How to stream events from within a tool

Prerequisites

This guide assumes familiarity with the following concepts:

If you have tools that call LLMs, retrievers, or other runnables, you may want to access internal events from those runnables. This guide shows you a few ways you can do this using the astream_events() method.

caution

LangChain cannot automatically propagate callbacks to child runnables if you are running async code in python<=3.10.

This is a common reason why you may fail to see events being emitted from custom runnables or tools.

We'll define a custom tool below that calls a chain that summarizes its input in a special way by prompting an LLM to return only 10 words, then reversing the output:

pip install -qU langchain-openai

import getpass
import os

os.environ["OPENAI_API_KEY"] = getpass.getpass()

from langchain_openai import ChatOpenAI

model = ChatOpenAI(model="gpt-3.5-turbo-0125")

pip install -qU langchain-anthropic

import getpass
import os

os.environ["ANTHROPIC_API_KEY"] = getpass.getpass()

from langchain_anthropic import ChatAnthropic

model = ChatAnthropic(model="claude-3-sonnet-20240229")

pip install -qU langchain-openai

import getpass
import os

os.environ["AZURE_OPENAI_API_KEY"] = getpass.getpass()

from langchain_openai import AzureChatOpenAI

model = AzureChatOpenAI(
    azure_endpoint=os.environ["AZURE_OPENAI_ENDPOINT"],
    azure_deployment=os.environ["AZURE_OPENAI_DEPLOYMENT_NAME"],
    openai_api_version=os.environ["AZURE_OPENAI_API_VERSION"],
)

pip install -qU langchain-google-vertexai

import getpass
import os

os.environ["GOOGLE_API_KEY"] = getpass.getpass()

from langchain_google_vertexai import ChatVertexAI

model = ChatVertexAI(model="gemini-pro")

pip install -qU langchain-cohere

import getpass
import os

os.environ["COHERE_API_KEY"] = getpass.getpass()

from langchain_cohere import ChatCohere

model = ChatCohere(model="command-r")

pip install -qU langchain-fireworks

import getpass
import os

os.environ["FIREWORKS_API_KEY"] = getpass.getpass()

from langchain_fireworks import ChatFireworks

model = ChatFireworks(model="accounts/fireworks/models/mixtral-8x7b-instruct")

pip install -qU langchain-groq

import getpass
import os

os.environ["GROQ_API_KEY"] = getpass.getpass()

from langchain_groq import ChatGroq

model = ChatGroq(model="llama3-8b-8192")

pip install -qU langchain-mistralai

import getpass
import os

os.environ["MISTRAL_API_KEY"] = getpass.getpass()

from langchain_mistralai import ChatMistralAI

model = ChatMistralAI(model="mistral-large-latest")

pip install -qU langchain-openai

import getpass
import os

os.environ["TOGETHER_API_KEY"] = getpass.getpass()

from langchain_openai import ChatOpenAI

model = ChatOpenAI(
    base_url="https://api.together.xyz/v1",
    api_key=os.environ["TOGETHER_API_KEY"],
    model="mistralai/Mixtral-8x7B-Instruct-v0.1",
)

from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.tools import tool


@tool
def special_summarization_tool(long_text: str) -> str:
    """A tool that summarizes input text using advanced techniques."""
    prompt = ChatPromptTemplate.from_template(
        "You are an expert writer. Summarize the following text in 10 words or less:\n\n{long_text}"
    )

    def reverse(x: str):
        return x[::-1]

    chain = prompt | model | StrOutputParser() | reverse
    summary = chain.invoke({"long_text": long_text})
    return summary

API Reference:StrOutputParser | ChatPromptTemplate | tool

If you just invoke the tool directly, you can see that you only get the final response:

LONG_TEXT = """
NARRATOR:
(Black screen with text; The sound of buzzing bees can be heard)
According to all known laws of aviation, there is no way a bee should be able to fly. Its wings are too small to get its fat little body off the ground. The bee, of course, flies anyway because bees don't care what humans think is impossible.
BARRY BENSON:
(Barry is picking out a shirt)
Yellow, black. Yellow, black. Yellow, black. Yellow, black. Ooh, black and yellow! Let's shake it up a little.
JANET BENSON:
Barry! Breakfast is ready!
BARRY:
Coming! Hang on a second.
"""

special_summarization_tool.invoke({"long_text": LONG_TEXT})

'.yad noitaudarg rof tiftuo sesoohc yrraB ;scisyhp seifed eeB'

If you wanted to access the raw output from the chat model, you could use the astream_events() method and look for on_chat_model_end events:

stream = special_summarization_tool.astream_events(
    {"long_text": LONG_TEXT}, version="v2"
)

async for event in stream:
    if event["event"] == "on_chat_model_end":
        print(event)

