatWatsonx
from pydantic import BaseModel
function__schema = {
"name": "AnswerWithJustification",
"description": "An answer to the user question along with justification for the answer.",
"parameters": {
"type": "object",
"properties": {
"answer": {"type": "string"},
"justification": {
"description": "A justification for the answer.",
"type": "string",
},
},
"required": ["answer"],
},
}
model = ChatWatsonx(...)
structured_model = model.with_structured_output(
function_schema, method="json_schema", include_raw=False
)
structured_model.invoke(
"What weighs more a pound of bricks or a pound of feathers"
)
Example: schema=Pydantic class, method='json_mode', include_raw=True
from langchain_ibm import ChatWatsonx
from pydantic import BaseModel
class AnswerWithJustification(BaseModel):
answer: str
justification: str
model = ChatWatsonx(...)
structured_model = model.with_structured_output(
AnswerWithJustification, method="json_mode", include_raw=True
)
structured_model.invoke(
"Answer the following question. "
"Make sure to return a JSON blob with keys 'answer' and 'justification'.\n\n"
"What's heavier a pound of bricks or a pound of feathers?"
)
{
"raw": AIMessage(
content='{\n "answer": "They are both the same weight.",\n "justification": "Both a pound of bricks and a pound of feathers weigh one pound. The difference lies in the volume and density of the materials, not the weight." \n}'
),
"parsed": AnswerWithJustification(
answer="They are both the same weight.",
justification="Both a pound of bricks and a pound of feathers weigh one pound. The difference lies in the volume and density of the materials, not the weight.",
),
"parsing_error": None,
}
Example: schema=None, method='json_mode', include_raw=True
from langchain_ibm import ChatWatsonx
model = ChatWatsonx(...)
structured_model = model.with_structured_output(
method="json_mode", include_raw=True
)
structured_model.invoke(
"Answer the following question. "
"Make sure to return a JSON blob with keys 'answer' and 'justification'.\n\n"
"What's heavier a pound of bricks or a pound of feathers?"
)
{
"raw": AIMessage(
content='{\n "answer": "They are both the same weight.",\n "justification": "Both a pound of bricks and a pound of feathers weigh one pound. The difference lies in the volume and density of the materials, not the weight." \n}'
),
"parsed": {
"answer": "They are both the same weight.",
"justification": "Both a pound of bricks and a pound of feathers weigh one pound. The difference lies in the volume and density of the materials, not the weight.",
},
"parsing_error": None,
}
get_name
¶
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:
|
| 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:
|
| RETURNS | DESCRIPTION |
|---|---|
dict[str, Any]
|
A JSON schema that represents the input to the |
Example
Added in langchain-core 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:
|
| 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:
|
| RETURNS | DESCRIPTION |
|---|---|
dict[str, Any]
|
A JSON schema that represents the output of the |
Example
Added in langchain-core 0.3.0
config_schema
¶
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. |
| RETURNS | DESCRIPTION |
|---|---|
type[BaseModel]
|
A Pydantic model that can be used to validate config. |
get_config_jsonschema
¶
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
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Input, Other]
|
A new |
__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
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Other, Output]
|
A new |
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
TYPE:
|
name
|
An optional name for the resulting
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Input, Other]
|
A new |
pick
¶
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. |
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Any, Any]
|
a new |
assign
¶
assign(
**kwargs: Runnable[dict[str, Any], Any]
| Callable[[dict[str, Any]], Any]
| Mapping[str, Runnable[dict[str, Any], Any] | Callable[[dict[str, Any]], Any]],
) -> RunnableSerializable[Any, Any]
Assigns new fields to the dict output of this Runnable.
from langchain_core.language_models.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
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Any, Any]
|
A new |
invoke
¶
invoke(
input: LanguageModelInput,
config: RunnableConfig | None = None,
*,
stop: list[str] | None = None,
**kwargs: Any,
) -> AIMessage
Transform a single input into an output.
| PARAMETER | DESCRIPTION |
|---|---|
input
|
The input to the
TYPE:
|
config
|
A config to use when invoking the The config supports standard keys like Please refer to
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Output
|
The output of the |
ainvoke
async
¶
ainvoke(
input: LanguageModelInput,
config: RunnableConfig | None = None,
*,
stop: list[str] | None = None,
**kwargs: Any,
) -> AIMessage
Transform a single input into an output.
| PARAMETER | DESCRIPTION |
|---|---|
input
|
The input to the
TYPE:
|
config
|
A config to use when invoking the The config supports standard keys like Please refer to
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Output
|
The output of the |
batch
¶
batch(
inputs: list[Input],
config: RunnableConfig | list[RunnableConfig] | None = None,
*,
return_exceptions: bool = False,
**kwargs: Any | None,
) -> list[Output]
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
TYPE:
|
config
|
A config to use when invoking the Please refer to
TYPE:
|
return_exceptions
|
Whether to return exceptions instead of raising them.
