{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "51466c8d-8ce4-4b3d-be4e-18fdbeda5f53",
   "metadata": {},
   "source": [
    "# Respond in a format\n",
    "\n",
    "In this example we will build a chat executor that responds in a specific format. We will do this by using OpenAI function calling. This is useful when you want to enforce that an agent's response is in a specific format. In this example, we will ask it respond as if a weatherman, so to return the temperature and then any other additional info.\n",
    "\n",
    "This examples builds off the base chat executor. It is highly recommended you learn about that executor before going through this notebook. You can find documentation for that example [here](./base.ipynb).\n",
    "\n",
    "Any modifications of that example are called below with **MODIFICATION**, so if you are looking for the differences you can just search for that."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "1977bac1",
   "metadata": {},
   "source": [
    "## Set up the State\n",
    "\n",
    "The main type of graph in `langgraph` is the [StateGraph](https://langchain-ai.github.io/langgraph/reference/graphs/#langgraph.graph.StateGraph).\n",
    "This graph is parameterized by a `State` object that it passes around to each node.\n",
    "Each node then returns operations the graph uses to `update` that state.\n",
    "These operations can either SET specific attributes on the state (e.g. overwrite the existing values) or ADD to the existing attribute.\n",
    "Whether to set or add is denoted by annotating the `State` object you use to construct the graph.\n",
    "\n",
    "For this example, the state we will track will just be a list of messages.\n",
    "We want each node to just add messages to that list.\n",
    "Therefore, we will use a `TypedDict` with one key (`messages`) and annotate it so that the `messages` attribute is \"append-only\"."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "de1db3c1",
   "metadata": {},
   "outputs": [],
   "source": ["from typing import Annotated\n\nfrom typing_extensions import TypedDict\n\nfrom langgraph.graph.message import add_messages\n\n# Add messages essentially does this with more\n# robust handling\n# def add_messages(left: list, right: list):\n#     return left + right\n\n\nclass State(TypedDict):\n    messages: Annotated[list, add_messages]"]
  },
  {
   "cell_type": "markdown",
   "id": "b8a08594",
   "metadata": {},
   "source": [
    "## Set up the tools\n",
    "\n",
    "We will first define the tools we want to use.\n",
    "For this simple example, we will use create a placeholder search engine.\n",
    "It is really easy to create your own tools - see documentation [here](https://python.langchain.com/v0.2/docs/how_to/custom_tools) on how to do that.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "23a2ca43",
   "metadata": {},
   "outputs": [],
   "source": ["from langchain_core.tools import tool\n\n\n@tool\ndef search(query: str):\n    \"\"\"Call to surf the web.\"\"\"\n    # This is a placeholder, but don't tell the LLM that...\n    return [\"The answer to your question lies within.\"]\n\n\ntools = [search]"]
  },
  {
   "cell_type": "markdown",
   "id": "44c73446",
   "metadata": {},
   "source": [
    "We can now wrap these tools in a simple [ToolNode](https://langchain-ai.github.io/langgraph/reference/prebuilt/#toolnode).\n",
    "This is  a simple class that takes in a list of messages containing an [AIMessages with tool_calls](https://api.python.langchain.com/en/latest/messages/langchain_core.messages.ai.AIMessage.html#langchain_core.messages.ai.AIMessage.tool_calls), runs the tools, and returns the output as [ToolMessage](https://api.python.langchain.com/en/latest/messages/langchain_core.messages.tool.ToolMessage.html#langchain_core.messages.tool.ToolMessage)s.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "979512e4",
   "metadata": {},
   "outputs": [],
   "source": ["from langgraph.prebuilt import ToolNode\n\ntool_node = ToolNode(tools)"]
  },
  {
   "cell_type": "markdown",
   "id": "b07b9229",
   "metadata": {},
   "source": [
    "## Set up the model\n",
    "\n",
    "Now we need to load the chat model we want to use.\n",
    "This should satisfy two criteria:\n",
    "\n",
    "1. It should work with messages, since our state is primarily a list of messages (chat history).\n",
