runnable powered agent (#10407)

docs/extras/expression_language/cookbook/agent.ipynb

@@ -0,0 +1,203 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "e89f490d",
+   "metadata": {},
+   "source": [
+    "# Agents\n",
+    "\n",
+    "You can pass a Runnable into an agent."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "af4381de",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from langchain.agents import XMLAgent, tool, AgentExecutor\n",
+    "from langchain.chat_models import ChatAnthropic"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "24cc8134",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "model = ChatAnthropic(model=\"claude-2\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "67c0b0e4",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "@tool\n",
+    "def search(query: str) -> str:\n",
+    "    \"\"\"Search things about current events.\"\"\"\n",
+    "    return \"32 degrees\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "7203b101",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "tool_list = [search]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "b68e756d",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Get prompt to use\n",
+    "prompt = XMLAgent.get_default_prompt()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "61ab3e9a",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Logic for going from intermediate steps to a string to pass into model\n",
+    "# This is pretty tied to the prompt\n",
+    "def convert_intermediate_steps(intermediate_steps):\n",
+    "    log = \"\"\n",
+    "    for action, observation in intermediate_steps:\n",
+    "        log += (\n",
+    "            f\"<tool>{action.tool}</tool><tool_input>{action.tool_input}\"\n",
+    "            f\"</tool_input><observation>{observation}</observation>\"\n",
+    "        )\n",
+    "    return log\n",
+    "\n",
+    "\n",
+    "# Logic for converting tools to string to go in prompt\n",
+    "def convert_tools(tools):\n",
+    "    return \"\\n\".join([f\"{tool.name}: {tool.description}\" for tool in tools])"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "260f5988",
+   "metadata": {},
+   "source": [
+    "Building an agent from a runnable usually involves a few things:\n",
+    "\n",
+    "1. Data processing for the intermediate steps. These need to represented in a way that the language model can recognize them. This should be pretty tightly coupled to the instructions in the prompt\n",
+    "\n",
+    "2. The prompt itself\n",
+    "\n",
+    "3. The model, complete with stop tokens if needed\n",
+    "\n",
+    "4. The output parser - should be in sync with how the prompt specifies things to be formatted."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "e92f1d6f",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "agent = (\n",
+    "    {\n",
+    "        \"question\": lambda x: x[\"question\"],\n",
+    "        \"intermediate_steps\": lambda x: convert_intermediate_steps(x[\"intermediate_steps\"])\n",
+    "    }\n",
+    "    | prompt.partial(tools=convert_tools(tool_list))\n",
+    "    | model.bind(stop=[\"</tool_input>\", \"</final_answer>\"])\n",
+    "    | XMLAgent.get_default_output_parser()\n",
+    ")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "6ce6ec7a",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "agent_executor = AgentExecutor(agent=agent, tools=tool_list, verbose=True)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "fb5cb2e3",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new AgentExecutor chain...\u001b[0m\n",
+      "\u001b[32;1m\u001b[1;3m <tool>search</tool>\n",
+      "<tool_input>weather in new york\u001b[0m\u001b[36;1m\u001b[1;3m32 degrees\u001b[0m\u001b[32;1m\u001b[1;3m\n",
+      "\n",
+      "<final_answer>The weather in New York is 32 degrees\u001b[0m\n",
+      "\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "{'question': 'whats the weather in New york?',\n",
+       " 'output': 'The weather in New York is 32 degrees'}"
+      ]
+     },
+     "execution_count": 9,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "agent_executor.invoke({\"question\": \"whats the weather in New york?\"})"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "bce86dd8",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.1"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

docs/extras/modules/agents/agent_types/xml_agent.ipynb

@@ -141,7 +141,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.1"
+   "version": "3.10.1"
   }
  },
  "nbformat": 4,

libs/langchain/langchain/agents/agent.py

@@ -7,7 +7,16 @@ import logging
 import time
 from abc import abstractmethod
 from pathlib import Path
-from typing import Any, Callable, Dict, List, Optional, Sequence, Tuple, Union
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    List,
+    Optional,
+    Sequence,
+    Tuple,
+    Union,
+)
 
 import yaml
 
@@ -36,6 +45,7 @@ from langchain.schema import (
 )
 from langchain.schema.language_model import BaseLanguageModel
 from langchain.schema.messages import BaseMessage
+from langchain.schema.runnable import Runnable
 from langchain.tools.base import BaseTool
 from langchain.utilities.asyncio import asyncio_timeout
 from langchain.utils.input import get_color_mapping
@@ -307,6 +317,71 @@ class AgentOutputParser(BaseOutputParser):
         """Parse text into agent action/finish."""
 
 
+class RunnableAgent(BaseSingleActionAgent):
+    """Agent powered by runnables."""
+
+    runnable: Runnable[dict, Union[AgentAction, AgentFinish]]
+    """Runnable to call to get agent action."""
+    _input_keys: List[str] = []
+    """Input keys."""
+
+    class Config:
+        """Configuration for this pydantic object."""
+
+        arbitrary_types_allowed = True
+
+    @property
+    def input_keys(self) -> List[str]:
+        """Return the input keys.
+
+        Returns:
+            List of input keys.
+        """
+        return self._input_keys
+
+    def plan(
+        self,
+        intermediate_steps: List[Tuple[AgentAction, str]],
+        callbacks: Callbacks = None,
+        **kwargs: Any,
+    ) -> Union[AgentAction, AgentFinish]:
+        """Given input, decided what to do.
+
+        Args:
+            intermediate_steps: Steps the LLM has taken to date,
+                along with the observations.
+            callbacks: Callbacks to run.
+            **kwargs: User inputs.
+
+        Returns:
+            Action specifying what tool to use.
+        """
+        inputs = {**kwargs, **{"intermediate_steps": intermediate_steps}}
+        output = self.runnable.invoke(inputs, config={"callbacks": callbacks})
+        return output
+
+    async def aplan(
+        self,
+        intermediate_steps: List[Tuple[AgentAction, str]],
+        callbacks: Callbacks = None,
+        **kwargs: Any,
+    ) -> Union[AgentAction, AgentFinish]:
+        """Given input, decided what to do.
+
+        Args:
+            intermediate_steps: Steps the LLM has taken to date,
+                along with observations
+            callbacks: Callbacks to run.
+            **kwargs: User inputs.
+
+        Returns:
+            Action specifying what tool to use.
+        """
+        inputs = {**kwargs, **{"intermediate_steps": intermediate_steps}}
+        output = await self.runnable.ainvoke(inputs, config={"callbacks": callbacks})
+        return output
+
+
 class LLMSingleActionAgent(BaseSingleActionAgent):
     """Base class for single action agents."""
 
@@ -725,6 +800,14 @@ s
                     )
         return values
 
+    @root_validator(pre=True)
+    def validate_runnable_agent(cls, values: Dict) -> Dict:
+        """Convert runnable to agent if passed in."""
+        agent = values["agent"]
+        if isinstance(agent, Runnable):
+            values["agent"] = RunnableAgent(runnable=agent)
+        return values
+
     def save(self, file_path: Union[Path, str]) -> None:
         """Raise error - saving not supported for Agent Executors."""
         raise ValueError(