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
list[Output]
|
A list of outputs from the |
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
TYPE:
|
config
|
A config to use when invoking the The config supports standard keys like Please refer to
TYPE:
|
return_exceptions
|
Whether to return exceptions instead of raising them.
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
tuple[int, Output | Exception]
|
Tuples of the index of the input and the output from the |
abatch
async
¶
abatch(
inputs: list[Input],
config: RunnableConfig | list[RunnableConfig] | None = None,
*,
return_exceptions: bool = False,
**kwargs: Any | None,
) -> list[Output]
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
TYPE:
|
config
|
A config to use when invoking the The config supports standard keys like Please refer to
TYPE:
|
return_exceptions
|
Whether to return exceptions instead of raising them.
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
list[Output]
|
A list of outputs from the |
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
TYPE:
|
config
|
A config to use when invoking the The config supports standard keys like Please refer to
TYPE:
|
return_exceptions
|
Whether to return exceptions instead of raising them.
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
AsyncIterator[tuple[int, Output | Exception]]
|
A tuple of the index of the input and the output from the |
stream
¶
stream(
input: LanguageModelInput,
config: RunnableConfig | None = None,
*,
stop: list[str] | None = None,
**kwargs: Any,
) -> Iterator[AIMessageChunk]
Default implementation of stream, which calls invoke.
Subclasses must override this method if they support streaming output.
| PARAMETER | DESCRIPTION |
|---|---|
input
|
The input to the
TYPE:
|
config
|
The config to use for the
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
Output
|
The output of the |
astream
async
¶
astream(
input: LanguageModelInput,
config: RunnableConfig | None = None,
*,
stop: list[str] | None = None,
**kwargs: Any,
) -> AsyncIterator[AIMessageChunk]
Default implementation of astream, which calls ainvoke.
Subclasses must override this method if they support streaming output.
| PARAMETER | DESCRIPTION |
|---|---|
input
|
The input to the
TYPE:
|
config
|
The config to use for the
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
AsyncIterator[Output]
|
The output of the |
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
TYPE:
|
config
|
The config to use for the
TYPE:
|
diff
|
Whether to yield diffs between each step or the current state.
TYPE:
|
with_streamed_output_list
|
Whether to yield the
TYPE:
|
include_names
|
Only include logs with these names. |
include_types
|
Only include logs with these types. |
include_tags
|
Only include logs with these tags. |
exclude_names
|
Exclude logs with these names. |
exclude_types
|
Exclude logs with these types. |
exclude_tags
|
Exclude logs with these tags. |
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
AsyncIterator[RunLogPatch] | AsyncIterator[RunLog]
|
A |
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 theRunnablethat generated the event.run_id: Randomly generated ID associated with the given execution of theRunnablethat emitted the event. A childRunnablethat gets invoked as part of the execution of a parentRunnableis assigned its own unique ID.parent_ids: The IDs of the parent runnables that generated the event. The rootRunnablewill 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 theRunnablethat generated the event.metadata: The metadata of theRunnablethat 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:
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": [],
},
]
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
TYPE:
|
config
|
The config to use for the
TYPE:
|
version
|
The version of the schema to use either
TYPE:
|
include_names
|
Only include events from |
include_types
|
Only include events from |
include_tags
|
Only include events from |
exclude_names
|
Exclude events from |
exclude_types
|
Exclude events from |
exclude_tags
|
Exclude events from |
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
AsyncIterator[StreamEvent]
|
An async stream of |
| RAISES | DESCRIPTION |
|---|---|
NotImplementedError
|
If the version is not |
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
TYPE:
|
config
|
The config to use for the
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
Output
|
The output of the |
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
TYPE:
|
config
|
The config to use for the
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| YIELDS | DESCRIPTION |
|---|---|
AsyncIterator[Output]
|
The output of the |
bind
¶
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
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[Input, Output]
|
A new |
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
TYPE:
|
**kwargs
|
Additional keyword arguments to pass to the
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[Input, Output]
|
A new |
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
TYPE:
|
on_end
|
Called after the
TYPE:
|
on_error
|
Called if the
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[Input, Output]
|
A new |
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
TYPE:
|
on_end
|
Called asynchronously after the
TYPE:
|
on_error
|
Called asynchronously if the
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[Input, Output]
|
A new |
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
TYPE:
|
output_type
|
The output type to bind to the
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[Input, Output]
|
A new |
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:
|
wait_exponential_jitter
|
Whether to add jitter to the wait time between retries.
TYPE:
|
stop_after_attempt
|
The maximum number of attempts to make before giving up.
TYPE:
|
exponential_jitter_params
|
Parameters for
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
Runnable[Input, Output]
|
A new |
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
¶
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 |
exceptions_to_handle
|
A tuple of exception types to handle.
TYPE:
|
exception_key
|
If If If used, the base
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableWithFallbacks[Input, Output]
|
A new |
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 |
exceptions_to_handle
|
A tuple of exception types to handle.
TYPE:
|
exception_key
|
If If If used, the base
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableWithFallbacks[Input, Output]
|
A new |
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. |
name
|
The name of the tool.