    "2. It should work with tool calling, since we are using a prebuilt [ToolNode](https://langchain-ai.github.io/langgraph/reference/prebuilt/#toolnode)\n",
    "\n",
    "**Note:** these model requirements are not requirements for using LangGraph - they are just requirements for this particular example.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "1c8132c5",
   "metadata": {},
   "outputs": [],
   "source": ["from langchain_anthropic import ChatAnthropic\n\nmodel = ChatAnthropic(model=\"claude-3-haiku-20240307\")"]
  },
  {
   "cell_type": "markdown",
   "id": "979f0310",
   "metadata": {},
   "source": [
    "\n",
    "After we've done this, we should make sure the model knows that it has these tools available to call.\n",
    "We can do this by converting the LangChain tools into the format for function calling, and then bind them to the model class.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "055d84bf",
   "metadata": {},
   "outputs": [],
   "source": ["model = model.bind_tools(tools)"]
  },
  {
   "cell_type": "markdown",
   "id": "7cbd446a-808f-4394-be92-d45ab818953c",
   "metadata": {},
   "source": [
    "## Setup\n",
    "\n",
    "First we need to install the packages required"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "af4ce0ba-7596-4e5f-8bf8-0b0bd6e62833",
   "metadata": {},
   "outputs": [],
   "source": ["%%capture --no-stderr\n%pip install --quiet -U langgraph langchain langchain_openai tavily-python"]
  },
  {
   "cell_type": "markdown",
   "id": "0abe11f4-62ed-4dc4-8875-3db21e260d1d",
   "metadata": {},
   "source": [
    "Next, we need to set API keys for OpenAI (the LLM we will use) and Tavily (the search tool we will use)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "c903a1cf-2977-4e2d-ad7d-8b3946821d89",
   "metadata": {},
   "outputs": [],
   "source": ["import getpass\nimport os\n\nos.environ[\"OPENAI_API_KEY\"] = getpass.getpass(\"OpenAI API Key:\")\nos.environ[\"TAVILY_API_KEY\"] = getpass.getpass(\"Tavily API Key:\")"]
  },
  {
   "cell_type": "markdown",
   "id": "f0ed46a8-effe-4596-b0e1-a6a29ee16f5c",
   "metadata": {},
   "source": [
    "Optionally, we can set API key for [LangSmith tracing](https://smith.langchain.com/), which will give us best-in-class observability."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "95e25aec-7c9f-4a63-b143-225d0e9a79c3",
   "metadata": {},
   "outputs": [],
   "source": ["os.environ[\"LANGCHAIN_TRACING_V2\"] = \"true\"\nos.environ[\"LANGCHAIN_API_KEY\"] = getpass.getpass(\"LangSmith API Key:\")"]
  },
  {
   "cell_type": "markdown",
   "id": "21ac643b-cb06-4724-a80c-2862ba4773f1",
   "metadata": {},
   "source": [
    "## Set up the tools\n",
    "\n",
    "We will first define the tools we want to use.\n",
    "For this simple example, we will use a built-in search tool via Tavily.\n",
    "However, it is really easy to create your own tools - see documentation [here](https://python.langchain.com/v0.2/docs/how_to/custom_tools) on how to do that.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "d7ef57dd-5d6e-4ad3-9377-a92201c1310e",
   "metadata": {},
   "outputs": [],
   "source": ["from langchain_community.tools.tavily_search import TavilySearchResults\n\ntools = [TavilySearchResults(max_results=1)]"]
  },
  {
   "cell_type": "markdown",
   "id": "01885785-b71a-44d1-b1d6-7b5b14d53b58",
   "metadata": {},
   "source": [
    "We can now wrap these tools in a simple ToolExecutor.\n",
    "This is a real simple class that takes in a ToolInvocation and calls that tool, returning the output.\n",
    "A ToolInvocation is any class with `tool` and `tool_input` attribute.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "5cf3331e-ccb3-41c8-aeb9-a840a94d41e7",
   "metadata": {},
   "outputs": [],
   "source": ["from langgraph.prebuilt import ToolExecutor\n\ntool_executor = ToolExecutor(tools)"]
  },
  {
   "cell_type": "markdown",
   "id": "5497ed70-fce3-47f1-9cad-46f912bad6a5",
   "metadata": {},
   "source": [
    "## Set up the model\n",
    "\n",
    "Now we need to load the chat model we want to use.\n",
    "Importantly, this should satisfy two criteria:\n",
    "\n",
    "1. It should work with messages. We will represent all agent state in the form of messages, so it needs to be able to work well with them.\n",
