wip dynamic agent tools

docs/modules/agents/tools/custom_tools.ipynb

@@ -1,7 +1,6 @@
 {
  "cells": [
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "5436020b",
    "metadata": {},
@@ -56,7 +55,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "f8bc72c2",
    "metadata": {},
@@ -69,7 +67,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "b63fcc3b",
    "metadata": {},
@@ -111,7 +108,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "e9b560f7",
    "metadata": {},
@@ -145,7 +141,24 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 7,
+   "id": "5f040378",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "tools = [\n",
+    "    Tool(\n",
+    "        name=\"FooBar\",\n",
+    "        description=\"Useful to answer questions related to FooBar\",\n",
+    "        func=lambda x: \"FooBar is well and alive !\",\n",
+    "        return_direct=True\n",
+    "    )\n",
+    "]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
    "id": "5b93047d",
    "metadata": {
     "tags": []
@@ -154,7 +167,46 @@
    "source": [
     "# Construct the agent. We will use the default agent type here.\n",
     "# See documentation for a full list of options.\n",
-    "agent = initialize_agent(tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True)"
+    "agent = initialize_agent(tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True, max_iterations=3)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "2bb58cac",
+   "metadata": {
+    "scrolled": true
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new AgentExecutor chain...\u001b[0m\n",
+      "\u001b[32;1m\u001b[1;3mI should use FooBar to answer this question\n",
+      "Action: FooBar\n",
+      "Action Input: \"Who is FooBar?\"\u001b[0m\n",
+      "Observation: \u001b[36;1m\u001b[1;3mFooBar is well and alive !\u001b[0m\n",
+      "\u001b[32;1m\u001b[1;3m\u001b[0m\n",
+      "\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "'FooBar is well and alive !'"
+      ]
+     },
+     "execution_count": 9,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "agent.run(\"Who is FooBar\")"
    ]
   },
   {
@@ -220,7 +272,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "6f12eaf0",
    "metadata": {},
@@ -459,7 +510,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "61d2e80b",
    "metadata": {},
@@ -470,7 +520,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "5be41722",
    "metadata": {},
@@ -499,7 +548,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "fb0a38eb",
    "metadata": {},
@@ -561,7 +609,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "7d68b0ac",
    "metadata": {},
@@ -589,7 +636,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "1d0430d6",
    "metadata": {},
@@ -857,7 +903,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.2"
+   "version": "3.9.11"
   },
   "vscode": {
    "interpreter": {

langchain/agents/agent.py

@@ -619,7 +619,7 @@ class ExceptionTool(BaseTool):
 class AgentExecutor(Chain):
     """Consists of an agent using tools."""
 
-    agent: Union[BaseSingleActionAgent, BaseMultiActionAgent]
+    agent: Union[Agent, BaseSingleActionAgent, BaseMultiActionAgent]
     tools: Sequence[BaseTool]
     return_intermediate_steps: bool = False
     max_iterations: Optional[int] = 15
@@ -703,6 +703,23 @@ class AgentExecutor(Chain):
         """Lookup tool by name."""
         return {tool.name: tool for tool in self.tools}[name]
 
+    def add_tools(self, tools: Sequence[BaseTool]) -> None:
+        """Add extra tools to an active agent instance."""
+        self.agent._validate_tools(tools)
+
+        #HACK: should not cast to list
+        self.tools = list(self.tools) + list(tools)
+
+        # update allowed_tools
+        new_tool_names = [tool.name for tool in tools]
+        self.agent._allowed_tools = self.agent.get_allowed_tools().extend(new_tool_names)
+
+        # how to update the agent prompt
+        # update the agent's llm_chain prompt
+        self.agent.llm_chain.prompt.update
+
+
+
     def _should_continue(self, iterations: int, time_elapsed: float) -> bool:
         if self.max_iterations is not None and iterations >= self.max_iterations:
             return False