TYPE:
|
description
|
The description of the tool.
TYPE:
|
arg_types
|
A dictionary of argument names to types. |
| RETURNS | DESCRIPTION |
|---|---|
BaseTool
|
A |
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]})
str input:
get_lc_namespace
classmethod
¶
lc_id
classmethod
¶
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
¶
Serialize the Runnable to JSON.
| RETURNS | DESCRIPTION |
|---|---|
SerializedConstructor | SerializedNotImplemented
|
A JSON-serializable representation of the |
to_json_not_implemented
¶
Serialize a "not implemented" object.
| RETURNS | DESCRIPTION |
|---|---|
SerializedNotImplemented
|
|
configurable_fields
¶
configurable_fields(
**kwargs: AnyConfigurableField,
) -> RunnableSerializable[Input, Output]
Configure particular Runnable fields at runtime.
| PARAMETER | DESCRIPTION |
|---|---|
**kwargs
|
A dictionary of
TYPE:
|
| RAISES | DESCRIPTION |
|---|---|
ValueError
|
If a configuration key is not found in the |
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Input, Output]
|
A new |
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
TYPE:
|
default_key
|
The default key to use if no alternative is selected.
TYPE:
|
prefix_keys
|
Whether to prefix the keys with the
TYPE:
|
**kwargs
|
A dictionary of keys to
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
RunnableSerializable[Input, Output]
|
A new |
from langchain_anthropic import ChatAnthropic
from langchain_core.runnables.utils import ConfigurableField
from langchain_openai import ChatOpenAI
model = ChatAnthropic(
model_name="claude-sonnet-4-5-20250929"
).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
¶
generate_prompt
¶
generate_prompt(
prompts: list[PromptValue],
stop: list[str] | None = None,
callbacks: Callbacks = 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:
- Take advantage of batched calls,
- Need more output from the model than just the top generated value,
- 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 A
TYPE:
|
stop
|
Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings. |
callbacks
|
Used for executing additional functionality, such as logging or streaming, throughout generation.
TYPE:
|
**kwargs
|
Arbitrary additional keyword arguments. These are usually passed to the model provider API call.
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
LLMResult
|
An |
agenerate_prompt
async
¶
agenerate_prompt(
prompts: list[PromptValue],
stop: list[str] | None = None,
callbacks: Callbacks = 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:
- Take advantage of batched calls,
- Need more output from the model than just the top generated value,
- 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 A
TYPE:
|
stop
|
Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings. |
callbacks
|
Used for executing additional functionality, such as logging or streaming, throughout generation.
TYPE:
|
**kwargs
|
Arbitrary additional keyword arguments. These are usually passed to the model provider API call.
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
LLMResult
|
An |
get_token_ids
¶
get_num_tokens
¶
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:
|
tools
|
If provided, sequence of dict,
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
int
|
The sum of the number of tokens across the messages. |
generate
¶
generate(
messages: list[list[BaseMessage]],
stop: list[str] | None = None,
callbacks: Callbacks = None,
*,
tags: list[str] | None = None,
metadata: dict[str, Any] | None = None,
run_name: str | None = None,
run_id: UUID | 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:
- Take advantage of batched calls,
- Need more output from the model than just the top generated value,
- Are building chains that are agnostic to the underlying language model type (e.g., pure text completion models vs chat models).
| PARAMETER | DESCRIPTION |
|---|---|
messages
|
List of list of messages.
TYPE:
|
stop
|
Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings. |
callbacks
|
Used for executing additional functionality, such as logging or streaming, throughout generation.
TYPE:
|
tags
|
The tags to apply. |
metadata
|
The metadata to apply. |
run_name
|
The name of the run.
TYPE:
|
run_id
|
The ID of the run.
TYPE:
|
**kwargs
|
Arbitrary additional keyword arguments. These are usually passed to the model provider API call.
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
LLMResult
|
An |
agenerate
async
¶
agenerate(
messages: list[list[BaseMessage]],
stop: list[str] | None = None,
callbacks: Callbacks = None,
*,
tags: list[str] | None = None,
metadata: dict[str, Any] | None = None,
run_name: str | None = None,
run_id: UUID | 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:
- Take advantage of batched calls,
- Need more output from the model than just the top generated value,
- Are building chains that are agnostic to the underlying language model type (e.g., pure text completion models vs chat models).
| PARAMETER | DESCRIPTION |
|---|---|
messages
|
List of list of messages.
TYPE:
|
stop
|
Stop words to use when generating. Model output is cut off at the first occurrence of any of these substrings. |
callbacks
|
Used for executing additional functionality, such as logging or streaming, throughout generation.
TYPE:
|
tags
|
The tags to apply. |
metadata
|
The metadata to apply. |
run_name
|
The name of the run.
TYPE:
|
run_id
|
The ID of the run.
TYPE:
|
**kwargs
|
Arbitrary additional keyword arguments. These are usually passed to the model provider API call.
TYPE:
|
| RETURNS | DESCRIPTION |
|---|---|
LLMResult
|
An |