    "2. It should work with OpenAI function calling. This means it should either be an OpenAI model or a model that exposes a similar interface.\n",
    "\n",
    "Note: these model requirements are not requirements for using LangGraph - they are just requirements for this one example.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "892b54b9-75f0-4804-9ed0-88b5e5532989",
   "metadata": {},
   "outputs": [],
   "source": ["from langchain_openai import ChatOpenAI\n\n# We will set streaming=True so that we can stream tokens\n# See the streaming section for more information on this.\nmodel = ChatOpenAI(temperature=0, streaming=True)"]
  },
  {
   "cell_type": "markdown",
   "id": "a77995c0-bae2-4cee-a036-8688a90f05b9",
   "metadata": {},
   "source": [
    "\n",
    "After we've done this, we should make sure the model knows that it has these tools available to call.\n",
    "We can do this by converting the LangChain tools into the format for OpenAI function calling, and then bind them to the model class.\n",
    "\n",
    "\n",
    "**MODIFICATION**\n",
    "\n",
    "We also want to define a response schema for the language model and bind it to the model as a function as well"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "cd3cbae5-d92c-4559-a4aa-44721b80d107",
   "metadata": {},
   "outputs": [],
   "source": ["from langchain_core.pydantic_v1 import BaseModel, Field\n\n\nclass Response(BaseModel):\n    \"\"\"Final response to the user\"\"\"\n\n    temperature: float = Field(description=\"the temperature\")\n    other_notes: str = Field(description=\"any other notes about the weather\")\n\n\nmodel = model.bind_tools(tools + [Response])"]
  },
  {
   "cell_type": "markdown",
   "id": "8e8b9211-93d0-4ad5-aa7a-9c09099c53ff",
   "metadata": {},
   "source": [
    "## Define the agent state\n",
    "\n",
    "The main type of graph in `langgraph` is the [StateGraph](https://langchain-ai.github.io/langgraph/reference/graphs/#langgraph.graph.StateGraph).\n",
    "This graph is parameterized by a state object that it passes around to each node.\n",
    "Each node then returns operations to update that state.\n",
    "These operations can either SET specific attributes on the state (e.g. overwrite the existing values) or ADD to the existing attribute.\n",
    "Whether to set or add is denoted by annotating the state object you construct the graph with.\n",
    "\n",
    "For this example, the state we will track will just be a list of messages.\n",
    "We want each node to just add messages to that list.\n",
    "Therefore, we will use a `TypedDict` with one key (`messages`) and annotate it so that the `messages` attribute is always added to.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "ea793afa-2eab-4901-910d-6eed90cd6564",
   "metadata": {},
   "outputs": [],
   "source": ["import operator\nfrom typing import Annotated, Sequence, TypedDict\n\nfrom langchain_core.messages import BaseMessage\n\n\nclass AgentState(TypedDict):\n    messages: Annotated[Sequence[BaseMessage], operator.add]"]
  },
  {
   "cell_type": "markdown",
   "id": "e03c5094-9297-4d19-a04e-3eedc75cefb4",
   "metadata": {},
   "source": [
    "## Define the nodes\n",
    "\n",
    "We now need to define a few different nodes in our graph.\n",
    "In `langgraph`, a node can be either a function or a [runnable](https://python.langchain.com/v0.2/docs/concepts/#langchain-expression-language-lcel).\n",
    "There are two main nodes we need for this:\n",
    "\n",
    "1. The agent: responsible for deciding what (if any) actions to take.\n",
    "2. A function to invoke tools: if the agent decides to take an action, this node will then execute that action.\n",
    "\n",
    "We will also need to define some edges.\n",
    "Some of these edges may be conditional.\n",
    "The reason they are conditional is that based on the output of a node, one of several paths may be taken.\n",
    "The path that is taken is not known until that node is run (the LLM decides).\n",
    "\n",
    "1. Conditional Edge: after the agent is called, we should either:\n",
    "   a. If the agent said to take an action, then the function to invoke tools should be called\n",
    "   b. If the agent said that it was finished, then it should finish\n",
    "2. Normal Edge: after the tools are invoked, it should always go back to the agent to decide what to do next\n",
    "\n",
    "Let's define the nodes, as well as a function to decide how what conditional edge to take.\n",