langchain/agents/conversational_chat/base.py

@@ -71,36 +71,34 @@ class ConversationalChatAgent(Agent):
         output_parser: Optional[BaseOutputParser] = None,
     ) -> BasePromptTemplate:
         tool_strings = "\n".join(
-            [f"> {tool.name}: {tool.description}" for tool in tools]
-        )
+            [f"> {tool.name}: {tool.description}" for tool in tools])
         tool_names = ", ".join([tool.name for tool in tools])
         _output_parser = output_parser or cls._get_default_output_parser()
         format_instructions = human_message.format(
-            format_instructions=_output_parser.get_format_instructions()
-        )
-        final_prompt = format_instructions.format(
-            tool_names=tool_names, tools=tool_strings
-        )
+            format_instructions=_output_parser.get_format_instructions())
+        final_prompt = format_instructions.format(tool_names=tool_names,
+                                                  tools=tool_strings)
         if input_variables is None:
             input_variables = ["input", "chat_history", "agent_scratchpad"]
         messages = [
             SystemMessagePromptTemplate.from_template(system_message),
             MessagesPlaceholder(variable_name="chat_history"),
-            HumanMessagePromptTemplate.from_template(final_prompt),
+            HumanMessagePromptTemplate.from_template(final_prompt,
+                                                     alias="instructions_tools"),
             MessagesPlaceholder(variable_name="agent_scratchpad"),
         ]
-        return ChatPromptTemplate(input_variables=input_variables, messages=messages)
+        return ChatPromptTemplate(input_variables=input_variables,
+                                  messages=messages)
 
     def _construct_scratchpad(
-        self, intermediate_steps: List[Tuple[AgentAction, str]]
-    ) -> List[BaseMessage]:
+        self, intermediate_steps: List[Tuple[AgentAction,
+                                             str]]) -> List[BaseMessage]:
         """Construct the scratchpad that lets the agent continue its thought process."""
         thoughts: List[BaseMessage] = []
         for action, observation in intermediate_steps:
             thoughts.append(AIMessage(content=action.log))
-            human_message = HumanMessage(
-                content=TEMPLATE_TOOL_RESPONSE.format(observation=observation)
-            )
+            human_message = HumanMessage(content=TEMPLATE_TOOL_RESPONSE.format(
+                observation=observation))
             thoughts.append(human_message)
         return thoughts
 

langchain/prompts/chat.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 
 from abc import ABC, abstractmethod
 from pathlib import Path
-from typing import Any, Callable, List, Sequence, Tuple, Type, TypeVar, Union
+from typing import Any, Callable, List, Sequence, Tuple, Type, TypeVar, Union, Optional
 
 from pydantic import BaseModel, Field
 
@@ -21,6 +21,8 @@ from langchain.schema import (
 
 
 class BaseMessagePromptTemplate(BaseModel, ABC):
+    alias: Optional[str] = None
+
     @abstractmethod
     def format_messages(self, **kwargs: Any) -> List[BaseMessage]:
         """To messages."""
@@ -212,6 +214,18 @@ class ChatPromptTemplate(BaseChatPromptTemplate, ABC):
                 raise ValueError(f"Unexpected input: {message_template}")
         return result
 
+    def update(self, msg_alias: str,
+               replacement_msg: Union[BaseMessagePromptTemplate, BaseMessage]) -> None:
+        for i, message in enumerate(self.messages):
+            if isinstance(message, BaseMessage) and message.alias == msg_alias:
+                if type(message) != type(replacement_msg):
+                    raise ValueError("Replacement message is not of the same type as the original.")
+                self.messages[i] = replacement_msg
+                return
+        raise ValueError(f"No message with alias {msg_alias} found.")
+
+
+
     def partial(self, **kwargs: Union[str, Callable[[], str]]) -> BasePromptTemplate:
         raise NotImplementedError
 

langchain/schema.py

@@ -68,6 +68,7 @@ class BaseMessage(BaseModel):
     """Message object."""
 
     content: str
+    alias: Optional[str] = None
     additional_kwargs: dict = Field(default_factory=dict)
 
     @property