{ "cells": [ { "cell_type": "markdown", "id": "3631f2b9-aa79-472e-a9d6-9125a90ee704", "metadata": {}, "source": [ "# How to stream full state of your graph" ] }, { "cell_type": "markdown", "id": "858c7499-0c92-40a9-bd95-e5a5a5817e92", "metadata": {}, "source": [ "LangGraph supports multiple streaming modes. The main ones are:\n", "\n", "- `values`: This streaming mode streams back values of the graph. This is the **full state of the graph** after each node is called.\n", "- `updates`: This streaming mode streams back updates to the graph. This is the **update to the state of the graph** after each node is called.\n", "\n", "This guide covers `stream_mode=\"values\"`." ] }, { "cell_type": "markdown", "id": "7c2f84f1-0751-4779-97d4-5cbb286093b7", "metadata": {}, "source": [ "## Setup" ] }, { "cell_type": "markdown", "id": "323db423-b644-40bd-9c2d-976a53f602f7", "metadata": {}, "source": [ "We'll be using a simple ReAct agent for this guide." ] }, { "cell_type": "code", "execution_count": 1, "id": "6b4285e4-7434-4971-bde0-aabceef8ee7e", "metadata": {}, "outputs": [], "source": [ "%%capture --no-stderr\n", "%pip install -U langgraph langchain-openai" ] }, { "cell_type": "code", "execution_count": 2, "id": "f7f9f24a-e3d0-422b-8924-47950b2facd6", "metadata": {}, "outputs": [ { "name": "stdin", "output_type": "stream", "text": [ "OPENAI_API_KEY: ········\n" ] } ], "source": [ "import getpass\n", "import os\n", "\n", "\n", "def _set_env(var: str):\n", " if not os.environ.get(var):\n", " os.environ[var] = getpass.getpass(f\"{var}: \")\n", "\n", "\n", "_set_env(\"OPENAI_API_KEY\")" ] }, { "cell_type": "code", "execution_count": 3, "id": "ef5a3ec6-0cd0-4541-ab1b-d63ede22720e", "metadata": {}, "outputs": [], "source": [ "from typing import Literal\n", "from langchain_community.tools.tavily_search import TavilySearchResults\n", "from langchain_core.runnables import ConfigurableField\n", "from langchain_core.tools import tool\n", "from langchain_openai import ChatOpenAI\n", "from langgraph.prebuilt import create_react_agent\n", "\n", "\n", "@tool\n", "def get_weather(city: Literal[\"nyc\", \"sf\"]):\n", " \"\"\"Use this to get weather information.\"\"\"\n", " if city == \"nyc\":\n", " return \"It might be cloudy in nyc\"\n", " elif city == \"sf\":\n", " return \"It's always sunny in sf\"\n", " else:\n", " raise AssertionError(\"Unknown city\")\n", "\n", "\n", "tools = [get_weather]\n", "\n", "model = ChatOpenAI(model_name=\"gpt-4o\", temperature=0)\n", "graph = create_react_agent(model, tools)" ] }, { "cell_type": "markdown", "id": "002a715b-e0be-4e89-8d42-f0098882586b", "metadata": {}, "source": [ "## Stream values" ] }, { "cell_type": "code", "execution_count": 4, "id": "e9e9ffb0-2cd5-466f-b70b-b6ed51b852d1", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "================================\u001b[1m Human Message \u001b[0m=================================\n", "\n", "what's the weather in sf\n", "==================================\u001b[1m Ai Message \u001b[0m==================================\n", "Tool Calls:\n", " get_weather (call_61VvIzqVGtyxcXi0z6knZkjZ)\n", " Call ID: call_61VvIzqVGtyxcXi0z6knZkjZ\n", " Args:\n", " city: sf\n", "=================================\u001b[1m Tool Message \u001b[0m=================================\n", "Name: get_weather\n", "\n", "It's always sunny in sf\n", "==================================\u001b[1m Ai Message \u001b[0m==================================\n", "\n", "The weather in San Francisco is currently sunny.\n" ] } ], "source": [ "inputs = {\"messages\": [(\"human\", \"what's the weather in sf\")]}\n", "async for chunk in graph.astream(inputs, stream_mode=\"values\"):\n", " chunk[\"messages\"][-1].pretty_print()" ] }, { "cell_type": "markdown", "id": "d73de237-bf45-4fa7-93ef-6dae7eacffc0", "metadata": {}, "source": [ "If we want to just get the final result, we can use the same method and just keep track of the last value we received" ] }, { "cell_type": "code", "execution_count": 5, "id": "c122bf15-a489-47bf-b482-a744a54e2cc4", "metadata": {}, "outputs": [], "source": [ "inputs = {\"messages\": [(\"human\", \"what's the weather in sf\")]}\n", "async for chunk in graph.astream(inputs, stream_mode=\"values\"):\n", " final_result = chunk" ] }, { "cell_type": "code", "execution_count": 6, "id": "316022e5-4c65-48e4-9878-8d94a2425ed4", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "{'messages': [HumanMessage(content=\"what's the weather in sf\", id='54b39b6f-054b-4306-980b-86905e48a6bc'),\n", " AIMessage(content='', additional_kwargs={'tool_calls': [{'id': 'call_avoKnK8reERzTUSxrN9cgFxY', 'function': {'arguments': '{\"city\":\"sf\"}', 'name': 'get_weather'}, 'type': 'function'}]}, response_metadata={'token_usage': {'completion_tokens': 14, 'prompt_tokens': 57, 'total_tokens': 71}, 'model_name': 'gpt-4o-2024-05-13', 'system_fingerprint': 'fp_5e6c71d4a8', 'finish_reason': 'tool_calls', 'logprobs': None}, id='run-f2f43c89-2c96-45f4-975c-2d0f22d0d2d1-0', tool_calls=[{'name': 'get_weather', 'args': {'city': 'sf'}, 'id': 'call_avoKnK8reERzTUSxrN9cgFxY'}], usage_metadata={'input_tokens': 57, 'output_tokens': 14, 'total_tokens': 71}),\n", " ToolMessage(content=\"It's always sunny in sf\", name='get_weather', id='fc18a798-c7b2-4f73-84fa-8ffdffb6ddcb', tool_call_id='call_avoKnK8reERzTUSxrN9cgFxY'),\n", " AIMessage(content='The weather in San Francisco is currently sunny. Enjoy the sunshine!', response_metadata={'token_usage': {'completion_tokens': 14, 'prompt_tokens': 84, 'total_tokens': 98}, 'model_name': 'gpt-4o-2024-05-13', 'system_fingerprint': 'fp_5e6c71d4a8', 'finish_reason': 'stop', 'logprobs': None}, id='run-21418147-da8e-4738-a076-239377397c40-0', usage_metadata={'input_tokens': 84, 'output_tokens': 14, 'total_tokens': 98})]}" ] }, "execution_count": 6, "metadata": {}, "output_type": "execute_result" } ], "source": [ "final_result" ] }, { "cell_type": "code", "execution_count": 7, "id": "0f64ebbe-535c-4b35-a95f-0a7490cfed90", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "==================================\u001b[1m Ai Message \u001b[0m==================================\n", "\n", "The weather in San Francisco is currently sunny. Enjoy the sunshine!\n" ] } ], "source": [ "final_result[\"messages\"][-1].pretty_print()" ] } ], "metadata": { "kernelspec": { "display_name": "langgraph", "language": "python", "name": "langgraph" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.12.3" } }, "nbformat": 4, "nbformat_minor": 5 }