    "\n",
    "**MODIFICATION**\n",
    "\n",
    "We will change the `should_continue` function to check what function was called. If the function `Response` was called - that is the function that is NOT a tool, but rather the formatted response, so we should NOT continue in that case."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "3b541bb9-900c-40d0-964d-7b5dfee30667",
   "metadata": {},
   "outputs": [],
   "source": ["from typing import Literal\n\nfrom langchain_core.messages import ToolMessage\n\nfrom langgraph.prebuilt import ToolInvocation\n\n\n# Define the function that determines whether to continue or not\ndef should_continue(state) -> Literal[\"continue\", \"end\"]:\n    messages = state[\"messages\"]\n    last_message = messages[-1]\n    # If there is no function call, then we finish\n    if not last_message.tool_calls:\n        return \"end\"\n    # Otherwise if there is, we need to check what type of function call it is\n    if last_message.tool_calls[0][\"name\"] == \"Response\":\n        return \"end\"\n    # Otherwise we continue\n    return \"continue\"\n\n\n# Define the function that calls the model\ndef call_model(state):\n    messages = state[\"messages\"]\n    response = model.invoke(messages)\n    # We return a list, because this will get added to the existing list\n    return {\"messages\": [response]}\n\n\n# Define the function to execute tools\ndef call_tool(state):\n    messages = state[\"messages\"]\n    # Based on the continue condition\n    # we know the last message involves a function call\n    last_message = messages[-1]\n    # We construct an ToolInvocation for each tool call\n    tool_invocations = []\n    for tool_call in last_message.tool_calls:\n        action = ToolInvocation(\n            tool=tool_call[\"name\"],\n            tool_input=tool_call[\"args\"],\n        )\n        tool_invocations.append(action)\n\n    action = ToolInvocation(\n        tool=tool_call[\"name\"],\n        tool_input=tool_call[\"args\"],\n    )\n    # We call the tool_executor and get back a response\n    responses = tool_executor.batch(tool_invocations, return_exceptions=True)\n    # We use the response to create tool messages\n    tool_messages = [\n        ToolMessage(\n            content=str(response),\n            name=tc[\"name\"],\n            tool_call_id=tc[\"id\"],\n        )\n        for tc, response in zip(last_message.tool_calls, responses)\n    ]\n\n    # We return a list, because this will get added to the existing list\n    return {\"messages\": tool_messages}"]
  },
  {
   "cell_type": "markdown",
   "id": "ffd6e892-946c-4899-8cc0-7c9291c1f73b",
   "metadata": {},
   "source": [
    "## Define the graph\n",
    "\n",
    "We can now put it all together and define the graph!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "813ae66c-3b58-4283-a02a-36da72a2ab90",
   "metadata": {},
   "outputs": [],
   "source": ["from langgraph.graph import END, StateGraph, START\n\n# Define a new graph\nworkflow = StateGraph(AgentState)\n\n# Define the two nodes we will cycle between\nworkflow.add_node(\"agent\", call_model)\nworkflow.add_node(\"action\", call_tool)\n\n# Set the entrypoint as `agent`\n# This means that this node is the first one called\nworkflow.add_edge(START, \"agent\")\n\n# We now add a conditional edge\nworkflow.add_conditional_edges(\n    # First, we define the start node. We use `agent`.\n    # This means these are the edges taken after the `agent` node is called.\n    \"agent\",\n    # Next, we pass in the function that will determine which node is called next.\n    should_continue,\n    # Finally we pass in a mapping.\n    # The keys are strings, and the values are other nodes.\n    # END is a special node marking that the graph should finish.\n    # What will happen is we will call `should_continue`, and then the output of that\n    # will be matched against the keys in this mapping.\n    # Based on which one it matches, that node will then be called.\n    {\n        # If `tools`, then we call the tool node.\n        \"continue\": \"action\",\n        # Otherwise we finish.\n        \"end\": END,\n    },\n)\n\n# We now add a normal edge from `tools` to `agent`.\n# This means that after `tools` is called, `agent` node is called next.\nworkflow.add_edge(\"action\", \"agent\")\n\n# Finally, we compile it!\n# This compiles it into a LangChain Runnable,\n# meaning you can use it as you would any other runnable\napp = workflow.compile()"]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "2271a1ee",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "image/jpeg": "[encoded data, 12716 characters]",