{'event': 'on_chat_model_end', 'data': {'output': AIMessage(content='Bee defies physics; Barry chooses outfit for graduation day.', response_metadata={'stop_reason': 'end_turn', 'stop_sequence': None}, id='run-195c0986-2ffa-43a3-9366-f2f96c42fe57', usage_metadata={'input_tokens': 182, 'output_tokens': 16, 'total_tokens': 198}), 'input': {'messages': [[HumanMessage(content="You are an expert writer. Summarize the following text in 10 words or less:\n\n\nNARRATOR:\n(Black screen with text; The sound of buzzing bees can be heard)\nAccording to all known laws of aviation, there is no way a bee should be able to fly. Its wings are too small to get its fat little body off the ground. The bee, of course, flies anyway because bees don't care what humans think is impossible.\nBARRY BENSON:\n(Barry is picking out a shirt)\nYellow, black. Yellow, black. Yellow, black. Yellow, black. Ooh, black and yellow! Let's shake it up a little.\nJANET BENSON:\nBarry! Breakfast is ready!\nBARRY:\nComing! Hang on a second.\n")]]}}, 'run_id': '195c0986-2ffa-43a3-9366-f2f96c42fe57', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['370919df-1bc3-43ae-aab2-8e112a4ddf47', 'de535624-278b-4927-9393-6d0cac3248df']}

And you can see that you get the raw response from the chat model.

astream_events() will automatically call internal runnables in a chain with streaming enabled if possible, so if you wanted to a stream of tokens as they are generated from the chat model, you could simply filter our calls to look for on_chat_model_stream events with no other changes:

stream = special_summarization_tool.astream_events(
    {"long_text": LONG_TEXT}, version="v2"
)

async for event in stream:
    if event["event"] == "on_chat_model_stream":
        print(event)

{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', usage_metadata={'input_tokens': 182, 'output_tokens': 0, 'total_tokens': 182})}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='Bee', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' def', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='ies physics', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=';', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' Barry', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' cho', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='oses outfit', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' for', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' graduation', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' day', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='.', id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3')}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='', response_metadata={'stop_reason': 'end_turn', 'stop_sequence': None}, id='run-cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', usage_metadata={'input_tokens': 0, 'output_tokens': 16, 'total_tokens': 16})}, 'run_id': 'cd8c1bd9-64d8-463c-a4d7-4bceed7911b3', 'name': 'ChatAnthropic', 'tags': ['seq:step:2'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['8ddd1325-07c4-4213-8a2f-4462db8c6c70', '9f8654b4-b3f6-414e-b41d-dd201342a2fa']}

Note that you still have access to the final tool response as well. You can access it by looking for an on_tool_end event.

To make events your tool emits easier to identify, you can also add identifiers to runnables using the with_config() method. run_name will apply to only to the runnable you attach it to, while tags will be inherited by runnables called within your initial runnable.

Let's redeclare the tool with a tag, then run it with astream_events() with some filters. You should only see streamed events from the chat model and the final tool output:

tagged_tool = special_summarization_tool.with_config({"tags": ["bee_movie"]})

stream = tagged_tool.astream_events(
    {"long_text": LONG_TEXT}, version="v2", include_tags=["bee_movie"]
)

async for event in stream:
    event_type = event["event"]
    if event_type == "on_chat_model_stream" or event_type == "on_tool_end":
        print(event)

{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630', usage_metadata={'input_tokens': 182, 'output_tokens': 0, 'total_tokens': 182})}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='Bee', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' def', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='ies physics', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=';', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' Barry', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' cho', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='oses outfit', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' for', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' graduation', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content=' day', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='.', id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630')}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_chat_model_stream', 'data': {'chunk': AIMessageChunk(content='', response_metadata={'stop_reason': 'end_turn', 'stop_sequence': None}, id='run-696f4fc8-6c6f-46a0-8c82-e2e3f7625630', usage_metadata={'input_tokens': 0, 'output_tokens': 16, 'total_tokens': 16})}, 'run_id': '696f4fc8-6c6f-46a0-8c82-e2e3f7625630', 'name': 'ChatAnthropic', 'tags': ['seq:step:2', 'bee_movie'], 'metadata': {'ls_provider': 'anthropic', 'ls_model_name': 'claude-3-5-sonnet-20240620', 'ls_model_type': 'chat', 'ls_temperature': 0.0, 'ls_max_tokens': 1024}, 'parent_ids': ['49d9d7d3-2b02-4964-a6c5-12f57a063146', '8922d0e3-4199-4ba5-9a7a-fc4f2fca3e72']}
{'event': 'on_tool_end', 'data': {'output': '.yad noitaudarg rof tiftuo sesoohc yrraB ;scisyhp seifed eeB'}, 'run_id': '49d9d7d3-2b02-4964-a6c5-12f57a063146', 'name': 'special_summarization_tool', 'tags': ['bee_movie'], 'metadata': {}, 'parent_ids': []}

Next steps

Now you've learned how to stream events from within a tool. Next, you can learn more about how to use tools:

You can also check out some more specific uses of tool calling:

Building tool-using chains and agents
Getting structured outputs from models

How to stream events from within a tool

Next steps

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How to stream events from within a tool

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