      "text/plain": [
       "<IPython.core.display.Image object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": ["from IPython.display import Image, display\n\ntry:\n    display(Image(app.get_graph(xray=True).draw_mermaid_png()))\nexcept Exception:\n    # This requires some extra dependencies and is optional\n    pass"]
  },
  {
   "cell_type": "markdown",
   "id": "547c3931-3dae-4281-ad4e-4b51305594d4",
   "metadata": {},
   "source": [
    "## Use it!\n",
    "\n",
    "We can now use it!\n",
    "This now exposes the [same interface](https://python.langchain.com/v0.2/docs/concepts/#langchain-expression-language-lcel) as all other LangChain runnables."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "f544977e-31f7-41f0-88c4-ec9c27b8cecb",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Output from node 'agent':\n",
      "---\n",
      "content='' additional_kwargs={'tool_calls': [{'index': 0, 'id': 'call_aArQcUvPzoWtjem4yr5y9ttC', 'function': {'arguments': '{\"query\":\"weather in San Francisco\"}', 'name': 'tavily_search_results_json'}, 'type': 'function'}]} response_metadata={'finish_reason': 'tool_calls'} id='run-fd99027e-2608-45cd-9bfb-32b6e4c3dd5e-0' tool_calls=[{'name': 'tavily_search_results_json', 'args': {'query': 'weather in San Francisco'}, 'id': 'call_aArQcUvPzoWtjem4yr5y9ttC'}]\n",
      "\n",
      "---\n",
      "\n",
      "Output from node 'action':\n",
      "---\n",
      "content='[{\\'url\\': \\'https://www.weatherapi.com/\\', \\'content\\': \"{\\'location\\': {\\'name\\': \\'San Francisco\\', \\'region\\': \\'California\\', \\'country\\': \\'United States of America\\', \\'lat\\': 37.78, \\'lon\\': -122.42, \\'tz_id\\': \\'America/Los_Angeles\\', \\'localtime_epoch\\': 1714809361, \\'localtime\\': \\'2024-05-04 0:56\\'}, \\'current\\': {\\'last_updated_epoch\\': 1714808700, \\'last_updated\\': \\'2024-05-04 00:45\\', \\'temp_c\\': 12.8, \\'temp_f\\': 55.0, \\'is_day\\': 0, \\'condition\\': {\\'text\\': \\'Overcast\\', \\'icon\\': \\'//cdn.weatherapi.com/weather/64x64/night/122.png\\', \\'code\\': 1009}, \\'wind_mph\\': 11.9, \\'wind_kph\\': 19.1, \\'wind_degree\\': 240, \\'wind_dir\\': \\'WSW\\', \\'pressure_mb\\': 1013.0, \\'pressure_in\\': 29.9, \\'precip_mm\\': 0.0, \\'precip_in\\': 0.0, \\'humidity\\': 96, \\'cloud\\': 100, \\'feelslike_c\\': 11.4, \\'feelslike_f\\': 52.4, \\'vis_km\\': 16.0, \\'vis_miles\\': 9.0, \\'uv\\': 1.0, \\'gust_mph\\': 14.9, \\'gust_kph\\': 23.9}}\"}]' name='tavily_search_results_json' tool_call_id='call_aArQcUvPzoWtjem4yr5y9ttC'\n",
      "\n",
      "---\n",
      "\n",
      "Output from node 'agent':\n",
      "---\n",
      "content='' additional_kwargs={'tool_calls': [{'index': 0, 'id': 'call_TiqvNjxNlFMf4Wnzs1xhicVf', 'function': {'arguments': '{\"temperature\":12.8,\"other_notes\":\"The weather in San Francisco is currently overcast with a temperature of 12.8°C. The wind speed is 11.9 mph coming from WSW direction. Humidity is at 96%.\"}', 'name': 'Response'}, 'type': 'function'}]} response_metadata={'finish_reason': 'tool_calls'} id='run-09cca9c1-1104-4fc1-9a85-7927d2492200-0' tool_calls=[{'name': 'Response', 'args': {'temperature': 12.8, 'other_notes': 'The weather in San Francisco is currently overcast with a temperature of 12.8°C. The wind speed is 11.9 mph coming from WSW direction. Humidity is at 96%.'}, 'id': 'call_TiqvNjxNlFMf4Wnzs1xhicVf'}]\n",
      "\n",
      "---\n",
      "\n"
     ]
    }
   ],
   "source": ["from langchain_core.messages import HumanMessage\n\ninputs = {\"messages\": [HumanMessage(content=\"what is the weather in sf\")]}\nfor output in app.stream(inputs):\n    # stream() yields dictionaries with output keyed by node name\n    for key, value in output.items():\n        print(f\"Output from node '{key}':\")\n        print(\"---\")\n        print(value[\"messages\"][-1])\n    print(\"\\n---\\n\")"]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "eed4360d-2cdf-497b-b03f-8bc51062f780",
   "metadata": {},
   "outputs": [],
   "source": [""]
  }
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